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Sample records for antigens surface

  1. 21 CFR 660.40 - Hepatitis B Surface Antigen.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this...

  2. Immunity to intracellular Salmonella depends on surface-associated antigens.

    Directory of Open Access Journals (Sweden)

    Somedutta Barat

    Full Text Available Invasive Salmonella infection is an important health problem that is worsening because of rising antimicrobial resistance and changing Salmonella serovar spectrum. Novel vaccines with broad serovar coverage are needed, but suitable protective antigens remain largely unknown. Here, we tested 37 broadly conserved Salmonella antigens in a mouse typhoid fever model, and identified antigen candidates that conferred partial protection against lethal disease. Antigen properties such as high in vivo abundance or immunodominance in convalescent individuals were not required for protectivity, but all promising antigen candidates were associated with the Salmonella surface. Surprisingly, this was not due to superior immunogenicity of surface antigens compared to internal antigens as had been suggested by previous studies and novel findings for CD4 T cell responses to model antigens. Confocal microscopy of infected tissues revealed that many live Salmonella resided alone in infected host macrophages with no damaged Salmonella releasing internal antigens in their vicinity. In the absence of accessible internal antigens, detection of these infected cells might require CD4 T cell recognition of Salmonella surface-associated antigens that could be processed and presented even from intact Salmonella. In conclusion, our findings might pave the way for development of an efficacious Salmonella vaccine with broad serovar coverage, and suggest a similar crucial role of surface antigens for immunity to both extracellular and intracellular pathogens.

  3. Immunogenicity of transgenic plant-derived hepatitis B surface antigen.

    OpenAIRE

    Thanavala, Y; Yang, Y. F.; Lyons, P; Mason, H S; Arntzen, C

    1995-01-01

    The focus of the Children's Vaccine Initiative is to encourage the discovery of technology that will make vaccines more readily available to developing countries. Our strategy has been to genetically engineer plants so that they can be used as inexpensive alternatives to fermentation systems for production of subunit antigens. In this paper we report on the immunological response elicited in vivo by using recombinant hepatitis B surface antigen (rHBsAg) purified from transgenic tobacco leaves...

  4. Antigenicity and Immunogenicity of Plasmodium vivax Merozoite Surface Protein-3

    OpenAIRE

    Amanda R Bitencourt; Elaine C Vicentin; Jimenez, Maria C.; Ricardo Ricci; Leite, Juliana A.; Fabio T Costa; Luis C Ferreira; Bruce Russell; François Nosten; Laurent Rénia; Galinski, Mary R.; Barnwell, John W.; Rodrigues, Mauricio M; Soares, Irene S

    2013-01-01

    A recent clinical trial in African children demonstrated the potential utility of merozoite surface protein (MSP)-3 as a vaccine against Plasmodium falciparum malaria. The present study evaluated the use of Plasmodium vivax MSP-3 (PvMSP-3) as a target antigen in vaccine formulations against malaria caused by P. vivax. Recombinant proteins representing MSP-3α and MSP-3β of P. vivax were expressed as soluble histidine-tagged bacterial fusions. Antigenicity during natural infection was evaluated...

  5. 21 CFR 660.1 - Antibody to Hepatitis B Surface Antigen.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Antibody to Hepatitis B Surface Antigen. 660.1... Hepatitis B Surface Antigen § 660.1 Antibody to Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product shall be Antibody to Hepatitis B Surface Antigen. The product...

  6. Conformational dynamics and antigenicity in the disordered malaria antigen merozoite surface protein 2.

    Directory of Open Access Journals (Sweden)

    Christopher A MacRaild

    Full Text Available Merozoite surface protein 2 (MSP2 of Plasmodium falciparum is an abundant, intrinsically disordered protein that is GPI-anchored to the surface of the invasive blood stage of the malaria parasite. Recombinant MSP2 has been trialled as a component of a malaria vaccine, and is one of several disordered proteins that are candidates for inclusion in vaccines for malaria and other diseases. Nonetheless, little is known about the implications of protein disorder for the development of an effective antibody response. We have therefore undertaken a detailed analysis of the conformational dynamics of the two allelic forms of MSP2 (3D7 and FC27 using NMR spectroscopy. Chemical shifts and NMR relaxation data indicate that conformational and dynamic properties of the N- and C-terminal conserved regions in the two forms of MSP2 are essentially identical, but significant variation exists between and within the central variable regions. We observe a strong relationship between the conformational dynamics and the antigenicity of MSP2, as assessed with antisera to recombinant MSP2. Regions of increased conformational order in MSP2, including those in the conserved regions, are more strongly antigenic, while the most flexible regions are minimally antigenic. This suggests that modifications that increase conformational order may offer a means to tune the antigenicity of MSP2 and other disordered antigens, with implications for vaccine design.

  7. Conformational Dynamics and Antigenicity in the Disordered Malaria Antigen Merozoite Surface Protein 2

    Science.gov (United States)

    Andrew, Dean; Krishnarjuna, Bankala; Nováček, Jiří; Žídek, Lukáš; Sklenář, Vladimír; Richards, Jack S.; Beeson, James G.; Anders, Robin F.; Norton, Raymond S.

    2015-01-01

    Merozoite surface protein 2 (MSP2) of Plasmodium falciparum is an abundant, intrinsically disordered protein that is GPI-anchored to the surface of the invasive blood stage of the malaria parasite. Recombinant MSP2 has been trialled as a component of a malaria vaccine, and is one of several disordered proteins that are candidates for inclusion in vaccines for malaria and other diseases. Nonetheless, little is known about the implications of protein disorder for the development of an effective antibody response. We have therefore undertaken a detailed analysis of the conformational dynamics of the two allelic forms of MSP2 (3D7 and FC27) using NMR spectroscopy. Chemical shifts and NMR relaxation data indicate that conformational and dynamic properties of the N- and C-terminal conserved regions in the two forms of MSP2 are essentially identical, but significant variation exists between and within the central variable regions. We observe a strong relationship between the conformational dynamics and the antigenicity of MSP2, as assessed with antisera to recombinant MSP2. Regions of increased conformational order in MSP2, including those in the conserved regions, are more strongly antigenic, while the most flexible regions are minimally antigenic. This suggests that modifications that increase conformational order may offer a means to tune the antigenicity of MSP2 and other disordered antigens, with implications for vaccine design. PMID:25742002

  8. Monoclonal Antibody Production against Human Spermatozoal Surface Antigens

    Directory of Open Access Journals (Sweden)

    M Jedi-Tehrani

    2005-10-01

    Full Text Available Introduction: As monoclonal antibodies are potential tools for characterization of soluble or cellular surface antigens, use of these proteins has always been considered in infertility and reproduction research. Therefore, in this study, monoclonal antibodies against human sperm surface antigens were produced. Material and Methods: To produce specific clones against human sperm surface antigens, proteins were extracted using solubilization methods. Balb/c mice were immunized intraperitoneally with the proteins using complete Freund’s adjuvant in the first injection and incomplete Adjuvant in the following booster injections. Hybridoma cells producing ASA were cloned by limiting dilution. Results: Five stable ASA producing hybridoma clones were achieved and their antibody isotypes were determined by ELISA. All the isotypes were of IgG class. Their cross reactivity with rat and mice spermatozoa was examined but they did not have any cross reactivity. Conclusion: The produced antibodies can be used in further studies to characterize and evaluate each of the antigens present on human sperm surface and determining their role in fertilization.

  9. Glycosylation of the major human Pneumocystis carinii surface antigen

    DEFF Research Database (Denmark)

    Lundgren, Bettina; Koch, C; Mathiesen, Lars Reinhardt;

    1993-01-01

    It has recently been shown that the major rat P. carinii surface antigen is important for initial host-organism attachment, possibly through binding to fibronectin, mannose-binding protein, or surfactant protein A. Since a carbohydrate/lectin interaction may be involved in adhesion, we undertook...

  10. Expression of hepatitis B surface antigen in transgenic plants.

    OpenAIRE

    Mason, H S; Lam, D M; Arntzen, C J

    1992-01-01

    Tobacco plants were genetically transformed with the gene encoding hepatitis B surface antigen (HBsAg) linked to a nominally constitutive promoter. Enzyme-linked immunoassays using a monoclonal antibody directed against human serum-derived HBsAg revealed the presence of HBsAg in extracts of transformed leaves at levels that correlated with mRNA abundance. This suggests that there were no major inherent limitations of transcription or translation of this foreign gene in plants. Recombinant HBs...

  11. Antigenicity and immunogenicity of Plasmodium vivax merozoite surface protein-3.

    Science.gov (United States)

    Bitencourt, Amanda R; Vicentin, Elaine C; Jimenez, Maria C; Ricci, Ricardo; Leite, Juliana A; Costa, Fabio T; Ferreira, Luis C; Russell, Bruce; Nosten, François; Rénia, Laurent; Galinski, Mary R; Barnwell, John W; Rodrigues, Mauricio M; Soares, Irene S

    2013-01-01

    A recent clinical trial in African children demonstrated the potential utility of merozoite surface protein (MSP)-3 as a vaccine against Plasmodium falciparum malaria. The present study evaluated the use of Plasmodium vivax MSP-3 (PvMSP-3) as a target antigen in vaccine formulations against malaria caused by P. vivax. Recombinant proteins representing MSP-3α and MSP-3β of P. vivax were expressed as soluble histidine-tagged bacterial fusions. Antigenicity during natural infection was evaluated by detecting specific antibodies using sera from individuals living in endemic areas of Brazil. A large proportion of infected individuals presented IgG antibodies to PvMSP-3α (68.2%) and at least 1 recombinant protein representing PvMSP-3β (79.1%). In spite of the large responder frequency, reactivity to both antigens was significantly lower than was observed for the immunodominant epitope present on the 19-kDa C-terminal region of PvMSP-1. Immunogenicity of the recombinant proteins was studied in mice in the absence or presence of different adjuvant formulations. PvMSP-3β, but not PvMSP-3α, induced a TLR4-independent humoral immune response in the absence of any adjuvant formulation. The immunogenicity of the recombinant antigens were also tested in formulations containing different adjuvants (Alum, Salmonella enterica flagellin, CpG, Quil A,TiterMax® and incomplete Freunds adjuvant) and combinations of two adjuvants (Alum plus flagellin, and CpG plus flagellin). Recombinant PvMSP-3α and PvMSP-3β elicited higher antibody titers capable of recognizing P. vivax-infected erythrocytes harvested from malaria patients. Our results confirm that P. vivax MSP-3 antigens are immunogenic during natural infection, and the corresponding recombinant proteins may be useful in elucidating their vaccine potential. PMID:23457498

  12. Antigenicity and immunogenicity of Plasmodium vivax merozoite surface protein-3.

    Directory of Open Access Journals (Sweden)

    Amanda R Bitencourt

    Full Text Available A recent clinical trial in African children demonstrated the potential utility of merozoite surface protein (MSP-3 as a vaccine against Plasmodium falciparum malaria. The present study evaluated the use of Plasmodium vivax MSP-3 (PvMSP-3 as a target antigen in vaccine formulations against malaria caused by P. vivax. Recombinant proteins representing MSP-3α and MSP-3β of P. vivax were expressed as soluble histidine-tagged bacterial fusions. Antigenicity during natural infection was evaluated by detecting specific antibodies using sera from individuals living in endemic areas of Brazil. A large proportion of infected individuals presented IgG antibodies to PvMSP-3α (68.2% and at least 1 recombinant protein representing PvMSP-3β (79.1%. In spite of the large responder frequency, reactivity to both antigens was significantly lower than was observed for the immunodominant epitope present on the 19-kDa C-terminal region of PvMSP-1. Immunogenicity of the recombinant proteins was studied in mice in the absence or presence of different adjuvant formulations. PvMSP-3β, but not PvMSP-3α, induced a TLR4-independent humoral immune response in the absence of any adjuvant formulation. The immunogenicity of the recombinant antigens were also tested in formulations containing different adjuvants (Alum, Salmonella enterica flagellin, CpG, Quil A,TiterMax® and incomplete Freunds adjuvant and combinations of two adjuvants (Alum plus flagellin, and CpG plus flagellin. Recombinant PvMSP-3α and PvMSP-3β elicited higher antibody titers capable of recognizing P. vivax-infected erythrocytes harvested from malaria patients. Our results confirm that P. vivax MSP-3 antigens are immunogenic during natural infection, and the corresponding recombinant proteins may be useful in elucidating their vaccine potential.

  13. Human leukocyte antigen-DO regulates surface presentation of human leukocyte antigen class II-restricted antigens on B cell malignancies

    NARCIS (Netherlands)

    Kremer, A.N.; Meijden, E.D. van der; Honders, M.W.; Pont, M.J.; Goeman, J.J.; Falkenburg, J.H.F.; Griffioen, M.

    2014-01-01

    Hematological malignancies often express surface HLA class II, making them attractive targets for CD4+ T cell therapy. We previously demonstrated that HLA class II ligands can be divided into DM-resistant and DM-sensitive antigens. In contrast to presentation of DM-resistant antigens, presentation o

  14. Immunosensor Based on Surface Plasmon Resonance for Antigen Recognition

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel immunosensor based on surface plasmon resonance(SPR)has been developed for the recognition of antigen.The sensor was designed on the basis of the fixed angle of incidence and measuring the reflected intensities in a wavelength range of 430-750 nm in real-time. An ultra-bright white light-emitting diode(LED)was used as the light source. Molecular self-assembling in solution was used to form the sensing membrane on gold substrate. It has been seen that the sensitivity of the SPR sensor with 3-mercaptopropionic acid(MPA)/protein A(SPA) sensing membrane is considerably higher than that with MPA or SPA modified Sensing membrane. The kinetic processes on the sensing membrane were studied. The human B factor(Bf), an activator of complement 3(C3), was recognized among the other antigens. This sensor can also be used for other antigen/antibody or adaptor/receptor recognition. Under optimized experimental conditions, the sensor has good selectivity, repeatability, and reversibility.

  15. Cloning and Expression of Hepatitis B Surface Antigen

    OpenAIRE

    Bahram Kazemi; Mahvash Khodabandeh; Mojgan Bandehpour

    2008-01-01

    Background and Aims: Hepatitis B virus (HBV) is a major cause of both acute and chronic liver disease. It is estimated that there are 350 million carriers of the virus in the world, and a high proportion will develop serious liver disease, including hepatocellular carcinoma. The aim of this study was cloning and expression hepatitis B surface antigen (HBsAg) gene to design a DNA vaccine.Methods: In this study, we amplified the HBsAg gene from Iranian patients. The gene was cloned in pGEMEX-1...

  16. A Molecular-Level Account of the Antigenic Hantaviral Surface.

    Science.gov (United States)

    Li, Sai; Rissanen, Ilona; Zeltina, Antra; Hepojoki, Jussi; Raghwani, Jayna; Harlos, Karl; Pybus, Oliver G; Huiskonen, Juha T; Bowden, Thomas A

    2016-05-01

    Hantaviruses, a geographically diverse group of zoonotic pathogens, initiate cell infection through the concerted action of Gn and Gc viral surface glycoproteins. Here, we describe the high-resolution crystal structure of the antigenic ectodomain of Gn from Puumala hantavirus (PUUV), a causative agent of hemorrhagic fever with renal syndrome. Fitting of PUUV Gn into an electron cryomicroscopy reconstruction of intact Gn-Gc spike complexes from the closely related but non-pathogenic Tula hantavirus localized Gn tetramers to the membrane-distal surface of the virion. The accuracy of the fitting was corroborated by epitope mapping and genetic analysis of available PUUV sequences. Interestingly, Gn exhibits greater non-synonymous sequence diversity than the less accessible Gc, supporting a role of the host humoral immune response in exerting selective pressure on the virus surface. The fold of PUUV Gn is likely to be widely conserved across hantaviruses. PMID:27117403

  17. A Molecular-Level Account of the Antigenic Hantaviral Surface

    Directory of Open Access Journals (Sweden)

    Sai Li

    2016-05-01

    Full Text Available Hantaviruses, a geographically diverse group of zoonotic pathogens, initiate cell infection through the concerted action of Gn and Gc viral surface glycoproteins. Here, we describe the high-resolution crystal structure of the antigenic ectodomain of Gn from Puumala hantavirus (PUUV, a causative agent of hemorrhagic fever with renal syndrome. Fitting of PUUV Gn into an electron cryomicroscopy reconstruction of intact Gn-Gc spike complexes from the closely related but non-pathogenic Tula hantavirus localized Gn tetramers to the membrane-distal surface of the virion. The accuracy of the fitting was corroborated by epitope mapping and genetic analysis of available PUUV sequences. Interestingly, Gn exhibits greater non-synonymous sequence diversity than the less accessible Gc, supporting a role of the host humoral immune response in exerting selective pressure on the virus surface. The fold of PUUV Gn is likely to be widely conserved across hantaviruses.

  18. Bacterial surface antigen-specific monoclonal antibodies used to detect beer spoilage pediococci.

    Science.gov (United States)

    Whiting, M S; Ingledew, W M; Lee, S Y; Ziola, B

    1999-08-01

    Fourteen monoclonal antibodies (Mabs) were isolated that react with surface antigens of Pediococcus beer spoilage organisms, including P. damnosus, P. pentosaceous, P. acidilactici, and unspeciated isolates. Immunoblotting, enzyme immunoassays (EIAs) of protease- and neuraminidase-treated surface antigen extracts, carbohydrate competition EIAs, and cardiolipin EIAs were used to characterize the bacterial antigens involved in Mab binding. Antigen stability in situ was tested by protease treatment or surface antigen extraction of washed bacteria. In most cases, the Mabs bind to Pediococcus surface antigens that appear to be covalently bound cell wall polymers resistant to alteration or removal from the bacterial surface. These bacterial surface antigen reactive Mabs show good potential for rapid, sensitive, and specific immunoassay detection of Pediococcus beer spoilage organisms.

  19. Highly sensitive potentiometric immunosensor for hepatitis B surface antigen diagnosis

    Institute of Scientific and Technical Information of China (English)

    YUAN; Ruo; TANG; Dianping; CHAI; Yaqin; ZHANG; Lingyan; LI

    2005-01-01

    A highly sensitive potentiometric immunosensor for the diagnoses of epidemic diseases has been developed by means of self-assembly to immobilize hepatitis B surface antibody (HBsAb) for the detection of hepatitis B surface antigen (HBsAg) as a model. At first, the Nafion containing -SO3- groups was immobilized on a platinum electrode surface to absorb the -NH3+ groups of antibody molecules via the opposite-charged adsorption technique, in the meantime, hepatitis B surface antibodies were adsorbed onto the surface of Au nanoparticles, then hepatitis B surface antibodies and Au nanopartilces were entrapped into polyvinyl butyral on the surface of Nafion film. The modified procedure was further characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The influence and factors influencing the performance of resulting immunosensor were studied in detail. The resulting immunosensor exhibited sigmoid curve with log HBsAg concentrations, high sensitivity, wide linear range from 26 to 1280 ng·mL-1 with a detection limit of 3.1 ng·mL-1, rapid potentiometric response (4 months). Analytical results of clinical samples show that the developed immunoassay is comparable with the enzyme-linked immunosorbent assays (ELISAs) method, implying a promising alternative approach for detecting HBsAg in the clinical diagnosis.

  20. Cloning and Expression of Hepatitis B Surface Antigen

    Directory of Open Access Journals (Sweden)

    Bahram Kazemi

    2008-02-01

    Full Text Available Background and Aims: Hepatitis B virus (HBV is a major cause of both acute and chronic liver disease. It is estimated that there are 350 million carriers of the virus in the world, and a high proportion will develop serious liver disease, including hepatocellular carcinoma. The aim of this study was cloning and expression hepatitis B surface antigen (HBsAg gene to design a DNA vaccine.Methods: In this study, we amplified the HBsAg gene from Iranian patients. The gene was cloned in pGEMEX-1 expression vector and recombinant plasmid was transformed in to JM109 E. coli strain and induced by IPTG.Results: We amplified, cloned and expressed hepatitis B virus surface antigen successfully and expressed protein was serologically assayed using gel diffusion and western blot analysis. Gene was sequenced and submitted to GenBank. Conclusions: The cloned HBsAg gene is ready for using in experimental DNA vaccine animal study. There are some mutations on this recombinant protein (T45D, Y206C and S207R which will affect on folding and function of recombinant protein.Keywords: Hepatitis B Virus, HBsAg, Recombinant Protein, Vaccine

  1. Stable isotope labeling of oligosaccharide cell surface antigens

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Silks, L.A. III; Martinez, R.A. [and others

    1998-12-31

    The overall goal of this Laboratory Directed Research and Development (LDRD) project was to develop new methods for synthesis of {sup 13}C-labeled oligosaccharides that are required for nuclear magnetic resonance (NMR) studies of their solution conformation. Oligosaccharides are components of the cell`s outer surface and are involved in important processes such as cell-cell recognition and adhesion. Recently, Danishefsky and coworkers at Slone-Kettering Cancer Center developed a method for the solid-phase chemical synthesis of oligosaccharides. The specific goal of this LDRD project was to prepare uniform {sup 13}C-labeled aldohexose precursors required for the solid-phase synthesis of the Lewis blood-group antigenic determinants. We report the synthesis of {sup 13}C-labeled D-glucal, D-galactal and Fucosyl precursors. We have been collaborating with the Danishefsky group on the synthesis of the Lewis oligosaccharides and the NMR analysis of their solution conformation.

  2. Detection of Carcinoembryonic Antigens Using a Surface Plasmon Resonance Biosensor

    Directory of Open Access Journals (Sweden)

    Shin-Ichiro Nishimura

    2008-07-01

    Full Text Available Carcinoembryonic antigen (CEA is an oncofoetal cell-surface glycoprotein that serves as an important tumor marker for colorectal and some other carcinomas. In this work, a CEA immunoassay using a surface plasmon resonance (SPR biosensor has been developed. SPR could provide label-free, real-time detection with high sensitivity, though its ability to detect CEA in human serum was highly dependent on the analytical conditions employed. We investigated the influences of various analytical conditions including immobilization methods for anti-CEA antibody and composition of sensor surface on the selective and sensitive detection of CEA. The results show that anti-CEA antibody immobilized via Protein A or Protein G caused a large increase in the resonance signal upon injection of human serum due to the interactions with IgGs in serum, while direct covalent immobilization of anti-CEA antibody could substantially reduce it. An optimized protocol based on further kinetic analysis and the use of 2nd and 3rd antibodies for the sandwich assay allowed detecting spiked CEA in human serum as low as 25 ng/mL. Furthermore, a self-assembled monolayer of mixed ethylene-glycol terminated alkanethiols on gold was found to have a comparable ability in detecting CEA as CM5 with thick dextran matrix and C1 with short flat layer on gold.

  3. Effect of hepatitis B immunisation in newborn infants of mothers positive for hepatitis B surface antigen

    DEFF Research Database (Denmark)

    Lee, Chuanfang; Gong, Yan; Brok, Jesper;

    2006-01-01

    To evaluate the effects of hepatitis B vaccine and immunoglobulin in newborn infants of mothers positive for hepatitis B surface antigen.......To evaluate the effects of hepatitis B vaccine and immunoglobulin in newborn infants of mothers positive for hepatitis B surface antigen....

  4. Clinical significance of hepatitis B surface antigen mutants

    Institute of Scientific and Technical Information of China (English)

    Nicola; Coppola; Lorenzo; Onorato; Carmine; Minichini; Giovanni; Di; Caprio; Mario; Starace; Caterina; Sagnelli; Evangelista; Sagnelli

    2015-01-01

    Hepatitis B virus(HBV) infection is a major public health problem in many countries, with nearly 300 million people worldwide carrying HBV chronic infection and over 1 million deaths per year due to cirrhosis and liver cancer. Several hepatitis B surface antigen(HBs Ag) mutations have been described, most frequently due to a single amino acid substitution and seldom to a nucleotide deletion. The majority of mutations are located in the S region, but they have also been found in the pre-S1 and pre-S2 regions. Single amino acid substitutions in the major hydrophilic region of HBs Ag, called the "a" determinant, have been associated with immune escape and the consequent failure of HBV vaccination and HBs Ag detection, whereas deletions in the pre-S1 or pre-S2 regions have been associated with the development of hepatocellular carcinoma. This review article will focus on the HBs Ag mutants and their biological and clinical implications.

  5. Antigenic characterization of dimorphic surface protein in Mycobacterium tuberculosis.

    Science.gov (United States)

    Matsuba, Takashi; Siddiqi, Umme Ruman; Hattori, Toshio; Nakajima, Chie; Fujii, Jun; Suzuki, Yasuhiko

    2016-05-01

    The Mycobacterium tuberculosis Rv0679c protein is a surface protein that contributes to host cell invasion. We previously showed that a single nucleotide transition of the Rv0679c gene leads to a single amino acid substitution from asparagine to lysine at codon 142 in the Beijing genotype family. In this study, we examined the immunological effect of this substitution. Several recombinant proteins were expressed in Escherichia coli and Mycobacterium smegmatis and characterized with antisera and two monoclonal antibodies named 5D4-C2 and 8G10-H2. A significant reduction of antibody binding was detected by enzyme-linked immunosorbent assay (ELISA) and western blot analysis in the Lys142-type protein. This reduction of 8G10-H2 binding was more significant, with the disappearance of a signal in the proteins expressed by recombinant mycobacteria in western blot analysis. In addition, epitope mapping analysis of the recombinant proteins showed a linear epitope by 5D4-C2 and a discontinuous epitope by 8G10-H2. The antibody recognizing the conformational epitope detected only mycobacterial Asn142-type recombinant protein. Our results suggest that a single amino acid substitution of Rv0679c has potency for antigenic change in Beijing genotype strains. PMID:27190237

  6. Construction and Screening of Antigen Targeted Immune Yeast Surface Display Antibody Libraries

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Keith D.; Pefaur, Noah B.; Baird, Cheryl L.

    2008-07-01

    These protocols describe a yeast surface display-based process for the rapid selection of antibodies from immunized mice, eliminating the need for creating and screening hybridoma fusions. A yeast surface display library of single-chain antibody fragments (scFvs) is created from antigen-binding B cells from the splenocytes of immunized mice. The antigen targeted library is then screened for antigen specific scFv by magnetic activated cell sorting (MACS) and fluorescence activated cell sorting (FACS). Library construction and screening can be accomplished in as little as 2 weeks resulting in a panel of scFvs specific for the target antigen.

  7. Construction and Screening of Antigen Targeted Immune Yeast Surface Display Antibody Libraries

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Keith D.; Pefaur, Noah B.; Baird, Cheryl L.

    2009-08-02

    These protocols describe a yeast surface display-based process for the rapid selection of antibodies from immunized mice, eliminating the need for creating and screening hybridoma fusions. A yeast surface display library of single-chain antibody fragments (scFvs) is created from antigen-binding B cells from the splenocytes of immunized mice. The antigen targeted library is then screened for antigen specific scFv by magneticactivated cell sorting (MACS) and fluorescence-activated cell sorting (FACS). Library construction and screening can be accomplished in as little as 2 weeks, resulting in a panel of scFvs specific for the target antigen.

  8. Hepatitis B Virus DNA in Blood Samples Positive for Antibodies to Core Antigen and Negative for Surface Antigen

    Science.gov (United States)

    Gutiérrez, C.; León, G.; Loureiro, C. L.; Uzcátegui, N.; Liprandi, F.; Pujol, F. H.

    1999-01-01

    Anti-hepatitis B core antigen (HBcAg)-positive hepatitis B surface antigen (HBsAg)-negative plasma samples from blood donors were tested by nested PCR. DNA positivity was more significantly associated with high levels of anti-HBcAg than with low levels of anti-HBsAg antibodies. Analysis of a dilution of anti-HBcAg antibodies might result in a more rational exclusion of anti-HBcAg-positive HBsAg-negative samples, reducing the number of donations discarded and enabling more countries to incorporate anti-HBcAg testing. PMID:10473534

  9. Typing of murine cell-surface antigens by cellular radioimmunoassay

    International Nuclear Information System (INIS)

    A cellular radioimmunoassay utilizing 125I-labelled Protein A was used for detecting antigen-antibody complexes on gultaraldehyde fixed cells attached to microtiter plates. This method is rapid, sensitive and specific for revealing H-2 private and public specificities as well as Ia and Lyt antigens. As plates may be kept for months, several reactivities can be tested in one step on a large panel rendering a regular supply of animals unnecessary. (Auth.)

  10. Artificial neural network accurately predicts hepatitis B surface antigen seroclearance.

    Directory of Open Access Journals (Sweden)

    Ming-Hua Zheng

    Full Text Available BACKGROUND & AIMS: Hepatitis B surface antigen (HBsAg seroclearance and seroconversion are regarded as favorable outcomes of chronic hepatitis B (CHB. This study aimed to develop artificial neural networks (ANNs that could accurately predict HBsAg seroclearance or seroconversion on the basis of available serum variables. METHODS: Data from 203 untreated, HBeAg-negative CHB patients with spontaneous HBsAg seroclearance (63 with HBsAg seroconversion, and 203 age- and sex-matched HBeAg-negative controls were analyzed. ANNs and logistic regression models (LRMs were built and tested according to HBsAg seroclearance and seroconversion. Predictive accuracy was assessed with area under the receiver operating characteristic curve (AUROC. RESULTS: Serum quantitative HBsAg (qHBsAg and HBV DNA levels, qHBsAg and HBV DNA reduction were related to HBsAg seroclearance (P<0.001 and were used for ANN/LRM-HBsAg seroclearance building, whereas, qHBsAg reduction was not associated with ANN-HBsAg seroconversion (P = 0.197 and LRM-HBsAg seroconversion was solely based on qHBsAg (P = 0.01. For HBsAg seroclearance, AUROCs of ANN were 0.96, 0.93 and 0.95 for the training, testing and genotype B subgroups respectively. They were significantly higher than those of LRM, qHBsAg and HBV DNA (all P<0.05. Although the performance of ANN-HBsAg seroconversion (AUROC 0.757 was inferior to that for HBsAg seroclearance, it tended to be better than those of LRM, qHBsAg and HBV DNA. CONCLUSIONS: ANN identifies spontaneous HBsAg seroclearance in HBeAg-negative CHB patients with better accuracy, on the basis of easily available serum data. More useful predictors for HBsAg seroconversion are still needed to be explored in the future.

  11. Evidence for glycosyl-phosphatidylinositol anchoring of Toxoplasma gondii major surface antigens

    Energy Technology Data Exchange (ETDEWEB)

    Tomavo, S.; Schwarz, R.T.; Dubremetz, J.F. (Institut National de la Recheche Medicale, Villeneuve d' Ascq (France))

    1989-10-01

    The four major surface antigens of Toxoplasma gondii tachyzoites (P43, P35, P30, and P22) were made water soluble by phosphatidylinositol-specific phospholipase C (PI-PLC). These antigens were biosynthetically labeled with {sup 3}H-fatty acids, ({sup 3}H)ethanolamine, and ({sup 3}H)carbohydrates. Treatment of {sup 3}H-fatty-acid-labeled parasite lysates with PI-PLC removed the radioactive label from these antigens. A cross-reacting determinant was exposed on these antigens after PI-PLC treatment.

  12. Identification and characterization of surface antigens in parasites, using radiolabelling techniques

    International Nuclear Information System (INIS)

    Surface proteins of Schistosoma sp and Leishmania sp were studied using 125-Iodine as tracer. The surface proteins were labelled by the Lactoperoxidase method and the proteins then separated using SDS PAG electrophoresis and autoradiography. The possible immunogens were then separated using immunoprecipitation and Fluorescent Antibody techniques using sera from patients or from artificially immunized rabbits. Four common antigens were identified from the surfaces of male and female adult worms, cercariae and schistosomulae of S.mansoni. These antigens, which had molecular weights of 150,000, 78,000, 45,000, and 22,000 were also isolated from the surfaces of S.haematobium adults. The surface antigens on promastigotes of a Kenyan strain of Leishmania donovani were separated into three protein antigens with molecular weights of 66,000, 59,000 and 43,000 respectively. The 59,000 molecular weight antigen was a glycoprotein and was common to promastigotes of an American and Indian strain of L.donovani and to L.braziliensis mexicana. None of the isolated antigens have been shown to have a protective effect when vaccinated into mice, but the study illustrates the value of radionuclide tracers in the unravelling of the mosaic of antigens which parasites possess

  13. Variability in expression of cell surface antigens of Candida albicans during morphogenesis.

    OpenAIRE

    Brawner, D L; Cutler, J. E.

    1986-01-01

    The location and expression of two different cell surface antigens on germinating and nongerminating Candida albicans cells was examined by using transmission electron microscopy after labeling with monoclonal antibodies (H9 or C6) and immunocolloidal gold. Immunodeterminant expression of the two carbohydrate antigens was followed from early germination events through 20 h of development. The determinant detected by H9 antibody, which was initially lost from the mother cell surface and prefer...

  14. Linearized hepatitis B surface antigen and hepatitis B core-related antigen in the natural history of chronic hepatitis B.

    Science.gov (United States)

    Seto, W-K; Wong, D K-H; Fung, J; Huang, F-Y; Liu, K S-H; Lai, C-L; Yuen, M-F

    2014-11-01

    Changes in two novel HBV serological markers, linearized hepatitis B surface antigen (HQ-HBsAg) and hepatitis B core-related antigen (HBcrAg), in the natural history of chronic hepatitis B (CHB) have not been well characterized. Serum HQ-HBsAg and HBcrAg levels of 404 Asian treatment-naïve CHB patients were analysed in a cross-sectional manner. Patients were categorized into five groups: immune tolerant (IT group, n=52), immune clearance (IC group, n=105), hepatitis B e antigen (HBeAg)-negative hepatitis (ENH group, n=97), HBeAg-negative quiescent group (ENQ group, n=95) and CHB with hepatitis B surface antigen (HBsAg) seroclearance (SC group, n=55). HQ-HBsAg and HBcrAg were measured and correlated with HBV DNA, HBsAg, HBV genotype and clinical parameters. HQ-HBsAg showed good correlation with HBsAg, especially in the ENQ group (r=0.874, pHBcrAg correlated best with HBV DNA in the ENQ group (r=0.537, pHBcrAg; this subgroup of patients, when compared with those with detectable HBcrAg, had significantly lower median HBV DNA (3.17/4.48 log IU/mL, pHBcrAg up to 42 months after HBsAg seroclearance. When comparing anti-HBs positivity and median time after HBsAg seroclearance in the SC group with and without detectable HQ-HBsAg/HBcrAg, there was no significant difference (22.7% and 36.4%, respectively, p 0.284, and 76.5 and 93.2 months, respectively, p 0.245). HQ-HBsAg and HBcrAg showed unique patterns of distribution throughout the five disease phases of CHB, including high detectability rates after HBsAg seroclearance, opening up different possibilities for their applicability.

  15. Ultrastructural study of Chlamydia trachomatis surface antigens by immunogold staining with monoclonal antibodies.

    OpenAIRE

    Kuo, C C; Chi, E Y

    1987-01-01

    Surface antigens of Chlamydia trachomatis were studied by immunogold staining with monoclonal antibodies and by electron microscopy. The serovar- and subspecies-specific epitopes were the most surface accessible. The species- and genus-specific epitopes were the least surface exposed. Similar serological specificity as that in the microimmunofluorescence test was demonstrated by immunogold staining.

  16. Expression and purification of hepatitis B surface antigen S from Escherichia coli; a new simple method

    OpenAIRE

    Elghanam Mohamed S; Attia Ahmed S; Shoeb Hussein A; Hashem Abd Elgawad M

    2012-01-01

    Abstract Background Hepatitis B is a liver disease primarily caused by hepatitis B virus (HBV) infection. It is distributed worldwide and associated with high mortality and morbidity rates. HBV infections can be avoided by the administration of the currently available vaccine and can be easily diagnosed through commercially available kits. Both the vaccine and the diagnostic kits depend on using the hepatitis B surface antigen (HBsAg) as an antigen. Developing countries such as, Egypt, suffer...

  17. Hepatitis B surface antigen variants in voluntary blood donors in Nanjing, China

    OpenAIRE

    Yong-lin Yang; Qiang Fu; Ming-shun Zhang; Jie Cai; Gui-ming Ma; Zu-hu Huang; Xu-bing Cai

    2012-01-01

    Abstract Background Hepatitis B virus (HBV) is still one of the serious infectious risks for the blood transfusion safety in China. One plausible reason is the emergence of the variants in the major antigenic alpha determinant within the major hydrophilic region (MHR) of hepatitis B surface antigen (HBsAg), which have been assumed to evade the immune surveillance and pose a challenge to the disease diagnosis. It is well documented that some commercial ELISA kits could detect the wild-type but...

  18. Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies

    International Nuclear Information System (INIS)

    The authors used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several different antihistone monoclonal antibodies (BWH-1, MH-1, and MH-2). These antibodies recognize separate antigenic determinants on chromatin and histones extracted from chromatin. The histone antigen-positive cells were viable, and the monoclonal antibodies could be shown to be binding to the cell surface and not to the nucleus. Using monoclonal antibodies specific for monocytes and T cells, and complement-mediated cytotoxicity, the cells bearing histone antigens were shown to be primarily monocytes. The appearance of histone and DNA antigen-positive cells was nearly completely inhibited by the addition of low concentrations of cycloheximide at initiation of the cultures. In contrast, little effect on the percentage of positive cells was detected if cells were exposed to high doses of gamma irradiation before culture. These data further support the existence of cell surface nuclear antigens on selected cell subsets, which may provide insight into the immunopathogenesis of systemic lupus erythematosus and related autoimmune diseases

  19. Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Holers, V.M.; Kotzin, B.L.

    1985-09-01

    The authors used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several different antihistone monoclonal antibodies (BWH-1, MH-1, and MH-2). These antibodies recognize separate antigenic determinants on chromatin and histones extracted from chromatin. The histone antigen-positive cells were viable, and the monoclonal antibodies could be shown to be binding to the cell surface and not to the nucleus. Using monoclonal antibodies specific for monocytes and T cells, and complement-mediated cytotoxicity, the cells bearing histone antigens were shown to be primarily monocytes. The appearance of histone and DNA antigen-positive cells was nearly completely inhibited by the addition of low concentrations of cycloheximide at initiation of the cultures. In contrast, little effect on the percentage of positive cells was detected if cells were exposed to high doses of gamma irradiation before culture. These data further support the existence of cell surface nuclear antigens on selected cell subsets, which may provide insight into the immunopathogenesis of systemic lupus erythematosus and related autoimmune diseases.

  20. Studies on the surface coat of Paramecium aurelia. II. Relationship to the immobilization antigen.

    Science.gov (United States)

    Wyroba, E

    1977-07-11

    Correlations between the presence of surface coat and immobilization antigen of Paramecium tetraurelia were studied. Supravital, partial removal of the surface coat resulted in accelerated response of monobacterially and axenically grown cells to the homologous antiserum. Ciliates pretreated with trypsin or pronase (0.5 mg/ml for 45 min at 0-4 degrees C) were immobilized approximately twice as fast as untreated control cells. The probable localization of at least part, of the immobilization antigen within the surface coat of P. tetraurelia is discussed.

  1. The role of Plasmodium falciparum variant surface antigens in protective immunity and vaccine development

    DEFF Research Database (Denmark)

    Hviid, Lars

    2010-01-01

    There is substantial immuno-epidemiological evidence that the parasite-encoded, so-called variant surface antigens (VSAs) such as PfEMP1 on the surface of infected erythrocytes (IEs) are important-in some cases probably decisive-determinants of clinical outcome of P. falciparum malaria. The evide...

  2. Sarcocystis neurona Merozoites Express a Family of Immunogenic Surface Antigens That Are Orthologues of the Toxoplasma gondii Surface Antigens (SAGs) and SAG-Related Sequences†

    OpenAIRE

    Howe, Daniel K.; Rajshekhar Y Gaji; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

    2005-01-01

    Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been describe...

  3. Radioimmunoassay in the detection of the hepatitis Be antigen/antibody system in asymptomatic carriers of hepatitis B surface antigen

    International Nuclear Information System (INIS)

    A radioimmunoassay for hepatitis e antigen (HBeAg) and antibody to e (anti-HBe) was developed and sera of 71 asymptomatic chronic carriers of hepatitis B surface antigen (HBsAg), in 44 of whom liver biopsy was obtained, were tested. In addition, testing for Dane particle associated DNA polymerase activity was performed in all sera. HBeAg was detected in 14 subjects (19.7%) and anti-HBe in 46 (64.8%). The highest proportion of HBeAg positivity (40%) was found among carriers with histological evidence of chronic hepatitis, whereas anti-HBe was present in 80% of carriers with normal liver histology, in 58% of carriers with non-specific reactive hepatitis and in 60% of carriers with chronic liver lesions. DNA polymerase activity was present in 92.8% of sera positive for HBeAg, in 13% of sera positive for anti HBe, and in 9% of sera negative for both markers. Our results demonstrate that not all HBsAg carriers reactive to HBeAg show evidence of chronic hepatitis nor, conversely, that anti-HBe is invariably associated with the healthy carrier state of HBsAg. Finally, circulating Dane particles, as revealed by the presence of serum specific DNA polymerase activity, may also be present in anti-HBe positive sera other than those of some HBsAg carriers lacking both HBeAg and anti-HBe. (orig.)

  4. Identification of Babesia bigemina infected erythrocyte surface antigens containing epitopes conserved among strains.

    Science.gov (United States)

    Shompole, S; McElwain, T F; Jasmer, D P; Hines, S A; Katende, J; Musoke, A J; Rurangirwa, F R; McGuire, T C

    1994-03-01

    The presence of previously uncharacterized antigens (new antigens) on the surface of intact erythrocytes infected with three strains of Babesia bigemina from Kenya and one each from Puerto Rico, Mexico, St. Croix, and Texcoco-Mexico was demonstrated by indirect immunofluorescent antibody (IFA) reactions. These antigens were not strain specific because antibodies in bovine immune serum to either the Mexico or Kenya isolates reacted with all seven strains tested. Homologous and heterologous immune serum antibodies bound a maximum of 83% and 55%, respectively, of intact erythrocytes infected with the Kenya-Ngong strain but not uninfected erythrocytes. Both sera caused agglutination of only infected erythrocytes. Antibodies eluted from the surface of glutaraldehyde (0.25%) fixed infected erythrocytes had IFA reaction patterns among strains similar to those of immune sera before elution. Eluted antibodies were used to determine if these antigens were protein and encoded by B. bigemina. Eluted antibodies bound seven parasite-encoded proteins of 240, 220, 66, 62, 58, 52 and 38 kDa in an erythrocyte surface-specific immunoprecipitation reaction of 35S-methionine labelled proteins. It was concluded that the surface of B. bigemina infected erythrocytes had parasite-encoded proteins and that these proteins had surface exposed epitopes that were conserved among the seven strains examined which were from two continents.

  5. Solid-phase radioimmunoassay for the measurement of surface antigens expressed on intact lymphocytes

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay was developed for the measurement of lymphocyte surface antigens. The assay was performed in microplates, using cells that were initially fixed to the wells by air drying. The method was used for the measurement of Thy-1, Lyt-1,2,3, IL-2-R, H-2Kb and DR antigens on the surface of mouse thymus, spleen and bone marrow cells, mouse cell lines CTLL, EL-4 and DA-1 and human thymocytes and consisted of sequential incubations with rat or mouse monoclonal antibodies directed against the above antigens, rabbit anti-rat or goat anti-mouse IgG and 125I-protein A. The assay permits the processing of large numbers of samples, is easy to perform, reliable and highly specific. (Auth.)

  6. Solid-phase radioimmunoassay for the measurement of surface antigens expressed on intact lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Savion, S.; Sharabi, Y.; Shoham, J.

    1987-02-26

    A solid-phase radioimmunoassay was developed for the measurement of lymphocyte surface antigens. The assay was performed in microplates, using cells that were initially fixed to the wells by air drying. The method was used for the measurement of Thy-1, Lyt-1,2,3, IL-2-R, H-2K/sup b/ and DR antigens on the surface of mouse thymus, spleen and bone marrow cells, mouse cell lines CTLL, EL-4 and DA-1 and human thymocytes and consisted of sequential incubations with rat or mouse monoclonal antibodies directed against the above antigens, rabbit anti-rat or goat anti-mouse IgG and /sup 125/I-protein A. The assay permits the processing of large numbers of samples, is easy to perform, reliable and highly specific. 13 refs.; 10 figs.

  7. Serological survey of normal humans for natural antibody to cell surface antigens of melanoma.

    Science.gov (United States)

    Houghton, A N; Taormina, M C; Ikeda, H; Watanabe, T; Oettgen, H F; Old, L J

    1980-01-01

    Sera of 106 normal adult men were tested for antibodies reacting with cell surface antigens of three established lines of cultured malignant melanoma. Positive reactions with a protein A assay for IgG antibodies were extremely rare (1-2%). The frequency of positive reactions with assays for IgM antibodies was higher: 5-15% in immune adherence assays and 55-82% in anti-C3 mixed hemadsorption assays. After low-titered sera and sera reacting with fetal calf serum components, conventional alloantigens, and widely distributed class 3 antigens were excluded, sera from seven individuals (one with IgG antibody and six with IgM antibodies) were selected for detailed analysis. The serum containing the IgG antibody came from a healthy 65-year-old Caucasian man; titers of antibody in his serum ranged from < 1/10 to 1/40,000 in tests with different melanoma cell lines. This IgG antibody identifies a differentiation antigen of melanocytes, provisionally designated Mel 1, that distinguishes two classes of melanomas: 22 melanoma cell lines typed Mel 1+ and 17 types Mel 1-. Mel 1 is expressed by fetal fibroblasts but not adult fibroblasts and can be found on a proportion of cultured epithelial cancer cell lines (5 out of 23) but not on glioma or B-cell lines. The melanoma antigens detected by the naturally occurring IgM antibodies are serologically unrelated to Mel 1 but, like Mel 1, appear to be differentiation antigens that distinguish subsets of melanoma. These IgM antibodies detect antigens that are identical or closely related to the AH antigen, a melanoma surface antigen that was initially defined by autologous antibody in a patient with melanoma. In view of the immunogenicity of both Mel 1 and the AH antigens in humans and their occurrence on more than 50% of melanomas, it remains to be seen whether antibody to these antigens can be elicited by specific vaccination of seronegative melanoma patients and whether this will have an influence on the clinical course of the disease

  8. Prevalence of hepatitis B surface antigen (HBsAg) in blood donors from Bombay.

    Science.gov (United States)

    Satoskar, A; Ray, V

    1992-01-01

    Analysis of serum samples from 3104 blood donors from Bombay screened for hepatitis B surface antigen (HBsAg) by ELISA. HBsAg was detected in 4.7% of the subjects. Relatives showed a significantly higher prevalence of HBsAg than volunteer donors. There was no significant association between HBsAg positivity and a particular blood group.

  9. Identification and Characterization of Ixodes scapularis Antigens That Elicit Tick Immunity Using Yeast Surface Display

    NARCIS (Netherlands)

    T.J. Schuijt; S. Narasimhan; S. Daffre; K. Deponte; J.W.R. Hovius; C. van 't Veer; T. van der Poll; K. Bakhtiari; J.C.M. Meijers; E.T. Boder; A.P. van Dam; E. Fikrig

    2011-01-01

    Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary a

  10. A putative, novel coli surface antigen 8B (CS8B) of enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Njoroge, Samuel M; Boinett, Christine J; Madé, Laure F; Ouko, Tom T; Fèvre, Eric M; Thomson, Nicholas R; Kariuki, Samuel

    2015-10-01

    Enterotoxigenic Escherichia coli (ETEC) strains harbor multiple fimbriae and pili to mediate host colonization, including the type IVb pilus, colonization factor antigen III (CFA/III). Not all colonization factors are well characterized or known in toxin positive ETEC isolates, which may have an impact identifying ETEC isolates based on molecular screening of these biomarkers. We describe a novel coli surface antigen (CS) 8 subtype B (CS8B), a family of CFA/III pilus, in a toxin producing ETEC isolate from a Kenyan collection. In highlighting the existence of this putative CS, we provide the sequence and specific primers, which can be used alongside other ETEC primers previously described.

  11. Some problems associated with radiolabeling surface antigens on helminth parasites: a brief review

    Energy Technology Data Exchange (ETDEWEB)

    Hayunga, E.G. (Division of Tropical Public Health, Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD (USA)); Murrell, K.D. (Agricultural Research Service, Beltsville, MD (USA))

    1982-06-01

    Recent developments in technology have facilitated substantial advances in the characterization of surface antigens from a wide variety of both normal and neoplastic cells. However, the immunochemistry of parasites has lagged behind. Efforts to apply conventional radiolabeling methods to helminths have not always been successful. Experimental work with Schistosoma mansoni is reviewed to illustrate common problems encountered in surface labeling studies. These findings should provide insight for the future investigation of other helminth species.

  12. Soluble recombinant merozoite surface antigen-142kDa of Plasmodium vivax: An improved diagnostic antigen for vivax malaria.

    Science.gov (United States)

    Mirahmadi, Hadi; Fallahi, Shirzad; Seyyed Tabaei, Seyyed Javad

    2016-04-01

    Enzyme Linked Immunosorbent Assay (ELISA), as a serological test, can be a beneficial tool for epidemiological studies by screening blood donors and diagnosis of specific antibodies from Plasmodium vivax (P. vivax) infected cases. Since P. vivax cannot easily be acquired in vitro, ELISA assays using total or semi-purified antigens are seldom used. On the basis of this restriction, we examined whether recombinant protein 42 kDa related to C-terminal region of the merozoite surface antigen-1 of P. vivax (MSA-1(42)) could be suitable for serological detection of vivax malaria infection. Purified recombinant protein produced in Escherichia coli (E. coli) (GST-MSA-1(42)) was examined for its ability to bind to IgG antibodies of individuals with patent P. vivax infection. The method was tested with 262 serum samples collected from individuals living in the south and southeastern regions of Iran where malaria is endemic. Samples exposed to Plasmodium falciparum (P. falciparum) infection and patients with other infectious disease (toxoplasmosis, Leishmania infantum infection, echinococcosis and FUO (fever with unknown origin)) except for P. falciparum were residing in non- malaria endemic areas in Iran. Generally, the sensitivity of ELISA evaluated with sera from naturally infected individuals was 86.9%. The specificity value of the ELISA determined with sera from healthy individuals and from individuals with other infectious diseases was 94.05%. The positive predictive value (PPV), negative predictive value (NPV) provided, and the diagnostic efficiency of anti-rPvMSA-1(42) antibody using indirect ELISA were determined 93.58, 87.77 and 91.06% respectively. Our study demonstrated that, because MSA-1(42) kDa contains both the 33 and 19 kDa fragments in its structure, it can serve as the basis for the development of a sensitive serological test which can be used for epidemiological studies, screening blood donors and diagnosis of P. vivax malaria. PMID:26851675

  13. Identification and characterization of Ixodes scapularis antigens that elicit tick immunity using yeast surface display.

    Science.gov (United States)

    Schuijt, Tim J; Narasimhan, Sukanya; Daffre, Sirlei; DePonte, Kathleen; Hovius, Joppe W R; Van't Veer, Cornelis; van der Poll, Tom; Bakhtiari, Kamran; Meijers, Joost C M; Boder, Eric T; van Dam, Alje P; Fikrig, Erol

    2011-01-05

    Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary antigens that react with tick-immune serum. We constructed an Ixodes scapularis nymphal salivary gland yeast surface display library and screened the library with nymph-immune rabbit sera and identified five salivary antigens. Four of these proteins, designated P8, P19, P23 and P32, had a predicted signal sequence. We generated recombinant (r) P8, P19 and P23 in a Drosophila expression system for functional and immunization studies. rP8 showed anti-complement activity and rP23 demonstrated anti-coagulant activity. Ixodes scapularis feeding was significantly impaired when nymphs were fed on rabbits immunized with a cocktail of rP8, rP19 and rP23, a hall mark of tick-immunity. These studies also suggest that these antigens may serve as potential vaccine candidates to thwart tick feeding.

  14. Identification and characterization of Ixodes scapularis antigens that elicit tick immunity using yeast surface display.

    Directory of Open Access Journals (Sweden)

    Tim J Schuijt

    Full Text Available Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary antigens that react with tick-immune serum. We constructed an Ixodes scapularis nymphal salivary gland yeast surface display library and screened the library with nymph-immune rabbit sera and identified five salivary antigens. Four of these proteins, designated P8, P19, P23 and P32, had a predicted signal sequence. We generated recombinant (r P8, P19 and P23 in a Drosophila expression system for functional and immunization studies. rP8 showed anti-complement activity and rP23 demonstrated anti-coagulant activity. Ixodes scapularis feeding was significantly impaired when nymphs were fed on rabbits immunized with a cocktail of rP8, rP19 and rP23, a hall mark of tick-immunity. These studies also suggest that these antigens may serve as potential vaccine candidates to thwart tick feeding.

  15. Targeted surface expression of an exogenous antigen in stably transfected Babesia bovis.

    Directory of Open Access Journals (Sweden)

    Jacob M Laughery

    Full Text Available Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1α intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1α locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as

  16. Targeted surface expression of an exogenous antigen in stably transfected Babesia bovis.

    Science.gov (United States)

    Laughery, Jacob M; Knowles, Donald P; Schneider, David A; Bastos, Reginaldo G; McElwain, Terry F; Suarez, Carlos E

    2014-01-01

    Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1α intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1α locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as a future vaccine

  17. Detection and Characterization of Autoantibodies to Neuronal Cell-Surface Antigens in the Central Nervous System.

    Science.gov (United States)

    van Coevorden-Hameete, Marleen H; Titulaer, Maarten J; Schreurs, Marco W J; de Graaff, Esther; Sillevis Smitt, Peter A E; Hoogenraad, Casper C

    2016-01-01

    Autoimmune encephalitis (AIE) is a group of disorders in which autoantibodies directed at antigens located on the plasma membrane of neurons induce severe neurological symptoms. In contrast to classical paraneoplastic disorders, AIE patients respond well to immunotherapy. The detection of neuronal surface autoantibodies in patients' serum or CSF therefore has serious consequences for the patients' treatment and follow-up and requires the availability of sensitive and specific diagnostic tests. This mini-review provides a guideline for both diagnostic and research laboratories that work on the detection of known surface autoantibodies and/or the identification of novel surface antigens. We discuss the strengths and pitfalls of different techniques for anti-neuronal antibody detection: (1) Immunohistochemistry (IHC) and immunofluorescence on rat/primate brain sections; (2) Immunocytochemistry (ICC) of living cultured hippocampal neurons; and (3) Cell Based Assay (CBA). In addition, we discuss the use of immunoprecipitation and mass spectrometry analysis for the detection of novel neuronal surface antigens, which is a crucial step in further disease classification and the development of novel CBAs. PMID:27303263

  18. Detection and Characterization of Autoantibodies to Neuronal Cell-Surface Antigens in the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Marleen eVan Coevorden-Hameete

    2016-05-01

    Full Text Available Autoimmune encephalitis (AIE is a group of disorders in which autoantibodies directed at antigens located on the plasma membrane of neurons induce severe neurological symptoms. In contrast to classical paraneoplastic disorders, AIE patients respond well to immunotherapy. The detection of neuronal surface autoantibodies in patients’ serum or CSF therefore has serious consequences for the patients’ treatment and follow-up and requires the availability of sensitive and specific diagnostic tests. This mini-review provides a guideline for both diagnostic and research laboratories that work on the detection of known surface autoantibodies and/or the identification of novel surface antigens. We discuss the strengths and pitfalls of different techniques for anti-neuronal antibody detection: 1 Immunohistochemistry and immunofluorescence on rat/ primate brain sections, 2 Immunocytochemistry of living cultured hippocampal neurons, 3 Cell Based Assay (CBA. In addition, we discuss the use of immunoprecipitation and mass spectrometry analysis for the detection of novel neuronal surface antigens, which is a crucial step in further disease classification and the development of novel CBAs.

  19. European collaborative evaluation of Enzygnost HBsAg 6.0: performance on hepatitis B virus surface antigen variants

    OpenAIRE

    Avellón, Ana; Echevarría, Jose-Manuel; Weber, Bernard; Weik, Michael; Schobel, Uwe-Peter; Willems, Wulf R.; Gerlich, Wolfram

    2010-01-01

    Abstract Amino acid changes within the major antigenic determinant of the hepatitis B virus (HBV) surface antigen (HBsAg) may eventually modify the antigenic properties of the protein and may have impact on the sensitivity of diagnostic assays. Modifications in the design of an assay can, however, improve significantly its capability to detect these mutants. One-hundred and forty-seven clinical samples containing HBsAg variants, and 54 supernatants of cells expressing recombinant H...

  20. Transcriptional Regulation of the Borrelia burgdorferi Antigenically Variable VlsE Surface Protein

    OpenAIRE

    Bykowski, Tomasz; Babb, Kelly; von Lackum, Kate; Riley, Sean P.; Norris, Steven J; Stevenson, Brian

    2006-01-01

    The Lyme disease agent Borrelia burgdorferi can persistently infect humans and other animals despite host active immune responses. This is facilitated, in part, by the vls locus, a complex system consisting of the vlsE expression site and an adjacent set of 11 to 15 silent vls cassettes. Segments of nonexpressed cassettes recombine with the vlsE region during infection of mammalian hosts, resulting in combinatorial antigenic variation of the VlsE outer surface protein. We now demonstrate that...

  1. Bioencapsulation of the hepatitis B surface antigen and its use as an effective oral immunogen

    OpenAIRE

    Hayden, Celine A; Streatfield, Stephen J.; Lamphear, Barry J.; Fake, Gina M.; Keener, Todd K.; John H Walker; Clements, John D.; Turner, Debra D.; Tizard, Ian R.; Howard, John A.

    2012-01-01

    Hepatitis B remains a major global health problem despite the availability of a safe and effective vaccine. Segments of the population lack access to or respond poorly to the parenteral vaccine, perpetuating the infection-transmission cycle. A low cost, orally-delivered vaccine has the potential to alleviate many of these problems. Here we describe the expression of a bioencapsulated hepatitis B surface antigen (HBsAg) in maize and its immunogenicity, demonstrating for the first time a commer...

  2. Oral immunization with hepatitis B surface antigen expressed in transgenic plants

    OpenAIRE

    Kong, Qingxian; Richter, Liz; Yang, Yu Fang; Arntzen, Charles J.; Mason, Hugh S.; Thanavala, Yasmin

    2001-01-01

    Oral immunogenicity of recombinant hepatitis B surface antigen (HBsAg) derived from yeast (purified product) or in transgenic potatoes (uncooked unprocessed sample) was compared. An oral adjuvant, cholera toxin, was used to increase immune responses. Transgenic plant material containing HBsAg was the superior means of both inducing a primary immune response and priming the mice to respond to a subsequent parenteral injection of HBsAg. Electron microscopy of transgenic ...

  3. Detection and Characterization of Autoantibodies to Neuronal Cell-Surface Antigens in the Central Nervous System

    OpenAIRE

    Marleen eVan Coevorden-Hameete; Maarten eTitulaer; Marco eSchreurs; Esther ede Graaff; Peter eSillevis Smitt; Casper eHoogenraad

    2016-01-01

    Autoimmune encephalitis (AIE) is a group of disorders in which autoantibodies directed at antigens located on the plasma membrane of neurons induce severe neurological symptoms. In contrast to classical paraneoplastic disorders, AIE patients respond well to immunotherapy. The detection of neuronal surface autoantibodies in patients’ serum or CSF therefore has serious consequences for the patients’ treatment and follow-up and requires the availability of sensitive and specific diagnostic tests...

  4. Surface antigen expression in chronic lymphocytic leukemia: clustering analysis, interrelationships and effects of chromosomal abnormalities.

    Science.gov (United States)

    Hulkkonen, J; Vilpo, L; Hurme, M; Vilpo, J

    2002-02-01

    Chronic lymphocytic leukemia (CLL) is a phenotypically distinguishable form of B-lymphoid leukemias. The regularity of surface membrane antigen expression patterns, their interrelationships as well as the effects of the three frequent chromosomal aberrations, ie 11q deletion, 13q deletion and trisomy 12, were investigated in 35 classic CLL cases by flow cytometry. The two-way cluster analysis of 31 individual antigens revealed three expression patterns: (1) most cells in most cases positive (CD5, CD19, CD20, CD23, CD27, CD40, CD45, CD45RA); (2) most cells in most cases negative (CD10, CD14, CD34, CD122, CD154, mIgG); and (3) a mixed pattern with a variable number of positive cases and a variable percentage of positive cells in individual cases (CD11c, CD21, CD22, CD25, CD38, CD45RO, CD79b, CD80, CD95, CD124, CD126, CD130, FMC7, mIgD, mIgkappa, mIglambda, mIgM). The expressions of several antigens were strongly interdependent, even when antigens belonged to entirely different gene families. Such antigen pairs were: CD11c/CD21; CD19/CD45; CD19/CD79b; CD22/CD45RA; CD23/Igkappa; CD25/mIgM; CD27/CD45; CD45/CD79b; CD45RA/Igkappa. In contrast, the expression of some antigens was mutually exclusive, the best examples being CD45RA/CD45RO, CD38/CD80 and CD45RA/CD80. Deletion of chromosome arm 11q attenuated expression of splicing variant CD45RA, but enhanced CD45RO expression. In contrast, cases of trisomy 12 were associated with enhanced CD45RA and attenuated CD45RO expression. Similarly, trisomy 12 was associated with enhanced CD27 and mIgkappa expression. The variable levels of signaling surface membrane antigens, their interactions and interference by genetic aberrations are likely to affect the clinical progression and drug response of CLL. PMID:11840283

  5. Biological role of surface Toxoplasma gondii antigen in development of vaccine

    Institute of Scientific and Technical Information of China (English)

    Ke-Yi Liu; Dian-Bo Zhang; Qing-Kuan Wei; Jin Li; Gui-Ping Li; Jin-Zhi Yu

    2006-01-01

    AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii (T gondii) in development of vaccine.METHODS: The surface antigen of Tgondii (SAG1)was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1and challenged with lethal strain of T gondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on T gondii tachyzoites under electromicroscope.RESULTS:The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group.The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-γ, IL-2 and IL-4cytokines in mice. In contrast, IL-12, IL-6 and TNF-αwere undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed,swollen, and holes and gaps formed on the surface.CONCLUSION: SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.

  6. Role of TLR-2 and fungal surface antigens on innate immune response against Sporothrix schenckii.

    Science.gov (United States)

    Negrini, Thais de C; Ferreira, Lucas S; Alegranci, Pâmela; Arthur, Rodrigo A; Sundfeld, Pedro P; Maia, Danielle C G; Spolidorio, Luis C; Carlos, Iracilda Z

    2013-01-01

    Sporotrichosis is an infection caused by the dimorphic fungus Sporothrix schenckii. Toll-like receptors (TLRs) play an important role in immunity, since they bind to pathogen surface antigens and initiate the immune response. However, little is known about the role of TLR-2 and fungal surface antigens in the recognition of S. schenckii and in the subsequent immune response. This study aimed to evaluate the involvement of TLR-2 and fungal surface soluble (SolAg) and lipidic (LipAg) antigens in phagocytosis of S. schenckii and production of immune mediators by macrophages obtained from WT and TLR-2(-/-) animals. The results showed that TLR-2(-/-) animals had had statistical lower percentage of macrophages with internalized yeasts compared to WT. SolAg and LipAg impaired phagocytosis and immunological mediator production for both WT and TLR-2(-/-). The absence of TLR-2 led to lower production of the cytokines TNF-α, IL-1β, IL-12 and IL-10 compared to WT animals. These results suggest a new insight in relation to how the immune system, through TLR-2, recognizes and induces the production of mediators in response to the fungus S. schenckii.

  7. Simulation and Theory of Antibody Binding to Crowded Antigen-Covered Surfaces.

    Directory of Open Access Journals (Sweden)

    Cristiano De Michele

    2016-03-01

    Full Text Available In this paper we introduce a fully flexible coarse-grained model of immunoglobulin G (IgG antibodies parametrized directly on cryo-EM data and simulate the binding dynamics of many IgGs to antigens adsorbed on a surface at increasing densities. Moreover, we work out a theoretical model that allows to explain all the features observed in the simulations. Our combined computational and theoretical framework is in excellent agreement with surface-plasmon resonance data and allows us to establish a number of important results. (i Internal flexibility is key to maximize bivalent binding, flexible IgGs being able to explore the surface with their second arm in search for an available hapten. This is made clear by the strongly reduced ability to bind with both arms displayed by artificial IgGs designed to rigidly keep a prescribed shape. (ii The large size of IgGs is instrumental to keep neighboring molecules at a certain distance (surface repulsion, which essentially makes antigens within reach of the second Fab always unoccupied on average. (iii One needs to account independently for the thermodynamic and geometric factors that regulate the binding equilibrium. The key geometrical parameters, besides excluded-volume repulsion, describe the screening of free haptens by neighboring bound antibodies. We prove that the thermodynamic parameters govern the low-antigen-concentration regime, while the surface screening and repulsion only affect the binding at high hapten densities. Importantly, we prove that screening effects are concealed in relative measures, such as the fraction of bivalently bound antibodies. Overall, our model provides a valuable, accurate theoretical paradigm beyond existing frameworks to interpret experimental profiles of antibodies binding to multi-valent surfaces of different sorts in many contexts.

  8. Construction of Recombinant Modified Vaccinia Ankara (MVA) Expressing Hepatitis B Virus Surface Antigen

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The T lymphocyte response has been shown to be the determinant in the clearance of many viral infections.Hence, therapeutic vaccine candidates against HBV are designed to enhance this response of the immune system.Vaccinia virus vector-based vaccines have been proposed as excellent candidates to elicit long-term and strong T lymphocyte mediated immune responses. In this study, the recombinant MVA expressing HBV surface antigen has been constructed, which can elicit a potent T cell mediated response. The ELISA results for the surface protein in the medium of the recombinant MVA, strongly indicate that the recombinant virus has been successfully obtained.

  9. Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

    Energy Technology Data Exchange (ETDEWEB)

    Patters, M.R.; Landsberg, R.L.; Johansson, L.A.; Trummel, C.L.; Robertson, P.R. (Department of Periodontology, University of Connecticut, School of Dental Medicine, Farmington, Connecticut, U.S.A.)

    1982-01-01

    Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated /sup 45/Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis.

  10. Merozoite Surface Antigen 2 Proteins of Babesia bovis Vaccine Breakthrough Isolates Contain a Unique Hypervariable Region Composed of Degenerate Repeats

    OpenAIRE

    Berens, Shawn J.; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The merozoite surface antigen 2 (MSA-2) proteins of Babesia bovis are members of the variable merozoite surface antigen (VMSA) family that have been implicated in erythrocyte invasion and are important targets for antibody-mediated blocking of invasion. Extensive sequence variation in another VMSA member, MSA-1, has been shown in all vaccine breakthrough isolates. To test the hypothesis that the msa-2 genes of vaccine breakthrough isolates would also encode a diverse set of proteins, the comp...

  11. Rapid and specific biotin labelling of the erythrocyte surface antigens of both cultured and ex-vivo Plasmodium parasites

    Directory of Open Access Journals (Sweden)

    Thompson Joanne

    2007-05-01

    Full Text Available Abstract Background Sensitive detection of parasite surface antigens expressed on erythrocyte membranes is necessary to further analyse the molecular pathology of malaria. This study describes a modified biotin labelling/osmotic lysis method which rapidly produces membrane extracts enriched for labelled surface antigens and also improves the efficiency of antigen recovery compared with traditional detergent extraction and surface radio-iodination. The method can also be used with ex-vivo parasites. Methods After surface labelling with biotin in the presence of the inhibitor furosemide, detergent extraction and osmotic lysis methods of enriching for the membrane fractions were compared to determine the efficiency of purification and recovery. Biotin-labelled proteins were identified on silver-stained SDS-polyacrylamide gels. Results Detergent extraction and osmotic lysis were compared for their capacity to purify biotin-labelled Plasmodium falciparum and Plasmodium chabaudi erythrocyte surface antigens. The pellet fraction formed after osmotic lysis of P. falciparum-infected erythrocytes is notably enriched in suface antigens, including PfEMP1, when compared to detergent extraction. There is also reduced co-extraction of host proteins such as spectrin and Band 3. Conclusion Biotinylation and osmotic lysis provides an improved method to label and purify parasitised erythrocyte surface antigen extracts from both in vitro and ex vivo Plasmodium parasite preparations.

  12. T cell responses to hepatitis B surface antigen are detectable in non-vaccinated individuals

    Institute of Scientific and Technical Information of China (English)

    Martin R Weihrauch; Michael von Bergwelt-Baildon; Milos Kandic; Martin Weskott; Winfried Klamp; Joachim R(o)sier; Joachim L Schultze

    2008-01-01

    AIM: To evaluate, whether humoral hepatitis-B-vaccine non-responders also fail to mount a T cell response and to compare these results to normal vaccinees.METHODS: Fourty-seven health care employees were enrolled in this study including all available nonresponders (n = 13) with an anti-HBsAg titer 1000 kU/L as controls.PBMC from all subjects were analyzed by IFN-γ and IL-4 ELISPOT assays for the presence of hepatitis B surface antigen (HBsAg) reactive T cells.RESULTS: Non-responders and low-responders had no or only very limited T cell responses, respectively.Individuals responding to vaccination with the induction of a high anti-HBsAg titer showed a strong T cell response after the third vaccination.Surprisingly, these individuals showed response even before the first vaccination.T cell response to control antigens and mitogens was similar in all groups.CONCLUSION: Our data suggest that there is no general immune deficiency in non-/low-responders.Thus,we hypothesize that the induction of anti-HBsAg responses by vaccination is significantly dependent on the pre-existing T cell repertoire against the specific antigen rather than the presence of a general T cell defect.

  13. Autoantibodies to neuronal surface antigens in thyroid antibody-positive and -negative limbic encephalitis

    Directory of Open Access Journals (Sweden)

    Erdem Tuzun

    2011-01-01

    Full Text Available Background : Thyroid antibodies (Thy-Abs are frequently detected in various autoimmune disorders in coexistence with other systemic autoantibodies. In association with an encephalopathy, they are often taken as evidence of Hashimoto′s encephalitis (HE. However, the presence of Thy-Abs in a cohort of limbic encephalitis (LE patients and their association with anti-neuronal autoimmunity has not been explored. Patients and Methods : We investigated thyroid and anti-neuronal antibodies in the sera of 24 LE patients without identified tumors by cell-based assay and radioimmunoassay and evaluated their clinical features. Results : There was a female predominance in Thy-Ab-positive LE patients. Five of the eight Thy-Ab-positive patients and six of the 16 Thy-Ab-negative patients had antibodies to voltage-gated potassium channel (VGKC, N-methyl-D-aspartate receptor (NMDAR or undefined surface antigens on cultured hippocampal neurons. There were trends towards fewer VGKC antibodies (1/8 vs. 5/16, P = 0.159 and more NMDAR antibodies (2/8 vs. 1/16, P = 0.095 among the Thy-Ab-positive LE patients; antibodies to undefined surface antigens were only identified in Thy-Ab-positive patients (2/8 vs. 0/16, P = 0.018. There were no distinguishing clinical features between Thy-Ab-positive patients with and without neuronal antibodies. However, patients with anti-neuronal antibodies showed a better treatment response. Conclusion : Thy-Abs can be found in a high proportion of patients with non-paraneoplastic LE, often in association with antibodies to specific or as yet undefined neuronal surface antigens. These results suggest that acute idiopathic encephalitis patients with Thy-Abs should be closely monitored for ion-channel antibodies and it should not be assumed that they have HE.

  14. Cellular immune responses in patients with hepatitis B surface antigen seroclearance induced by antiviral therapy

    Directory of Open Access Journals (Sweden)

    Zhu Xiaolin

    2011-02-01

    Full Text Available Abstract Background The mechanisms by which chronic hepatitis B is completely resolved through antiviral therapy are unknown, and the contribution of acquired T cell immunity to hepatitis B surface antigen (HBsAg seroclearance has not been investigated. Therefore, we measured the T-cell responses to core and envelope antigens in patients with HBsAg seroclearance. Methods Fourteen subjects with HBsAg seroclearance following antiviral treatment for chronic hepatitis B, 7 HBeAg-positive immunotolerant HBV carriers and 9 HBeAg-negative inactive HBsAg carriers were recruited. HBV-specific T-cell responses to recombinant HBV core (rHBcAg and envelope (rHBsAg proteins and pools of core and envelope peptides were measured using an ELISPOT assay detecting interferon-gamma and intracellular cytokine staining (ICS assays detecting interferon-gamma or interleukin 2. Results Interferon-gamma ELISPOT assays showed a low frequency of weak responses to the rHBsAg and S peptide pool in the HBsAg seroclearance group, and the response frequency to the rHBcAg and the C peptide pool was higher than to the rHBsAg (P P = 0.001 respectively. A higher response frequency to C than S peptide pools was confirmed in the interferon-gamma ICS assays for both CD4+ (P = 0.033 and CD8+ (P = 0.040 T cells in the HBsAg seroclearance group. The responses to C and S antigens in the inactive carriers were similar. Conclusions There was a low frequency of CD4+ and CD8+ T cell immune responses to envelope antigens in Chinese subjects with HBsAg seroclearance following antiviral therapy. It is unlikely that these immune responses are responsible for HBsAg seroclearance in these subjects.

  15. A Rough Energy Landscape to Describe Surface-Linked Antibody and Antigen Bond Formation

    Science.gov (United States)

    Limozin, Laurent; Bongrand, Pierre; Robert, Philippe

    2016-01-01

    Antibodies and B cell receptors often bind their antigen at cell-cell interface while both molecular species are surface-bound, which impacts bond kinetics and function. Despite the description of complex energy landscapes for dissociation kinetics which may also result in significantly different association kinetics, surface-bound molecule (2D) association kinetics usually remain described by an on-rate due to crossing of a single free energy barrier, and few experimental works have measured association kinetics under conditions implying force and two-dimensional relative ligand-receptor motion. We use a new laminar flow chamber to measure 2D bond formation with systematic variation of the distribution of encounter durations between antigen and antibody, in a range from 0.1 to 10 ms. Under physiologically relevant forces, 2D association is 100-fold slower than 3D association as studied by surface plasmon resonance assays. Supported by brownian dynamics simulations, our results show that a minimal encounter duration is required for 2D association; an energy landscape featuring a rough initial part might be a reasonable way of accounting for this. By systematically varying the temperature of our experiments, we evaluate roughness at 2kBT, in the range of previously proposed rough parts of landscapes models during dissociation. PMID:27731375

  16. High affinity mouse-human chimeric Fab against Hepatitis B surface antigen

    OpenAIRE

    Bose, Biplab; Khanna, Navin; Acharya, Subrat K; Sinha, Subrata

    2005-01-01

    AIM: Passive immunotherapy using antibody against hepatitis B surface antigen (HBsAg) has been advocated in certain cases of Hepatitis B infection. We had earlier reported on the cloning and expression of a high affinity scFv derived from a mouse monoclonal (5S) against HBsAg. However this mouse antibody cannot be used for therapeutic purposes as it may elicit anti-mouse immune responses. Chimerization by replacing mouse constant domains with human ones can reduce the immunogenicity of this a...

  17. Production of highly concentrated, heat stable hepatitis B surface antigen in maize

    OpenAIRE

    Hayden, Celine A; Egelkrout, Erin M.; Moscoso, Alessa M.; Enrique, Cristina; Keener, Todd K.; Jimenez-Flores, Rafael; Wong, Jeffrey C.; Howard, John A.

    2012-01-01

    Plant-based oral vaccines are a promising emergent technology that could help alleviate disease burden worldwide by providing a low-cost, heat stable, oral alternative to parenterally administered commercial vaccines. Here we describe high-level accumulation of the hepatitis B surface antigen (HBsAg) at a mean concentration of 0.51%TSP in maize T1 seeds using an improved version of the globulin1 promoter. This concentration is more than four-fold higher than any previously reported lines. HBs...

  18. Immunogenicity and safety of hepatitis E vaccine in healthy hepatitis B surface antigen positive adults

    OpenAIRE

    Wu, Ting; Huang, Shou-Jie; Zhu, Feng-Cai; Zhang, Xue-Feng; AI, XING; Yan, Qiang; Wang, Zhong-Ze; Yang, Chang-Lin; Jiang, Han-Min; Liu, Xiao-Hui; Guo, Meng; Du, Hai-Lian; Ng, Mun-Hon; Zhang, Jun; Xia, Ningshao

    2013-01-01

    A recombinant hepatitis E vaccine, Hecolin®, has been proven safe and effective in healthy adults. As hepatitis B surface antigen (HBsAg) positive individuals have a higher risk of poor prognosis after super-infection with hepatitis E virus (HEV), the safety and immunogenicity of Hecolin® in this population should be assessed. The present study is an extending analysis of data from a large randomized controlled clinical trial of Hecolin®. Healthy participants (n = 14,065) without current or p...

  19. Failure of preexisting antibody against hepatitis B surface antigen to prevent subsequent hepatitis B infection.

    OpenAIRE

    Swenson, P D; Escobar, M R; Carithers, R L; Sobieski, T J

    1983-01-01

    We studied a patient who developed acute hepatitis B virus (HBV) infection despite the presence of preexisting antibody to the surface antigen of HBV (anti-HBs). Anti-HBs has been reported to consist primarily of antibody against the common a determinant of HBV. Antibody directed against this major determinant appears to confer protection against HBV, regardless of the subtype. Our patient was shown to have had preexisting anti-HBs of anti-d but not anti-a specificity. She subsequently develo...

  20. Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies.

    OpenAIRE

    Holers, V.M.; Kotzin, B L

    1985-01-01

    We used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several differe...

  1. Effects of 60Co γ-ray irradiation on expression of surface antigens in endothelial cells of human umbilical veins

    International Nuclear Information System (INIS)

    Culture of endothelial cells of human umbilical veins and avidin-biotin peroxidase complex (ABC) immunochemical technique were used in the experiment to detect the surface antigens in endothelial cells. Endothelial cells separated from five umbilical cords in original culture were divided into two groups, irradiated and non-irradiated. The cells were irradiated with 15 Gy of 60Co γ-rays at dose rates of 21.78 cGy/min. Then antigens RBC A, HLA-ABC, HLA-DR, CD4 and CD8 were assayed for both groups by the method of ABC. The results showed that the values of integrated optical density (IOD) for the surface antigens in the irradiated cells were lower than those in the non-irradiated cells with the difference in antigen expression in endothelial cells being significant (P<0.05) between the two groups

  2. Yeast surface display of a noncovalent MHC class II heterodimer complexed with antigenic peptide.

    Science.gov (United States)

    Boder, Eric T; Bill, Jerome R; Nields, Andrew W; Marrack, Philippa C; Kappler, John W

    2005-11-20

    Microbial protein display technologies have enabled directed molecular evolution of binding and stability properties in numerous protein systems. In particular, dramatic improvements to antibody binding affinity and kinetics have been accomplished using these tools in recent years. Examples of successful application of display technologies to other immunological proteins have been limited to date. Herein, we describe the expression of human class II major histocompatibility complex allele (MHCII) HLA-DR4 on the surface of Saccharomyces cerevisiae as a noncovalently associated heterodimer. The yeast-displayed MHCII is fully native as assessed by binding of conformationally specific monoclonal antibodies; failure of antibodies specific for empty HLA-DR4 to bind yeast-displayed protein indicates antigenic peptide is bound. This report represents the first example of a noncovalent protein dimer displayed on yeast and of successful display of wild-type MHCII. Results further point to the potential for using yeast surface display for engineering and analyzing the antigen binding properties of MHCII.

  3. Detection of cells captured with antigens on shear horizontal surface-acoustic-wave sensors.

    Science.gov (United States)

    Hao, Hsu-Chao; Chang, Hwan-You; Wang, Tsung-Pao; Yao, Da-Jeng

    2013-02-01

    Techniques to separate cells are widely applied in immunology. The technique to separate a specific antigen on a microfluidic platform involves the use of a shear horizontal surface-acoustic-wave (SH-SAW) sensor. With specific antibodies conjugated onto the surface of the SH-SAW sensors, this technique can serve to identify specific cells in bodily fluids. Jurkat cells, used as a target in this work, provide a model of cells in small abundance (1:1000) for isolation and purification with the ultimate goal of targeting even more dilute cells. T cells were separated from a mixed-cell medium on a chip (Jurkat cells/K562 cells, 1/1000). A novel microchamber was developed to capture cells during the purification, which required a large biosample. Cell detection was demonstrated through the performance of genetic identification on the chip.

  4. The role of Plasmodium falciparum variant surface antigens in protective immunity and vaccine development

    DEFF Research Database (Denmark)

    Hviid, Lars

    2010-01-01

    There is substantial immuno-epidemiological evidence that the parasite-encoded, so-called variant surface antigens (VSAs), such as PfEMP1 on the surface of infected erythrocytes (IEs) are important-in some cases probably decisive determinants of clinical outcome of P. falciparum malaria. The...... evidence is increasingly being underpinned by specific molecular understanding of the pathogenic processes involved. Pregnancy-associated malaria (PAM) caused by placenta-sequestering IEs expressing the PfEMP1 variant VAR2CSA is a particularly striking example of this. These findings have raised hopes that...... development of PfEMP1-based vaccines to protect specifically against severe malaria syndromes-in particular PAM-is feasible. This review summarizes the evidence that VSAs are important targets of NAI, discusses why VSA-based vaccines might be feasible despite the extensive intra- and interclonal variation of...

  5. Surface expression of Mo3e antigen by activated human monocytes and U-937 cells

    Energy Technology Data Exchange (ETDEWEB)

    Todd R.F. III; Bury, M.J.; Liu, D.Y.

    1986-03-05

    The surface expression of a protease-sensitive antigen, Mo3e, by activated human monocytes and U-937 cells is a plasma membrane feature of the activated state. Mo3e, which is an 80 kD protein on Western blot analysis, may represent the surface receptor for migration inhibitory factor (MIF), as evidenced by inhibition of MIF responsiveness produced by anti-Mo3e monoclonal antibody. Mo3e is barely detectable (by surface immunofluorescence) on freshly isolated monocytes but becomes expressed in high antigen density during 18-24 hrs culture in medium containing E. coli lipopolysaccharide (> 1 ng/ml), 4..beta..-phorbol 12-myristate 13-acetate (PMA) (5-10 nM), or muramyl dipeptide (0.1-1 ..mu..M). In U-937 cells, Mo3e surface expression is detectable after 24 hrs exposure to PMA and other pharmacological activators of protein kinase C: 4..beta..-phorbol 12, 13 dibutyrate, 4..beta..-phorbol 12, 13 didecanoate, mezerein, or Sn-1,2-dioctanoylglycerol. The biologically-inactivate phorbol compounds, 4..cap alpha..-phorbol 12, 13 didecanoate and 4/sub ..beta../-phorbol do not stimulate Mo3e expression. The calcium ionophore, ionomycin, has a synergistic effect on Mo3e expression stimulated by PMA; conversely, calcium antagonists block PMA-induced Mo3e expression. These results suggest the involvement of protein kinase C activation and intracellular calcium mobilization in the stimulated expression of Mo3e by activated human mononuclear phagocytes.

  6. Expression of hepatitis B surface antigen in the methylotrophic yeast Pichia pastoris using the GAP promoter.

    Science.gov (United States)

    Vassileva, A; Chugh, D A; Swaminathan, S; Khanna, N

    2001-06-01

    High-level expression and efficient assembly of Hepatitis B surface Antigen (HBsAg) particles have been reported in Pichia pastoris by integrating a single copy of the HBsAg gene under the control of the alcohol oxidase (AOX1) promoter. However, the time taken to reach peak product concentration is usually very long ( approximately 240 h). In this paper, we describe the expression of HBsAg in P. pastoris using the recently described glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter. Unlike the previously described AOX1 promoter based system (in which biomass is generated first followed by methanol-induced antigen production), biomass generation and antigen production occur simultaneously in medium containing glycerol or glucose. Maximal levels of HBsAg expression in case of the single copy AOX1 integrant (attained after 6 days of induction) exceeded the levels of antigen produced by the single copy GAP integrant. However, this was offset by continuous antigen production by the GAP clone. In an attempt to further enhance antigen production levels of the GAP clones, we isolated multicopy Pichia integrants containing up to four copies of the GAP promoter-driven constitutive expression cassette using the Zeocin screening procedure. The data demonstrated a direct correlation between the gene dosage and the levels of HBsAg expressed by the GAP clones. The effect of copy number was additive and the four copy clone resulted in about four-fold higher yield of HBsAg. The majority of HBsAg produced in the constitutive expression system was found to be of particulate form, based on sedimentation behaviour and particle-specific ELISA, suggesting that it has the potential to serve as an effective immunogen. These particles were sensitive to thiol reagents. We also explored the possibility of secreting the GAP expressed HBsAg in P. pastoris. In-frame fusion of the Saccharomyces cerevisiae alpha-factor secretion signal under the constitutive GAP promoter resulted in

  7. Proteasomal targeting and minigene repetition improve cell-surface presentation of a transfected, modified melanoma tumour antigen

    DEFF Research Database (Denmark)

    Rasmussen, A B; Zocca, M-B; Bonefeld, C M;

    2004-01-01

    on the density of specific major histocompatibility complex-peptide complexes on the surface of the antigen-presenting cell. In this study, we explored the cell-surface presentation of a substituted MART-1 peptide encoded by transfected minigenes. We investigated the potential of proteasomal targeting compared...

  8. Longitudinal microarray analysis of cell surface antigens on peripheral blood mononuclear cells from HIV+ individuals on highly active antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Wang Bin

    2008-03-01

    Full Text Available Abstract Background The efficacy of highly active antiretroviral therapy (HAART determined by simultaneous monitoring over 100 cell-surface antigens overtime has not been attempted. We used an antibody microarray to analyze changes in the expression of 135 different cell-surface antigens overtime on PBMC from HIV+ patients on HAART. Two groups were chosen, one (n = 6 achieved sustainable response by maintaining below detectable plasma viremia and the other (n = 6 responded intermittently. Blood samples were collected over an average of 3 years and 5–8 time points were selected for microarray assay and statistical analysis. Results Significant trends over time were observed for the expression of 7 cell surface antigens (CD2, CD3epsilon, CD5, CD95, CD36, CD27 and CD28 for combined patient groups. Between groups, expression levels of 10 cell surface antigens (CD11a, CD29, CD38, CD45RO, CD52, CD56, CD57, CD62E, CD64 and CD33 were found to be differential. Expression levels of CD9, CD11a, CD27, CD28 and CD52, CD44, CD49d, CD49e, CD11c strongly correlated with CD4+ and CD8+ T cell counts, respectively. Conclusion Our findings not only detected markers that may have potential prognostic/diagnostic values in evaluating HAART efficacy, but also showed how density of cell surface antigens could be efficiently exploited in an array-like manner in relation to HAART and HIV-infection. The antigens identified in this study should be further investigated by other methods such as flow cytometry for confirmation as biological analysis of these antigens may help further clarify their role during HAART and HIV infection.

  9. Expression and purification of hepatitis B surface antigen S from Escherichia coli; a new simple method

    Directory of Open Access Journals (Sweden)

    Elghanam Mohamed S

    2012-03-01

    Full Text Available Abstract Background Hepatitis B is a liver disease primarily caused by hepatitis B virus (HBV infection. It is distributed worldwide and associated with high mortality and morbidity rates. HBV infections can be avoided by the administration of the currently available vaccine and can be easily diagnosed through commercially available kits. Both the vaccine and the diagnostic kits depend on using the hepatitis B surface antigen (HBsAg as an antigen. Developing countries such as, Egypt, suffer from the widespread of HBV infections and the limited resources to provide adequate supplies of either the vaccine or the diagnostic kits. Therefore the need for an easy, rapid, low cost method to produce HBsAg is urgently needed within this setting. Findings To achieve this goal, the gene encoding the HBsAg(S protein was cloned and expressed as a fusion protein with a GST tag in Escherichia coli. The recombinant protein was successfully expressed and purified in both good quality and quantity. Conclusions The simplified and the relatively low cost of the used protocol make this an attractive alternative to protocols currently used for the purification of HBsAg(S. The exploiting of this achievement for new diagnostics can be directed for application in the developing countries where they are extremely needed.

  10. Adhesion molecule expression stimulated by Bacteroides thetaiotaomicron cell-surface antigens.

    Science.gov (United States)

    Rokosz, A; Meisel-Mikołajczyk, F; Malchar, C; Nowaczyk, M; Górski, A

    1999-01-01

    Bacteroides thetaiotaomicron, a Gram-negative anaerobic rod belonging to the Bacteroides fragilis group (BFG), is involved in many systemic and local, most frequently suppurative infections in man. The cell envelope of these rods is composed of two carbohydrate-containing antigens: lipopolysaccharide (LPS) and capsular polysaccharide (CPS). Adhesion molecules ICAM-1, VCAM-1 and E-selectin (ELAM-1) are induced on the endothelial cells by mediators of inflammation. The aim of this study was to assay the ability of B. thetaiotaomicron surface antigens to induce adhesion molecule expression on the endothelial cells. The influence of LPS and CPS on the expression of adhesion molecules on HMEC-1 cell line was examined in an ELISA test. ELISA was performed with monoclonal mouse anti-human: ICAM-1, VCAM-1 and E-selectin antibodies of the IgG class. B. thetaiotaomicron lipopolysaccharides revealed the ability to induce ICAM-1, VCAM-1 and E-selectin expression on the endothelial cells. Their activities were similar, but lower than the activity of Eschericha coli LPS. ICAM-1 was the most stimulated adhesion molecule. The strongest activation by LPS was achieved at the concentrations of 10.0 and 1.0 micrograms/ml. The ability of capsular polysaccharide to induce the expression of adhesion molecules was considerably weaker.

  11. Antigenicity and Immunogenicity of Rotavirus VP6 Protein Expressed on the Surface of Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    L. E. Esteban

    2013-01-01

    Full Text Available Group A rotaviruses are the major etiologic agents of acute gastroenteritis worldwide in children and young animals. Among its structural proteins, VP6 is the most immunogenic and is highly conserved within this group. Lactococcus lactis is a food-grade, Gram-positive, and nonpathogenic lactic acid bacteria that has already been explored as a mucosal delivery system of heterologous antigens. In this work, the nisin-controlled expression system was used to display the VP6 protein at the cell surface of L. lactis. Conditions for optimal gene expression were established by testing different nisin concentrations, cell density at induction, and incubation times after induction. Cytoplasmic and cell wall protein extracts were analyzed by Western blot and surface expression was confirmed by flow cytometry. Both analysis provided evidence that VP6 was efficiently expressed and displayed on the cell surface of L. lactis. Furthermore, the humoral response of mice immunized with recombinant L. lactis was evaluated and the displayed recombinant VP6 protein proved to be immunogenic. In conclusion, this is the first report of displaying VP6 protein on the surface of L. lactis to induce a specific immune response against rotavirus. These results provide the basis for further evaluation of this VP6-displaying L. lactis as a mucosal delivery vector in a mouse model of rotavirus infection.

  12. Preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens and their use for bacterial detection.

    Science.gov (United States)

    Dykman, Lev A; Staroverov, Sergei A; Guliy, Olga I; Ignatov, Oleg V; Fomin, Alexander S; Vidyasheva, Irina V; Karavaeva, Olga A; Bunin, Viktor D; Burygin, Gennady L

    2012-01-01

    This article reports the first preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens by using a combinatorial phage library of sheep antibodies. The prepared phage antibodies were used for the first time for lipopolysaccharide and flagellin detection by dot assay, electro-optical analysis of cell suspensions, and transmission electron microscopy. Interaction of A. brasilense Sp245 with antilipopolysaccharide and antiflagellin phage-displayed miniantibodies caused the magnitude of the electro-optical signal to change considerably. The electro-optical results were in good agreement with the electron microscopic data. This is the first reported possibility of employing phage-displayed miniantibodies in bacterial detection aided by electro-optical analysis of cell suspensions.

  13. Detection of dengue NS1 antigen using long-range surface plasmon waveguides.

    Science.gov (United States)

    Wong, Wei Ru; Sekaran, Shamala Devi; Adikan, Faisal Rafiq Mahamd; Berini, Pierre

    2016-04-15

    The non-structural 1 (NS1) protein of the dengue virus circulates in infected patients' blood samples and can be used for early diagnosis of dengue infection. In this paper, we present the detection of naturally-occurring dengue NS1 antigen in infected patient blood plasma using straight long-range surface plasmon waveguides. Three commercially-available anti-NS1 monoclonal antibodies were used for recognition and their performance was compared and discussed. A similar figure of merit to the one used in conventional dengue NS1 capture using an enzyme-linked immunosorbent assay (ELISA) was applied to our results. In general, the positive patient samples can be clearly differentiated from the negative ones and the results agree with those obtained using ELISA. The largest signal-to-noise ratio observed during the experiments was 356 and the best detection limit observed is estimated as 5.73 pg/mm(2).

  14. Detection of dengue NS1 antigen using long-range surface plasmon waveguides.

    Science.gov (United States)

    Wong, Wei Ru; Sekaran, Shamala Devi; Adikan, Faisal Rafiq Mahamd; Berini, Pierre

    2016-04-15

    The non-structural 1 (NS1) protein of the dengue virus circulates in infected patients' blood samples and can be used for early diagnosis of dengue infection. In this paper, we present the detection of naturally-occurring dengue NS1 antigen in infected patient blood plasma using straight long-range surface plasmon waveguides. Three commercially-available anti-NS1 monoclonal antibodies were used for recognition and their performance was compared and discussed. A similar figure of merit to the one used in conventional dengue NS1 capture using an enzyme-linked immunosorbent assay (ELISA) was applied to our results. In general, the positive patient samples can be clearly differentiated from the negative ones and the results agree with those obtained using ELISA. The largest signal-to-noise ratio observed during the experiments was 356 and the best detection limit observed is estimated as 5.73 pg/mm(2). PMID:26599483

  15. Malaria-induced acquisition of antibodies to Plasmodium falciparum variant surface antigens

    DEFF Research Database (Denmark)

    Ofori, Michael F; Dodoo, Daniel; Staalsoe, Trine;

    2002-01-01

    In areas of intense Plasmodium falciparum transmission, protective immunity is acquired during childhood in parallel with acquisition of agglutinating antibodies to parasite-encoded variant surface antigens (VSA) expressed on parasitized red blood cells. In a semi-immune child in such an area......, clinical disease is caused mainly by parasites expressing VSA not recognized by preexisting VSA-specific antibodies in that child. Such malaria episodes are known to cause an increase in agglutinating antibodies specifically recognizing VSA expressed by the parasite isolate causing the illness, whereas...... donors (the malaria patient). The data from this first detailed longitudinal study of acquisition of VSA antibodies support the hypothesis that naturally acquired protective immunity to P. falciparum malaria is mediated, at least in part, by VSA-specific antibodies....

  16. Expression of hepatitis B surface antigen gene (HBsAg) in Laminaria japonica (Laminariales, Phaeophyta)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A transformation model for Laminaria japonica was established from 1993 to 1998, on the basis of which the transgenic kelp with heterologous gene encoding hepatitis B surface antigen (HBsAg) was obtained by using the micro- particle bombardment transformation method. Results of quantitative ELISA showed that HBsAg in transgenic kelp was 0.529 μg/mg soluble proteins on average and the highest value was 2.497 μg/mg, implying that recombinant HBsAg had natural epitope. Further support for the integration of HBsAg gene into kelp genome was obtained by PCR- Southern and total DNA hybridization. Prospect of kelp bioreactor producing high value materials such as edible HBV vaccine was discussed as well.

  17. Small-angle neutron scattering study of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particle

    Science.gov (United States)

    Sato, M.; Ito, Y.; Kameyama, K.; Imai, M.; Ishikawa, N.; Takagi, T.

    1995-02-01

    The overall and internal structure of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particles was investigated by small-angle neutron scattering using the contrast variation method. The vaccine is a nearly spherical particle, and its contrast-matching point was determined to be at about 24% D 2O content, indicating that a large part of the vaccine particle is occupied by lipids and carbohydrates from the yeast. The Stuhrmann plot suggests that the surface antigens exist predominantly in the peripheral region of the particle, which is favorable to the induction of anti-virus antibodies.

  18. Successful kidney transplantation from a hepatitis B surface antigen-positive donor to an antigen-negative recipient using a novel vaccination regimen.

    Science.gov (United States)

    Singh, Gurmukteshwar; Hsia-Lin, Andrea; Skiest, Daniel; Germain, Michael; O'Shea, Michael; Braden, Gregory

    2013-04-01

    Transplanting a kidney from a hepatitis B surface antigen (HBsAg)-positive donor to an HBsAg-negative recipient who is naturally immune has been successful in countries endemic for hepatitis B virus (HBV). However, in most of these cases, the donors were deceased. We present a report of a successful HBsAg-discordant kidney transplantation in the United States; in this case, a living donor kidney was transplanted to a vaccinated recipient. The wife of a 58-year-old HBsAg-negative man volunteered to donate a kidney to her husband. She had chronic hepatitis B but undetectable HBV DNA. She tested positive for HBsAg and antibody to hepatitis B core antigen, but hepatitis B e antigen was undetectable. The recipient failed to develop an antibody response to 3 doses of intramuscular recombinant HBV vaccine given in consecutive months. Immunity was induced by using biweekly intradermal vaccine. However, antibody titer tapered to vaccine resulted in a prolonged anamnestic response, allowing for successful living unrelated donor transplantation. During the 10 years since transplantation, the patient has continued to have normal liver function, with undetectable HBsAg and HBV DNA. Antibody titers to HBsAg slowly decreased to 5.8 mIU/mL during the 10 years. Transplant function has been well preserved. This approach to inducing long-term immunity for transplantation merits further study in the United States. PMID:23219109

  19. Systemic and mucosal immune response induced by transcutaneous immunization using Hepatitis B surface antigen-loaded modified liposomes.

    Science.gov (United States)

    Mishra, Dinesh; Mishra, Pradyumna Kumar; Dubey, Vaibhav; Nahar, Manoj; Dabadghao, Sunil; Jain, N K

    2008-04-23

    We have evaluated the efficiency of novel modified liposomes (ethosomes) for transcutaneous immunization (TCI) against Hepatitis B. Antigen-loaded ethosomes were prepared and characterized for shape, lamellarity, fluidity, size distribution, and entrapment efficiency. Spectral bio-imaging and flow cytometric studies showed efficient uptake of Hepatitis B surface antigen (HBsAg)-loaded ethosomes by murine dendritic cells (DCs) in vitro, reaching a peak by 180 min. Transcutaneous delivery potential of the antigen-loaded system using human cadaver skin demonstrated a much higher skin permeation of the antigen in comparison to conventional liposomes and soluble antigen preparation. Topically applied HBsAg-loaded ethosomes in experimental mice showed a robust systemic and mucosal humoral immune response compared to intramuscularly administered alum-adsorbed HBsAg suspension, topically applied plain HBsAg solution and hydroethanolic (25%) HBsAg solution. The ability of the antigen-pulsed DCs to stimulate autologous peripheral blood lymphocytes was demonstrated by BrdU assay and a predominantly TH1 type of immune response was observed by multiplex cytometric bead array analysis. HBsAg-loaded ethosomes are able to generate a protective immune response and their ability to traverse and target the immunological milieu of the skin may find a potential application in the development of a transcutaneous vaccine against Hepatitis B virus (HBV).

  20. cDNA sequence analysis of a 29-kDa cysteine-rich surface antigen of pathogenic Entamoeba histolytica

    Energy Technology Data Exchange (ETDEWEB)

    Torian, B.E.; Stroeher, V.L.; Stamm, W.E. (Univ. of Washington, Seattle (USA)); Flores, B.M. (Louisiana State Univ. Medical Center, New Orleans (USA)); Hagen, F.S. (Zymogenetics Incorporated, Seattle, WA (USA))

    1990-08-01

    A {lambda}gt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate 22 monoclonal antibodies (mAbs) and a mouse polyclonal antiserum specific for the E. histolytica portion of the fusion protein. A 29-kDa protein was identified as a surface antigen when mAbs were used to immunoprecipitate the antigen from metabolically {sup 35}S-labeled live trophozoites. The surface location of the antigen was corroborated by mAb immunoprecipitation of a 29-kDa protein from surface-{sup 125}I-labeled whole trophozoites as well as by the reaction of mAbs with live trophozoites in an indirect immunofluorescence assay performed at 4{degree}C. Immunoblotting with mAbs demonstrated that the antigen was present on four axenic isolates tested. mAbs recognized epitopes on the 29-kDa native antigen on some but not all clinical isolates tested.

  1. Biodegradable polylactide microspheres enhance specific immune response induced by Hepatitis B surface antigen.

    Science.gov (United States)

    Qiu, Shaohui; Wei, Qiang; Liang, Zhenglun; Ma, Guanghui; Wang, Lianyan; An, Wenqi; Ma, Xiaowei; Fang, Xin; He, Peng; Li, Hemin; Hu, Zhongyu

    2014-01-01

    Hepatitis B (HB) infection caused by Hepatitis B virus (HBV) is the most common liver disease in the world. HB vaccine, when administered in conjunction with alum adjuvants, induces Th2 immunity that confers protection against HBV. However, currently available vaccine formulations and adjuvants do not elicit adequate Th1 and CTL responses that are important for prevention of maternal transmission of the virus. Microspheres synthesized from poly (D, L-lactide-co-glycolide) (PLGA) or poly (D, L-lactide) (PLA) polymers have been considered as promising tools for in vivo delivery of antigens and drugs. Here we describe PLA microspheres synthesized by premix membrane emulsification method and their application in formulating a new microsphere based HB vaccine. To evaluate the immunogenicity of this microsphere vaccine, BALB/c mice were immunized with microsphere vaccine and a series of immunological assays were conducted. Results of Enzyme-linked ImmunoSpot (ELISPOT) assays revealed that the number of interferon-gamma (IFN-γ)-producing splenocytes and CD8(+) T cells increased significantly in the microsphere vaccine group. Microsphere vaccine group showed enhanced specific cell lysis when compared with HB surface antigen (HBsAg) only group in (51)Cr cytotoxicity assays. Moreover, microsphere vaccine elicited a comparable level of antibody production as that of HB vaccine administered with alum adjuvant. We show that phagocytosis of HBsAg by dendritic cells is more pronounced in microsphere vaccine group when compared with other control groups. These results clearly demonstrate the potential of using PLA microspheres as effective HB vaccine adjuvants for an enhanced Th1 immune response. PMID:25424942

  2. Identification of new meningococcal serogroup B surface antigens through a systematic analysis of neisserial genomes.

    Science.gov (United States)

    Pajon, Rolando; Yero, Daniel; Niebla, Olivia; Climent, Yanet; Sardiñas, Gretel; García, Darién; Perera, Yasser; Llanes, Alejandro; Delgado, Maité; Cobas, Karem; Caballero, Evelin; Taylor, Stephen; Brookes, Charlotte; Gorringe, Andrew

    2009-12-11

    The difficulty of inducing an effective immune response against the Neisseria meningitidis serogroup B capsular polysaccharide has lead to the search for vaccines for this serogroup based on outer membrane proteins. The availability of the first meningococcal genome (MC58 strain) allowed the expansion of high-throughput methods to explore the protein profile displayed by N. meningitidis. By combining a pan-genome analysis with an extensive experimental validation to identify new potential vaccine candidates, genes coding for antigens likely to be exposed on the surface of the meningococcus were selected after a multistep comparative analysis of entire Neisseria genomes. Eleven novel putative ORF annotations were reported for serogroup B strain MC58. Furthermore, a total of 20 new predicted potential pan-neisserial vaccine candidates were produced as recombinant proteins and evaluated using immunological assays. Potential vaccine candidate coding genes were PCR-amplified from a panel of representative strains and their variability analyzed using maximum likelihood approaches for detecting positive selection. Finally, five proteins all capable of inducing a functional antibody response vs N. meningitidis strain CU385 were identified as new attractive vaccine candidates: NMB0606 a potential YajC orthologue, NMB0928 the neisserial NlpB (BamC), NMB0873 a LolB orthologue, NMB1163 a protein belonging to a curli-like assembly machinery, and NMB0938 (a neisserial specific antigen) with evidence of positive selection appreciated for NMB0928. The new set of vaccine candidates and the novel proposed functions will open a new wave of research in the search for the elusive neisserial vaccine.

  3. Circulating hepatitis B surface antigen particles carry hepatocellular microRNAs.

    Science.gov (United States)

    Novellino, Luisa; Rossi, Riccardo L; Bonino, Ferruccio; Cavallone, Daniela; Abrignani, Sergio; Pagani, Massimiliano; Brunetto, Maurizia R

    2012-01-01

    Hepatitis B virus (HBV) produces high quantities of subviral surface antigen particles (HBsAg) which circulate in the blood outnumbering virions of about 1\\10(3-6) times. In individuals coinfected with the defective hepatitis Delta virus (HDV) the small HDV-RNA-genome and Delta antigen circulate as ribonucleoprotein complexes within HBsAg subviral particles. We addressed the question whether subviral HBsAg particles may carry in the same way cellular microRNAs (miRNAs) which are released into the bloodstream within different subcellular forms such as exosomes and microvescicles. Circulating HBsAg particles were isolated from sera of 11 HBsAg carriers by selective immunoprecipitation with monoclonal anti-HBs-IgG, total RNA was extracted and human miRNAs were screened by TaqMan real-time quantitative PCR Arrays. Thirty-nine human miRNAs were found to be significantly associated with the immunoprecipitated HBsAg, as determined by both comparative DDCT analysis and non-parametric tests (Mann-Whitney, p<0.05) with respect to controls. Moreover immunoprecipitated HBsAg particles contained Ago2 protein that could be revealed in ELISA only after 0.5% NP40. HBsAg associated miRNAs were liver-specific (most frequent = miR-27a, miR-30b, miR-122, miR-126 and miR-145) as well as immune regulatory (most frequent = miR-106b and miR-223). Computationally predicted target genes of HBsAg-associated miRNAs highlighted molecular pathways dealing with host-pathogen. The finding that HBsAg particles carry selective pools of hepatocellular miRNAs opens new avenues of research to disentangle the complex interactions between host and HBV and provides a non invasive tool to study the physiopathology of liver epigenetics.

  4. Circulating hepatitis B surface antigen particles carry hepatocellular microRNAs.

    Directory of Open Access Journals (Sweden)

    Luisa Novellino

    Full Text Available Hepatitis B virus (HBV produces high quantities of subviral surface antigen particles (HBsAg which circulate in the blood outnumbering virions of about 1\\10(3-6 times. In individuals coinfected with the defective hepatitis Delta virus (HDV the small HDV-RNA-genome and Delta antigen circulate as ribonucleoprotein complexes within HBsAg subviral particles. We addressed the question whether subviral HBsAg particles may carry in the same way cellular microRNAs (miRNAs which are released into the bloodstream within different subcellular forms such as exosomes and microvescicles. Circulating HBsAg particles were isolated from sera of 11 HBsAg carriers by selective immunoprecipitation with monoclonal anti-HBs-IgG, total RNA was extracted and human miRNAs were screened by TaqMan real-time quantitative PCR Arrays. Thirty-nine human miRNAs were found to be significantly associated with the immunoprecipitated HBsAg, as determined by both comparative DDCT analysis and non-parametric tests (Mann-Whitney, p<0.05 with respect to controls. Moreover immunoprecipitated HBsAg particles contained Ago2 protein that could be revealed in ELISA only after 0.5% NP40. HBsAg associated miRNAs were liver-specific (most frequent = miR-27a, miR-30b, miR-122, miR-126 and miR-145 as well as immune regulatory (most frequent = miR-106b and miR-223. Computationally predicted target genes of HBsAg-associated miRNAs highlighted molecular pathways dealing with host-pathogen. The finding that HBsAg particles carry selective pools of hepatocellular miRNAs opens new avenues of research to disentangle the complex interactions between host and HBV and provides a non invasive tool to study the physiopathology of liver epigenetics.

  5. Preparation and testing of a Haemophilus influenzae Type b/Hepatitis B surface antigen conjugate vaccine.

    Science.gov (United States)

    An, So Jung; Woo, Joo Sung; Chae, Myung Hwa; Kothari, Sudeep; Carbis, Rodney

    2015-03-24

    The majority of conjugate vaccines focus on inducing an antibody response to the polysaccharide antigen and the carrier protein is present primarily to induce a T-cell dependent response. In this study conjugates consisting of poly(ribosylribitolphosphate) (PRP) purified from Haemophilus influenzae Type b bound to Hepatitis B virus surface antigen (HBsAg) virus like particles were prepared with the aim of inducing an antibody response to not only the PRP but also the HBsAg. A conjugate consisting of PRP bound to HBsAg via an adipic acid dihydrazide (ADH) spacer induced strong IgG antibodies to both the PRP and HBsAg. When conjugation was performed without the ADH spacer the induction of an anti-PRP response was equivalent to that seen by conjugate with the ADH spacer, however, a negligible anti-HBsAg response was induced. For comparison, PRP was conjugated to diphtheria toxoid (DT) and Vi polysaccharide purified from Salmonella Typhi conjugated to HBsAg both using an ADH spacer. The PRPAH-DT conjugate induced strong anti-PRP and anti-DT responses, the Vi-AHHBsAg conjugate induced a good anti-HBsAg response but not as strong as that induced by the PRPAH-HBsAg conjugate. This study demonstrated that in mice it was possible to induce robust antibody responses to both polysaccharide and carrier protein provided the conjugate has certain physico-chemical properties. A PRPAH-HBsAg conjugate with the capacity to induce anti-PRP and anti-HBsAg responses could be incorporated into a multivalent pediatric vaccine and simplify formulation of such a vaccine.

  6. Fusion to green fluorescent protein improves expression levels of Theileria parva sporozoite surface antigen p67 in insect cells

    NARCIS (Netherlands)

    Kaba, S.A.; Nene, V.; Musoke, A.J.; Vlak, J.M.; Oers, van M.M.

    2002-01-01

    East Coast fever (ECF) is a fatal disease of cattle caused by the protozoan parasite Theileria parva. The development of a subunit vaccine, based on the sporozoite-specific surface antigen p67, has been hampered by difficulties in achieving high-level expression of recombinant p67 in a near-authenti

  7. Baculovirus surface display of Theileria parva p67 antigen preserves the conformation of sporozoite-neutralizing epitopes

    NARCIS (Netherlands)

    Kaba, S.A.; Hemmes, J.C.; Lent, van J.W.M.; Vlak, J.M.; Nene, V.; Musoke, A.J.; Oers, van M.M.

    2003-01-01

    Theileria parva is an intracellular protozoan parasite that causes East Coast fever, a severe lymphoproliferative disease in cattle. Previous attempts to produce recombinant sporozoite surface antigen (p67) in bacterial or insect cells for vaccine purposes have not resulted in a correctly folded pro

  8. The Expression of Sperm Membrane Peptide-Hepatitis B Surface Antigen Fusion Protein with Recombinant Vaccinia Virus

    Institute of Scientific and Technical Information of China (English)

    杨晓鸣; 赵峰; 严缘昌; 李光地; 汪垣

    1998-01-01

    A synthetic oligonucleotide, HSD-2a, encoding a peptide segment of the extracellular domain of a human sperm membrane protein, YWK-Ⅱ, was fused with hepatitis B surface antigen gene (HBs gene). The fused gene was then cloned to pUC18 plasmid.

  9. Plasmodium falciparum parasites expressing pregnancy-specific variant surface antigens adhere strongly to the choriocarcinoma cell line BeWo

    DEFF Research Database (Denmark)

    Haase, Rikke N; Megnekou, Rosette; Lundquist, Maja;

    2006-01-01

    Placenta-sequestering Plasmodium falciparum parasites causing pregnancy-associated malaria express pregnancy-specific variant surface antigens (VSA(PAM)). We report here that VSA(PAM)-expressing patient isolates adhere strongly to the choriocarcinoma cell line BeWo and that the BeWo line can...

  10. Major surface antigen, P30, of Toxoplasma gondii is anchored by a glycolipid

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, S.D.; Boothroyd, J.C.

    1989-04-05

    P30, the major surface antigen of the parasitic protozoan Toxoplasma gondii, can be specifically labeled with (/sup 3/H)palmitic acid and with myo-(2-/sup 3/H)inositol. The fatty acid label can be released by treatment of P30 with phosphatidylinositol-specific phospholipase C (PI-PLC). Such treatment exposes an immunological cross-reacting determinant first described on Trypanosoma brucei variant surface glycoprotein. PI-PLC cleavage of intact parasites metabolically labeled with (/sup 35/S)methionine results in the release of intact P30 polypeptide in a form which migrates faster in polyacrylamide gel electrophoresis. These results argue that P30 is anchored by a glycolipid. Results from thin layer chromatography analysis of purified (/sup 3/H) palmitate-labeled P30 treated with PI-PLC, together with susceptibility to mild alkali hydrolysis and to cleavage with phospholipase A2, suggest that the glycolipid anchor of T. gondii P30 includes a 1,2-diacylglycerol moiety.

  11. Review of hepatitis B surface antigen-1018 ISS adjuvant-containing vaccine safety and efficacy.

    Science.gov (United States)

    Barry, Mazin; Cooper, Curtis

    2007-11-01

    Existing hepatitis B virus (HBV) vaccines produce seroprotective titers in > 90% of healthy adult recipients following 3 doses administered over 6 months. The durability of this response is variable. Vaccine efficacy is greatly diminished in immune compromised patients. Given the high worldwide prevalence and burden of disease produced by chronic HBV infection, vaccines capable of producing high rates of durable seroprotective HBV surface antibody titers are required. Immunostimulatory sequences (ISS) containing repeating sequences of cytosine phosphoguanosine (CpG) dinucleotide motifs have emerged as useful tools for modulating immune responses. Dynavax Technologies produced a synthetic oligodexynucleotide (ODN) containing these motifs, resulting in an unmethylated cytosine and phosphoguanosine ODN called 1018 ISS. Dynavax's hepatitis B virus vaccine HEPLISAV is comprised of 1018 ISS mixed with recombinant hepatitis B surface antigen. Clinical trials, to date, have shown that HEPLISAV produces rapid, high titer, sustained seroprotection in healthy adults and vaccine hyporesponsive populations. Although additional supporting data are required, this represents a promising strategy to facilitate worldwide HBV prevention efforts. PMID:17961095

  12. Measurement of Hepatitis B Surface Antigen Concentrations Using a Piezoelectric Microcantilever as a Mass Sensor

    Directory of Open Access Journals (Sweden)

    Sangkyu Lee

    2012-01-01

    Full Text Available Hepatitis B surface antigen (HBsAg concentrations were measured using a piezoelectric microcantilever sensor (PEMS developed by the authors. The developed PEMS is label-free and detects the sensing signal electrically. It was designed to measure the mass of biomolecules attached to it using an accurate mass-microbalancing technique; its probe area is confined to the end of the cantilever, and its equivalent spring constant is relatively high to minimize the effect of changes in the surface stress when the biomolecules are attached to it. The “dip- and-dry” technique was used to enable the probe area of the sensor to react with reagents in controlled environmental conditions. HBsAg was detected by an immunoreaction whereas the reaction time, antibody density, and its area on the probe were kept at a constant level. The mass of the detected HBsAg was measured in the range of 0.1–100 ng/mL.

  13. Application of functional microsphere in human hepatitis B virus surface antigen detection.

    Science.gov (United States)

    Ma, Ningning; Ma, Chao; Wang, Nianyue; Li, Chuanyan; Elingarami, Sauli; Mou, Xianbo; Tang, Yongjun; Zheng, Shuang; He, Nongyue

    2014-05-01

    A novel and simple emulsifier-free emulsion polymerization technique was developed for preparation of mono-dispersed amino functionalized polymer microspheres with well defined diameters (about 400 nm). Various characterization methods demonstrated that the obtained amino microspheres had a uniform size and good dispersity which were confirmed by scanning electron microscope (SEM). Zeta potential and Fourier transform infrared spectrometer (FT-IR) demonstrated that amino groups have been successfully introduced to the microsphere surface. These functionalized microspheres have been shown to be efficient and controllable carriers capable of immobilizing and enriching monoclonal antibodies. Moreover, a newest chemiluminescent enzyme-linked immunoassay (ELISA) approach has been developed for human Hepatitis B virus surface antigen (HBsAg) detection. HBsAg was sandwiched between goat anti-HBsAg polyclonal antibody and mouse anti-HBsAg antibody. Alkaline phosphatase (ALP) conjugated horse anti-mouse immunnogloblin was used to bond with monoclonal antibody. Finally, chemiluminesent (CL) signals were recorded after adding 3-(2-spiroadamantane)-4-methoxy-4-(3-phosphoryloxy) phenyl-1,2-dioxetane (AMPPD) which was used as a chemiluminescent substrate reagent of ALP. This novel chemiluminescent ELISA assay was proved to be of excellent specificity and high sensitivity when using ALP and AMPPD luminescence systems for specific HBsAg detection. PMID:24734551

  14. Induction of anti-human immunodeficiency virus (HIV) neutralizing antibodies in rabbits immunized with recombinant HIV--hepatitis B surface antigen particles.

    OpenAIRE

    Michel, M L; M. Mancini; Sobczak, E.; Favier, V.; Guetard, D; Bahraoui, E M; Tiollais, P

    1988-01-01

    Fragments of the human immunodeficiency virus (HIV) envelope coding region have been fused with the hepatitis B virus envelope middle protein. In this system, HIV antigenic determinants are exposed at the surface of a highly antigenic structure, the hepatitis B surface antigen particle. Immunization of rabbits with these particles elicited antibodies directed against both parts of the hybrid protein. One of the rabbit antisera not only exhibited a neutralizing effect on the original HIV1 isol...

  15. SEROEPIDEMIOLOGIC ASSESSMENT OF MALARIA USING AN ELISA FOR RING-INFECTED ERYTHROCYTE SURFACE ANTIGEN OF PLASMODIUM FALCIPARUM

    Directory of Open Access Journals (Sweden)

    J. Kevin Baird

    2012-09-01

    Full Text Available Zat anti terhadap antigen permukaan dari sel eritrosit yang terinfeksi dengan parasit bentuk cincin (Ring-infected Erythrocyte Surface Antigen/RESA Plasmodium falcipa­rum telah diukur dari sera yang dikumpulkan di Jawa Tengah, Jawa Timur, dan Irian Ja­ya. Untuk mendeteksi IgG terhadap RESA tersebut digunakan ELISA (Enzyme Linked Immuno Sorbent Assay. Dari pengukuran tersebut menunjukkan adanya korelasi antara RESA ELISA dengan pengukuran epidemiologis transmisi malaria secara konvensional. Pada tulisan ini diuraikan tentang prosedur standar untuk melakukan RESA ELISA dan membahas hal-hal yang menguntungkan maupun keterbatasan-keterbatasan dalam ekstrapolasi data untuk menggambarkan perkiraan transmisi malaria.

  16. Protective efficacy of bacterial membranes containing surface-exposed BM95 antigenic peptides for the control of cattle tick infestations.

    Science.gov (United States)

    Canales, Mario; Labruna, Marcelo B; Soares, João F; Prudencio, Carlos R; de la Fuente, José

    2009-12-01

    The Rhipicephalus (Boophilus) microplus BM86 and BM95 glycoproteins are homologous proteins that protect cattle against tick infestations. In this study, we demonstrated that the recombinant chimeric protein comprising tick BM95 immunogenic peptides fused to the A. marginale MSP1a N-terminal region for presentation on the Escherichia coli membrane was protective against R. microplus infestations in rabbits. This system provides a novel and simple approach for the production of tick protective antigens by surface display of antigenic protein chimera on live E. coli and suggests the possibility of using recombinant bacterial membrane fractions for vaccination against cattle tick infestations. PMID:19835826

  17. Linear antigenic mapping of flagellin (FliC) from Salmonella enterica serovar Enteritidis with yeast surface expression system.

    Science.gov (United States)

    Wang, Gaoling; Shi, Bingtian; Li, Tao; Zuo, Teng; Wang, Bin; Si, Wei; Xin, Jiuqing; Yang, Kongbin; Shi, Xuanlin; Liu, Siguo; Liu, Henggui

    2016-02-29

    Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major cause of food-borne illness around the world and can have significant health implications in humans, poultry and other animals. Flagellin (FliC) is the primary component of bacterial flagella. It has been shown that the FliC of S. Enteritidis is a significant antigenic structure and can elicit strong humoral responses against S. Enteritidis infection in chickens. Here, we constructed a FliC antigen library using a yeast surface expression system. Yeast cells expressing FliC peptide antigens were labeled with chicken sera against S. Enteritidis and sorted using FACS. The analyses of FliC peptides revealed that the FliC linear antigenicity in chickens resided on three domains which were able to elicit strong humoral responses in vivo. Animal experiments further revealed that the antibodies elicited by these antigenic domains were able to significantly inhibit the invasion of S. Enteritidis into the liver and spleen of chickens. These findings will facilitate our better understanding of the humoral responses elicited by FliC in chickens upon infection by S. Enteritidis.

  18. A prophylactic approach for bone marrow transplantation from a hepatitis B surface antigen-positive donor

    Institute of Scientific and Technical Information of China (English)

    Abhasnee Sobhonslidsuk; Artit Ungkanont

    2007-01-01

    It has been accepted that bone marrow transplantation (BMT)is the only curative therapeutic option for certain hematologic malignancies.The southeast Asia region is an endemic area of hepatitis B virus(HBV)infection;thus,BMT using a hepatitis B surface antigen(HBsAg)-positive donor is occasionally unavoidable.Organ transplantation using a HBsAg-positive donor can lead to post-transplantation de novo HBV infection and severe HBV-related hepatitis if no effective prophylactic measures are taken prior to and after transplantation.In this report,a four-level approach was designed for a patient with chronic myeloid leukemia,beginning with a booster HBV vaccination before performing BMT with a HBsAg-positive donor.Prior to BMT,the HBV viral load of the donor was reduced to an undetectable level by antiviral therapy.After BMT,hepatitis B immunoglobulin was administered intramuscularly for 1 wk together with a long-term antiviral drug,lamivudine.One year after discontinuation of lamivudine,the patient is still free of HBV infection.

  19. Liver grafts from hepatitis B surface antigen-positive donors: A review of the literature

    Science.gov (United States)

    Loggi, Elisabetta; Conti, Fabio; Cucchetti, Alessandro; Ercolani, Giorgio; Pinna, Antonio Daniele; Andreone, Pietro

    2016-01-01

    The scarcity of available organs and the gap between supply and demand continue to be the main limitations of liver transplantation. To relieve the organ shortage, current transplant strategies have implemented extended criteria, which include the use of liver from patients with signs of past or present hepatitis B virus (HBV) infection. While the use of liver grafts from donors with evidence of past HBV infection is quite limited, some data have been collected regarding the feasibility of transplanting a liver graft from a hepatitis B surface antigen (HBsAg) positive donor. The aim of the present work was to review the literature regarding liver transplants from HBsAg-positive donors. A total of 17 studies were identified by a search in Medline. To date, HBsAg positive grafts have preferentially been allocated to HBsAg positive recipients. The large majority of these patients continue to be HBsAg positive despite the use of immunoglobulin, and infection prevention can only be guaranteed by using antiviral prophylaxis. Although serological persistence is evident, no significant HBV-related disease has been observed, except in patients coinfected with delta virus. Consistently less data are available for HBsAg negative recipients, although they are mostly promising. HBsAg-positive grafts could be an additional organ source for liver transplantation, provided that the risk of reinfection/reactivation is properly prevented. PMID:27672295

  20. Quantitative Measurement of Serum Hepatitis B Surface Antigen Using an Immunoradiometric Assay in Chronic Hepatitis B

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyun Woo; Lee, Ho Young; Kim, Seog Gyun; Kim, Won; Jung, Wong Jin; Kang, Keon Wook; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National Univ. Seoul (Korea, Republic of)

    2011-03-15

    Measurement of serum hepatitis B virus surface antigen (HBsAg) levels is important for the management of chronic hepatitis D patients in terms of monitoring response to antiviral therapy. This study aimed to evaluate the diagnostic performance of a new diagnostic kit, which quantitatively measures serum HBsAg level using an immunoradiometric assay (IRMA) based method. Measurements were compared with those obtained using a chemiluminescent microparticle immunoassay (CMIA) based method. The blood samples of 96 patients with chronic hepatitis B were used in this study. Copy numbers of serum hepatitis B virus (HBV) DNA were determined in 23 of these samples. The correlation between and the concordance of IRMA and CMIA results were determined using Pearson's correlation coefficients. P values of 0.05 were considered to be statistically significant throughout. Laboratory diagnoses based on CMIA. Furthermors, serum HBsAg levels by IRMA were found to be highly correlated with those determined by CMIA (correlation coefficient R{sup 2=}0.838, P<0.001). Serum HBsAg level and serum HBV DNA copies were found to be linearly related by both methods (R{sup 2=}0.067, P=0.316 by IRMA, and R{sup 2=}0.101, P=0.215 by CMIA). The diagnostic performance of the investigated IRMA method of determining HBsAg levels was found to be comparable with that of a CMIA based method in chronic hepatitis B patients.

  1. Inhibition of hepatitis B virus surface antigen expression by small hairpin RNA in vitro

    Institute of Scientific and Technical Information of China (English)

    Zheng-Gang Yang; Zhi Chen; Qin Ni; Ning Xu; Jun-Bin Shao; Hang-Ping Yao

    2005-01-01

    AIM: To explore the anti-hepatitis B virus effect of RNA interference (RNAi) using small hairpin RNA (shRNA)expression vector.METHODS: Hepatitis B virus surface antigen green fluorescent protein (HBs-GFP) fusion vector and shRNA expression vectors were constructed and cotransfected transiently into HepG2 cells. mRNAs extracted from HepG2 cells were detected by real-time PCR. Fluorescence of HBs-GFP protein was detected by fluorescence-activated cell sorting (FACS). The effective shRNA expression vector was transfected into HepG2.2.15 cells. HBsAg and HBeAg in HepG2.2.15 cells were analyzed by radioimmunoassay (RIA) method.RESULTS: FACS revealed that shRNA targeting at HBsAg reduced the GFP signal by 56% compared to the control.Real-time PCR showed that HBs-GFP mRNA extracted from HepG2 cells cotransfected with pAVU6+27 and HBs-GFP expression plasmids decreased by 90% compared to the empty vector control. The expressions of HBsAg and HBeAg were also inhibited by 43% and 64%, respectively.CONCLUSION: RNAi using shRNA expression vector can inhibit the expression of HBsAg, providing a fresh approach to screening the efficient small interfering RNAs (siRNAs).

  2. High affinity mouse-human chimeric Fab against Hepatitis B surface antigen

    Institute of Scientific and Technical Information of China (English)

    Biplab Bose; Navin Khanna; Subrat K Acharya; Subrata Sinha

    2005-01-01

    AIM: Passive immunotherapy using antibody against hepatitis B surface antigen (HBsAg) has been advocated in certain cases of Hepatitis B infection. We had earlier reported on the cloning and expression of a high affinity scFv derived from a mouse monoclonal (5S) against HBsAg. However this mouse antibody cannot be used for therapeutic purposes as it may elicit anti-mouse immune responses. Chimerization by replacing mouse constant domains with human ones can reduce the immunogenicity of this antibody.METHODS: We cloned the VH and VL genes of this mouse antibody; and fused them with CH1 domain of human IgG1 and CL domain of human kappa chain respectively. These chimeric genes were cloned into a phagemid vector. After initial screening using the phage display system, the chimeric Fab was expressed in soluble form in E. Coli.RESULTS: The chimeric Fab was purified from the bacterial periplasmic extract. We characterized the chimeric Fab using several in vitro techniques and it was observed that the chimeric molecule retained the high affinity and specificity of the original mouse monoclonal.This chimeric antibody fragment was further expressed in different strains of E> coli to increase the yield.CONCLUSION: We have generated a mouse-human chimeric Fab against HBsAg without any significant loss in binding and epitope specificity. This chimeric Fab fragment can be further modified to generate a fulllength chimeric antibody for therapeutic uses.

  3. Ultraviolet radiation (UVR) induces cell-surface Ro/SSA antigen expression by human keratinocytes in vitro: a possible mechanism for the UVR induction of cutaneous lupus lesions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S.K. (Bristol Royal Infirmary (United Kingdom))

    1992-06-01

    Antinuclear antibodies are useful markers of connective tissue disease. In this study, UVB but not UVA induced the expression of Ro/SSA antigen on keratinocyte surfaces in vitro. This expression was also found with the extractable nuclear antigens RnP and Sm, but not with single or double-stranded DNA. The expression was prevented by blocking protein synthesis, suggesting that it was an active process. The results suggest that UVB exposure may result in the expression of Ro/SSA antigen on the surfaces of basal keratinocytes in vivo. This antigen could then bind circulating antibody leading to the cutaneous lesions in neonatal and subacute cutaneous lupus erythematosus. (Author).

  4. Optimization of immune responses induced by therapeutic vaccination with cross-reactive antigens in a humanized hepatitis B surface antigen transgenic mouse model.

    Science.gov (United States)

    Bourgine, Maryline; Dion, Sarah; Godon, Ophélie; Guillen, Gerardo; Michel, Marie-Louise; Aguilar, Julio Cesar

    2012-08-15

    The absence of relevant animal models of chronic hepatitis B virus (HBV) infection has hampered the evaluation and development of therapeutic HBV vaccines. In this study, we generated a novel transgenic mouse lineage that expresses human class I and II HLA molecules and the hepatitis B surface antigen (HBsAg). HBsAg and hepatitis B core antigen (HBcAg) administered as plasmid DNAs and recombinant proteins, either alone or in combination, were evaluated as therapeutic vaccine candidates in this mouse model. Our results emphasize the importance of the route of administration in breaking HBsAg tolerance. Although immunizing the transgenic mice with DNA encoding homologous HBsAg was sufficient to induce CD8+ T-cell responses, HBsAg from a heterologous subtype was required to induce a CD4+ T-cell response. Importantly, only prime-boost immunization protocols that combined plasmid DNA injection followed by protein injection induced the production of antibodies against the HBsAg expressed by the transgenic mice. PMID:22591777

  5. Performance evaluation of new automated hepatitis B viral markers in the clinical laboratory: two quantitative hepatitis B surface antigen assays and an HBV core-related antigen assay.

    Science.gov (United States)

    Park, Yongjung; Hong, Duck Jin; Shin, Saeam; Cho, Yonggeun; Kim, Hyon-Suk

    2012-05-01

    We evaluated quantitative hepatitis B surface antigen (qHBsAg) assays and a hepatitis B virus (HBV) core-related antigen (HBcrAg) assay. A total of 529 serum samples from patients with hepatitis B were tested. HBsAg levels were determined by using the Elecsys (Roche Diagnostics, Indianapolis, IN) and Architect (Abbott Laboratories, Abbott Park, IL) qHBsAg assays. HBcrAg was measured by using Lumipulse HBcrAg assay (Fujirebio, Tokyo, Japan). Serum aminotransferases and HBV DNA were respectively quantified by using the Hitachi 7600 analyzer (Hitachi High-Technologies, Tokyo, Japan) and the Cobas AmpliPrep/Cobas TaqMan test (Roche). Precision of the qHBsAg and HBcrAg assays was assessed, and linearity of the qHBsAg assays was verified. All assays showed good precision performance with coefficients of variation between 4.5% and 5.3% except for some levels. Both qHBsAg assays showed linearity from 0.1 to 12,000.0 IU/mL and correlated well (r = 0.9934). HBsAg levels correlated with HBV DNA (r = 0.3373) and with HBcrAg (r = 0.5164), and HBcrAg also correlated with HBV DNA (r = 0.5198; P HBcrAg assays.

  6. Transformation of hepatitis B serologic markers in babies born to hepatitis B surface antigen positive mothers

    Institute of Scientific and Technical Information of China (English)

    Jian-She Wang; Hui Chen; Qi-Rong Zhu

    2005-01-01

    AIM: To better understand the clinical significance of hepatitis B serologic markers in babies born to hepatitis B surface antigen (HBsAg) positive mothers, the incidence of maternal serologic markers of hepatitis B via placenta and its transformation in these babies were investigated.METHODS: Mothers with positive HBsAg were selected in the third trimester of pregnancy. Their babies received immunoprophylaxis with hepatitis B immunoglobulin and hepatitis B vaccine after birth, and were consecutively followed up for hepatitis B serologic markers and HBV DNA at birth, mo 1, 4, 7, 12, and 24. RESULTS: Forty-two babies entered the study, including 16 born to hepatitis B e antigen (HBeAg)-positive HBsAg carrier mothers and 26 to HBeAg-negative HBsAg carrier mothers. Apart from four babies born to HBeAg-positive carrier mothers and demonstrated persistent positive HBeAg eventually became HBV carriers, all other babies developed anti-HBs before 12 mo of age. Among the other 12 babies born to HBeAg-positive carrier mothers,HBeAg was detected in 7 at birth, in 4 at mo 1, and in none of them thereafter. No antibody response to the transplacental HBeAg was detected. Among the babies born to HBeAg-negative carrier mothers, anti-HBe was detected 100% at birth and mo 1, in 88.5% at mo 4, in 46.2% at mo 7, in 4.2% at mo 12 and none in mo 24. Among all the immunoprophylaxis-protected babies born to either HBeAg-positive or HBeAg-negative carrier mothers, anti-HBc was detected in 100% at birth, mo 1 and mo 4, in 78.9% at mo 7, in 36.1% at mo 12 and in none at mo 24.CONCLUSION: HBeAg can pass through human placenta from mother to fetus and become undetectable before 4 mo of age, but no antibodies response to the transplacental HBeAg can be detected till mo 24 in the immunoprophylaxisprotected babies. The sole existence of anti-HBe before 1 year of age or anti-HBc before 2 years of age in babies born to HBsAg carrier mothers may simply represent the transplacental maternal

  7. New broadly reactive neutralizing antibodies against hepatitis B virus surface antigen.

    Science.gov (United States)

    Kucinskaite-Kodze, Indre; Pleckaityte, Milda; Bremer, Corinna M; Seiz, Pia L; Zilnyte, Milda; Bulavaite, Aiste; Mickiene, Gitana; Zvirblis, Gintautas; Sasnauskas, Kestutis; Glebe, Dieter; Zvirbliene, Aurelija

    2016-01-01

    Hepatitis B virus (HBV) surface antigen (HBsAg) is considered to be the most important target for the diagnosis and immune prophylaxis of HBV infection. HBsAg-specific monoclonal antibodies (MAbs) are extensively used for studying the complex structure of the HBsAg, mapping the neutralizing epitopes and development of HBV diagnostic tests. However, the efficiency of anti-HBV binding strongly depends on the epitope structure and MAb capability to recognize different HBV variants. In the current study, 9 MAbs against yeast-expressed HBsAg of ayw2 serotype were generated and 7 of them were shown to recognize a linear epitope comprising amino acid (aa) residues 119-GPCRTCT-125 within the main antigenic "a" determinant of HBsAg. One MAb of the highest affinity (clone HB1) was selected for detailed cross-reactivity studies, generation of recombinant single-chain antibody (scFv) and molecular modelling of antibody-epitope interaction. The importance of each aa residue within the identified MAb epitope was determined by alanine substitution study that revealed aa residues C(121), T(123), C(124) and T(125) as essential for binding. These aa residues are highly conserved among HBV variants. In contrast, alanine substitution of G119, P120 and R122 had no or minor influence on the reactivity with the MAb. Certain aa residues at position 122 (either R or K) define different HBV serotypes (either d or y), therefore, the affinity of the MAb HB1 for the epitope with R122K substitution was determined to evaluate its diagnostic potential. The MAb recognized both epitope variants with high affinity. Sequence alignment of the MAb epitope within different HBV strains demonstrated that the shortest peptide recognized by the MAb 121-CR(K)TCT-125 is identical among different human HBV genotypes (HBV A-F, H) and monkey HBV species (HBVCP, HBVGO, HBVGB, WMHBV). In line with these data, the MAb HB1 was cross-reactive in Western blot with a large panel of antigens derived from different HBV

  8. Control of tick infestations in cattle vaccinated with bacterial membranes containing surface-exposed tick protective antigens.

    Science.gov (United States)

    Almazán, Consuelo; Moreno-Cantú, Orlando; Moreno-Cid, Juan A; Galindo, Ruth C; Canales, Mario; Villar, Margarita; de la Fuente, José

    2012-01-01

    Vaccines containing the Rhipicephalus (Boophilus) microplus BM86 and BM95 antigens protect cattle against tick infestations. Tick subolesin (SUB), elongation factor 1a (EF1a) and ubiquitin (UBQ) are new candidate protective antigens for the control of cattle tick infestations. Previous studies showed that R. microplus BM95 immunogenic peptides fused to the Anaplasma marginale major surface protein (MSP) 1a N-terminal region (BM95-MSP1a) for presentation on the Escherichia coli membrane were protective against R. microplus infestations in rabbits. In this study, we extended these results by expressing SUB-MSP1a, EF1a-MSP1a and UBQ-MSP1a fusion proteins on the E. coli membrane using this system and demonstrating that bacterial membranes containing the chimeric proteins BM95-MSP1a and SUB-MSP1a were protective (>60% vaccine efficacy) against experimental R. microplus and Rhipicephalus annulatus infestations in cattle. This system provides a novel, simple and cost-effective approach for the production of tick protective antigens by surface display of antigenic protein chimera on the E. coli membrane and demonstrates the possibility of using recombinant bacterial membrane fractions in vaccine preparations to protect cattle against tick infestations. PMID:22085549

  9. Antibody responses to surface antigens of Plasmodium falciparum gametocyte-infected erythrocytes and their relation to gametocytaemia.

    Science.gov (United States)

    Dinko, B; King, E; Targett, G A T; Sutherland, C J

    2016-06-01

    An essential element for continuing transmission of Plasmodium falciparum is the availability of mature gametocytes in human peripheral circulation for uptake by mosquitoes. Natural immune responses to circulating gametocytes may play a role in reducing transmission from humans to mosquitoes. Here, antibody recognition of the surface of mature intra-erythrocytic gametocytes produced either by a laboratory-adapted parasite, 3D7, or by a recent clinical isolate of Kenyan origin (HL1204), was evaluated longitudinally in a cohort of Ghanaian school children by flow cytometry. This showed that a proportion of children exhibited antibody responses that recognized gametocyte surface antigens on one or both parasite lines. A subset of the children maintained detectable anti-gametocyte surface antigen (GSA) antibody levels during the 5 week study period. There was indicative evidence that children with anti-GSA antibodies present at enrolment were less likely to have patent gametocytaemia at subsequent visits (odds ratio = 0·29, 95% CI 0·06-1·05; P = 0·034). Our data support the existence of antigens on the surface of gametocyte-infected erythrocytes, but further studies are needed to confirm whether antibodies against them reduce gametocyte carriage. The identification of GSA would allow their evaluation as potential anti-gametocyte vaccine candidates and/or biomarkers for gametocyte carriage. PMID:27084060

  10. Prevalence of hepatitis B surface antigen among refugees entering the United States between 2006 and 2008.

    Science.gov (United States)

    Rein, David B; Lesesne, Sarah B; O'Fallon, Ann; Weinbaum, Cindy M

    2010-02-01

    The Centers for Disease Control and Prevention recommends hepatitis B surface antigen (HBsAg) testing to identify chronic hepatitis B virus infection for foreign-born persons from countries or regions with HBsAg prevalence of >or=2%. However, limited data exist to indicate which countries meet this definition. To address this data gap, we estimated the HBsAg prevalence among refugees entering the United States between 2006 and 2008. We contacted state refugee health coordinators and asked them to report the number of refugees, country of origin, and HBsAg prevalence among refugees screened in their jurisdiction during the most recently available 12-month period prior to August 2008. We pooled data across jurisdictions and calculated the prevalence for any country with more than 30 refugees entering the United States, and where this level of data was not available by country, continents were considered. Of the 47 jurisdictions contacted, we received basic information from 31, with nine jurisdictions reporting HBsAg prevalence by country of origin applicable to 31,980 refugees (approximately 42% of refugees entering the United States during the observation period). We estimated an HBsAg prevalence of 2.8% (95% confidence interval 2.6%-3.0%) for refugees overall. Of the 37 countries with 30 or more refugees entering the United States, 25 had a prevalence of >or=2%. Prevalence was highest among refugees from Africa and Southeast Asia, and lowest among refugees from the Middle East and South/Central America. In the eight countries for which we had comparison data, six had lower HBsAg prevalence than in 1991.

  11. Diversity of Babesia bovis merozoite surface antigen genes in the Philippines.

    Science.gov (United States)

    Tattiyapong, Muncharee; Sivakumar, Thillaiampalam; Ybanez, Adrian Patalinghug; Ybanez, Rochelle Haidee Daclan; Perez, Zandro Obligado; Guswanto, Azirwan; Igarashi, Ikuo; Yokoyama, Naoaki

    2014-02-01

    Babesia bovis is the causative agent of fatal babesiosis in cattle. In the present study, we investigated the genetic diversity of B. bovis among Philippine cattle, based on the genes that encode merozoite surface antigens (MSAs). Forty-one B. bovis-positive blood DNA samples from cattle were used to amplify the msa-1, msa-2b, and msa-2c genes. In phylogenetic analyses, the msa-1, msa-2b, and msa-2c gene sequences generated from Philippine B. bovis-positive DNA samples were found in six, three, and four different clades, respectively. All of the msa-1 and most of the msa-2b sequences were found in clades that were formed only by Philippine msa sequences in the respective phylograms. While all the msa-1 sequences from the Philippines showed similarity to those formed by Australian msa-1 sequences, the msa-2b sequences showed similarity to either Australian or Mexican msa-2b sequences. In contrast, msa-2c sequences from the Philippines were distributed across all the clades of the phylogram, although one clade was formed exclusively by Philippine msa-2c sequences. Similarities among the deduced amino acid sequences of MSA-1, MSA-2b, and MSA-2c from the Philippines were 62.2-100, 73.1-100, and 67.3-100%, respectively. The present findings demonstrate that B. bovis populations are genetically diverse in the Philippines. This information will provide a good foundation for the future design and implementation of improved immunological preventive methodologies against bovine babesiosis in the Philippines. The study has also generated a set of data that will be useful for futher understanding of the global genetic diversity of this important parasite.

  12. Maternal ABO and rhesus blood group phenotypes and hepatitis B surface antigen carriage.

    Science.gov (United States)

    Lao, T T; Sahota, D S; Chung, M-K; Cheung, T K W; Cheng, Y K Y; Leung, T Y

    2014-11-01

    In view of a persistently high prevalence of hepatitis B surface antigen (HBsAg) carriage in our obstetric population, we examined the association between HBsAg carriage with maternal ABO and rhesus (Rh) blood group phenotypes determined at routine antenatal screening. In a retrospective study, the antenatal screening results of women booked for confinement between 1998 and 2011 in our hospital were examined for the relationship between HBsAg carriage with the ABO and rhesus blood groups, taking into account also the effects of advanced maternal age (≥ 35 years) and parity status (nulliparous or multiparous), and year of birth before or following the availability of the hepatitis B vaccine (1984). HBsAg carriage was found in 9.9%, 9.6%, 9.1% and 10.2% (P = 0.037) for group-A (n = 20 581 or 26.1%), -B (n = 20 744 or 26.4%), -AB (n = 5138 or 6.5%) and -O (n = 32 242 or 41.0%) among the 78705 women in the study cohort. Rhesus negativity was found in 0.6%, and HBsAg carriage was 12.3% and 9.8%, respectively, for the Rh-negative and Rh-positive women (P = 0.071). Carriage rate between group-O and non-O was influenced by nulliparity, age ≥ 35 years and Rh-positive status. Regression analysis indicated that group-B (P = 0.044, aOR = 1.062, 95% CI 1.002-1.127) and group-AB (P = 0.016, aOR = 1.134, 95% CI 1.024-1.256) were associated with HBsAg carriage. Blood groups-B and -AB are associated with increased hepatitis B virus (HBV) infection in our population, and further studies are warranted to elucidate the implications of this on the sequelae of HBV infection.

  13. Multicenter Evaluation of the Elecsys Hepatitis B Surface Antigen Quantitative Assay ▿

    Science.gov (United States)

    Zacher, B. J.; Moriconi, F.; Bowden, S.; Hammond, R.; Louisirirotchanakul, S.; Phisalprapa, P.; Tanwandee, T.; Wursthorn, K.; Brunetto, M. R.; Wedemeyer, H.; Bonino, F.

    2011-01-01

    The Elecsys hepatitis B surface antigen (HBsAg) II quantitative assay is a new quantitative electrochemiluminescence immunoassay which uses onboard dilution and a simple algorithm to determine HBsAg levels expressed in international units (IU)/ml (standardized against the World Health Organization [WHO] Second International Standard). This study evaluated its performance using routine serum samples from a wide range of HBsAg carriers and patients with chronic hepatitis B (CHB). HBsAg levels were measured in serum samples collected independently by five centers in Europe, Australia, and Asia. Serial dilution analyses were performed to assess the recommended dilution algorithm and determine the assay range free of hook effect. Assay precision was also established. Following assessment of serial dilutions (1:100 to 1:1,000,000) of the 611 samples analyzed, 70.0% and 85.6% of samples tested with analyzers incorporating 1:100 (Elecsys 2010 and cobas e 411) and 1:400 (Modular Analytics E170) onboard dilution, respectively, fell within the linear range of the assay, providing a final result on the first test. No high-dose hook effect was seen up to the maximum HBsAg serum level tested (870,000 IU/ml) using the dilution algorithm. HBsAg levels were reliably determined across all hepatitis B virus (HBV) genotypes, phases of HBV infection, and stages of disease tested. Precision was high across all analyzers (% coefficient of variation [CV], 1.4 to 9.6; HBsAg concentrations, 0.1 to 37,300 IU/ml). The Elecsys HBsAg II quantitative assay accurately and reliably quantifies HBsAg in routine clinical samples. Onboard dilution minimizes retesting and reduces the potential for error. PMID:21880853

  14. Multicenter evaluation of the Elecsys hepatitis B surface antigen quantitative assay.

    Science.gov (United States)

    Zacher, B J; Moriconi, F; Bowden, S; Hammond, R; Louisirirotchanakul, S; Phisalprapa, P; Tanwandee, T; Wursthorn, K; Brunetto, M R; Wedemeyer, H; Bonino, F

    2011-11-01

    The Elecsys hepatitis B surface antigen (HBsAg) II quantitative assay is a new quantitative electrochemiluminescence immunoassay which uses onboard dilution and a simple algorithm to determine HBsAg levels expressed in international units (IU)/ml (standardized against the World Health Organization [WHO] Second International Standard). This study evaluated its performance using routine serum samples from a wide range of HBsAg carriers and patients with chronic hepatitis B (CHB). HBsAg levels were measured in serum samples collected independently by five centers in Europe, Australia, and Asia. Serial dilution analyses were performed to assess the recommended dilution algorithm and determine the assay range free of hook effect. Assay precision was also established. Following assessment of serial dilutions (1:100 to 1:1,000,000) of the 611 samples analyzed, 70.0% and 85.6% of samples tested with analyzers incorporating 1:100 (Elecsys 2010 and cobas e 411) and 1:400 (Modular Analytics E170) onboard dilution, respectively, fell within the linear range of the assay, providing a final result on the first test. No high-dose hook effect was seen up to the maximum HBsAg serum level tested (870,000 IU/ml) using the dilution algorithm. HBsAg levels were reliably determined across all hepatitis B virus (HBV) genotypes, phases of HBV infection, and stages of disease tested. Precision was high across all analyzers (% coefficient of variation [CV], 1.4 to 9.6; HBsAg concentrations, 0.1 to 37,300 IU/ml). The Elecsys HBsAg II quantitative assay accurately and reliably quantifies HBsAg in routine clinical samples. Onboard dilution minimizes retesting and reduces the potential for error.

  15. Localization of immunodominant epitopes within the "a" determinant of hepatitis B surface antigen using monoclonal antibodies.

    Science.gov (United States)

    Golsaz-Shirazi, Forough; Mohammadi, Hamed; Amiri, Mohammad Mehdi; Khoshnoodi, Jalal; Kardar, Gholam Ali; Jeddi-Tehrani, Mahmood; Shokri, Fazel

    2016-10-01

    The common "a" determinant is the major immunodominant region of hepatitis B surface antigen (HBsAg) shared by all serotypes and genotypes of hepatitis B virus (HBV). Antibodies against this region are thought to confer protection against HBV and are essential for viral clearance. Mutations within the "a" determinant may lead to conformational changes in this region, which can affect the binding of neutralizing antibodies. There is an increasing concern about identification and control of mutant viruses which is possible by comprehensive structural investigation of the epitopes located within this region. Anti-HBs monoclonal antibodies (mAbs) against different epitopes of HBsAg are a promising tool to meet this goal. In the present study, 19 anti-HBs mAbs were employed to map epitopes localized within the "a" determinant, using a panel of recombinant mutant HBsAgs. The topology of the epitopes was analyzed by competitive enzyme-linked immunosorbent assay (ELISA). Our results indicate that all of the mAbs seem to recognize epitopes within or in the vicinity of the "a" determinant of HBsAg. Different patterns of binding with mutant forms were observed with different mAbs. Amino acid substitutions at positions 123, 126, 129, 144, and 145 dramatically reduced the reactivity of antibodies with HBsAg. The T123N mutation had the largest impact on antibody binding to HBsAg. The reactivity pattern of our panel of mAbs with mutant forms of HBsAg could have important clinical implications for immunoscreening, diagnosis of HBV infection, design of a new generation of recombinant HB vaccines, and immunoprophylaxis of HBV infection as an alternative to therapy with hepatitis B immune globulin (HBIG). PMID:27439498

  16. Establishment of an in vivo potency assay for the recombinant hepatit is B surface antigen in monovalent and combined vaccines

    OpenAIRE

    Mabel Izquierdo-López; Karelia Cosme-Diaz; Gerardo García-Illera; Zoe Núñez-Lamotte; Yamila Martínez- Cuéllar; Maribel Vega-Simón; Lourdes Costa-Anguiano; Marisel Quintana-Esquivel; Ileana Rosales-Torres; Omar Mosqueda-Lobaina

    2014-01-01

    In this paper the development of potency assay in animals (mice) was made, with the objective of demonstrating the immunogenic power of the recombinant Hepatitis B surface antigen in monovalent and combined vaccines, produced at the Center of Genetic Engineering and Biotechnology. The potency test is a parameter in quality control and it is also a tool to demonstrate the consistency of the production process. Parameters such as duration of the test, number of animals in the test, ...

  17. Human immunodeficiency virus type 1 major neutralizing determinant exposed on hepatitis B surface antigen particles is highly immunogenic in primates.

    OpenAIRE

    Schlienger, K; M. Mancini; Rivière, Y; Dormont, D; Tiollais, P; Michel, M L

    1992-01-01

    Hepatitis B surface antigen (HBsAg) produced by recombinant DNA technology is now widely and safely used worldwide for hepatitis B vaccination. We used the HBsAg particle as a carrier molecule for presentation of selected human immunodeficiency virus type 1 (HIV-1) determinants to the immune system. Immunization of rhesus monkeys with an HBsAg chimera carrying the HIV-1 envelope major neutralizing determinant allowed us to generate proliferative T-cell responses and, in some cases, neutralizi...

  18. Evaluation of hepatitis B surface antigen and hepatitis B virus-DNA results in postmortem plasma specimens

    OpenAIRE

    Nihan Ziyade; Sermet Koc; Fatih Abali

    2015-01-01

    Objective: To assess the presence of hepatitis B surface antigen, one of the serologic markers of hepatitis B virus (HBV) infection, in postmortem blood samples from autopsy cases using ELISA, and to compare the results with those obtained by PCR, which is the gold standard method in assessing HBV infection. Methods: The HBV test results of the blood samples from 880 autopsy cases determined in our laboratory, were retrospectively studied. Results: When compared with the gol...

  19. Changes in seroprevalence of hepatitis B surface antigen and epidemiologic characteristics in the Republic of Korea, 1998-2013

    OpenAIRE

    Lee, Hyerin; Lee, Hyungmin; Cho, Yumi; Oh, Kyungwon; Ki, Moran

    2015-01-01

    OBJECTIVES: This study investigated changes in hepatitis B seroprevalence from 1998 to 2013, and to identify differences in epidemiologic characteristics between hepatitis B surface antigen (HBsAg)-positive and HBsAg-negative people. METHODS: HBsAg seropositive rates were compared by year, sex, and age using the blood test data from the periods I to VI (1998-2013) of the Korea National Health and Nutrition Examination Survey. Interviews and self-administered surveys were conducted to collect ...

  20. Prevalence of Hepatitis B Surface Antigen in US-Born and Foreign-Born Asian/Pacific Islander College Students

    Science.gov (United States)

    Quang, Yen N.; Vu, Joanne; Yuk, Jihey; Li, Chin-Shang; Chen, Moon; Bowlus, Christopher L.

    2010-01-01

    The prevalence of chronic hepatitis B (HBV) among college-age US-born Asian and Pacific Islanders (A/PI) is not well known. Objectives: To compare the prevalence of hepatitis B surface antigen (HBsAg) seropositivity in US-born to A/PI-born students at a public university. Participants: Undergraduate who self-identified themselves as A/PI. Results:…

  1. Sero-survey of Hepatitis B surface antigen amongst pregnant women attending Infectious Disease Hospital Bayara, Bauchi State, Nigeria

    OpenAIRE

    Ndako, James A; Georgebest ON. Echeonwu; Nwankiti, Obinna O; Emamuzou M. Onovoh; Alloysius U. Jah; Shidali, Nathaniel N; Patrick A. Ikani

    2012-01-01

    Hepatitis B virus (HBV) continues to cause serious health problems in developing countries. Neonatal infection with HBV, which is often acquired during delivery, carries a high risk resulting in persistent infection. This research aims to detect the prevalence of Hepatitis B surface Antigen (HBsAg) among pregnant women in our location of study. One hundred and eighty (180) sera samples were screened among pregnant women aged 13-49, using standard enzyme-linked immunosorbent assay (ELISA) meth...

  2. CD4+ T Cells and Toll-Like Receptors Recognize Salmonella Antigens Expressed in Bacterial Surface Organelles

    OpenAIRE

    Bergman, Molly A.; Cummings, Lisa A.; Barrett, Sara L. Rassoulian; Smith, Kelly D.; Lara, J. Cano; Aderem, Alan; Cookson, Brad T.

    2005-01-01

    A better understanding of immunity to infection is revealed from the characteristics of microbial ligands recognized by host immune responses. Murine infection with the intracellular bacterium Salmonella generates CD4+ T cells that specifically recognize Salmonella proteins expressed in bacterial surface organelles such as flagella and membrane vesicles. These natural Salmonella antigens are also ligands for Toll-like receptors (TLRs) or avidly associated with TLR ligands such as lipopolysacc...

  3. Construction of cell surface-engineered yeasts displaying antigen to detect antibodies by immunofluorescence and yeast-ELISA.

    Science.gov (United States)

    Tang, Yu Qian; Han, Shuang Yan; Zheng, Hong; Wu, Lin; Ueda, Mitsuyoshi; Wang, Xiao Ning; Lin, Ying

    2008-07-01

    In order to detect monoclonal antibodies (MAbs) from insufficient and unavailable human proteins, yeast cells were engineered to display human antigens on their surface and consequently endowed with the ability to specifically bind antibodies. Thus, a fusion gene for the expression of the human proteasome subunit alpha 6 (hPSA6) and human profilin I (hProI) were assembled, respectively, with a His.tag marker at the C-terminal and displayed on yeast surface. With anti-His.tag MAb as the primary antibody and the fluorescein isothiocyanate-conjugated goat anti-mouse Immunoglobulin G as the second antibody, the surface display of hPSA6 and hProI were verified by immunofluorescence labeling. The antigen-displayed yeast particles were used for MAbs detection from ascites through both immunofluorescence and yeast-enzyme-linked immunosorbent assay (ELISA) methods. The results were verified by Western blotting and indirect ELISA. By improving the sensitivity, the novel MAbs detection can be applied in the generation and screening of positive hybridoma. It is suggested that by combining the DNA immunization, the present study can evolve into a quick and protein-free way of MAbs production for insufficient and unavailable antigen. PMID:18542951

  4. Characterisation of peptide microarrays for studying antibody-antigen binding using surface plasmon resonance imagery.

    Directory of Open Access Journals (Sweden)

    Claude Nogues

    Full Text Available BACKGROUND: Non-specific binding to biosensor surfaces is a major obstacle to quantitative analysis of selective retention of analytes at immobilized target molecules. Although a range of chemical antifouling monolayers has been developed to address this problem, many macromolecular interactions still remain refractory to analysis due to the prevalent high degree of non-specific binding. We describe how we use the dynamic process of the formation of self assembling monolayers and optimise physical and chemical properties thus reducing considerably non-specific binding and allowing analysis of specific binding of analytes to immobilized target molecules. METHODOLOGY/PRINCIPAL FINDINGS: We illustrate this approach by the production of specific protein arrays for the analysis of interactions between the 65kDa isoform of human glutamate decarboxylase (GAD65 and a human monoclonal antibody. Our data illustrate that we have effectively eliminated non-specific interactions with the surface containing the immobilised GAD65 molecules. The findings have several implications. First, this approach obviates the dubious process of background subtraction and gives access to more accurate kinetic and equilibrium values that are no longer contaminated by multiphase non-specific binding. Second, an enhanced signal to noise ratio increases not only the sensitivity but also confidence in the use of SPR to generate kinetic constants that may then be inserted into van't Hoff type analyses to provide comparative DeltaG, DeltaS and DeltaH values, making this an efficient, rapid and competitive alternative to ITC measurements used in drug and macromolecular-interaction mechanistic studies. Third, the accuracy of the measurements allows the application of more intricate interaction models than simple Langmuir monophasic binding. CONCLUSIONS: The detection and measurement of antibody binding by the type 1 diabetes autoantigen GAD65 represents an example of an antibody-antigen

  5. Trichinella britovi human infection in Spain : antibody response to surface, excretory/secretory and somatic antigens

    Directory of Open Access Journals (Sweden)

    Rodríguez-Osorio M.

    2003-06-01

    Full Text Available A third outbreak of Trichinella britovi with 140 people involved, occurred in Granada Spain (December 1998. The source of infection was sausage made from uninspected wild boar meat. Fifty-two patients agreed to participated in this study. An elevated eosinophil level (> 5 % was detected in 59.6 % of patients, and persisted in most of these cases for two months. A moderate IgG response was observed. At the onset of symptoms, Western blot (WB test detected more positive cases than Enzyme linked immunosorbent assay (ELISA and indirect immunofluorescence (IIF. Six months from infection, ELISA revealed fewer positive cases than the other two tests. It would appear that the response to somatic antigens starts earlier than those to cuticular and excretory/secretory (ES antigens and that the response to ES antigens is the first to decrease.

  6. Analyses of gonococcal H8 antigen. Surface location, inter- and intrastrain electrophoretic heterogeneity, and unusual two-dimensional electrophoretic characteristics

    OpenAIRE

    1985-01-01

    The H8 protein is a surface-exposed antigen that is found, among members of the Neisseria genus, primarily on pathogenic species. In this study, the surface exposure of H8 was reassessed by four techniques. Results of slide agglutination, indirect fluorescent antibody binding, absorption of sera with whole gonococci, and immune electron microscopy all confirmed the presence of H8 in the outer membrane. The degree to which protein A-gold-labeled monoclonal antibodies bound to H8 was marked, an...

  7. Serological analysis of cell surface antigens of null cell acute lymphocytic leukemia by mouse monoclonal antibodies.

    OpenAIRE

    Ueda, R; Tanimoto, M; Takahashi, T.; Ogata, S; Nishida, K; Namikawa, R.; Nishizuka, Y; Ota, K.

    1982-01-01

    Nine antigens systems were defined. Two were related to HLA-A,B,C and to Ia-like antigens; the others could be grouped into three categories. (i) NL-22, NL-1: NL-22 antibody reacted with leukemia cells from 12 to 16 cases of null cell acute lymphocytic leukemia (null-ALL) but not with any other type of leukemia tested or with lymphoid cells of various origins. Among cultured cell lines tested, one (NALM-6) of three null-ALL cell lines was positive, the others were negative. Absorption analysi...

  8. Intraspecific epitopic variation in a carbohydrate antigen exposed on the surface of Trichostrongylus colubriformis infective L3 larvae.

    Directory of Open Access Journals (Sweden)

    David R Maass

    2009-09-01

    Full Text Available The carbohydrate larval antigen, CarLA, is present on the exposed surface of all strongylid nematode infective L3 larvae tested, and antibodies against CarLA can promote rapid immune rejection of incoming Trichostrongylus colubriformis larvae in sheep. A library of ovine recombinant single chain Fv (scFv antibody fragments, displayed on phage, was prepared from B cell mRNA of field-immune sheep. Phage displaying scFvs that bind to the surface of living exsheathed T. colubriformis L3 larvae were identified, and the majority of worm-binding scFvs recognized CarLA. Characterization of greater than 500 worm surface binding phage resulted in the identification of nine different anti-CarLA scFvs that recognized three distinct T. colubriformis CarLA epitopes based on blocking and additive ELISA. All anti-CarLA scFvs were specific to the T. colubriformis species of nematode. Each of the three scFv epitope classes displayed identical Western blot recognition patterns and recognized the exposed surface of living T. colubriformis exsheathed L3 larvae. Surprisingly, each of the anti-CarLA scFvs was able to bind to only a subset of worms. Double-labelling indirect immunofluorescence revealed that the three classes of anti-CarLA scFvs recognize distinct, non-overlapping, T. colubriformis sub-populations. These results demonstrate that individual T. colubriformis L3 larvae display only one of at least three distinct antigenic forms of CarLA on their surface at any given time, and suggest that antigenic variation within CarLA is likely a mechanism of immune evasion in strongylid nematodes.

  9. Macrophage migration inhibition factor against cell-surface antigens coded by the major histocompatibility complex and other genes in mice.

    Directory of Open Access Journals (Sweden)

    Ohashi,Katsuhide

    1983-02-01

    Full Text Available We developed an indirect capillary tube method to improve reproducibility of macrophage migration inhibition (MI tests using a one-way mixed lymphocyte culture. MI response could be induced to cell-surface antigens coded by either H-2 or non-H-2 (background genes. The sensitivity was more readily induced across H-2 + background differences. The presence of only background difference did not induce the MI response to much extent. High MI activities were obtained to antigens coded by either K end or D end of the H-2 complex + background difference. Moderate activities were induced across the H-2D difference + background. These results suggest that the D region of the H-2 complex may direct a MI response when an H-2I difference is present during sensitization.

  10. [Species-specific sera against surface antigens of Bacillus anthracis strains].

    Science.gov (United States)

    Barkova, I A; Barkov, A M; Alekseev, V V; Lipnitskiĭ, A V

    2010-11-01

    The species-related specificity of sera against 94-KD proteins isolated from culture filtrates of B. anthracis strains with different levels of virulence plasmids was studied to determine whether they might be used to identify the pathogen of anthrax. Sera against fractions 1 of culture filtrates of B. anthracis strains CTI (pXO1+ pXO2-), 81/1TR (pXO1- pXO2-), Davies (pXO1- pXO) separated by gel chromatography on Sephacryl S-300 were examined. In the gel immunodiffusion test with growing cultures, the sera exhibited non-identical antigens and differed in the presence of antibodies to antigens of related bacilli. The sera against fractions 1 of culture filtrates of toxin-producing and plasmidless strains displayed antigens produced only by B. anthracis strains into nutrient agar. Electroimmunotransblotting revealed that they contained antibodies mainly to 94-kD proteins and failed to react with B. cereus proteins with a molecular weight of 94 kD and with B. thuringiensis proteins with a molecular weight of 97 kD, which were extracted from autonomous cells. In the immunofluorescence test, immunoglobulins of sera against fractions 1 of culture filtrates of three strains stained autonomous cells and spores of 23 B. anthracis strains with different levels of virulence plasmids. In working dilutions, they did not react with antigens of 18 strains of related bacilli, which presents a possibility of using them for species identification of B. anthracis. PMID:21319392

  11. A method for visualizing surface-exposed and internal PfEMP1 adhesion antigens in Plasmodium falciparum infected erythrocytes

    DEFF Research Database (Denmark)

    Bengtsson, Dominique; Sowa, Kordai M; Salanti, Ali;

    2008-01-01

    BACKGROUND: The insertion of parasite antigens into the host erythrocyte membrane and the structure and distribution of Plasmodium falciparum adhesion receptors on that membrane are poorly understood. Laser scanning confocal microscopy (LSCM) and a novel labelling and fixation method have been used......-ionic detergent to permit access of antibodies to internal parasite antigens. Differentiation between surface and internal antigens is achieved using antibodies labelled with different fluorochromes and confocal microscopy RESULTS: Surface exposed PfEMP1 is first detectable by antibodies at the trophozoite stage...

  12. Immunophenotyping of Waldenstroms macroglobulinemia cell lines reveals distinct patterns of surface antigen expression: potential biological and therapeutic implications.

    Directory of Open Access Journals (Sweden)

    Aneel Paulus

    Full Text Available Waldenströms macroglobulinemia (WM is a subtype of Non-Hodgkin's lymphoma in which the tumor cell population is markedly heterogeneous, consisting of immunoglobulin-M secreting B-lymphocytes, plasmacytoid lymphocytes and plasma cells. Due to rarity of disease and scarcity of reliable preclinical models, many facets of WM molecular and phenotypic architecture remain incompletely understood. Currently, there are 3 human WM cell lines that are routinely used in experimental studies, namely, BCWM.1, MWCL-1 and RPCI-WM1. During establishment of RPCI-WM1, we observed loss of the CD19 and CD20 antigens, which are typically present on WM cells. Intrigued by this observation and in an effort to better define the immunophenotypic makeup of this cell line, we conducted a more comprehensive analysis for the presence or absence of other cell surface antigens that are present on the RPCI-WM1 model, as well as those on the two other WM cell lines, BCWM.1 and MWCL-1. We examined expression of 65 extracellular and 4 intracellular antigens, comprising B-cell, plasma cell, T-cell, NK-cell, myeloid and hematopoietic stem cell surface markers by flow cytometry analysis. RPCI-WM1 cells demonstrated decreased expression of CD19, CD20, and CD23 with enhanced expression of CD28, CD38 and CD184, antigens that were differentially expressed on BCWM.1 and MWCL-1 cells. Due to increased expression of CD184/CXCR4 and CD38, RPCI-WM1 represents a valuable model in which to study the effects anti-CXCR4 or anti-CD38 targeted therapies that are actively being developed for treatment of hematologic cancers. Overall, differences in surface antigen expression across the 3 cell lines may reflect the tumor clone population predominant in the index patients, from whom the cell lines were developed. Our analysis defines the utility of the most commonly employed WM cell lines as based on their immunophenotype profiles, highlighting unique differences that can be further studied for

  13. Surface membrane antigen expression changes induced in vitro by exogenous growth factors in chronic lymphocytic leukemia cells.

    Science.gov (United States)

    Vilpo, J; Hulkkonen, J; Hurme, M; Vilpo, L

    2002-09-01

    The factors determining the growth and survival of cells in B chronic lymphocytic leukemia (CLL) have remained poorly understood. We investigated the effects of optimal mitogen combinations (OMCs) on the expression of 26 surface membrane antigens among 33 CLL patients. The seven OMCs used were selected after pre-testing 14 combinations of (1) S. aureus Cowan I (SAC), (2) interleukin-2 (IL-2), (3) tumor necrosis factor alpha (TNF-alpha) and (4) 12-O-tetradecanoylphorbol 13-acetate (TPA; also known as phorbol 12-myristate 13-acetate or PMA). In flow cytometry we revealed that OMCs induced statistically highly significant upregulation of the expression of CD5, CD11c, CD19, CD22, CD23, CD25, CD38, CD40, CD45, CD45RO, CD95, CD126, CD130 and FMC7, and downregulation of CD20 and CD124 expression. Interestingly, the expression of CD27, CD45RA, CD79b, CD80, CD122 and that of the immunoglobulin gene superfamily members CD21, Ig-kappa, Ig-lambda, Ig-delta and Ig-micro were not significantly affected under similar conditions. The expression of several antigens was co-regulated, suggesting common regulatory pathways. These antigens include CD11c/CD5, CD11c/CD22, CD11c/CD126, CD11c/FMC7 as well as CD27/CD45, CD27/CD45RA and CD27/CD79b. Upregulation of surface antigen expression, induced by OMCs, should be applicable in antibody therapy in vitro and in vivo, and in negative stem cell selection for autotransplantation. Furthermore, the current strategy to enhance cell surface antigen expression may be a versatile tool to raise humoral and cell-mediated host defense against CLL cells. Upregulation of proteins mediating positive growth signals (eg CD25, CD40) and negative signals or apoptosis (eg CD95) may be used to sensitize cells to chemotherapy and programmed cell death. PMID:12200683

  14. Expression of the hepatitis B surface antigen gene containing the preS2 region in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Yoshida,Iwao

    1991-02-01

    Full Text Available We constructed a plasmid, pBH103-ME5, in which the region encoding the 10 preS2 amino acid residues and the S domain of the hepatitis B surface antigen (HBsAg were regulated by the promoter of the yeast repressible acid phosphatase gene. Saccharomyces cerevisiae carrying pBH103-ME5 produced the HBs antigen (yHBsAg, when it was cultured in a medium containing a low concentration of phosphate. The antigen was purified to homogeneity. Its molecular weight was determined by Western blotting to be 24,000, and its amino acid composition agreed well with that deduced from the nucleotide sequence. The C-terminal amino acid sequence of yHBsAg was exactly the same as that predicted from the nucleotide sequence, while the N-terminal amino acid acetylserine, which was followed by 8 amino acid residues coded by the preS2 region. These results indicate that the recombinant yeast produced a single polypeptide consisting of the preS2 region and the subsequent S domain after being processed at the N-terminus

  15. Cell surface antigens detected on mature and leukemic granulocytic populations by cytotoxicity testing.

    Science.gov (United States)

    Drew, S I; Carter, B M; Terasaki, P I; Naiem, F; Nathanson, D S; Abromowitz, B; Gale, R P

    1978-08-01

    Using a microcytotoxicity assay, the serological reactivity of human granulocytes, namely neutrophils and eosinophils, and chronic myeloid leukemia (CML) cells and cultured CML cell lines (K562, NALM-1) were examined. Mature granulocyte forms and cord granulocytes are readily lysed by specific granulocyte cytotoxins that do not react with random T and B lymphocytes, monocytes, red blood cells, or platelets. Furthermore, certain antisera were preferentially cytotoxic for eosinophil-enriched populations. Granulocytotoxin detected antigens on one of three CML blast cell populations tested and K562, but failed to react with NALM-1. By cytotoxicity, mature granulocytes were poor targets for B2-microglobulin and the appropriate HLA antisera although both sera types are absorbed with granulocytes. Furthermore, granulocytes did not possess B-lymphocytes (Ia-like) or blood group A, B, and Rh (D) antigens. Except for K562, both HLA and heterologous B-lymphocyte antisera were cytotoxic for the CML blast cell populations tested.

  16. Two methods for the quantitative analysis of surface antigen expression in acute myeloid leukemia (AML.

    Directory of Open Access Journals (Sweden)

    Jolanta Woźniak

    2004-10-01

    Full Text Available The expression of lineage molecules (CD13 and CD33, c-Kit receptor (CD117, CD34, HLA-DR and adhesion molecule CD49d was assessed in acute myeloid leukemia (AML blast cells from 32 cases, using direct and indirect quantitative cytometric analysis. High correlation (r=0.8 was found between antigen expression intensity values calculated by direct analysis method (ABC and by indirect analysis method (RFI. Moreover, the differences in expression intensity of CD13, CD117 and CD34 antigens were found between leukemic and normal myeloblasts. This may be helpful in identification of leukemic cells in the diagnostics of minimal residual disease after treatment in AML patients.

  17. A Major Cell Surface Antigen of Coccidioides immitis Which Elicits Both Humoral and Cellular Immune Responses

    OpenAIRE

    Hung, Chiung-Yu; Ampel, Neil M.; Christian, Lara; Seshan, Kalpathi R.; Cole, Garry T.

    2000-01-01

    Multinucleate parasitic cells (spherules) of Coccidioides immitis isolates produce a membranous outer wall component (SOW) in vitro which has been reported to be reactive with antibody from patients with coccidioidal infection, elicits a potent proliferative response of murine immune T cells, and has immunoprotective capacity in a murine model of coccidioidomycosis. To identify the antigenic components of SOW, the crude wall material was first subjected to Triton X-114 extraction, and a water...

  18. Cloning and surface expression of Pseudomonas aeruginosa O antigen in Escherichia coli.

    OpenAIRE

    Goldberg, J B; Hatano, K; Meluleni, G S; Pier, G B

    1992-01-01

    As a step toward developing recombinant oral vaccines, we have explored the feasibility of expression of O polysaccharide antigens from Pseudomonas aeruginosa by Escherichia coli. We cloned in E. coli HB101 a 26.2-kilobase DNA fragment from P. aeruginosa strain PA103 that specifies the production of the O polysaccharide of Fisher immunotype 2 (IT-2) strains. The recombinant organism incorporated the P. aeruginosa IT-2 O polysaccharide onto the core of the E. coli lipopolysaccharide (LPS). Tra...

  19. A Delayed Type Hypersensitivity (DTH) Skin Reaction to Hepatitis B Surface Antigen (HBsAg) and Intradermal Hepatitis B Vaccination

    OpenAIRE

    Nagafuchi, Seiho; Kashiwagi, Seizaburo; Hayashi, Jun; Katsuta, Hitoshi; Ikematsu, Hideyuki; Harada, Mine

    2004-01-01

    The significance of a delayed type hypersensitivity skin reaction to hepatitis B surface antigen (HBsAg) (HBs-DTH) in type B viral hepatitis (VHB) and in intradermal hepatitis B (HB) vaccination is reviewed. HBs-DTH could be developed by the intradermal injection of HB vaccine in anti-HBs positive people and also in persons immunized with HB vaccine. Thus, HBs-DTH could serve as a useful marker for the acquisition of an active Thl type immunoreactivity to HBsAg. HBs-DTH was absent in patients...

  20. Expression of immunogenic epitopes of hepatitis B surface antigen with hybrid flagellin proteins by a vaccine strain of Salmonella.

    OpenAIRE

    Wu, J Y; Newton, S; Judd, A; Stocker, B; Robinson, W S

    1989-01-01

    A nonvirulent Salmonella dublin flagellin-negative, aromatic-dependent live vaccine strain has been used to express hepatitis B virus surface antigen epitopes in an immunogenic form. The envelope proteins of the virion are encoded by the S gene, which contains the pre-S1, pre-S2, and S coding regions. Synthetic oligonucleotides corresponding to amino acid residues S-(122-137) and pre-S2-(120-145) were inserted in-frame into the hypervariable region of a cloned Salmonella flagellin gene, and t...

  1. Synthesis in animal cells of hepatitis B surface antigen particles carrying a receptor for polymerized human serum albumin.

    OpenAIRE

    1984-01-01

    A recombinant plasmid (pSVS dhfr) encoding the pre-S region and the S gene of human hepatitis B virus (HBV) and murine dihydrofolate reductase (DHFR) cDNA has been used for the transfection of Chinese hamster ovary (CHO) DHFR- cells. Selection of clones resistant to methotrexate has permitted amplification of HBV sequences and an increase in production of hepatitis B surface antigen (HBsAg). HBV-specific transcripts have been characterized. The HBsAg 22-nm particles contain a receptor for pol...

  2. A Vectored Measles Virus Induces Hepatitis B Surface Antigen Antibodies While Protecting Macaques against Measles Virus Challenge▿

    OpenAIRE

    del Valle, Jorge Reyes; Devaux, Patricia; Hodge, Gregory; Wegner, Nicholas J.; McChesney, Michael B.; Cattaneo, Roberto

    2007-01-01

    Hepatitis B virus (HBV) acute and chronic infections remain a major worldwide health problem. Towards developing an anti-HBV vaccine with single-dose scheme potential, we engineered infectious measles virus (MV) genomic cDNAs with a vaccine strain background and expression vector properties. Hepatitis B surface antigen (HBsAg) expression cassettes were inserted into this cDNA and three MVs expressing HBsAg at different levels generated. All vectored MVs, which secrete HBsAg as subviral partic...

  3. Protective Effect of Vaccination with a Combination of Recombinant Surface Antigen 1 and Interleukin-12 against Toxoplasmosis in Mice

    OpenAIRE

    Letscher-Bru, Valerie; Villard, Odile; Risse, Bernhard; Zauke, Michael; Klein, Jean-Paul; Kien, Truong T.

    1998-01-01

    We studied the immune response induced in mice by recombinant Toxoplasma gondii surface antigen 1 (rSAG1) protein, alone or combined with interleukin-12 (IL-12) as an adjuvant, and the protective effect against toxoplasmosis. Immunization with rSAG1 alone induced a specific humoral type 2 immunity and did not protect the animals from infection. In contrast, immunization with rSAG1 plus IL-12 redirected humoral and cellular immunity toward a type 1 pattern and reduced the brain parasite load b...

  4. Surface antigen expression and correlation with variable heavy-chain gene mutation status in chronic lymphocytic leukemia.

    Science.gov (United States)

    Vilpo, Juhani; Tobin, Gerard; Hulkkonen, Janne; Hurme, Mikko; Thunberg, Ulf; Sundström, Christer; Vilpo, Leena; Rosenquist, Richard

    2003-01-01

    Recent studies have demonstrated that B-cell chronic lymphocytic leukemia (CLL) consists of two clinical entities with either somatically hypermutated (M-CLL) or unmutated (UM-CLL) immunoglobulin variable heavy-chain (VH) regions. In view of the fact that the cellular biology of these two subsets of disease is currently unexplored, we performed an extensive analysis of the surface antigen expression and correlated this with the VH gene mutation status in a cohort of 32 CLL patients. Using polymerase chain reaction amplification and nucleotide sequencing, the VH genes were shown to be mutated in 10 cases (31%) and unmutated in 22 (69%). The expression of 27 surface membrane antigens in peripheral blood leukemic cells was analyzed by flow cytometry, measuring both the percentage of positive cells as well as the geometric mean fluorescence intensity (GMF). Most of the surface membrane antigens (CD5, CD11c, CD19, CD20, CD21, CD22, CD23, CD25, CD40, CD45, VD79b, CD80, CD95, CD122, CD124, CD126, CD130, CD154, IgM, and IgD) showed a similar expression pattern in both UM-CLL and M-CLL patients. The similarity of M-CLL and UM-CLL, as demonstrated here for the first time with many protein markers, indicates a considerably homogeneous phenotype in both subsets. Furthermore, CD27 was strongly expressed in all cases, which may suggest a memory cell phenotype for both M-CLL and UM-CLL. More positive cells in the UM-CLL group were observed regarding CD38, but CD38 was not a good predictor of VH gene mutation status. Seventy percent of the M-CLL cases, but only 36% of UM-CLL cases, were Ig-lambda+. The most striking differential expression, however, was observed in the two slicing variants of the common leukocyte antigen CD45, namely CD45RO and CD45RA. CD45RO expression was significantly associated with M-CLL, whereas the GMF intensity of CD45RA tended to be associated with UM-CLL. The role of these CD45 splicing variants in the pathogenesis of CLL deserves further investigation

  5. Well-known surface and extracellular antigens of pathogenic microorganisms among the immunodominant proteins of the infectious microalgae Prototheca zopfii

    Science.gov (United States)

    Irrgang, Alexandra; Murugaiyan, Jayaseelan; Weise, Christoph; Azab, Walid; Roesler, Uwe

    2015-01-01

    Microalgae of the genus Prototheca (P.) are associated with rare but severe infections (protothecosis) and represent a potential zoonotic risk. Genotype (GT) 2 of P. zopfii has been established as pathogenic agent for humans, dogs, and cattle, whereas GT1 is considered to be non-pathogenic. Since pathogenesis is poorly understood, the aim of this study was to determine immunogenic proteins and potential virulence factors of P. zopfii GT2. Therefore, 2D western blot analyses with sera and isolates of two dogs naturally infected with P. zopfii GT2 have been performed. Cross-reactivity was determined by including the type strains of P. zopfii GT2, P. zopfii GT1, and P. blaschkeae, a close relative of P. zopfii, which is known to cause subclinical forms of bovine mastitis. The sera showed a high strain-, genotype-, and species-cross-reactivity. A total of 198 immunogenic proteins have been analyzed via MALDI—TOF MS. The majority of the 86 identified proteins are intracellularly located (e.g., malate dehydrogenase, oxidoreductase, 3-dehydroquinate synthase) but some antigens and potential virulence factors, known from other pathogens, have been found (e.g., phosphomannomutase, triosephosphate isomerase). One genotype-specific antigen could be identified as heat shock protein 70 (Hsp70), a well-known antigen of eukaryotic pathogens with immunological importance when located extracellularly. Both sera were reactive to glyceraldehyde-3-phosphate-dehydrogenase of all investigated strains. This house-keeping enzyme is found to be located on the surface of several pathogens as virulence factor. Flow-cytometric analysis revealed its presence on the surface of P. blaschkeae. PMID:26484314

  6. DNA secondary structures are associated with recombination in major Plasmodium falciparum variable surface antigen gene families

    DEFF Research Database (Denmark)

    Sander, Adam F.; Lavstsen, Thomas; Rask, Thomas Salhøj;

    2014-01-01

    -erythrocyte membrane protein 1 structural domains. The recombinogenic potential of these 50-mers is not parasite-specific because these sequences also induce recombination when transferred to the yeast Saccharomyces cerevisiae. Genetic cross data suggest that DNA secondary structures (DSS) act as inducers...... of recombination during DNA replication in P. falciparum sexual stages, and that these DSS-regulated genetic exchanges generate functional and diverse P. falciparum adhesion antigens. DSS-induced recombination may represent a common mechanism for optimizing the evolvability of virulence gene families in pathogens....

  7. Surface expression patterns of defined glycan antigens change during Schistosoma mansoni cercarial transformation and development of schistosomula.

    Science.gov (United States)

    Smit, Cornelis H; Homann, Arne; van Hensbergen, Vincent P; Schramm, Gabriele; Haas, Helmut; van Diepen, Angela; Hokke, Cornelis H

    2015-12-01

    During the complex lifecycle of Schistosoma mansoni, a large variety of glycans is expressed. To many of these glycans, antibodies are induced by the infected host and some might be targets for vaccines or diagnostic tests. Spatial changes in glycan expression during schistosome development are largely unexplored. To study the surface-exposed glycans during the important initial stages of infection, we analyzed the binding of a panel of anti-glycan monoclonal antibodies (mAbs) to cercariae and schistosomula up to 72 h after transformation by immunofluorescence microscopy. The mAb specificity toward their natural targets was studied using a microarray containing a wide range of schistosomal N-glycans, O-glycans and glycosphingolipid glycans. With the exception of GalNAcβ1-4(Fucα1-3)GlcNAc (LDN-F), mono- and multifucosylated GalNAcβ1-4GlcNAc (LDN)-motifs were exposed at the surface of all developmental stages studied. Multifucosylated LDN-motifs were present on cercarial glycocalyx-derived O-glycans as well as cercarial glycolipids. In contrast, the Galβ1-4(Fucα1-3)GlcNAc (Lewis X) and LDN-F-motifs, also expressed on cercarial glycolipids, and in addition on a range of cercarial N- and O-glycans, became surface expressed only after transformation of cercariae to schistosomula. In line with the documented shedding of the O-glycan-rich cercarial glycocalyx after transformation these observations suggest that surface accessible multifucosylated LDN-motifs are mostly expressed by O-glycans in cercariae, but principally by glycosphingolipids in schistosomula. We hypothesize that these temporal changes in surface exposure of glycan antigens are relevant to the interaction with the host during the initial stages of infection with schistosomes and discuss the potential of these glycan antigens as intervention targets. PMID:26347524

  8. A single point in protein trafficking by Plasmodium falciparum determines the expression of major antigens on the surface of infected erythrocytes targeted by human antibodies.

    Science.gov (United States)

    Chan, Jo-Anne; Howell, Katherine B; Langer, Christine; Maier, Alexander G; Hasang, Wina; Rogerson, Stephen J; Petter, Michaela; Chesson, Joanne; Stanisic, Danielle I; Duffy, Michael F; Cooke, Brian M; Siba, Peter M; Mueller, Ivo; Bull, Peter C; Marsh, Kevin; Fowkes, Freya J I; Beeson, James G

    2016-11-01

    Antibodies to blood-stage antigens of Plasmodium falciparum play a pivotal role in human immunity to malaria. During parasite development, multiple proteins are trafficked from the intracellular parasite to the surface of P. falciparum-infected erythrocytes (IEs). However, the relative importance of different proteins as targets of acquired antibodies, and key pathways involved in trafficking major antigens remain to be clearly defined. We quantified antibodies to surface antigens among children, adults, and pregnant women from different malaria-exposed regions. We quantified the importance of antigens as antibody targets using genetically engineered P. falciparum with modified surface antigen expression. Genetic deletion of the trafficking protein skeleton-binding protein-1 (SBP1), which is involved in trafficking the surface antigen PfEMP1, led to a dramatic reduction in antibody recognition of IEs and the ability of human antibodies to promote opsonic phagocytosis of IEs, a key mechanism of parasite clearance. The great majority of antibody epitopes on the IE surface were SBP1-dependent. This was demonstrated using parasite isolates with different genetic or phenotypic backgrounds, and among antibodies from children, adults, and pregnant women in different populations. Comparisons of antibody reactivity to parasite isolates with SBP1 deletion or inhibited PfEMP1 expression suggest that PfEMP1 is the dominant target of acquired human antibodies, and that other P. falciparum IE surface proteins are minor targets. These results establish SBP1 as part of a critical pathway for the trafficking of major surface antigens targeted by human immunity, and have key implications for vaccine development, and quantifying immunity in populations.

  9. Temporal differences in the activation of three classes of non-transmembrane protein tyrosine kinases following B-cell antigen receptor surface engagement.

    OpenAIRE

    Saouaf, S J; Mahajan, S.; Rowley, R B; Kut, S A; Fargnoli, J.; Burkhardt, A L; Tsukada, S; Witte, O. N.; Bolen, J B

    1994-01-01

    We evaluated in WEHI 231 B cells the time-dependent responses of Lyn, Blk, Btk, Syk, and three members of the Jak family of protein tyrosine kinases following antibody-mediated surface engagement of the B-cell antigen receptor. Our results show that the enzyme activities of Lyn and Blk were stimulated within seconds of antigen receptor engagement and correlated with the initial tyrosine phosphorylation of the Ig alpha and Ig beta subunits of the B-cell antigen receptor. Btk enzyme activity wa...

  10. Cloning and Characterization of Surface-Localized α-Enolase of Streptococcus iniae, an Effective Protective Antigen in Mice

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2015-06-01

    Full Text Available Streptococcus iniae is a major fish pathogen that can also cause human bacteremia, cellulitis and meningitis. Screening for and identification of protective antigens plays an important role in developing therapies against S. iniae infections. In this study, we indicated that the α-enolase of S. iniae was not only distributed in the cytoplasm and associated to cell walls, but was also secreted to the bacterial cell surface. The functional identity of the purified recombinant α-enolase protein was verified by its ability to catalyze the conversion of 2-phosphoglycerate (2-PGE to phosphoenolpyruvate (PEP, and both the recombinant and native proteins interacted with human plasminogen. The rabbit anti-rENO serum blockade assay shows that α-enolase participates in S. iniae adhesion to and invasion of BHK-21 cells. In addition, the recombinant α-enolase can confer effective protection against S. iniae infection in mice, which suggests that α-enolase has potential as a vaccine candidate in mammals. We conclude that S. iniae α-enolase is a moonlighting protein that also associates with the bacterial outer surface and functions as a protective antigen in mice.

  11. Improved detection of equine antibodies against Sarcocystis neurona using polyvalent ELISAs based on the parasite SnSAG surface antigens.

    Science.gov (United States)

    Yeargan, Michelle R; Howe, Daniel K

    2011-02-28

    Equine protozoal myeloencephalitis (EPM) is a common neurologic disease of horses that is caused by the apicomplexan pathogen Sarcocystis neurona. To help improve serologic diagnosis of S. neurona infection, we have modified existing enzyme-linked immunosorbent assays (ELISAs) based on the immunogenic parasite surface antigens SnSAG2, SnSAG3, and SnSAG4 to make the assays polyvalent, thereby circumventing difficulties associated with parasite antigenic variants and diversity in equine immune responses. Two approaches were utilized to achieve polyvalence: (1) mixtures of the individual recombinant SnSAGs (rSnSAGs) were included in single ELISAs; (2) a collection of unique SnSAG chimeras that fused protein domains from different SnSAG surface antigens into a single recombinant protein were generated for use in the ELISAs. These new assays were assessed using a defined sample set of equine sera and cerebrospinal fluids (CSFs) that had been characterized by Western blot and/or were from confirmed EPM horses. While all of the polyvalent ELISAs performed relatively well, the highest sensitivity and specificity (100%/100%) were achieved with assays containing the rSnSAG4/2 chimera (Domain 1 of SnSAG4 fused to SnSAG2) or using a mixture of rSnSAG3 and rSnSAG4. The rSnSAG4 antigen alone and the rSnSAG4/3 chimera (Domain 1 of SnSAG4 fused to Domain 2 of SnSAG3) exhibited the next best accuracy at 95.2% sensitivity and 100% specificity. Binding ratios and percent positivity (PP) ratios, determined by comparing the mean values for positive versus negative samples, showed that the most advantageous signal to noise ratios were provided by rSnSAG4 and the rSnSAG4/3 chimera. Collectively, our results imply that a polyvalent ELISA based on SnSAG4 and SnSAG3, whether as a cocktail of two proteins or as a single chimeric protein, can give optimal results in serologic testing of serum or CSF for the presence of antibodies against S. neurona. The use of polyvalent SnSAG ELISAs will

  12. Rapid Detection of Hepatitis B Virus Surface Antigen by an Agglutination Assay Mediated by a Bispecific Diabody against Both Human Erythrocytes and Hepatitis B Virus Surface Antigen▿

    OpenAIRE

    Chen, Yu-Ping; Qiao, Yuan-Yuan; Zhao, Xiao-Hang; Chen, Hong-Song; Wang, Yan; Wang, Zhuozhi

    2007-01-01

    Bispecific antibodies have immense potential for use in clinical applications. In the present study, a bispecific diabody against human red blood cells (RBCs) and hepatitis B virus surface antigen (HBsAg) was used to detect HBsAg in blood specimens. The bispecific diabody was constructed by crossing over the variable region of the heavy chains and the light chains of anti-RBC and anti-HBsAg antibodies with a short linker, SRGGGS. In enzyme-linked immunosorbent assays, this bispecific diabody ...

  13. Immune response by nasal delivery of hepatitis B surface antigen and codelivery of a CpG ODN in alginate coated chitosan nanoparticles

    OpenAIRE

    Borges, Olga; Cordeiro-Da-Silva, Anabela; Tavares, Joana; Santarém, Nuno; Sousa, Adriano de; Borchard, Gerrit; Junginger, Hans E.

    2008-01-01

    Alginate coated chitosan nanoparticles were previously developed with the aim of protecting the antigen, adsorbed on the surface of those chitosan nanoparticles, from enzymatic degradation at mucosal surfaces. In this work, this new delivery system was loaded with the recombinant hepatitis B surface antigen (HBsAg) and applied to mice by the intranasal route. Adjuvant effect of the delivery system was studied by measuring anti-HBsAg IgG in serum, anti-HBsAg sIgA in faeces extracts or nasal an...

  14. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA) Induce Protective Immune Responses in Dogs

    Science.gov (United States)

    Petitdidier, Elodie; Pagniez, Julie; Papierok, Gérard; Vincendeau, Philippe; Lemesre, Jean-Loup; Bras-Gonçalves, Rachel

    2016-01-01

    Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES) antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA), from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA) or its carboxy terminal part LaPSA-12S (Cter-rPSA), combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates. PMID:27223609

  15. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA Induce Protective Immune Responses in Dogs.

    Directory of Open Access Journals (Sweden)

    Elodie Petitdidier

    2016-05-01

    Full Text Available Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA, from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA or its carboxy terminal part LaPSA-12S (Cter-rPSA, combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates.

  16. A Novel Surface Antigen of Relapsing Fever Spirochetes Can Discriminate between Relapsing Fever and Lyme Borreliosis▿ † ‡

    Science.gov (United States)

    Lopez, Job E.; Schrumpf, Merry E.; Nagarajan, Vijayaraj; Raffel, Sandra J.; McCoy, Brandi N.; Schwan, Tom G.

    2010-01-01

    In a previous immunoproteome analysis of Borrelia hermsii, candidate antigens that bound IgM antibodies from mice and patients infected with relapsing fever spirochetes were identified. One candidate that was identified is a hypothetical protein with a molecular mass of 57 kDa that we have designated Borrelia immunogenic protein A (BipA). This protein was further investigated as a potential diagnostic antigen for B. hermsii given that it is absent from the Borrelia burgdorferi genome. The bipA locus was amplified and sequenced from 39 isolates of B. hermsii that had been acquired from western North America. bipA was also expressed as a recombinant fusion protein. Serum samples from mice and patients infected with B. hermsii or B. burgdorferi were used to confirm the immunogenicity of the recombinant protein in patients infected with relapsing fever spirochetes. Lastly, in silico and experimental analysis indicated that BipA is a surface-exposed lipoprotein in B. hermsii. These findings enhance the capabilities of diagnosing infection with relapsing fever spirochetes. PMID:20147497

  17. A self-amplified transistor immunosensor under dual gate operation: highly sensitive detection of hepatitis B surface antigen

    Science.gov (United States)

    Lee, I.-K.; Jeun, M.; Jang, H.-J.; Cho, W.-J.; Lee, K. H.

    2015-10-01

    Ion-sensitive field-effect transistors (ISFETs), although they have attracted considerable attention as effective immunosensors, have still not been adopted for practical applications owing to several problems: (1) the poor sensitivity caused by the short Debye screening length in media with high ion concentration, (2) time-consuming preconditioning processes for achieving the highly-diluted media, and (3) the low durability caused by undesirable ions such as sodium chloride in the media. Here, we propose a highly sensitive immunosensor based on a self-amplified transistor under dual gate operation (immuno-DG ISFET) for the detection of hepatitis B surface antigen. To address the challenges in current ISFET-based immunosensors, we have enhanced the sensitivity of an immunosensor by precisely tailoring the nanostructure of the transistor. In the pH sensing test, the immuno-DG ISFET showed superior sensitivity (2085.53 mV per pH) to both standard ISFET under single gate operation (58.88 mV per pH) and DG ISFET with a non-tailored transistor (381.14 mV per pH). Moreover, concerning the detection of hepatitis B surface antigens (HBsAg) using the immuno-DG ISFET, we have successfully detected trace amounts of HBsAg (22.5 fg mL-1) in a non-diluted 1× PBS medium with a high sensitivity of 690 mV. Our results demonstrate that the proposed immuno-DG ISFET can be a biosensor platform for practical use in the diagnosis of various diseases.Ion-sensitive field-effect transistors (ISFETs), although they have attracted considerable attention as effective immunosensors, have still not been adopted for practical applications owing to several problems: (1) the poor sensitivity caused by the short Debye screening length in media with high ion concentration, (2) time-consuming preconditioning processes for achieving the highly-diluted media, and (3) the low durability caused by undesirable ions such as sodium chloride in the media. Here, we propose a highly sensitive immunosensor

  18. Impaired cell surface expression of HLA-B antigens on mesenchymal stem cells and muscle cell progenitors

    DEFF Research Database (Denmark)

    Isa, Adiba; Nehlin, Jan; Sabir, Hardee Jawad;

    2010-01-01

    HLA class-I expression is weak in embryonic stem cells but increases rapidly during lineage progression. It is unknown whether all three classical HLA class-I antigens follow the same developmental program. In the present study, we investigated allele-specific expression of HLA-A, -B, and -C...... at the mRNA and protein levels on human mesenchymal stem cells from bone marrow and adipose tissue as well as striated muscle satellite cells and lymphocytes. Using multicolour flow cytometry, we found high cell surface expression of HLA-A on all stem cells and PBMC examined. Surprisingly, HLA-B was either...... undetectable or very weakly expressed on all stem cells protecting them from complement-dependent cytotoxicity (CDC) using relevant human anti-B and anti-Cw sera. IFNgamma stimulation for 48-72 h was required to induce full HLA-B protein expression. Quantitative real-time RT-PCR showed that IFNgamma induced...

  19. Evaluation of hepatitis B surface antigen and hepatitis B virus-DNA results in postmortem plasma specimens

    Directory of Open Access Journals (Sweden)

    Nihan Ziyade

    2015-03-01

    Full Text Available Objective: To assess the presence of hepatitis B surface antigen, one of the serologic markers of hepatitis B virus (HBV infection, in postmortem blood samples from autopsy cases using ELISA, and to compare the results with those obtained by PCR, which is the gold standard method in assessing HBV infection. Methods: The HBV test results of the blood samples from 880 autopsy cases determined in our laboratory, were retrospectively studied. Results: When compared with the gold standard method PCR, the sensitivity and specificity of postmortem ELISA were 100% and 84.1%, respectively. Conclusions: The increasingly used molecular diagnostic methods, such as PCR, should be used in cases where serological tests remain insufficient.We think that prospective studies on the comparison of ELISA and PCR assessment of postmortem blood samples with larger material should be carried out.

  20. Evaluation of hepatitis B surface antigen and hepatitis B virus-DNA results in postmortem plasma specimens

    Institute of Scientific and Technical Information of China (English)

    Nihan Ziyade; Sermet Koc; Fatih Abali

    2015-01-01

    Objective:To assess the presence of hepatitis B surface antigen, one of the serologic markers of hepatitis B virus (HBV) infection, in postmortem blood samples from autopsy cases using ELISA, and to compare the results with those obtained byPCR, which is the gold standard method in assessingHBV infection. Methods: TheHBV test results of the blood samples from 880 autopsy cases determined in our laboratory, were retrospectively studied. Results:When compared with the gold standard methodPCR, the sensitivity and specificity of postmortemELISA were 100% and 84.1%, respectively. Conclusions: The increasingly used molecular diagnostic methods, such asPCR, should be used in cases where serological tests remain insufficient.We think that prospective studies on the comparison ofELISA andPCR assessment of postmortem blood samples with larger material should be carried out.

  1. Antibodies to variant antigens on the surfaces of infected erythrocytes are associated with protection from malaria in Ghanaian children

    DEFF Research Database (Denmark)

    Dodoo, D; Staalsoe, T; Giha, H;

    2001-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a variant antigen expressed on the surface of infected erythrocytes. Each parasite genome contains about 40 PfEMP1 genes, but only 1 PfEMP1 gene is expressed at a given time. PfEMP1 serves as a parasite-sequestering ligand...... to endothelial cells and enables the parasites to avoid splenic passage. PfEMP1 antibodies may protect from disease by inhibiting sequestration, thus facilitating the destruction of infected erythrocytes in the spleen. In this study, we have measured antibodies in Ghanaian children to a conserved region of PfEMP...... during the season. The prevalences of antibodies to both the conserved PfEMP1 peptide and the variant epitopes were greater than 50%, and the levels of immunoglobulin G (IgG) correlated with age. The levels of antibodies to both the conserved peptide and the variant epitopes were higher in protected than...

  2. Serological Evaluation of Experimental Toxoplasma gondii Infection in Cats by Using Immunoblotting Based on an Affinity Purified Surface Antigen

    Directory of Open Access Journals (Sweden)

    Hosseininejad, M.

    2012-11-01

    Full Text Available Toxoplasma gondii is an apicomplexan parasite that infects human and almost all warm-blooded animals. The life cycle of the parasite includes an asexual reproduction in intermediate hosts (Mammals and birds and a sexual reproduction in definitive hosts (Felidae. Cats are both the intermediate and the definitive host for T. gondii. The aim of this study was to investigate anti-T. gondii antibodies in cats by using an immunoblot method based on a major surface antigen; SAG1. Six sero-negative kittens were infected intra-peritoneally by Rh strain of T. gondii. Serum samples were collected and evaluated for the presence of IgG antibodies by using two techniques; immunoblotting and indirect fluorescent antibody test (IFAT.SAG1 based immunoblotting was able to detect anti-T. gondii antibodies at least eight days after infection. Comparative evaluation showed that this method is as sensitive as IFAT to diagnose T. gondii infection in cats.

  3. Prevalence of Hepatitis B surface antigen (HBsAg among visitors of Shashemene General Hospital voluntary counseling and testing center

    Directory of Open Access Journals (Sweden)

    Medhin Girmay

    2011-02-01

    Full Text Available Abstract Background Hepatitis B virus (HBV infection is significant health problem, as it can lead to chronic hepatitis, liver cirrhosis, and hepatic carcinoma. Due to shared routes of transmission, HBV and human immunodeficiency virus (HIV co-infection is common and is an emerging concern in the clinical management of patients because of increased mortality, accelerated hepatic disease progression, and the frequent hepatotoxicity caused by anti-retroviral therapy. The aim of this study was to determine the prevalence of Hepatitis B surface antigen (HBsAg and its risk factors, among individuals visiting Shashemene General Hospital VCT center. Findings Institution based cross-sectional study was performed from November 3, 2008 to December 29, 2008 and 384 voluntary counseling and testing (VCT clients were investigated. Data on socio demographic and HBV risk factors was collected using structured questionnaires. Blood samples were collected and screened for hepatitis B surface antigen (HBsAg and HIV by commercially available rapid test kits. The prevalence of HBsAg in this study group was 5.7%. Fourteen percent of HIV positive subjects (8/57 and 4.3% (14/327 of HIV negative subjects were positive for HBsAg. Significantly high prevalence of HBsAg was observed among individuals who had history of invasive procedures, like tooth extraction, abortion and ear piercing; history of hospital admission, history of unsafe inject and HIV positives. Conclusions Although HBsAg prevalence is much higher among subjects who are HIV positive (14.0% versus 4.3%, the prevalence of HBsAg in HIV negative subjects is high enough to warrant a recommendation to screen all clients at VCT centers irrespective of HIV status.

  4. Merozoite Surface Antigen 2 Proteins of Babesia bovis Vaccine Breakthrough Isolates Contain a Unique Hypervariable Region Composed of Degenerate Repeats

    Science.gov (United States)

    Berens, Shawn J.; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The merozoite surface antigen 2 (MSA-2) proteins of Babesia bovis are members of the variable merozoite surface antigen (VMSA) family that have been implicated in erythrocyte invasion and are important targets for antibody-mediated blocking of invasion. Extensive sequence variation in another VMSA member, MSA-1, has been shown in all vaccine breakthrough isolates. To test the hypothesis that the msa-2 genes of vaccine breakthrough isolates would also encode a diverse set of proteins, the complete msa-2 locus was characterized from 12 Australian B. bovis strains and isolates, including two vaccine strains and eight vaccine breakthrough isolates, and compared to the loci in previously and newly characterized American strains. In contrast to American strains, the msa-2 loci of all Australian strains and isolates examined contain, in addition to msa-2c, only a solitary gene (designated msa-2a/b) closely related to American strain msa-2a and msa-2b. Nevertheless, the proteins encoded by these genes are quite diverse both between and within geographic regions and harbor evidence of genetic exchange among other VMSA family members, including msa-1. Moreover, all but one of the Australian breakthrough isolate MSA-2a/b proteins is markedly different from the vaccine strain from which immune escape occurred, consistent with their role in strain-specific protective immunity. The densest distribution of polymorphisms occurs in a hypervariable region (HVR) within the carboxy third of the molecule that is highly proline rich. Variation in length and content of the HVR is primarily attributable to differences in the order and number of degenerate nucleotide repeats encoding three motifs of unknown function. PMID:16239512

  5. A novel hepatitis B virus mutant with A-to-G at nt551 in the surface antigen gene

    Institute of Scientific and Technical Information of China (English)

    Hua-Biao Chen; De-Xing Fang; Fa-Qing Li; Hui-Ying Jing; Wei-Guo Tan; Su-Qin Li

    2003-01-01

    AIM: Hepatitis B surface antigen (HBsAg) mutant of hepatitisB virus (HBV) is one of the important factors that result inimmune escape and cause failure of immunization. In thisstudy we reported and characterized a novel HBV mutantwith A-to-G at nt551 and intended to provide theoreticaldata for prevention of HBV infection in China.METHODS: A methodology comprising polymerase chainreaction (PCR) amplifying, M13 bacteriophage cloning andnucleotide sequencing was used to analyze the sera of thepediatric patient who was hepatitis B (HB) immune failure.Expression plasmids containing the mutant S gene and awild-type (adr) S gene were constructed respectively andthe recombinant HBsAg were expressed in COS-7 cells underthe regulation of SV40 early promoter. The recombinantproteins were investigated for their immunological reactivitywith different monoclonal antibodies (mAb) against 'a'determinant and vaccine-raised human neutralizingantibodies.RESULTS: It was found that there was a new point mutationat nt551 of the HBV (adr) genome from A to G, leading to asubstitution of methionine (Met) to valine (Val) at position133 in the 'a' determinant of HBsAg. Compared to the wild-type HBsAg, the binding activity of the muant HBsAg tomAbs (A6, A11 and S17) and to vaccine-raised human anti-hepatitis B surface antibody (anti-HBs) decreased significantly.CONCLUSION: According to the facts that the patient hasbeen immunized with HB vaccine and that the serum is anti-HBs positive and HBsAg negative, and based on thenucleotide sequence analysis of the mutant HBV S geneand its alteration of antigenicity, the HBV is considered tobe a new vaccine-induced immune escape mutant differentfrom the known ones.

  6. Markedly prolonged incubation period of hepatitis B in a chimpanzee passively immunized with a human monoclonal antibody to the a determinant of hepatitis B surface antigen.

    OpenAIRE

    Ogata, N.; Ostberg, L; Ehrlich, P H; Wong, D C; Miller, R H; Purcell, R H

    1993-01-01

    The protective efficacy of a human monoclonal antibody directed against the a determinant of hepatitis B virus (HBV) surface antigen was studied in a chimpanzee. A single high dose of 5 mg/kg (body weight) of monoclonal antibody SDZ OST 577 was intravenously administered to a chimpanzee, followed by intravenous challenge with 10(3.5) chimpanzee infectious doses of a wild-type HBV, the MS-2 strain (ayw subtype). The passively acquired antibody to HBV surface antigen could be detected for 40 we...

  7. Analysis of IgG with specificity for variant surface antigens expressed by placental Plasmodium falciparum isolates

    Directory of Open Access Journals (Sweden)

    Kremsner Peter G

    2004-07-01

    Full Text Available Abstract Background Pregnancy-associated malaria (PAM is caused by Plasmodium falciparum-infected erythrocytes that can sequester in placental intervillous space by expressing particular variant surface antigens (VSA that can mediate adhesion to chondroitin sulfate A (CSA in vitro. IgG antibodies with specificity for the VSA expressed by these parasites (VSAPAM are associated with protection from maternal anaemia, prematurity and low birth weight, which is the greatest risk factor for death in the first month of life. Methods In this study, the development of anti-VSAPAM antibodies in a group of 151 women who presented to the maternity ward of Albert Schweitzer Hospital in Lambaréné, Gabon for delivery was analysed using flow cytometry assays. Plasma samples from placenta infected primiparous women were also investigated for their capacity to inhibit parasite binding to CSA in vitro. Results In the study cohort, primiparous as well as secundiparous women had the greatest risk of infection at delivery as well as during pregnancy. Primiparous women with infected placentas at delivery showed higher levels of VSAPAM-specific IgG compared to women who had no malaria infections at delivery. Placental isolates of Gabonese and Senegalese origin tested on plasma samples from Gabon showed parity dependency and gender specificity patterns. There was a significant correlation of plasma reactivity as measured by flow cytometry between different placental isolates. In the plasma of infected primiparous women, VSAPAM-specific IgG measured by flow cytometry could be correlated with anti-adhesion antibodies measured by the inhibition of CSA binding. Conclusion Recognition of placental parasites shows a parity- and sex- dependent pattern, like that previously observed in laboratory strains selected to bind to CSA. Placental infections at delivery in primiparous women appear to be sufficient to induce functional antibodies which can both recognize the surface of

  8. Temporal expression and localization patterns of variant surface antigens in clinical Plasmodium falciparum isolates during erythrocyte schizogony.

    Directory of Open Access Journals (Sweden)

    Anna Bachmann

    Full Text Available Avoidance of antibody-mediated immune recognition allows parasites to establish chronic infections and enhances opportunities for transmission. The human malaria parasite Plasmodium falciparum possesses a number of multi-copy gene families, including var, rif, stevor and pfmc-2tm, which encode variant antigens believed to be expressed on the surfaces of infected erythrocytes. However, most studies of these antigens are based on in vitro analyses of culture-adapted isolates, most commonly the laboratory strain 3D7, and thus may not be representative of the unique challenges encountered by P. falciparum in the human host. To investigate the expression of the var, rif-A, rif-B, stevor and pfmc-2tm family genes under conditions that mimic more closely the natural course of infection, ex vivo clinical P. falciparum isolates were analyzed using a novel quantitative real-time PCR approach. Expression patterns in the clinical isolates at various time points during the first intraerythrocytic developmental cycle in vitro were compared to those of strain 3D7. In the clinical isolates, in contrast to strain 3D7, there was a peak of expression of the multi-copy gene families rif-A, stevor and pfmc-2tm at the young ring stage, in addition to the already known expression peak in trophozoites. Furthermore, most of the variant surface antigen families were overexpressed in the clinical isolates relative to 3D7, with the exception of the pfmc-2tm family, expression of which was higher in 3D7 parasites. Immunofluorescence analyses performed in parallel revealed two stage-dependent localization patterns of RIFIN, STEVOR and PfMC-2TM. Proteins were exported into the infected erythrocyte at the young trophozoite stage, whereas they remained inside the parasite membrane during schizont stage and were subsequently observed in different compartments in the merozoite. These results reveal a complex pattern of expression of P. falciparum multi-copy gene families during

  9. Evaluation of three recombinant multi-antigenic vaccines composed of surface and secretory antigens of Toxoplasma gondii in murine models of experimental toxoplasmosis.

    Science.gov (United States)

    Dziadek, Bozena; Gatkowska, Justyna; Brzostek, Anna; Dziadek, Jaroslaw; Dzitko, Katarzyna; Grzybowski, Marcin; Dlugonska, Henryka

    2011-01-17

    The great clinical and economical impact of Toxoplasma gondii infections makes the development of an effective vaccine for controlling toxoplasmosis an extremely important aim. In the presented study, we evaluate the protective and immunogenic properties of three recombinant subunit vaccines composed of rROP2+rGRA4+rSAG1, rROP2+rROP4+rGRA4 and rROP2+rROP4+rSAG1 proteins of T. gondii in an experimental toxoplasmosis model in the C3H/HeJ and C57BL/6 mouse strains. All three recombinant vaccines induced partial protection as measured by the reduction of brain cyst burden following challenge with five tissue cysts of the low virulence DX T. gondii strain. The level of protection was dependent on the antigen composition of the vaccine and the genetic background of the laboratory animals. The strongest protection against chronic toxoplasmosis was induced in both C3H/HeJ and C57BL/6 mice by the mixture of rhoptry proteins rROP2 and rROP4 combined with tachyzoite major protein rSAG1. The average parasite burden in these groups of mice was reduced by 71% and 90%, respectively, compared to non-vaccinated mice. The observed protective effect was related to the vaccine-induced cellular and humoral immune responses, as measured by the antigen-induced release of the Th1 cytokines IFN-γ and IL-2, the antigen-stimulated proliferation of spleen cells of vaccinated animals in comparison to control animals and the development of systemic antigen-specific IgG1 and IgG2a (C3H/HeJ) or IgG2c (C57BL/6) antibodies. Our studies show that recombinant rROP2, rROP4, rGRA4 and rSAG1 antigens may be promising candidates for a subunit vaccine against toxoplasmosis. Additionally, we demonstrate that the ideal composition of vaccine antigens can be equally effective in mice with different genetic backgrounds and variable levels of innate resistance to toxoplasmosis, resulting in strong protection against T. gondii invasion.

  10. Production and Characterization of a Monoclonal Antibody Raised Against Surface Antigens from Mycelium of Gaeumannomyces graminis var. tritici: Evidence for an Extracellular Polyphenol Oxidase.

    Science.gov (United States)

    Thornton, C R; Dewey, F M; Gilligan, C A

    1997-01-01

    ABSTRACT A murine monoclonal antibody (MAb) of immunoglobulin class M (IgM) was raised against surface antigens from Gaeumannomyces graminis var. tritici and, by enzyme-linked immunosorbent assay, recognized isolates of G. graminis var. tritici, G. graminis var. avenae and G. graminis var. graminis. Characterization of the antigen by heat and protease treatments showed that the epitope recognized by the MAb was a protein. Antigen production was detected only in live mycelia. Immunofluorescence studies showed that the antigen was associated with both the broad melanized macrohyphae and hyaline mycelia of G. graminis var. tritici. Secretion of antigen into an aqueous minimal medium was promoted only by exposure of live mycelia to certain phenolic substrates, including monophenols ortho-, para-, and meta-cresol; 3,4,5-trihydroxybenzoic acid (gallic acid); and phenolic amino acid L-3-(3,4-dihydroxyphenyl) alanine (L-DOPA). Antigen secretion was not promoted by 3-(4-hydroxyphenyl) alanine (L-tyrosine). The MAb reacted strongly with purified enzyme laccase (polyphenol oxidase, EC 1.10.3.2) but did not recognize purified tyrosinase (monophenol oxidase, EC 1.14.18.1). Moreover, chemicals that bind to copper and inhibit copper-containing enzymes such as laccase completely inhibited antigen secretion in response to L-DOPA. The MAb was tested for specificity against a wide range of fungi, common yeast species, and gram positive and negative bacteria. It did not recognize antigens from a broad range of unrelated fungi, including Gliocladium roseum, Fusarium sp., Phoma exigua, Phialophora fastigiata, Penicillium crustosum, Pythium ultimum, Rhizopus stolonifer, Rhizoctonia carotae, R. oryzae, R. tuliparum, and Trichoderma viride, nor did it recognize surface antigens from yeasts or bacteria. The MAb cross-reacted with antigens from Botrytis spp., Chaetomium globosum, R. cerealis, and R. solani. However, secretion of antigen by R. solani and R. cerealis was not promoted by L

  11. Mechanism of Adherence of Streptococcus mutans to Smooth Surfaces I. Roles of Insoluble Dextran-Levan Synthetase Enzymes and Cell Wall Polysaccharide Antigen in Plaque Formation

    Science.gov (United States)

    Mukasa, Hidehiko; Slade, Hutton D.

    1973-01-01

    The mechanism of adherence of Streptococcus mutans to smooth glass surfaces has been studied. The results with both viable and heat-killed cells showed that the process required (i) the synthesis of a water-insoluble dextran-levan polymer by cell-bound enzymes and (ii) the participation of a binding site on the surface of the S. mutans cell. Synthesis of the polymer from sucrose in the presence of the cells was required for adherence, and indicates that an “active” form of the polymer was required. Polymer synthesized by cell-free S. mutans enzymes when added to S. mutans cells did not produce adherence. Purified antibody globulin, specific for the a-d site in the polysaccharide S. mutans group a antigen, completely inhibited adherence. Antibody to the second antigen present in the polysaccharide molecule, the a antigen, did not inhibit adherence. The evidence indicates that adherence did not require an antigenic binding site which might be common to all S. mutans strains. The orientation of the synthetase enzyme(s), antigenic binding site, and dextran-levan polymer on the cell surface is under study. Images PMID:4582634

  12. Surface co-expression of two different PfEMP1 antigens on single Plasmodium falciparum-infected erythrocytes facilitates binding to ICAM1 and PECAM1

    DEFF Research Database (Denmark)

    Joergensen, Louise; Bengtsson, Dominique C; Bengtsson, Anja;

    2010-01-01

    The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) antigens play a major role in cytoadhesion of infected erythrocytes (IE), antigenic variation, and immunity to malaria. The current consensus on control of variant surface antigen expression is that only one PfEMP1 encoded by one var...... gene is expressed per cell at a time. We measured var mRNA transcript levels by real-time Q-PCR, analysed var gene transcripts by single-cell FISH and directly compared these with PfEMP1 antigen surface expression and cytoadhesion in three different antibody-selected P. falciparum 3D7 sub-lines using......-line was found to bind both CD31/PECAM1 and CD54/ICAM1 and to adhere twice as efficiently to human endothelial cells, compared to infected cells having only one PfEMP1 variant on the surface. These new results on PfEMP1 antigen expression indicate that a re-evaluation of the molecular mechanisms involved in P...

  13. Human antibodies targeting cell surface antigens overexpressed by the hormone refractory metastatic prostate cancer cells: ICAM-1 is a tumor antigen that mediates prostate cancer cell invasion

    OpenAIRE

    Conrad, Fraser; Zhu, Xiaodong; Zhang, Xin; Chalkley, Robert J.; Burlingame, Alma L; Marks, James D.; Liu, Bin

    2009-01-01

    Transition from hormone-sensitive to hormone-refractory metastatic tumor types poses a major challenge for prostate cancer treatment. Tumor antigens that are differentially expressed during this transition are likely to play important roles in imparting prostate cancer cells with the ability to grow in a hormone-deprived environment and to metastasize to distal sites such as the bone and thus, are likely targets for therapeutic intervention. To identify those molecules and particularly cell s...

  14. Antigens of Setaria digitata: cross-reaction with surface antigens of Wuchereria bancrofti microfilariae and serum antibodies of W. bancrofti-infected subjects

    OpenAIRE

    Dissanayake, S.; Ismail, M. M.

    1980-01-01

    Extracts of Setaria digitata have been fractionated by DEAE-Sephadex A50 chromatography and the fractions obtained were used in the inhibition of indirect immunofluorescence of Wuchereria bancrofti microfilariae. The fractions were also tested by an enzyme-linked immunosorbent assay (ELISA) technique for reactivity against antibodies in the serum of patients with W. bancrofti infections. The results indicate that S. digitata contains several antigenic fractions that show cross-reactivity agai...

  15. Assessing stability and assembly of the hepatitis B surface antigen into virus-like particles during down-stream processing.

    Science.gov (United States)

    Zahid, Maria; Lünsdorf, Heinrich; Rinas, Ursula

    2015-07-17

    The hepatitis B surface antigen (HBsAg) is a recombinant protein-based vaccine being able to form virus-like particles (VLPs). HBsAg is mainly produced using yeast-based expression systems, however, recent results strongly suggest that VLPs are not formed within the yeast cells during the cultivation but are formed in a gradual manner during the following down-stream procedures. VLPs are also not detectable during the first down-stream steps including mechanical and EDTA/detergent-assisted cell destruction. Moreover, VLPs are not detectable in the cell lysate treated with polyethylene glycol and colloidal silica. The first VLP resembling structures appear after elution of HBsAg from colloidal silica to which it binds through hydrophobic interaction. These first VLP resembling structures are non-symmetrical as well as heterodisperse and exhibit a high tendency toward cluster formation presumably because of surface exposed hydrophobic patches. More symmetrical and monodisperse VLPs appear after the following ion-exchange and size-exclusion chromatography most likely as the result of buffer changes during these purification steps (toward more neutral pH and less salt). Final treatment of the VLPs with the denaturant KSCN at moderate concentrations with following KSCN removal by dialysis does not cause unfolding and VLP disassembly but results in a re- and fine-structuring of the VLP surface topology. PMID:26079614

  16. Cloning of a cDNA encoding a surface antigen of Schistosoma mansoni schistosomula recognized by sera of vassinated mice

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, J.P.; Tom, T.D.; Strand, M.

    1987-06-01

    Spleen cells of mice vaccinated with radiation-attenuated Schistosoma mansoni cercariae were used to produce monoclonal antibodies directed against newly transformed schistosomular surface antigens. One of these monoclonal antibodies recognized a polypeptide of 18 kDa. Binding was measured by radioimmunoassay. This glycoprotein was purified by monoclonal antibody immunoaffinity chromatography and a polyclonal antiserum was prepared against it. Immunofluorescence assays showed that the polyclonal antiserum bound to the surface of newly transformed schistosomula and lung-stage organisms but not to the surface of liver-stage and adult worms. Using this polyclonal antiserum we isolated recombinant clones from an adult worm cDNA expression library constructed in lambdagt11. Clone 654.2 contained an insert of 0.52 kilobase and hybridized to a 1.2-kilobase mRNA species from adult worms. Most importantly, clone 654.2 produced a fusion protein of 125 kDa that was reactive with sera of vaccinated mice that are capable of transferring resistance. This result encourages future vaccination trials with the fusion protein.

  17. Generation of a phage-display library of single-domain camelid VH H antibodies directed against Chlamydomonas reinhardtii antigens, and characterization of VH Hs binding cell-surface antigens.

    Science.gov (United States)

    Jiang, Wenzhi; Rosenberg, Julian N; Wauchope, Akelia D; Tremblay, Jacqueline M; Shoemaker, Charles B; Weeks, Donald P; Oyler, George A

    2013-11-01

    Single-domain antibodies (sdAbs) are powerful tools for the detection, quantification, purification and subcellular localization of proteins of interest in biological research. We have generated camelid (Lama pacos) heavy chain-only variable VH domain (VH H) libraries against antigens in total cell lysates from Chlamydomonas reinhardtii. The sdAbs in the sera from immunized animals and VH H antibody domains isolated from the library show specificity to C. reinhardtii and lack of reactivity to antigens from four other algae: Chlorella variabilis, Coccomyxa subellipsoidea, Nannochloropsis oceanica and Thalassiosira pseudonana. Antibodies were produced against a diverse representation of antigens as evidenced by sera ELISA and protein-blot analyses. A phage-display library consisting of the VH H region contained at least 10(6) individual transformants, and thus should represent a wide range of C. reinhardtii antigens. The utility of the phage library was demonstrated by using live C. reinhardtii cells to pan for VH H clones with specific recognition of cell-surface epitopes. The lead candidate VH H clones (designated B11 and H10) bound to C. reinhardtii with EC50 values ≤ 0.5 nm. Treatment of cells with VH H B11 fused to the mCherry or green fluorescent proteins allowed brilliant and specific staining of the C. reinhardtii cell wall and analysis of cell-wall genesis during cell division. Such high-complexity VH H antibody libraries for algae will be valuable tools for algal researchers and biotechnologists.

  18. Synthesis and evaluation of monoclonal antibody againstPlasmodium falciparum merozoite surface antigen 2

    Institute of Scientific and Technical Information of China (English)

    Afra Khosravi; Eghbaleh Asadollahy; Sobhan Ghafourian; Nourkhoda Sadeghifard; Reza Mohebi

    2013-01-01

    Objective:To assess the quality of expressedMSP-2 and also to confirm the immune response against different domains of these proteins.Methods:Mice were immunized with a schizont extract to stimulate the immune system to make antibodies against different antigens of the late stage parasite including production of antibodies against different domains of Plasmodium falciparum(P. falciparum)MSP-2.B lymphocytes of immunized mice were extracted from the spleen and the fusion was performed usingNS-1 myeloma cells and the hybridoma cells were assayed byELISA either with a schizont extract or different domains ofMSP-2 and/or byIFAT with whole schizont preparation.Fusion ofNS-1 and spleen cells was performed.The positive hybrids were cloned andELISA was applied against different dilutions.The positive clones were transferred to a small tissue culture flask and after developing they were assayed against schizont extract and the differentMSP-2 domains.The positive clones were expanded to large (75 cm2) flask and cultured under the same conditions, checking them using bothELISA and IFAT and the positive cells were frozen as soon as possible.Results:A total number of7 fusions including26 plates(2496 wells) were performed, ofwhich1336 hybrids were produced and the overall efficiency(1336/2496í100) was about53%.ELISA was performed to detect the positive hybrids against crude schizont extract by which the highest frequency to crude schizont extract was found for the supernatant of the hybrids produced in fusion number3(66 out of315 hybrids). The supernatant of bothB5 andF1 hybridoma cells were more positive against domain2 of the MSP-2 recombinant protein inWestern blotting test.Western blotting results also showed that different domains of theMSP-2 recombinant protein and also theMSP-2 of theP. falciparum parasite were recognized by some of the positive clones and also immune sera.Conclusions:Bringing together all the results of this study it has been confirmed that some clones

  19. Hepatitis B surface antigen positivity after twinrix vaccination: a case report.

    Science.gov (United States)

    Lee, Yirang; Kim, Jae-Seok; Park, Ji-Young; Kim, Soo Young; Hwang, In Hong; Cho, Hyoun Chan

    2014-01-01

    Travelers might have an increased risk of hepatitis B virus (HBV) infection. We report a case of prolonged transient hepatitis B surface antigenemia in a healthy Canadian female 8 days after administration of a combined hepatitis A and hepatitis B vaccine. Travel health providers providing hepatitis B vaccines need to be aware of this phenomenon and educate their patients accordingly. PMID:24861218

  20. Antigen 43-mediated autotransporter display, a versatile bacterial cell surface presentation system

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Hasman, Henrik; Schembri, Mark;

    2002-01-01

    bridges does not interfere with surface display, and Ag43 chimeras are correctly processed into alpha- and beta-modules, offering optional and easy release of the chimeric alpha-subunits. Furthermore, Ag43 can be displayed in many gram-negative bacteria. This feature is exploited for display of our...... chimeras in an attenuated Salmonella strain....

  1. Immunological evaluation of colonic delivered Hepatitis B surface antigen loaded TLR-4 agonist modified solid fat nanoparticles.

    Science.gov (United States)

    Sahu, Kantrol Kumar; Pandey, Ravi Shankar

    2016-10-01

    Hepatitis B is one of the leading liver diseases and remains a major global health problem. Currently available vaccines provide protection but often results in weaker/minimal mucosal immunity. Thus the present study is devoted to the development and in-vivo exploration of the colonically delivered biomimetic nanoparticles which capably enhance humoral as well as cellular immune response. In present work, Hepatitis B surface antigen (HBsAg) entrapped nanoparticles containing Monophosphoryl lipid A (MPLA) (HB+L-NP) were prepared by solvent evaporation method and characterized for particle size (~210nm), shape, zeta potential (-24mV±0.68), entrapment efficiency (58.45±1.68%), in-vitro release and antigen integrity. Dose escalation study was done to confirm prophylactic immune response following defined doses of prepared nanoparticulate formulations with or without MPLA. Intramuscular administered alum based marketed HBsAg (Genevac B) was used as standard (10μg) and were able to induce significant systemic (IgG) but remarkably low mucosal immune (IgA) response. Notably, HB+L-NP (0.5ml-10μg) induced strong systemic and robust mucosal immunity (510 and 470 mIU/ml respectively, p<0.001) from which mucosal was more significant due to the involvement of Common Mucosal Immune System (CMIS). Likewise, significant cellular immune response was elicited by HB+L-NP through T-cell activation (mixed Th1 and Th2) as confirmed by significantly increased cytokines level (IL-2 and Interferon-γ) in spleen homogenates. This study supports that delivery of HBsAg to the colon may open new vista in designing oral vaccines later being one of most accepted route for potential vaccines in future.

  2. Molecular basis for variable expression of merozoite surface antigen gp45 among American isolates of Babesia bigemina.

    Science.gov (United States)

    Fisher, T G; McElwain, T F; Palmer, G H

    2001-06-01

    Immunization with the merozoite surface glycoprotein gp45 induces protection against challenge using the homologous Babesia bigemina strain. However, gp45 B-cell epitopes are highly polymorphic among B. bigemina strains isolated from different geographical locations within North and South America. The molecular basis for this polymorphism was investigated using the JG-29 biological clone of a Mexico strain of B. bigemina and comparison with the Puerto Rico, St. Croix, and Texcoco strains. The molecular size and antibody reactivity of gp45 expressed by the JG-29 clone were identical to those of the parental Mexico strain. gp45 cDNA and the genomic locus encompassing gp45 were cloned and sequenced from JG-29. The locus sequence and Southern blot data were consistent with a single gp45 copy in the JG-29 genome. The JG-29 cDNA expressed the full-length protein recognized by the gp45-specific monoclonal antibody 14/1.3.2. The genomes of the Puerto Rico and St. Croix strains of B. bigemina were shown to lack a closely related gp45-like gene by PCR using multiple primer sets and by Southern blots using both full-length and region-specific gp45 probes. This genomic difference was confirmed using unpassaged isolates from a 1999 disease outbreak in Puerto Rico. In contrast, the Texcoco strain retains a gp45 gene, encoding an open reading frame identical to that of JG-29. However, the Texcoco gp45 gene is not transcribed. These two mechanisms, lack of a closely related gp45-like gene and failure to transcribe gp45, result in generation of antigenic polymorphism among B. bigemina strains, and the latter mechanism is unique compared to prior mechanisms of antigenic polymorphism identified in babesial parasites.

  3. Air sampling for hepatitis B surface antigen in a dental operatory.

    Science.gov (United States)

    Petersen, N J; Bond, W W; Favero, M S

    1979-09-01

    Forty samples of air with a mean sample volume of 104 liters were collected during the treatment of patients whose blood was positive for HBsAG: no samples contained HBsAG and occult blood. These findings suggest that, if environmentally mediated transmission of hepatitis B occurs in the dental operatory, it is more likely to occur through contact with contaminated surfaces than through the airborne route.

  4. Surface antigen cross-linking triggers forced exit of a protozoan parasite from its host.

    OpenAIRE

    Clark, T. G.; Lin, T. L.; Dickerson, H. W.

    1996-01-01

    We used the common fish pathogen Ichthyophthirius multifiliis as a model for studying interactions between parasitic ciliates and their vertebrate hosts. Although highly pathogenic, Ichthyophthirius can elicit a strong protective immune response in fish after exposure to controlled infections. To investigate the mechanisms underlying host resistance, a series of passive immunization experiments were carried out using mouse monoclonal antibodies against a class of surface membrane proteins, kn...

  5. Hepatitis B surface antigen quantity positively correlates with plasma levels of microRNAs differentially expressed in immunological phases of chronic hepatitis B in children

    DEFF Research Database (Denmark)

    Winther, Thilde Nordmann; Heiberg, Ida Louise; Bang-Berthelsen, Claus Heiner;

    2013-01-01

    Children with chronic hepatitis B (CHB) are at high risk of progressive liver disease. It is suggested that a newly-identified panel of 16 microRNAs is important in the pathogenesis of CHB in children. Subviral hepatitis B surface antigen (HBsAg) particles are produced in large excess over...

  6. Detection of HLA-D-region-associated antigens on the surface of adult T-cell leukemia virus particles by immunoelectron microscopy.

    Directory of Open Access Journals (Sweden)

    Ohtsuki,Yuji

    1984-12-01

    Full Text Available To search for lymphocyte marker antigens on the surface of human T-cell leukemia virus (HTLV, an immunoelectron microscopic study was performed on a HTLV-producing human T-cell line, MT-2, using monoclonal antibodies, such as anti-Leu-1, -Leu-2b, -Leu-3a, -Leu-5, -Leu-10 and -HLA-DR and OKIal. The reactivity of each antibody with MT-2 cells was tested by the immunoperoxidase method at the light microscopic level. OKIal, anti-HLA-DR and -Leu-10 gave positive results. At the ultrastructural level, the surface of HTLV as well as the plasma membranes of MT-2 cells were labeled with ferritin by the monoclonal antibodies OKIal, anti-HLA-DR and -Leu-10, but not by anti-Leu-1 and -Leu-3a. These findings suggest that HLA-D region -associated antigens are common antigenic determinants shared by the surface of HTLV and the plasma membranes of MT-2 cells. These antigens on the virus surface are probably picked up selectively from the plasma membranes and may play an important role in the interaction of HTLV and target T-cells.

  7. Determinants of variant surface antigen antibody response in severe Plasmodium falciparum malaria in an area of low and unstable malaria transmission

    DEFF Research Database (Denmark)

    A-Elgadir, T M E; Theander, T G; Elghazali, G;

    2006-01-01

    The variant surface antigens (VSA) of infected erythrocytes are important pathogenic markers, a set of variants (VSA(SM)), were assumed to be associated with severe malaria (SM), while SM constitutes clinically diverse forms, such as, severe malarial anemia (SMA) and cerebral malaria (CM). This s...

  8. P48 Major Surface Antigen of Mycoplasma agalactiae Is Homologous to a malp Product of Mycoplasma fermentans and Belongs to a Selected Family of Bacterial Lipoproteins

    OpenAIRE

    Rosati, Sergio; Pozzi, Sarah; Robino, Patrizia; Montinaro, Barbara; Conti, Amedeo; Fadda, Manlio; Pittau, Marco

    1999-01-01

    A major surface antigenic lipoprotein of Mycoplasma agalactiae, promptly recognized by the host's immune system, was characterized. The mature product, P48, showed significant similarity and shared conserved amino acid motifs with lipoproteins or predicted lipoproteins from Mycoplasma fermentans, Mycoplasma hyorhinis, relapsing fever Borrelia spp., Bacillus subtilis, and Treponema pallidum.

  9. Complexes of hepatitis B surface antigen and immunoglobulin M in the sera of patients with hepatitis B virus infection.

    Science.gov (United States)

    Palla, M; Rizzi, R; Toti, M; Almi, P; Rizzetto, M; Bonino, F; Purcell, R

    1983-01-01

    Hepatitis B surface antigen (HBsAg) bound to immunoglobulin M (IgM) was detected in sera of HBsAg carriers by a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. Isopycnic banding and rate-zonal sedimentation have shown that the reaction is related to particulate forms of the HBsAg complexed with IgM. The binding of IgM possibly occurred because of a selective affinity of these molecules to the surface of HBsAg particles. HBsAg/IgM was found transiently in 24 of 25 (96%) patients with acute self-limited hepatitis B and persistently in 6 of 25 patients whose acute hepatitis B progressed to chronicity. It was also found in 20 of 39 (51%) chronic HBsAg carriers with inactive and asymptomatic infection. The HBsAg/IgM phenomenon is not dependent on replication of hepatitis B virions; its persistence in patients with acute hepatitis B may provide complementary evidence of transition of the infection to chronicity. PMID:6309673

  10. Reverse Line Blot Assay for Direct Identification of Seven Streptococcus agalactiae Major Surface Protein Antigen Genes

    OpenAIRE

    Zhao, Zuotao; Kong, Fanrong; Gilbert, Gwendolyn L.

    2006-01-01

    We developed a multiplex PCR-based reverse line blot hybridization assay (mPCR/RLB) to detect the genes encoding members of the family of variable surface-localized proteins of Streptococcus agalactiae (group B streptococcus [GBS]), namely, Bca (Cα), Rib, Epsilon (Epsilon/Alp1/Alp5), Alp2, Alp3, and Alp4, and the immunoglobulin A binding protein, Bac (Cβ). We used the assay to identify these genes in a collection of well-characterized GBS isolates and reference strains. The results showed tha...

  11. Suppression of humoral immune response to hepatitis B surface antigen vaccine in BALB/c mice by 1-methyl-tryptophan co-administration

    OpenAIRE

    Sparopoulou, T; Eleftheriadis, T; Antoniadi, G; Liakopoulos, V; Stefanidis, I.; Galaktidou, G

    2011-01-01

      Background and the purpose of the study:Indoleamine 2,3-dioxygenase (IDO) suppresses adaptive immune response. The purpose of this study was to determine the effect of the IDO inhibitor namely 1-methyl-DL-tryptophan (DL-1-MT) on antibody production after vaccination with hepatitis B surface (HBs) antigen. Methods:Four groups of BALB/c mice were immunized with a HBs antigen vaccine. In the first group the vaccine had no DL-1-MT, whereas in the other three groups the vaccine containe...

  12. Human MHC class I antigens are associated with a 90-kDa cell surface protein.

    Science.gov (United States)

    Ferm, M T; Grönberg, A

    1991-08-01

    Human MHC class I proteins are expressed on almost all nucleated cells as a heavy chain (about 45 kDa) non-covalently associated with beta 2-microglobulin (12 kDa). In this report we show that MHC class I (MHC-I) proteins can also be associated with a 90-kDa protein in the cell membrane. Surface-radiolabelled cells were treated with dithiobis succinimidyl propionate (DSP) in order to preserve multimer protein complexes during cell lysis. The lysates were immunoprecipitated and analysed by SDS-PAGE and autoradiography. Immunoprecipitation of human MHC-I proteins co-precipitated another protein of about 90 kDa in molecular weight-p90. p90 was coprecipitated from all the MHC-I expressing cells tested: U937, Raji, Molt-4 and IFN-gamma treated K562, but not from untreated, MHC-I negative K562. A 90-kDa protein was also co-precipitated with MHC-I from fresh peripheral blood mononuclear cells (PBMC). Furthermore, p90 was coprecipitated by different MoAbs to the MHC-I heavy chain or beta 2-microglobulin, but not by control antibodies. Two additional co-precipitating proteins at 34 kDa and 28 kDa were seen in MHC-I precipitates from Raji cells. Our results suggest that MHC-I proteins and the 90-kDa protein are associated in the cell membrane, probably by a close but weak, non-covalent interaction. Two additional cell surface proteins at 34 kDa and 28 kDa seem to be MHC-I associated on Raji Burkitt's lymphoma cells.

  13. The herpes virus Fc receptor gE-gI mediates antibody bipolar bridging to clear viral antigens from the cell surface.

    Directory of Open Access Journals (Sweden)

    Blaise Ndjamen

    2014-03-01

    Full Text Available The Herpes Simplex Virus 1 (HSV-1 glycoprotein gE-gI is a transmembrane Fc receptor found on the surface of infected cells and virions that binds human immunoglobulin G (hIgG. gE-gI can also participate in antibody bipolar bridging (ABB, a process by which the antigen-binding fragments (Fabs of the IgG bind a viral antigen while the Fc binds to gE-gI. IgG Fc binds gE-gI at basic, but not acidic, pH, suggesting that IgG bound at extracellular pH by cell surface gE-gI would dissociate and be degraded in acidic endosomes/lysosomes if endocytosed. The fate of viral antigens associated with gE-gI-bound IgG had been unknown: they could remain at the cell surface or be endocytosed with IgG. Here, we developed an in vitro model system for ABB and investigated the trafficking of ABB complexes using 4-D confocal fluorescence imaging of ABB complexes with transferrin or epidermal growth factor, well-characterized intracellular trafficking markers. Our data showed that cells expressing gE-gI and the viral antigen HSV-1 gD endocytosed anti-gD IgG and gD in a gE-gI-dependent process, resulting in lysosomal localization. These results suggest that gE-gI can mediate clearance of infected cell surfaces of anti-viral host IgG and viral antigens to evade IgG-mediated responses, representing a general mechanism for viral Fc receptors in immune evasion and viral pathogenesis.

  14. Immunogenicity and safety of liposome-vaccine encapsulating hepatitis B surface antigen and phosphodiester CpG oligodeoxynucleotides

    Institute of Scientific and Technical Information of China (English)

    CHUN YAN HE; QING LIANG LIU

    2006-01-01

    CpG oligodeoxynucleotides (CpG ODN) as adjuvant have been extensively studied in recent years. Phosphodiester CpG ODN (PO CpG ODN) can perfectly mimic bacterial DNA in enhancing immune response but are vulnerable to nucleases in vivo. This study aimed to evaluate the immunostimu latory potential and safety of phosphodiester CpG ODN encapsulated in nonphospholipid liposomes.BALB/c mice were immunized intramuscularly with different formulations of liposomes, CpG ODN and hepatitis B surface antigen (HBsAg). The results demonstrated that the encapsulated PO CpG ODN were protected against rapid degradation in vivo and retained their adjuvant activity. PO CpG ODN encapsulated with HBsAg in liposomes induced strong Th1-biased or Th1/Th2 mixed humoral immune response in mice with the magnitude similar to their phosphothioate equivalent in the same formulation.High IFN-gamma production induced by this formulation confirmed the generation of strong cellular immune response. Additionally, co-delivery of HBsAg and PO CpG ODN improved the immune response over that obtained with separate delivery. Safety experiment showed that liposome-encapsulaed PO CpG ODN and HBsAg caused mild systemic and moderate local adverse reaction. In conclusion, our data shows that PO CpG ODN encapsulated in liposomes fully exhibit their Th1-type adjuvant activity and act as a potential adjuvant for vaccines.

  15. A molecular assembly system for presentation of antigens on the surface of HBc virus-like particles

    Energy Technology Data Exchange (ETDEWEB)

    Blokhina, Elena A.; Kuprianov, Victor V. [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); Stepanova, Ludmila A.; Tsybalova, Ludmila M. [Research Institute of Influenza, Russian Federation Ministry of Health and Social Development, St. Petersburg (Russian Federation); Kiselev, Oleg I. [Research Institute of Influenza, Russian Federation Ministry of Health and Social Development, St. Petersburg (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation); Ravin, Nikolai V., E-mail: nravin@biengi.ac.ru [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation); Skryabin, Konstantin G. [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation)

    2013-01-20

    Hepatitis B virus-like particles, icosahedral structures formed by multiple core protein dimers, are promising immune-enhancing vaccine carriers for foreign antigens. Insertions into the surface-exposed immunodominant loop are especially immunogenic. However, the need to conserve the particulate structure to ensure high immunogenicity imposes restraints on the nature of the heterologous sequence that can be inserted. We propose a new approach to constructing HBc particles linked to the target epitopes that relies on non-covalent interactions between the epitope and pre-assembled unmodified HBc particles. Interaction was enabled by fusion of the epitope to the GSLLGRMKGA peptide, binding to the spike tips. This peptide may be used as a 'binding tag' allowing in vitro construction of HBc particles carrying the target peptide. Such virus-like particles carrying multiple copies of the extracellular domain of the M2 protein of different influenza strains appeared to be highly immunogenic and protected immunised mice against a lethal influenza challenge.

  16. IgM response to a human Pneumocystis carinii surface antigen in HIV-infected patients with pulmonary symptoms

    DEFF Research Database (Denmark)

    Lundgren, Bettina; Kovacs, J A; Mathiesen, Lars Reinhardt;

    1993-01-01

    We have developed an ELISA to detect IgM antibodies to a major human Pneumocystis carinii surface antigen (gp95), and investigated the IgM response in 128 HIV-infected patients who underwent bronchoscopy for evaluation of pulmonary symptoms. Only 5 (4%) patients had IgM antibodies to P. carinii gp...... response to gp95. These patients also showed an increase in IgG antibodies to gp95 and had microbiologically proven PCP. Prior to the development of the IgM response, IgG antibodies to gp95 were detectable in all 3 patients. Thus, HIV-infected patients with PCP seldom produce IgM antibodies to the major......95. Four of the 5 patients with IgM antibodies also had IgG antibodies to gp95 and microbiologically proven P. carinii pneumonia (PCP). In 76/128 patients for whom serial samples were available, changes in antibody response were determined. In 3 patients we demonstrated an increase in IgM antibody...

  17. Hepatitis B Vaccination Coverage and Prevalence of Hepatitis B Surface Antigen Among Children in French Polynesia, 2014.

    Science.gov (United States)

    Patel, Minal K; Le Calvez, Evelyne; Wannemuehler, Kathleen; Ségalin, Jean-Marc

    2016-06-01

    French Polynesia is considered to be moderately endemic for chronic hepatitis B virus infection, with an estimated 3% of the population having hepatitis B surface antigen (HBsAg). From 1990 to 1992, a 3-dose hepatitis B vaccination series was introduced into the routine infant immunization schedule in French Polynesia, including a birth dose (BD). In 2014, a nationally representative 2-stage cluster survey was undertaken to evaluate the impact of the vaccination program on HBsAg prevalence among school children (∼6 years of age) in Cours Préparatoire (CP). Documented vaccination data were reviewed for all eligible children; children with consent were tested for HBsAg with a rapid point-of-care test. In total, 1,660 students were identified; 1,567 (94%) had vaccination data for review and 1,196 (72%) participated in the serosurvey. Three-dose vaccination coverage was 98%, while timely BD coverage, defined as a dose administered within 24 hours of life, was 89%. Receipt of the second and third doses was often delayed, with 75% and 55% receiving a second and third dose within 1 month of the recommended age, respectively. No children tested positive for HBsAg. French Polynesia's vaccination program has achieved high coverage and an HBsAg seroprevalence of 0% (0-0.5%) among CP school children, but timeliness of vaccination could be improved.

  18. Detection of Rubisco and mycotoxins as potential contaminants of a plantibody against the hepatitis B surface antigen purified from tobacco.

    Science.gov (United States)

    Geada, Déborah; Valdés, Rodolfo; Escobar, Arturo; Ares, Dulce M; Torres, Edel; Blanco, Reinaldo; Ferro, Williams; Dorta, Dayamí; González, Marcos; Alemán, María R; Padilla, Sigifredo; Gómez, Leonardo; Del Castillo, Norma; Mendoza, Otto; Urquiza, Dioslaida; Soria, Yordanka; Brito, José; Leyva, Alberto; Borroto, Carlos; Gavilondo, Jorge V

    2007-10-01

    Antibodies have been one of the proteins widely expressed in tobacco plants for pharmaceutical purposes, which demand contaminant free preparations. Rubisco constitutes 40-60% of tobacco leaf soluble proteins; therefore it is the major potential protein contaminant of plantibodies, while mycotoxins are toxic compounds that could be introduced during the biomass production and post-harvest stages with important consequences to human health. The objective of this paper was to investigate whether Rubisco and mycotoxins are present in Plantibody HB-01 preparations used in the immunopurification of the hepatitis B surface antigen. Rubisco was purified from Nicotiana tabacum yielding 154 microg of protein per gram of leaves and purity over 95%. Among mouse monoclonal antibodies generated against this enzyme, the CBSS.Rub-2 was selected for its immunodetection. It recognizes a conserved sequential epitope of Rubisco large subunit with an affinity constant of 0.13 x 10(8)M(-1). Rubisco quantification limit was 1 microg spreading to the measurement of this contaminant less than 4% of plantibodies samples. Additionally, according to a Reverse Phase-HPLC used to measure the level of adventitiously introduced contaminants, it can be concluded that aflatoxins B1, B2, G1 and G2 were undetected in the purified Plantibody HB-01 samples.

  19. Establishment of an in vivo potency assay for the recombinant hepatit is B surface antigen in monovalent and combined vaccines

    Directory of Open Access Journals (Sweden)

    Mabel Izquierdo-López

    2014-12-01

    Full Text Available In this paper the development of potency assay in animals (mice was made, with the objective of demonstrating the immunogenic power of the recombinant Hepatitis B surface antigen in monovalent and combined vaccines, produced at the Center of Genetic Engineering and Biotechnology. The potency test is a parameter in quality control and it is also a tool to demonstrate the consistency of the production process. Parameters such as duration of the test, number of animals in the test, as well as different areas for the maintenance of the animals were evaluated. The results on the applicability of the potency test, to two presentations of the vaccines; monovalent Heberbiovac HB and pentavalent liquid in one vial Heberpenta-L are shown, for which specificity studies, evaluating different vaccine lots, the behavior of linearity, and parallelism, as well as establishing quality specification of the test were performed. This assay led to the obtainment of reliable results for the vaccines evaluated, the consistent evaluation of the immunogenic power and the monitoring of different production processes.

  20. Hepatitis B Vaccination Coverage and Prevalence of Hepatitis B Surface Antigen Among Children in French Polynesia, 2014.

    Science.gov (United States)

    Patel, Minal K; Le Calvez, Evelyne; Wannemuehler, Kathleen; Ségalin, Jean-Marc

    2016-06-01

    French Polynesia is considered to be moderately endemic for chronic hepatitis B virus infection, with an estimated 3% of the population having hepatitis B surface antigen (HBsAg). From 1990 to 1992, a 3-dose hepatitis B vaccination series was introduced into the routine infant immunization schedule in French Polynesia, including a birth dose (BD). In 2014, a nationally representative 2-stage cluster survey was undertaken to evaluate the impact of the vaccination program on HBsAg prevalence among school children (∼6 years of age) in Cours Préparatoire (CP). Documented vaccination data were reviewed for all eligible children; children with consent were tested for HBsAg with a rapid point-of-care test. In total, 1,660 students were identified; 1,567 (94%) had vaccination data for review and 1,196 (72%) participated in the serosurvey. Three-dose vaccination coverage was 98%, while timely BD coverage, defined as a dose administered within 24 hours of life, was 89%. Receipt of the second and third doses was often delayed, with 75% and 55% receiving a second and third dose within 1 month of the recommended age, respectively. No children tested positive for HBsAg. French Polynesia's vaccination program has achieved high coverage and an HBsAg seroprevalence of 0% (0-0.5%) among CP school children, but timeliness of vaccination could be improved. PMID:27001757

  1. Study of the immunogenicity of hepatitis B surface antigen synthesized in transgenic potato plants with increased biosafety.

    Science.gov (United States)

    Rukavtsova, Elena B; Rudenko, Natalya V; Puchko, Elena N; Zakharchenko, Natalya S; Buryanov, Yaroslav I

    2015-06-10

    Oral immunogenicity of the hepatitis B surface antigen (HBsAg) synthesized in the tubers of marker-free potato plants has been demonstrated. Experiments were performed in the two groups of outbred NMRI mice. At the beginning of investigations, the mice of experimental group were fed the tubers of transgenic potato synthesizing the HBsAg three times. The mice of control group were fed nontransgenic potato. Intraperitoneal injection of the commercial vaccine against hepatitis B (0.5μg/mouse) was made on day 71 of the experiment. Enzyme-linked immunoassay (ELISA) of the serum of immunized animals showed an increase in the level of HBsAg antibodies significantly above the protective value, which was maintained for 1 year after the immunization. In 1 year, the experimental group of mice underwent additional oral immunization with HBsAg-containing potato tubers. As a result, the level of antibodies against the HBsAg increased and remained at a high protective level for several months. The findings show the possibility of using transgenic plants as a substance for obtaining a safe edible vaccine against hepatitis B. PMID:25840367

  2. First evaluation of the serum level of anti-hepatitis B surface antigen after vaccination in Libya.

    Science.gov (United States)

    Madour, A; Alkout, A; Vanin, S

    2013-12-01

    The hepatitis B virus (HBV) vaccination schedule in Libya follows international recommendations (1st dose at birth, 2nd after 1 month and 3rd after 6 months). This research aimed to evaluate the long-term protection of the HBV immunization programme in Tripoli and to determine the best age to administer booster doses. Serum levels of hepatitis B surface antigen were determined in 277 randomly selected children aged 1-12 years. The response to HBV vaccine in 1-3-year-olds was 93.2%, but this declined with age and at 7-9 years after initial vaccination only 53.1% of children had protective titres (> or = 10 mIU/mL). No significant differences between males and females in antibody persistence or response to vaccine were observed. We recommend continuing the HBV vaccination programme and that a booster dose be given to 6-year-old children to ensure maximum protection during the period of school entry and beyond.

  3. Quantum dots affect expression of CD133 surface antigen in melanoma cells

    Directory of Open Access Journals (Sweden)

    Steponkiene S

    2011-10-01

    Full Text Available Simona Steponkiene1-3, Simona Kavaliauskiene1, Rasa Purviniene4, Ricardas Rotomskis3,5, Petras Juzenas11Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Radiumhospital, Oslo, Norway; 2Faculty of Natural Sciences, Vilnius University, Vilnius, Lithuania; 3Biomedical Physics Laboratory of Oncology Institute, Vilnius University, Vilnius, Lithuania; 4Immunology Laboratory of Oncology Institute, Vilnius University, Vilnius, Lithuania; 5Biophotonics Laboratory, Laser Research Center, Vilnius University, Vilnius, LithuaniaBackground: In novel treatment approaches, therapeutics should be designed to target cancer stem cells (CSCs. Quantum dots (QDs are a promising new tool in fighting against cancer. However, little is known about accumulation and cytotoxicity of QDs in CSCs.Methods: Accumulation and cytotoxicity of CdTe-MPA (mercaptopropionic acid QDs in CSCs were assessed using flow cytometry and fluorescence-activated cell sorting techniques as well as a colorimetric cell viability assay.Results: We investigated the expression of two cell surface-associated glycoproteins, CD44 and CD133, in four different cancer cell lines (glioblastoma, melanoma, pancreatic, and prostate adenocarcinoma. Only the melanoma cells were positive to both markers of CD44 and CD133, whereas the other cells were only CD44-positive. The QDs accumulated to a similar extent in all subpopulations of the melanoma cells. The phenotypical response after QD treatment was compared with the response after ionizing radiation treatment. The percentage of the CD44high-CD133high subpopulation decreased from 72% to 55%–58% for both treatments. The stem-like subpopulation CD44highCD133low/- increased from 26%–28% in the untreated melanoma cells to 36%–40% for both treatments.Conclusion: Treatment of melanoma cells with QDs results in an increase of stem-like cell subpopulations. The changes in phenotype distribution of the melanoma cells after

  4. Dynamic Characteristics of Serum Hepatitis B Surface Antigen in Chinese Chronic Hepatitis B Patients Receiving 7 Years of Entecavir Therapy

    Institute of Scientific and Technical Information of China (English)

    Xia-Xia Zhang; Min-Ran Li; Hong-Li Xi; Ying Cao; Ren-Wen Zhang; Yu Zhang; Xiao-Yuan Xu

    2016-01-01

    Background:The ultimate goal of hepatitis B treatment is hepatitis B surface antigen (HBsAg) seroclearance.Several factors have been suggested to be associated with the rate of HBsAg reduction in antiviral-naive or lamivudine therapy cohorts.However,there are few studies evaluating the factors during long-term entecavir (ETV) therapy.In the present study,we aimed to evaluate the factors to predict the outcome of ETV therapy for 7 years.Methods:A total of 47 chronic hepatitis B (CHB) patients treated with ETV monotherapy were included in this study.Liver biochemistry,hepatitis B virus (HBV) serological markers,serum HBV DNA,and HBsAg titers were tested at baseline,3 months,6 months,and yearly from 1 to 7.The associations between factors and HBsAg reduction were assessed using multivariate tests with repeated measure analysis of variance.Results:At baseline,serum HBsAg levels showed a positive correlation with baseline HBV DNA levels (r =0.625,P < 0.001).The mean HBsAg titers after ETV treatment were significantly lower than the baseline titers (P ranges from 0.025 to 0.000,000,6).The HBsAg reduction rate during the 1st year was greater compared to after 1 year of treatment (P < 0.05).Multivariate test showed that hepatitis B e antigen (HBeAg) seroclearance and/or HBsAg reduction ≥0.5 log10 IU/ml at 6 months had a high negative predictive value (96.77%) for HBsAg seroclearance (P =0.002,P =0.012,respectively).Conclusions:The HBsAg reduction rate during the 1st year was greater than that after 1 year of treatment.Further,HBeAg status and HBsAg levels at month 6 are the optimal factors for the early prediction of HBsAg seroclearance after long-term ETV therapy in CHB patients.

  5. In vitro evaluation of a soluble Leishmania promastigote surface antigen as a potential vaccine candidate against human leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Rym Chamakh-Ayari

    Full Text Available PSA (Promastigote Surface Antigen belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L. species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm or L. braziliensis (CCLb or visceral leishmaniasis due to L. donovani (CVLd and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection or non immune/naive individuals (HLR: Healthy Low Responders, depending on whether they produce high or low levels of IFN-γ in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-γ, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-α in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-γ after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-γ-producing CD4+ T cells and the released IFN-γ. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection.

  6. Complete hepatitis B virus prophylaxis withdrawal in hepatitis B surface antigen-positive liver transplant recipients after longterm minimal immunosuppression.

    Science.gov (United States)

    Lenci, Ilaria; Baiocchi, Leonardo; Tariciotti, Laura; Di Paolo, Daniele; Milana, Martina; Santopaolo, Francesco; Manzia, Tommaso Maria; Toti, Luca; Svicher, Valentina; Tisone, Giuseppe; Perno, Carlo Federico; Angelico, Mario

    2016-09-01

    Tailored approaches have been attempted to prevent hepatitis B virus (HBV) reinfection in antibodies against hepatitis B surface antigen (HBsAg)-positive liver transplantation (LT) recipients in order to minimize the use of hepatitis B immune globulin (HBIG) and nucleoside analogues (NAs). We report the results of complete HBV prophylaxis withdrawal after a follow-up of at least 6 years in LT recipients with undetectable serum HBV DNA and intrahepatic total HBV DNA and covalently closed circular DNA at LT. We included 30 HBsAg positive, hepatitis B e antigen-negative recipients, 6 with hepatitis C virus and 7 with hepatitis D virus coinfection, who had received HBIG plus NA for at least 5 years after LT. Stepwise HBIG and NA withdrawal was performed in two 6-month periods under strict monitoring of HBV virology. All patients underwent a clinical, biochemical, and virological follow-up at 3-6 month intervals. HBV recurrence (HBsAg seroreversion ± detectable HBV DNA) occurred in 6 patients: in 1 patient after HBIG interruption and in 5 after both HBIG and NA cessation. Only 3 patients required reinstitution of HBV prophylaxis because of persistent HBV replication, and all achieved optimal control of HBV infection and did not experience clinical events. The other who recurred showed only short-lasting HBsAg positivity, with undetectable HBV DNA, followed by spontaneous anti-HBs seroconversion. An additional 15 patients mounted an anti-HBs titer, without previous serum HBsAg detectability. At the end of follow-up, 90% of patients were still prophylaxis-free, 93.3% were HBsAg negative, and 100% were HBV DNA negative; 60% had anti-HBs titers >10 IU/L (median, 143; range, 13-1000). This small series shows that complete prophylaxis withdrawal is safe in patients transplanted for HBV-related disease at low risk of recurrence and is often followed by spontaneous anti-HBs seroconversion. Further studies are needed to confirm this finding. Liver Transplantation 22 1205

  7. Development of a highly sensitive bioluminescent enzyme immunoassay for hepatitis B virus surface antigen capable of detecting divergent mutants.

    Science.gov (United States)

    Minekawa, Takayuki; Takehara, Shizuka; Takahashi, Masaharu; Okamoto, Hiroaki

    2013-08-01

    Hepatitis B virus (HBV) infections are sometimes overlooked when using commercial kits to measure hepatitis B virus surface antigen (HBsAg) due to their low sensitivities and reactivities to mutant strains of various genotypes. We developed an ultrasensitive bioluminescent enzyme immunoassay (BLEIA) for HBsAg using firefly luciferase, which is adaptable to a variety of HBsAg mutants, by combining four monoclonal antibodies with a polyclonal antibody against HBsAg. The measurement of seroconversion panels showed trace amounts of HBsAg during the early infection phase by the BLEIA because of its high sensitivity of 5 mIU/ml. The BLEIA detected HBsAg as early as did PCR in five of seven series and from 2.1 to 9.4 days earlier than commercial immunoassay methods. During the late infection phase, the BLEIA successfully detected HBsAg even 40 days after the disappearance of HBV DNA and the emergence of antibodies against HBsAg. The HBsAg BLEIA successfully detected all 13 recombinant HBsAg and 45 types of HBsAg mutants with various mutations within amino acids 90 to 164 in the S gene product. Some specimens had higher values determined by the BLEIA than those by a commercial chemiluminescent immunoassay; this suggests that such discrepancies were caused by the dissociation of preS1/preS2 peptides from the particle surface. With its highly sensitive detection of low-titer HBsAg, including various mutants, the HBsAg BLEIA is considered to be useful for the early diagnosis and prevention of HBV infection because of the shorter window of infection prior to detection, which facilitates early prediction of recurrence in HBV-infected individuals. PMID:23761660

  8. Limited polymorphism in Plasmodium falciparum ookinete surface antigen, von Willebrand factor A domain-related protein from clinical isolates

    Directory of Open Access Journals (Sweden)

    Eisen Damon P

    2006-07-01

    Full Text Available Abstract Background As malaria becomes increasingly drug resistant and more costly to treat, there is increasing urgency to develop effective vaccines. In comparison to other stages of the malaria lifecycle, sexual stage antigens are under less immune selection pressure and hence are likely to have limited antigenic diversity. Methods Clinical isolates from a wide range of geographical regions were collected. Direct sequencing of PCR products was then used to determine the extent of polymorphisms for the novel Plasmodium falciparum sexual stage antigen von Willebrand Factor A domain-related Protein (PfWARP. These isolates were also used to confirm the extent of diversity of sexual stage antigen Pfs28. Results PfWARP was shown to have non-synonymous substitutions at 3 positions and Pfs28 was confirmed to have a single non-synonymous substitution as previously described. Conclusion This study demonstrates the limited antigenic diversity of two prospective P. falciparum sexual stage antigens, PfWARP and Pfs28. This provides further encouragement for the proceeding with vaccine trials based on these antigens.

  9. Temporal differences in the activation of three classes of non-transmembrane protein tyrosine kinases following B-cell antigen receptor surface engagement.

    Science.gov (United States)

    Saouaf, S J; Mahajan, S; Rowley, R B; Kut, S A; Fargnoli, J; Burkhardt, A L; Tsukada, S; Witte, O N; Bolen, J B

    1994-09-27

    We evaluated in WEHI 231 B cells the time-dependent responses of Lyn, Blk, Btk, Syk, and three members of the Jak family of protein tyrosine kinases following antibody-mediated surface engagement of the B-cell antigen receptor. Our results show that the enzyme activities of Lyn and Blk were stimulated within seconds of antigen receptor engagement and correlated with the initial tyrosine phosphorylation of the Ig alpha and Ig beta subunits of the B-cell antigen receptor. Btk enzyme activity was also transiently stimulated and was maximal at approximately 5 min after B-cell receptor surface binding. Syk activity gradually increased to a maximum at 10-30 min following receptor ligation and was found to parallel the association of Syk with the tyrosine phosphorylated Ig alpha and Ig beta subunits of the receptor. While the specific activities of the Jak1, Jak2, and Tyk2 protein tyrosine kinases were unaltered following B-cell receptor ligation, the abundance of Jak1 and Jak2 were increased 3- to 4-fold within 10 min of receptor engagement. These results demonstrate that multiple families of non-transmembrane protein tyrosine kinases are temporally regulated during the process of B-cell antigen receptor-initiated intracellular signal transduction. PMID:7524079

  10. Stem Cell Physics. Laser Manipulation of Blood Types: Laser-Stripping-Away of Red Blood Cell Surface Antigens

    Science.gov (United States)

    Stefan, V. Alexander

    2014-03-01

    A novel mechanism of importance for the transfusion medicine[2] is proposed. The interaction of ultrashort wavelength multilaser beams with the flowing blood thin films can lead to a conversion of blood types A, B, and AB into O type.[3] The stripping away of antigens is done by the scanning-multiple-lasers of a high repetition rate in the blue-purple frequency domain. The guiding-lasers are in the red-green frequency domain. The laser force, (parametric interaction with the antigen eigen-oscillation),[4] upon the antigen protein molecule must exceed its weight. Supported by Nikola Tesla Labs, La Jolla, CA.

  11. Interferon-alpha-induced changes in surface antigens in a hairy-cell leukemia (JOK-1), and a Burkitt's lymphoma cell line (Daudi) during in vitro culture

    DEFF Research Database (Denmark)

    Nielsen, B; Madsen, P S; Jensen, A W;

    1992-01-01

    In further studying the mechanism of action of IFN-alpha in HCL, we cultured the HCL cell line JOK-1 and the IFN-sensitive Burkitt cell line Daudi with and without IFN-alpha and investigated the changes in density of a number of surface antigens by use of mAb and flow cytometry analyses. During...... culture with IFN-alpha, reproducible changes were induced in both cell lines, which were qualitatively similar but differed quantitatively with small and transient changes in JOK-1. Significant decreases in surface antigen expression were observed for CD 19, 23, 37, and for IgM on both cell lines...... was probably directly related to the mechanism of action of IFN-alpha, whereas the other changes were most consistent with an unspecific inhibition of protein synthesis, possibly due to an accumulation of cells in G0, even though a differentiating effect cannot be ruled out. Thus, the unique in vivo effect...

  12. Study of Admission Rate of Hepatitis B Surface Antigen Positive Patients in 50 Dentistry Centers in Tehran (Spring 2003

    Directory of Open Access Journals (Sweden)

    Seyed Moayed Alavian

    2008-02-01

    Full Text Available Background and Aims: Hepatitis B is one of the common diseases in the world and in Iran, caused by hepatitis B virus (HBV. This virus is transmitted by various ways including dentistry procedures and this may discourage dentists to admit hepatitis B surface antigen (HBsAg positive patients leading to hide the disease by the patients and increased transmission risk. Methods: During a cross-sectional descriptive study, 50 dentistry centers were chosen among dentistry centers of Tehran in various regions by cluster sampling. Two HBsAg positive medical students went to these centers and announced about their diseases and requested for dentistry. Samples (dentists and secretaries did not have any information about the research. They studied and examined reaction of dentists and their secretaries as well as admission rate.Results: Among 50 centers, 16 did not admit patients (5 cases by secretary and 11 cases by dentist and 16 centers admitted them as the last patient (last appointment and totally 32 cases met unfriendly. Among different regions of Tehran, the highest rate of non-admission was observed in the south (60% and the lowest rate in the north (P<0.01. Charity centers and private centers had the most and the least non-admission rate, respectively, and the difference was significant (P<0.01. There were 16 non-admission cases among general dentists but there was not any rejection in specialists.Conclusions: The higher rate of non-admission and unfriendly behavior in southern district of Tehran and military and charity centers may be related to the lack of awareness and proper communication between patient and dentist. It highlights the necessity of more educational workshop to promote dentists knowledge about HBV, encourage them to use disposable tools for the patients, more accurate supervision on centers by the ministry of health and finally to assume all patients as HBsAg positive.

  13. Sero-survey of Hepatitis B surface antigen amongst pregnant women attending Infectious Disease Hospital Bayara, Bauchi State, Nigeria

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    James A. Ndako

    2012-04-01

    Full Text Available Hepatitis B virus (HBV continues to cause serious health problems in developing countries. Neonatal infection with HBV, which is often acquired during delivery, carries a high risk resulting in persistent infection. This research aims to detect the prevalence of Hepatitis B surface Antigen (HBsAg among pregnant women in our location of study. One hundred and eighty (180 sera samples were screened among pregnant women aged 13-49, using standard enzyme-linked immunosorbent assay (ELISA method. Structured questionnaire were administered to the subjects to obtain demographic and other relevant data. Overall result showed that 31 (17.2% were found to be positive for HBsAg among the total subjects screened. The highest prevalence was found among those aged 20-29 with 11 (6.1% seropositivity (x2=7.902; P=0.048. Considering occupational distribution of volunteer subjects, a high prevalence of 12 (6.7%; P<0.05 was recorded among house wives, which shows a measure of significance compared to other women screened. Furthermore, based on various risk factors subjects with history of surgery and use of unsterilized sharp instruments recorded 15 (8.3% prevalence (P=0.233; P>0.05. How ever, women in their second trimester of pregnancy recorded a higher prevalence of 23 (12.8%:(P=0.080; P<0.05. This study therefore emphasizes the public health importance of HBV among pregnant women and equally suggests that children born to women with Hepatitis B Virus, be closely monitored for infection beyond the one and the half years of age, this also calls for a proper enlightenment on the dangers posed by the virus, while a well designed vaccination schedule is advocated among the general population.

  14. Vasopressin mRNA and neurophysin-related cell-surface antigen (NRSA) in small-cell carcinoma.

    Science.gov (United States)

    North, W G; Yu, X M

    1993-01-01

    Production by small-cell carcinoma (SCCL) of neurophysins (HNPs) and neurophysin-related cell-surface antigen (NRSA) was examined for two cell lines, for mouse xenografts, and for a resected human tumor, using polyclonal and monoclonal antibodies to vasopressin-associated human neurophysin (VP-HNP) and polyclonal antibodies to vasopressin (VP). The nature of the mRNA responsible for giving rise to these neurophysin-related products was investigated by performing Northern analysis on preparations of poly A+RNA and cDNA probes complimentary to portions of the exon A, exon B, and exon C regions of the human VP gene. SDS-electrophoresis and Western analysis revealed two prominent proteins of 42,000 and 20,000 Da in acid extracts from all SCCL sources when the monoclonal anti-HNP or one of the two polyclonal anti-HNP preparations were used. These antibodies also disclosed the presence of a minor component of 10,000 Da. A second polyclonal anti-HNP preparation reacted with one prominent protein of 30,000 Da and, for one cell line and mouse xenografts, another protein of 32,000 Da. Both of two anti-VP preparations reacted with proteins of 42,000, 30,000, 25,000, and 20,000 Da in extracts from all SCCL source material. The immunoreactive proteins of 42,000, 30,000, and 20,000 Da were all components of a membrane fraction from SCCL cells and tissues. In Northern analysis, a single RNA of about 900 bases hybridized with exon A and exon B probes, but not with the cDNA probe complimentary to exon C of the VP gene.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8387189

  15. Impaired cell surface expression of HLA-B antigens on mesenchymal stem cells and muscle cell progenitors.

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    Adiba Isa

    Full Text Available HLA class-I expression is weak in embryonic stem cells but increases rapidly during lineage progression. It is unknown whether all three classical HLA class-I antigens follow the same developmental program. In the present study, we investigated allele-specific expression of HLA-A, -B, and -C at the mRNA and protein levels on human mesenchymal stem cells from bone marrow and adipose tissue as well as striated muscle satellite cells and lymphocytes. Using multicolour flow cytometry, we found high cell surface expression of HLA-A on all stem cells and PBMC examined. Surprisingly, HLA-B was either undetectable or very weakly expressed on all stem cells protecting them from complement-dependent cytotoxicity (CDC using relevant human anti-B and anti-Cw sera. IFNgamma stimulation for 48-72 h was required to induce full HLA-B protein expression. Quantitative real-time RT-PCR showed that IFNgamma induced a 9-42 fold increase of all six HLA-A,-B,-C gene transcripts. Interestingly, prior to stimulation, gene transcripts for all but two alleles were present in similar amounts suggesting that post-transcriptional mechanisms regulate the constitutive expression of HLA-A,-B, and -C. Locus-restricted expression of HLA-A, -B and -C challenges our current understanding of the function of these molecules as regulators of CD8(+ T-cell and NK-cell function and should lead to further inquiries into their expression on other cell types.

  16. Prevalence of hepatitis B surface antigen seropositivity among HIV-infected and non-infected individuals in Nnewi, Nigeria

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    E C Okocha

    2012-01-01

    Full Text Available Background: Co-infection of human immunodeficiency virus (HIV and hepatitis B virus (HBV is common as both viruses share common routes of transmission. HIV significantly affects the natural history of HBV, hence the need to determine the prevalence of co-infection. Materials and Methods: This was a retrospective study between 2005 and 2009, in which is a total of 2018 subjects who reported at our University Teaching Hospital blood bank and human immunodeficiency virus clinic were studied. Hepatitis B surface antigen (HBsAg was tested for using a one step lateral flow rapid chromatographic immunoassay (Acumen labs and diagnostic centre, Bangalore, India and HIV 1/2 was tested using two kits, Determine (made by Abbot, Japan for Inverness Medical, Japan. Results: A total of 2018 subjects were studied out of which 1176 were HIV positive (964 males and 212 females and 842 (334 males and 508 females were negative. The prevalence of HBsAg positivity in the study population was 5.9%. It was 6.3% and 5.6% in the HIV-infected and un-infected population, respectively. Although the prevalence was higher in those who are HIV infected, the difference was not statistically significant ( P=0.52. Males who were HIV positive were found to be more likely to have co-infection than females (8.7% vs. 4.2%, P=0.02, OR=1.917. Conclusion: This study showed that in south-eastern Nigeria, infection with HBV is relatively common in both HIV-infected and un-infected individuals. Routine screening for HBV should be done for all HIV positive individuals.

  17. Cycling and Tai Chi Chuan exercises exert greater immunomodulatory effect on surface antigen expression of human hepatitis B virus

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-yawn; CHIANG Jasson; CHEN Yu-jen; CHEN Kung-tung; YANG Rong-sen; LIN Jaung-geng

    2008-01-01

    Background Both athletes with intensive exercise and aged people may have weakened immunity against virus infection.This study aimed to evaluate whether people undergoing aerobic exercises including competitive cyctists with moderate training (CMT) and middle-aged people practicing Tai Chi Chuan (TCC) exercise have higher immunity against hepatitis B virus than age-matched sedentary controls including college students (CSC) and middle-aged people (MSC).Methods Human peripheral blood mononuclear cells from competitive cyclists and sedentary controls were stimulated by phytohemagglutinin (PHA) to prepare conditioned medium (MNC-CM) for the assessment of inhibitory effects on hepatitis B surface antigen (HBsAg) expression in human hepatoma Hep3B cells.Results The inhibitory effects on the relative HBsAg expression of CMT's and TCC's MNC-CM were greater than those of the controls.The CMT's MNC-CM prepared from 5 pg/ml PHA decreased HBsAg expression to 61.5%,whereas that of CSC remained at 83.8%.Similarly,this expression by treatment of TCC group' MNC-CM was 68.4% whereas that of MSC group was 84.3%.The levels of cytokines such as interferon-y (IFN-y),tumor necrosis factor-a (TNF-α),IFN-α and interleukin-1β(1L-1β) in the MNC-CM from the CMT and TCC groups were greater than those in the controls.Antibody neutralization of CMT's MNC-CM and addition of recombinant cytokines into CSC's MNC-CM indicated that IFN-y,TNF-α and IFN-α had synergistic effects against HBsAg expression.Similar blocking effect was noted in TCC versus MSC groups.Conclusion These results suggest that the immunomodulatory response to suppress HBsAg expression in CMT and TCC with moderate aerobic exercise is greater than that in age-matched sedentary controls.

  18. Expression of transforming growth factor-α and hepatitis B surface antigen in human hepatocellular carcinoma tissues and its significance

    Institute of Scientific and Technical Information of China (English)

    Jing Zhang; Wen-Liang Wang; Qing Li; Qing Qiao

    2004-01-01

    AIM: To evaluate the expression of transforming growth factor-alpha (TGF-α) and hepatitis B surface antigen (HBsAg) in human hepatocellular carcinoma (HCC) tissues and its significance. METHODS: Seventy specimens of HCC tissues were detected by immunohistochemical method. Five specimens of normal human liver tissues were used as control. RESULTS: The TGF-α positive expression rates in HCC and its surrounding tissues were 74.3%(52/70) and 88. t%(52/59), respectively. TGF-α positive granules were mainly in the cytoplasm and fewer existed on the karyotheca. The TGF-α positive expressing rate in well differentiated HCC was significantly higher than that in moderately and poorly differentiated HCC (P<0.05). The TGF-α positive expression also was observed in intrahepatic bile ducts (part of those were hyperplastic ducts). The HBsAg positive expression rates in HCC and its surrounding tissues were 21.4%(15/70) and 79.7%(47/59), respectively. HBsAg positive granules were in the cytoplasm, inclusion and on the karyotheca. There was a prominent positive correlation between TGF-α and HBsAg expression in HCC surrounding tissues (P<0.05, γ=0.34). TGF-α was usually existed with HBsAg in regenerated and/or dysplastic liver cells. In the five normal liver tissues, TGF-α and HBsAg were not detectable in hepatocytes and bile ducts.CONCLUSION: Hepatitis B virus infection is closely related with hepatocarcinogenesis. The overexpression of TGF-α in the liver seems to be associated with the regeneration of hepatocytes injured by HBsAg. The continued expression of TGF-α might lead to dysplasia of liver cells and development of HCC. Furthermore, TGF-α might play a role in morphogenesis and regeneration of intrahepatic bile ducts.

  19. Purification of hepatitis B surface antigen virus-like particles from recombinant Pichia pastoris and in vivo analysis of their immunogenic properties.

    OpenAIRE

    Gurramkonda, Chandrasekhar; Zahid, Maria; Nemani, Satish Kumar; Adnan, Ahmad; Gudi, Satheesh Kumar; Khanna, Navin; Ebensen, Thomas; Lünsdorf, Heinrich; Guzmán, Carlos A.; Rinas, Ursula

    2013-01-01

    Following earlier studies on high-level intracellular production of hepatitis B surface antigen (HBsAg) using recombinant Pichia pastoris, we present here in detail an enhanced method for the purification of recombinant HBsAg virus-like particles (VLPs). We have screened various detergents for their ability to promote the solubilization of recombinant intracellular HBsAg. In addition, we have analyzed the effect of cell disruption and extraction regarding their impact on the release of HBsAg....

  20. Immunogenicity of Leishmania-derived hepatitis B small surface antigen particles exposing highly conserved E2 epitope of hepatitis C virus

    OpenAIRE

    Czarnota, Anna; Tyborowska, Jolanta; Peszyńska-Sularz, Grażyna; Gromadzka, Beata; Bieńkowska-Szewczyk, Krystyna; Grzyb, Katarzyna

    2016-01-01

    Background Hepatitis C virus (HCV) infection is a major health problem worldwide, affecting an estimated 2–3 % of human population. An HCV vaccine, however, remains unavailable. High viral diversity poses a challenge in developing a vaccine capable of eliciting a broad neutralizing antibody response against all HCV genotypes. The small surface antigen (sHBsAg) of hepatitis B virus (HBV) has the ability to form highly immunogenic subviral particles which are currently used as an efficient anti...

  1. Virus-like particle production with yeast: ultrastructural and immunocytochemical insights into Pichia pastoris producing high levels of the Hepatitis B surface antigen.

    OpenAIRE

    Adnan Ahmad; Gurramkonda Chandrasekhar; Lünsdorf Heinrich; Khanna Navin; Rinas Ursula

    2011-01-01

    Abstract Background A protective immune response against Hepatitis B infection can be obtained through the administration of a single viral polypeptide, the Hepatitis B surface antigen (HBsAg). Thus, the Hepatitis B vaccine is generated through the utilization of recombinant DNA technology, preferentially by using yeast-based expression systems. However, the polypeptide needs to assemble into spherical particles, so-called virus-like particles (VLPs), to elicit the required protective immune ...

  2. Trend of Hepatitis B Surface Antigen (HBsAg) among blood donors at the blood bank of a tertiary care referral teaching hospital in Southern India

    OpenAIRE

    Yashovardhan A.; Sreedhar Babu K.V.; Jothi Bai D.S.

    2015-01-01

    Background: Blood is a scarce, but lifesaving resource; it is also the most efficient vehicle for the transmission of Hepatitis B virus (HBV). Hence there is a need for accurate screening of hepatitis B surface antigen (HBsAg) among blood donors. The present study was designed to assess the seroprevalence of HBsAg, among the voluntary and replacement blood donors in the blood bank of a tertiary care referral teaching hospital in Andhra Pradesh. Methods: This is a prospective cross sectiona...

  3. Comprehensive Analysis and Characterization of Linear Antigenic Domains on HN Protein from Genotype VII Newcastle Disease Virus Using Yeast Surface Display System.

    Science.gov (United States)

    Li, Tao; Wang, Gaoling; Shi, Bingtian; Liu, Peixin; Si, Wei; Wang, Bin; Jiang, Li; Zhou, Lunjiang; Xiu, Jinsheng; Liu, Henggui

    2015-01-01

    Circulation of genotype VII Newcastle disease virus (NDV) has posed a great threat for the poultry industry worldwide. Antibodies against Hemagglutinin-neuraminidase (HN), a membrane protein of NDV with critical roles in NDV infection, have been reported to provide chickens protection from NDV infection. In this study, we comprehensively analyzed the in vivo antibody responses against the linear antigenic domains of the HN protein from genotype VII NDV using a yeast surface display system. The results revealed four distinct regions of HN, P1 (1-52aa), P2 (53-192aa), P3 (193-302aa) and P4 (303-571aa), respectively, according to their antigenic potency. Analysis by FACS and ELISA assay indicated P2 to be the dominant linear antigenic domain, with the immunogenic potency to protect the majority of chickens from NDV challenge. In contrast, the P1, P3 and P4 domains showed weak antigenicity in vivo and could not protect chickens from NDV challenge. These results provide important insight into the characteristic of humoral immune responses elicited by HN of NDV in vivo.

  4. Comprehensive Analysis and Characterization of Linear Antigenic Domains on HN Protein from Genotype VII Newcastle Disease Virus Using Yeast Surface Display System.

    Science.gov (United States)

    Li, Tao; Wang, Gaoling; Shi, Bingtian; Liu, Peixin; Si, Wei; Wang, Bin; Jiang, Li; Zhou, Lunjiang; Xiu, Jinsheng; Liu, Henggui

    2015-01-01

    Circulation of genotype VII Newcastle disease virus (NDV) has posed a great threat for the poultry industry worldwide. Antibodies against Hemagglutinin-neuraminidase (HN), a membrane protein of NDV with critical roles in NDV infection, have been reported to provide chickens protection from NDV infection. In this study, we comprehensively analyzed the in vivo antibody responses against the linear antigenic domains of the HN protein from genotype VII NDV using a yeast surface display system. The results revealed four distinct regions of HN, P1 (1-52aa), P2 (53-192aa), P3 (193-302aa) and P4 (303-571aa), respectively, according to their antigenic potency. Analysis by FACS and ELISA assay indicated P2 to be the dominant linear antigenic domain, with the immunogenic potency to protect the majority of chickens from NDV challenge. In contrast, the P1, P3 and P4 domains showed weak antigenicity in vivo and could not protect chickens from NDV challenge. These results provide important insight into the characteristic of humoral immune responses elicited by HN of NDV in vivo. PMID:26121247

  5. Comprehensive Analysis and Characterization of Linear Antigenic Domains on HN Protein from Genotype VII Newcastle Disease Virus Using Yeast Surface Display System.

    Directory of Open Access Journals (Sweden)

    Tao Li

    Full Text Available Circulation of genotype VII Newcastle disease virus (NDV has posed a great threat for the poultry industry worldwide. Antibodies against Hemagglutinin-neuraminidase (HN, a membrane protein of NDV with critical roles in NDV infection, have been reported to provide chickens protection from NDV infection. In this study, we comprehensively analyzed the in vivo antibody responses against the linear antigenic domains of the HN protein from genotype VII NDV using a yeast surface display system. The results revealed four distinct regions of HN, P1 (1-52aa, P2 (53-192aa, P3 (193-302aa and P4 (303-571aa, respectively, according to their antigenic potency. Analysis by FACS and ELISA assay indicated P2 to be the dominant linear antigenic domain, with the immunogenic potency to protect the majority of chickens from NDV challenge. In contrast, the P1, P3 and P4 domains showed weak antigenicity in vivo and could not protect chickens from NDV challenge. These results provide important insight into the characteristic of humoral immune responses elicited by HN of NDV in vivo.

  6. An Extended Surface Loop on Toxoplasma gondii Apical Membrane Antigen 1 (AMA1 Governs Ligand Binding Selectivity.

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    Michelle L Parker

    Full Text Available Apicomplexan parasites are the causative agents of globally prevalent diseases including malaria and toxoplasmosis. These obligate intracellular pathogens have evolved a sophisticated host cell invasion strategy that relies on a parasite-host cell junction anchored by interactions between apical membrane antigens (AMAs on the parasite surface and rhoptry neck 2 (RON2 proteins discharged from the parasite and embedded in the host cell membrane. Key to formation of the AMA1-RON2 complex is displacement of an extended surface loop on AMA1 called the DII loop. While conformational flexibility of the DII loop is required to expose the mature RON2 binding groove, a definitive role of this substructure has not been elucidated. To establish a role of the DII loop in Toxoplasma gondii AMA1, we engineered a form of the protein where the mobile portion of the loop was replaced with a short Gly-Ser linker (TgAMA1ΔDIIloop. Isothermal titration calorimetry measurements with a panel of RON2 peptides revealed an influential role for the DII loop in governing selectivity. Most notably, an Eimeria tenella RON2 (EtRON2 peptide that showed only weak binding to TgAMA1 bound with high affinity to TgAMA1ΔDIIloop. To define the molecular basis for the differential binding, we determined the crystal structure of TgAMA1ΔDIIloop in complex with the EtRON2 peptide. When analyzed in the context of existing AMA1-RON2 structures, spatially distinct anchor points in the AMA1 groove were identified that, when engaged, appear to provide the necessary traction to outcompete the DII loop. Collectively, these data support a model where the AMA1 DII loop serves as a structural gatekeeper to selectively filter out ligands otherwise capable of binding with high affinity in the AMA1 apical groove. These data also highlight the importance of considering the functional implications of the DII loop in the ongoing development of therapeutic intervention strategies targeting the AMA1-RON

  7. Negative staining and immunoelectron microscopy of adhesion-deficient mutants of Streptococcus salivarius reveal that the adhesive protein antigens are separate classes of cell surface fibril.

    Science.gov (United States)

    Weerkamp, A H; Handley, P S; Baars, A; Slot, J W

    1986-01-01

    The subcellular distribution of the cell wall-associated protein antigens of Streptococcus salivarius HB, which are involved in specific adhesive properties of the cells, was studied. Mutants which had lost the adhesive properties and lacked the antigens at the cell surface were compared with the parent strain. Immunoelectron microscopy of cryosections of cells labeled with affinity-purified, specific antisera and colloidal gold-protein A complexes was used to locate the antigens. Antigen C (AgC), a glycoprotein involved in attachment to host surfaces, was mainly located in the fibrillar layer outside the cell wall. A smaller amount of label was also found throughout the cytoplasmic area in the form of small clusters of gold particles, which suggests a macromolecular association. Mutant HB-7, which lacks the wall-associated AgC, accumulated AgC reactivity intracellularly. Intracellular AgC was often found associated with isolated areas of increased electron density, but sometimes seemed to fill the entire interior of the cell. Antigen B (AgB), a protein responsible for interbacterial coaggregation, was also located in the fibrillar layer, although its distribution differed from that of the wall-associated AgC since AgB was found predominantly in the peripheral areas. A very small amount of label was also found in the cytoplasmic area as discrete gold particles. Mutant HB-V5, which lacks wall-associated AgB, was not labeled in the fibrillar coat, but showed the same weak intracellular label as the parent strain. Immunolabeling with serum against AgD, another wall-associated protein but of unknown function, demonstrated its presence in the fibrillar layer of strain HB. Negatively stained preparations of whole cells of wild-type S. salivarius and mutants that had lost wall-associated AgB or AgC revealed that two classes of short fibrils are carried on the cell surface at the same time. AgB and AgC are probably located on separate classes of short, protease

  8. Differential presentation of endogenous and exogenous hepatitis B surface antigens influences priming of CD8(+) T cells in an epitope-specific manner.

    Science.gov (United States)

    Riedl, Petra; Reiser, Michael; Stifter, Katja; Krieger, Jana; Schirmbeck, Reinhold

    2014-07-01

    Little is known about whether presentation of endogenous and exogenous hepatitis B virus (HBV) surface antigens on APCs targeted by vaccination and/or virus-harboring hepatocytes influences de novo priming of CD8(+) T cells. We showed that surface antigen-expressing transfectants exclusively display a K(b) /S190 epitope, whereas cells pulsed with recombinant surface particles (rSPs) exclusively present a K(b) /S208 epitope to CD8(+) T cells. The differential presentation of these epitopes largely reflects the selective, but not exclusive, priming of K(b) /S190- and K(b) /S208-specific T cells in C57BL/6 mice by endogenous/DNA- or exogenous/protein-based vaccines, respectively. Silencing the K(b) /S190 epitope (K(b) /S190V194F ) in antigen-expressing vectors rescued the presentation of the K(b) /S208 epitope in stable transfectants and significantly enhanced priming of K(b) /S208-specific T cells in C57BL/6 mice. A K(b) /S190-mediated immunodominance operating in surface antigen-expressing cells, but not in rSP-pulsed cells, led to an efficient suppression in the presentation of the K(b) /S208 epitope and a consequent decrease in the priming of K(b) /S208-specific T cells. This K(b) /S190-mediated immunodominance also operated in 1.4HBV-S(mut) transgenic (tg) hepatocytes selectively expressing endogenous surface antigens and allowed priming of K(b) /S208- but not K(b) /S190-specific T cells in 1.4HBV-S(mut) tg mice. However, IFN-γ(+) K(b) /S208-specific T cells could not inhibit HBV replication in the liver of 1.4HBV-S(mut) tg mice. These results have practical implications for the design of T-cell-stimulating therapeutic vaccines. PMID:24723392

  9. Identification of ATP synthase beta subunit (ATPB on the cell surface as a non-small cell lung cancer (NSCLC associated antigen

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    Qian Zhi

    2009-01-01

    Full Text Available Abstract Background Antibody-based immuneotherapy has achieved some success for cancer. But the main problem is that only a few tumor-associated antigens or therapeutic targets have been known to us so far. It is essential to identify more immunogenic antigens (especially cellular membrane markers for tumor diagnosis and therapy. Methods The membrane proteins of lung adenocarcinoma cell line A549 were used to immunize the BALB/c mice. A monoclonal antibody 4E7 (McAb4E7 was produced with hybridoma technique. MTT cell proliferation assay was carried out to evaluate the inhibitory effect of McAb4E7 on A549 cells. Flow cytometric assay, immunohistochemistry, western blot and proteomic technologies based on 2-DE and mass spectrometry were employed to detect and identify the corresponding antigen of McAb4E7. Results The monoclonal antibody 4E7 (McAb4E7 specific against A549 cells was produced, which exhibited inhibitory effect on the proliferation of A549 cells. By the proteomic technologies, we identified that ATP synthase beta subunit (ATPB was the corresponding antigen of McAb4E7. Then, flow cytometric analysis demonstrated the localization of the targeting antigen of McAb4E7 was on the A549 cells surface. Furthermore, immunohistochemstry showed that the antigen of McAb4E7 mainly aberrantly expressed in tumor cellular membrane in non-small cell lung cancer (NSCLC, but not in small cell lung cancer (SCLC. The rate of ectopic expressed ATPB in the cellular membrane in lung adenocarcinoma, squamous carcinoma and their adjacent nontumourous lung tissues was 71.88%, 66.67% and 25.81% respectively. Conclusion In the present study, we identified that the ectopic ATPB in tumor cellular membrane was the non-small cell lung cancer (NSCLC associated antigen. ATPB may be a potential biomarker and therapeutic target for the immunotherapy of NSCLC.

  10. Uric acid enhances T cell immune responses to hepatitis B surface antigen-pulsed-dendritic cells in mice

    Institute of Scientific and Technical Information of China (English)

    Xiao-Jun Ma; De-Ying Tian; Dong Xu; Dao-Feng Yang; Hui-Fen Zhu; Zhi-Hui Liang; Zheng-Gang Zhang

    2007-01-01

    AIM:To study the induction of T cellular immune responses in BALB/c mice immunized with uric acid and dendritic cells(DCs)pulsed with hepatitis B virus surface antigen(HBsAg).METHODS:DCs were generated from bone-marrow cells of BABL/c mice,and then pulsed or unpulsed with HBsAg protein(HBsAg-pulsed-DCs or unpulsed-DCs)in vitro.BABL/c mice were immunized with HBsAg-pulsed-DCs(1×106)and uric acid,injected through the tail vein of each mouse.The mice in control groups were immunized with HBsAg-pulsed-DCs alone,unpulsed-DCs alone or 200 μg uric acid alone or PBS alone.The immunization was repeated 7 d later.Cytotoxic T lymphocytes(CTLs)/n vivo were determined by the CFSE labeled spleen lysis assay.Spleen cells or spleen T cells were isolated,and re-stimulated in vitro with HBsAg for 120 h or 72 h.Production of IFN-γ and IL-4 secreted by spleen cells were determined by ELISA method;proliferation of spleen T cells were detected by flow cytometry.RESULTS:The cytotoxicities of HBsAg-specific-CTLs,generated after immunization of HBsAg-pulsed-DCs and uric acid,were 68.63% ± 11.32% and significantly stronger than that in the control groups(P < 0.01).Compared with control groups,in mice treated with uric acid and HBsAg-pulsed-DCs,the spleen T cell proliferation to HBsAg re-stimulation was stronger(1.34 ± 0.093 vs 1.081 ± 0.028,P < 0.01),the level of IFN-γsecreted by splenocytes was higher(266.575 ± 51.323 vs 135.223 ± 32.563,P < 0.01),and IL-4 level was lower(22.385 ± 2.252 vs 40.598 ± 4.218,P < 0.01).CONCLUSION:Uric acid can strongly enhance T cell immune responses induced by HBsAg-pulsed-DCs vaccine.Uric acid may serve as an effective adjuvant of DC vaccine against HBV infection.

  11. Immunochromatographic assay for quantitative and sensitive detection of hepatitis B virus surface antigen using highly luminescent quantum dot-beads.

    Science.gov (United States)

    Shen, Jun; Zhou, Yaofeng; Fu, Fen; Xu, Hengyi; Lv, Jiaofeng; Xiong, Yonghua; Wang, Andrew

    2015-09-01

    Hepatitis B virus infection is one of the major causes of hepatitis, liver cirrhosis and liver cancer. In this study, we used highly luminescent quantum dot-beads (QBs) as signal amplification probes in the sandwich immunochromatographic assay (ICA) for ultrasensitive and quantitative detection of hepatitis B virus surface antigen (HBsAg) in human serum. Various parameters that influenced the sensitivity and stability of the QB-based ICA (QB-ICA) sensor were investigated. Two linear independent regression equations for detection of serum HBsAg were expressed with Y=0.3361X-0.0059 (R(2)=0.9983) for low HBsAg concentrations between 75 pg mL(-1) and 4.8 ng mL(-1), and Y=0.8404 X-2.9364 (R(2)=0.9939) for high HBsAg concentrations in the range from 4.8 ng mL(-1) to 75 ng mL(-1). The detection limit of the proposed ICA sensor achieved was 75 pg mL(-1), which is much higher than that of the routinely-used gold nanoparticle based ICA. The intra- and inter-assays recovery rates for spiked serum samples at HBsAg concentrations of 75 pg mL(-1), 3.75 ng mL(-1) and 18.75 ng mL(-1) ranged from 90.14% to 97.6%, and coefficients of variation were all below 7%, indicating that the QB-ICA sensor has an acceptable accuracy for HBsAg detection. Additionally, the quantitative method developed showed no false positive results in an analysis of 49 real HBsAg-negative serum samples, and exhibited excellent agreement (R(2)=0.9209) with a commercial chemiluminescence immunoassay kit in identifying 47 HBsAg-positive serum samples. In summary, due to its high fluorescence intensity, the sandwich QB-ICA sensor is a very promising point-of-care test for rapid, simple and ultrasensitive detection of HBsAg, as well as other disease-related protein biomarkers. PMID:26003704

  12. Amplification of Surface Antigen P43 Gene and Its Application in Detection of Toxoplasma Gondii in Allogeneic Hematopoietic Stem Cell Transplantation

    Institute of Scientific and Technical Information of China (English)

    ZHOUYongan; YUXinbing; 等

    2002-01-01

    Objective:To establish a rapid,specific and sensitive diagnostic technique for the human Toxoplasma gondii infection in the recipi-ents with allogeneic hematopoietic stem cell transplantation and discuss its clinical significance.Methods:30 patients undergoing allogeneic hematopoietic stem cell transplantation were detected by using ELISA and PCR.Results:Among 30 recipients undergiong allogeneic hematopoietic stem cell transplantation,3 were positive for Toxoplasma gondiii antigen and 5 for surface antigen p43 gene with the positive rate being 13.3% and 16.67% respectively.20 healthy people(negative for anti-Tox antibody)were also tested by using ELISA and PCR.Conclusion:PCR is an accurate,relatively rapid,sensitive and specific method for detecting P43 gene of Toxoplasma gondii.Be-canuse PCR can be applied to a variety of different clinical samples,it can be considered as a valuable additional tool for identification of Toxoplasma gondii infections.

  13. Immunoglobulin G antibodies to merozoite surface antigens are associated with recovery from chloroquine-resistant Plasmodium falciparum in Gambian children.

    NARCIS (Netherlands)

    Pinder, M.; Sutherland, C.J.; Sisay-Joof, F.; Ismaili, J.; McCall, M.B.B.; Ord, R.; Hallett, R.; Holder, A.A.; Milligan, P.

    2006-01-01

    We examined the hypothesis that recovery from uncomplicated malaria in patients carrying drug-resistant Plasmodium falciparum is a measure of acquired functional immunity and may therefore be associated with humoral responses to candidate vaccine antigens. Gambian children with malaria were treated

  14. Phage display used for gene cloning of human recombinant antibody against the erythrocyte surface antigen, rhesus D

    DEFF Research Database (Denmark)

    Dziegiel, M; Nielsen, L K; Andersen, P S;

    1995-01-01

    A novel phage display system has been developed for PCR amplification and cloning of the Fab fragments of human immunoglobulin genes. Using this system, we have cloned an antibody from a mouse-human hybridoma cell line directed against the erythrocyte antigen rhesus D. Intact erythrocytes were used...

  15. The SnSAG merozoite surface antigens of Sarcocystis neurona are expressed differentially during the bradyzoite and sporozoite life cycle stages.

    Science.gov (United States)

    Gautam, A; Dubey, J P; Saville, W J; Howe, D K

    2011-12-29

    Sarcocystis neurona is a two-host coccidian parasite whose complex life cycle progresses through multiple developmental stages differing at morphological and molecular levels. The S. neurona merozoite surface is covered by multiple, related glycosylphosphatidylinositol-linked proteins, which are orthologous to the surface antigen (SAG)/SAG1-related sequence (SRS) gene family of Toxoplasma gondii. Expression of the SAG/SRS proteins in T. gondii and another related parasite Neospora caninum is life-cycle stage specific and seems necessary for parasite transmission and persistence of infection. In the present study, the expression of S. neurona merozoite surface antigens (SnSAGs) was evaluated in the sporozoite and bradyzoite stages. Western blot analysis was used to compare SnSAG expression in merozoites versus sporozoites, while immunocytochemistry was performed to examine expression of the SnSAGs in merozoites versus bradyzoites. These analyses revealed that SnSAG2, SnSAG3 and SnSAG4 are expressed in sporozoites, while SnSAG5 was appeared to be downregulated in this life cycle stage. In S. neurona bradyzoites, it was found that SnSAG2, SnSAG3, SnSAG4 and SnSAG5 were either absent or expression was greatly reduced. As shown for T. gondii, stage-specific expression of the SnSAGs may be important for the parasite to progress through its developmental stages and complete its life cycle successfully. Thus, it is possible that the SAG switching mechanism by these parasites could be exploited as a point of intervention. As well, the alterations in surface antigen expression during different life cycle stages may need to be considered when designing prospective approaches for protective vaccination. PMID:21775062

  16. Seroprevalence of hepatitis B e antigen (HBe antigen and B core antibodies (IgG anti-HBcore and IgM anti-HBcore among hepatitis B surface antigen positive blood donors at a Tertiary Centre in Nigeria

    Directory of Open Access Journals (Sweden)

    Akinbami Akinsegun A

    2012-03-01

    Full Text Available Abstract Background Hepatitis B virus (HBV is a common cause of liver disease throughout the world. HBV is transmitted through blood and other body fluids, including semen and saliva. Chronic replication of HBV virons is characterized by persistence circulation of HBsAg, HBeAg and HBV DNA; usually with anti-HBc and occasionally with anti-HBs. Aim: To determine the prevalence of HBeAg, IgG anti-HBcore and IgM anti-HBcore amongst HBsAg positive blood donors. These parameters are reflective of transmissibility and active hepatitis B infection. A cross sectional study was carried out at the blood donor clinics of Lagos State University Teaching Hospital Ikeja and Lagos University Teaching Hospital Idiaraba. A total of 267 donors were recruited to determine HBe antigen, IgG and IgM anti-HBcore antibodies amongst hepatitis BsAg positive donors. Five milliliters of blood was collected from those who tested positive to HBsAg screen during donation. The sera were subjected to enzyme linked immunosorbent assay (ELISA. Pearson chi-squared test was used for the analytical assessment. Findings A total number of 267 HBsAg positive blood donors were studied. A seroprevalence of 8.2% (22 of 267 HBeAg was obtained, 4 of 267 (1.5% were indeterminate while 241 (90.3% tested negative. Only 27 out of 267 donors (10.1% tested positive to IgM anti-HBcore, 234(87.6% tested negative, while 6(2.2% were indeterminate. A higher percentage of 60.7% (162 of 267 tested positive to IgG anti-HBcore, while 39.3% (105 of 267 tested negative. Conclusion There is a low seroprevalence rate of HBeAg-positive chronic hepatitis and relatively high IgG anti-HBcore and IgM anti-HBcore rates in South West Nigeria.

  17. Suppression of humoral immune response to hepatitis B surface antigen vaccine in BALB/c mice by 1-methyl-tryptophan co-administration

    Directory of Open Access Journals (Sweden)

    T Sparopoulou

    2011-07-01

    Full Text Available   Background and the purpose of the study:Indoleamine 2,3-dioxygenase (IDO suppresses adaptive immune response. The purpose of this study was to determine the effect of the IDO inhibitor namely 1-methyl-DL-tryptophan (DL-1-MT on antibody production after vaccination with hepatitis B surface (HBs antigen. Methods:Four groups of BALB/c mice were immunized with a HBs antigen vaccine. In the first group the vaccine had no DL-1-MT, whereas in the other three groups the vaccine contained 1 mg , 10 mg and 20 mg DL-1-MT. Blood samples were collected 5 weeks post-vaccination and anti-HBs antibodies in the serum were measured by ELISA. Results:Compared to the three groups of mice that were immunized with the vaccines containing DL-1-MT, serum anti-HBs level was much higher in the mice that were immunized with the vaccine with out DL-1-MT. Conclusions:Inhibition of IDO at the time of vaccination decreased humoral immune response to HBs antigen vaccine. The idea that IDO activity is simply immunosuppressive may need to be re-evaluated.

  18. Phage display used for gene cloning of human recombinant antibody against the erythrocyte surface antigen, rhesus D

    DEFF Research Database (Denmark)

    Dziegiel, M; Nielsen, L K; Andersen, P S;

    1995-01-01

    A novel phage display system has been developed for PCR amplification and cloning of the Fab fragments of human immunoglobulin genes. Using this system, we have cloned an antibody from a mouse-human hybridoma cell line directed against the erythrocyte antigen rhesus D. Intact erythrocytes were used...... for absorption of the Fab phages. Soluble Fab fragments produced from the cloned material showed identical performance to the parental antibody in agglutination assays. Gel filtration confirmed that the Fab fragment consists of a kappa-Fd heterodimer. The successful use of intact cells for selection of specific...... Fab phages demonstrates that it is possible to by-pass purification of the antigen of interest. Comparison with published germline sequences demonstrated that the immunoglobulin coding regions had the highest homology to the VH 1.9III and V kappa Hum kappa v325 germline genes, respectively....

  19. Differences in Surface-Exposed Antigen Expression between Helicobacter pylori Strains Isolated from Duodenal Ulcer Patients and from Asymptomatic Subjects

    OpenAIRE

    Thoreson, Ann-Catrin E.; Hamlet, Annika; Çelik, Janet; Byström, Mona; Nyström, Susanne; Olbe, Lars; Svennerholm, Ann-Mari

    2000-01-01

    We have analyzed possible qualitative and quantitative differences in antigen expression between Helicobacter pylori strains isolated from the antrum and different locations in the duodenum of 21 duodenal ulcer (DU) patients and 20 asymptomatic subjects (AS) by enzyme-linked immunosorbent assay (ELISA) and inhibition ELISA. Almost all antral and duodenal strains grown in vitro expressed the N-acetyl-neuroaminyllactose-binding hemagglutinin, flagellins (subunits FlaA and FlaB), urease, a 26-kD...

  20. 确证TRFIA检测乙肝病毒表面抗体结果的研究%Detection of Hepatitis B Surface Antigen and Antibody by TRFIA

    Institute of Scientific and Technical Information of China (English)

    吉飞跃; 钱开成

    2011-01-01

    建立简易时间分辨免疫荧光法(TRFIA)检测乙型肝炎病毒表面抗体(抗-HBs)的中和试验方法,验证TRFIA检测结果.收集乙型肝炎病毒表面抗原(HBsAg)异常值血清,确定TRFIA中和抑制试验中和比为0.25-1.26ng/mL∶1mIU/mL,对抗-HBs的定量结果进行确认.结果显示,使用TRFIA定量检测的结果与中和抑制试验的结果符合率达100%.结论:使用中和抑制试验确认TRFIA定量检测乙型肝炎病毒(HBV)表面抗体的检测结果,可以排除非特异反应导致的结果.%To establish a simple neutralization test to detect hepatitis B surface antigen and antibody (anti-HBs) by TRFIA. The serum samples with outlier serum of heptatitis B surface antigen (HBsAg) were collected, and the neutralization inhibition test was carried out to confirm the quantitative result of anti-HBs which analysis by TRFIA. The results showed that the coincidence rate of anti-HBs analysis by TRFIA quantitative test and neu- tralization inhibition test was 100%. The neutralization inhibition test could be used to confirm the detection re- suits of hepatitis B surface antigen and antibody by TRFIA and to exclude the result of non-specific reaction.

  1. Removing N-terminal sequences in pre-S1 domain enhanced antibody and B-cell responses by an HBV large surface antigen DNA vaccine.

    Science.gov (United States)

    Ge, Guohong; Wang, Shixia; Han, Yaping; Zhang, Chunhua; Lu, Shan; Huang, Zuhu

    2012-01-01

    Although the use of recombinant hepatitis B virus surface (HBsAg) protein vaccine has successfully reduced global hepatitis B infection, there are still a number of vaccine recipients who do not develop detectable antibody responses. Various novel vaccination approaches, including DNA vaccines, have been used to further improve the coverage of vaccine protection. Our previous studies demonstrated that HBsAg-based DNA vaccines could induce both humoral and CMI responses in experimental animal models. However, one form of the the HBsAg antigen, the large S antigen (HBs-L), expressed by DNA vaccine, was not sufficiently immunogenic in eliciting antibody responses. In the current study, we produced a modified large S antigen DNA vaccine, HBs-L(T), which has a truncated N-terminal sequence in the pre-S1 region. Compared to the original HBs-L DNA vaccine, the HBs-L(T) DNA vaccine improved secretion in cultured mammalian cells and generated significantly enhanced HBsAg-specific antibody and B cell responses. Furthermore, this improved HBsL DNA vaccine, along with other HBsAg-expressing DNA vaccines, was able to maintain predominantly Th1 type antibody responses while recombinant HBsAg protein vaccines produced in either yeast or CHO cells elicited mostly Th2 type antibody responses. Our data indicate that HBsAg DNA vaccines with improved immunogenicity offer a useful alternative choice to recombinant protein-based HBV vaccines, particularly for therapeutic purposes against chronic hepatitis infection where immune tolerance led to poor antibody responses to S antigens. PMID:22844502

  2. Removing N-terminal sequences in pre-S1 domain enhanced antibody and B-cell responses by an HBV large surface antigen DNA vaccine.

    Directory of Open Access Journals (Sweden)

    Guohong Ge

    Full Text Available Although the use of recombinant hepatitis B virus surface (HBsAg protein vaccine has successfully reduced global hepatitis B infection, there are still a number of vaccine recipients who do not develop detectable antibody responses. Various novel vaccination approaches, including DNA vaccines, have been used to further improve the coverage of vaccine protection. Our previous studies demonstrated that HBsAg-based DNA vaccines could induce both humoral and CMI responses in experimental animal models. However, one form of the the HBsAg antigen, the large S antigen (HBs-L, expressed by DNA vaccine, was not sufficiently immunogenic in eliciting antibody responses. In the current study, we produced a modified large S antigen DNA vaccine, HBs-L(T, which has a truncated N-terminal sequence in the pre-S1 region. Compared to the original HBs-L DNA vaccine, the HBs-L(T DNA vaccine improved secretion in cultured mammalian cells and generated significantly enhanced HBsAg-specific antibody and B cell responses. Furthermore, this improved HBsL DNA vaccine, along with other HBsAg-expressing DNA vaccines, was able to maintain predominantly Th1 type antibody responses while recombinant HBsAg protein vaccines produced in either yeast or CHO cells elicited mostly Th2 type antibody responses. Our data indicate that HBsAg DNA vaccines with improved immunogenicity offer a useful alternative choice to recombinant protein-based HBV vaccines, particularly for therapeutic purposes against chronic hepatitis infection where immune tolerance led to poor antibody responses to S antigens.

  3. Extensively variable surface antigens of Sarcocystis spp. infecting Brazilian marsupials in the genus Didelphis occur in myriad allelic combinations, suggesting sexual recombination has aided their diversification.

    Science.gov (United States)

    Monteiro, R M; Keid, L B; Richtzenhain, L J; Valadas, S Y; Muller, G; Soares, R M

    2013-09-01

    Sarcocystis neurona and Sarcocystis falcatula are very similar species of Apicomplexan protozoa that use marsupials of the genus Didelphis as definitive hosts. These mammals can serve as definitive hosts not only for these two parasites, but for other Sarcocystis such as Sarcocystis speeri and Sarcocystis lindsayi. Sarcocystis shed by opossums (with the exception of S. neurona) can cause disease in a great variety of birds, being commonly associated with acute pulmonary sarcocystosis in zoos. S. neurona is the most commonly associated parasite with the equine protozoal myeloencephalitis in horses. Herein we assessed the variability of Sarcocystis spp. isolated from opossums of the state of Rio Grande do Sul, Brazil, by sequencing fragments of genes coding for glycosylphosphatidylinositol-anchored surface antigens (termed surface antigen or SAG), SAG2, SAG3 and SAG4. Two genetic groups were identified, one of them related to S. falcatula and the other related to S. neurona. Various allelic combinations of SAG2, SAG3 and SAG4 occur among S. falcatula related isolates and strong evidences suggest that such isolates may exchange high divergent alleles in possible sexual recombination processes. Regarding the group S. neurona-like (isolates G37 and G38), none of the individuals in this group share alleles with individuals of the other group. Comparing G37 and G38 strains and North American strains of S. neurona, four polymorphisms were identified at SAG-3, five at SAG-2 and three at SAG-4. Gene sequences of locus SAG-3 from isolates G37 and G38 differed from the other sequences by an insertion 81bp long. This insertion contains several dinucleotide repeats of AT, resembling a microsatellite locus and has already been detected in SAG3 sequences of S. neurona from North America. When aligned against North American strains of S. neurona, G37 and G38 isolates have a deletion of 8 nucleotides within this intron which indicate that S. neurona strains of South America are

  4. Antibodies to variable Plasmodium falciparum-infected erythrocyte surface antigens are associated with protection from novel malaria infections

    DEFF Research Database (Denmark)

    Giha, H A; Staalsoe, T; Dodoo, D;

    2000-01-01

    In areas of unstable transmission malaria affects all age groups, but the malaria incidence is lower in adults compared to children and teenagers. Under such conditions subclinical Plasmodium falciparum infections are common and some infections are controlled, because blood parasitaemia is...... susceptible and protected individuals. Together, the results indicate that pre-existing anti-PfEMP1 antibodies can reduce the risk of contracting clinical malaria when challenged by novel parasite clones expressing homologous, but not heterologous variable surface antigens. The results also confirm that...

  5. SnSAG5 is an alternative surface antigen of Sarcocystis neurona strains that is mutually exclusive to SnSAG1.

    Science.gov (United States)

    Crowdus, Carolyn A; Marsh, Antoinette E; Saville, Willliam J; Lindsay, David S; Dubey, J P; Granstrom, David E; Howe, Daniel K

    2008-11-25

    Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). Previous work has identified a gene family of paralogous surface antigens in S. neurona called SnSAGs. These surface proteins are immunogenic in their host animals, and are therefore candidate molecules for development of diagnostics and vaccines. However, SnSAG diversity exists in strains of S. neurona, including the absence of the major surface antigen gene SnSAG1. Instead, sequence for an alternative SnSAG has been revealed in two of the SnSAG1-deficient strains. Herein, we present data characterizing this new surface protein, which we have designated SnSAG5. The results indicated that the protein encoded by the SnSAG5 sequence is indeed a surface-associated molecule that has characteristics consistent with the other SAGs identified in S. neurona and related parasites. Importantly, Western blot analyses of a collection of S. neurona strains demonstrated that 6 of 13 parasite isolates express SnSAG5 as a dominant surface protein instead of SnSAG1. Conversely, SnSAG5 was not detected in SnSAG1-positive strains. One strain, which was isolated from the brain of a sea otter, did not express either SnSAG1 or SnSAG5. Genetic analysis with SnSAG5-specific primers confirmed the presence of the SnSAG5 gene in Western blot-positive strains, while also suggesting the presence of a novel SnSAG sequence in the SnSAG1-deficient, SnSAG5-deficient otter isolate. The findings provide further indication of S. neurona strain diversity, which has implications for diagnostic testing and development of vaccines against EPM as well as the population biology of Sarcocystis cycling in the opossum definitive host. PMID:18829171

  6. Antigenic topology of the P29 surface lipoprotein of Mycoplasma fermentans: differential display of epitopes results in high-frequency phase variation.

    Science.gov (United States)

    Theiss, P; Karpas, A; Wise, K S

    1996-05-01

    Antibodies to P29, a major lipid-modified surface protein of Mycoplasma fermentans, reveal phase variation of surface epitopes occurring with high frequency in clonal lineages of the organism. This occurs despite continuous expression of the entire epitope-bearing P29 product (detected by Western immunoblotting) and contrasts with phase variation of other surface antigens mediated by differential expression of proteins. To understand the structure and antigenic topology of P29, the single-copy p29 gene from strain PG18 was cloned and sequenced. The gene encodes a prolipoprotein containing a signal sequence predicted to be modified with lipid and cleaved at the N-terminal Cys-1 residue of the mature P29 lipoprotein. The remaining 218-residue hydrophilic sequence of P29 is predicted to be located external to the single plasma membrane. Additional Cys residues at positions 91 and 128 in the mature protein were shown to form a 36-residue disulfide loop by selectively labeling sulfhydryl groups that were liberated only after chemical reduction of monomeric P29. Two nearly identical charged amino acid sequences occurred in P29, within the disulfide loop and upstream of this structure. Two distinct epitopes binding different monoclonal antibodies were associated with opposite ends of the P29 protein, by mapping products expressed in Escherichia coli from PCR-generated 3' deletion mutations of the p29 gene. Each monoclonal antibody detected high-frequency and noncoordinate changes in accessibility of the corresponding epitopes in colony immunoblots of clonal variants, yet sequencing of the p29 gene from these variants and analysis of disulfide bonds revealed no associated changes in the primary sequence or disulfide loop structure of P29. These results suggest that P29 surface epitope variation may involve masking of selected regions of P29, possibly by other surface components undergoing phase variation by differential expression. Differential masking may be an important

  7. Phage display used for gene cloning of human recombinant antibody against the erythrocyte surface antigen, rhesus D

    DEFF Research Database (Denmark)

    Dziegiel, Morten Hanefeld; Nielsen, L K; Andersen, P S;

    1995-01-01

    A novel phage display system has been developed for PCR amplification and cloning of the Fab fragments of human immunoglobulin genes. Using this system, we have cloned an antibody from a mouse-human hybridoma cell line directed against the erythrocyte antigen rhesus D. Intact erythrocytes were used...... for absorption of the Fab phages. Soluble Fab fragments produced from the cloned material showed identical performance to the parental antibody in agglutination assays. Gel filtration confirmed that the Fab fragment consists of a kappa-Fd heterodimer. The successful use of intact cells for selection of specific...

  8. HD-03/ES: A Herbal Medicine Inhibits Hepatitis B Surface Antigen Secretion in Transfected Human Hepatocarcinoma PLC/PRF/5 Cells.

    Science.gov (United States)

    Varma, Sandeep R; Sundaram, R; Gopumadhavan, S; Vidyashankar, Satyakumar; Patki, Pralhad S

    2013-01-01

    HD-03/ES is a herbal formulation used for the treatment of hepatitis B. However, the molecular mechanism involved in the antihepatitis B (HBV) activity of this drug has not been studied using in vitro models. The effect of HD-03/ES on hepatitis B surface antigen (HBsAg) secretion and its gene expression was studied in transfected human hepatocarcinoma PLC/PRF/5 cells. The anti-HBV activity was tested based on the inhibition of HBsAg secretion into the culture media, as detected by HBsAg-specific antibody-mediated enzyme assay (ELISA) at concentrations ranging from 125 to 1000  μ g/mL. The effect of HD-03/ES on HBsAg gene expression was analyzed using semiquantitative multiplex RT-PCR by employing specific primers. The results showed that HD-03/ES suppressed HBsAg production with an IC50 of 380  μ g/mL in PLC/PRF/5 cells for a period of 24 h. HD-03/ES downregulated HBsAg gene expression in PLC/PRF/5 cells. In conclusion, HD-03/ES exhibits strong anti-HBV properties by inhibiting the secretion of hepatitis B surface antigen in PLC/PRF/5 cells, and this action is targeted at the transcription level. Thus, HD-03/ES could be beneficial in the treatment of acute and chronic hepatitis B infections.

  9. Progress on surface antigens of Toxoplasma gondii%弓形虫表面抗原研究进展

    Institute of Scientific and Technical Information of China (English)

    付婷霞; 仲维霞

    2009-01-01

    刚地弓形虫是一种广泛分布于人和哺乳动物组织细胞内的机会性致病原虫,可引起严重的人兽共患病.弓形虫抗原的研究对开发诊断制剂、疫苗以及从分子水平探讨弓形虫与宿主之间的相互关系具有重要意义,该文对近年来有关弓形虫抗原的研究进展作一综述.%Toxoplasma gondii is all obligate intracellular parasite that infects a wide range of hosts,in-cluding humans and domesticated animals throughout the wodd.The investigation of the antigens of Toxoplasma gondii is of great significance in developing diagnostic reagents,vaccines and studying on the relationship be-tween Toxoplasma gondii and its hosts.This review focused on the recent progress on the antigens of Toxoplas-ma gondii.

  10. Modulation of human leukocyte antigen and intracellular adhesion molecule-1 surface expression in malignant and nonmalignant human thyroid cells by cytokines in the context of extracellular matrix.

    Science.gov (United States)

    Miller, A; Kraiem, Z; Sobel, E; Lider, O; Lahat, N

    2000-11-01

    Interactions between malignant cells and their environment are achieved via cell-surface receptors and adhesion molecules. The extracellular matrix (ECM) and ECM-bound cytokines modulate the expression of cell-surface molecules on target malignant cells, which may lead to changes in their susceptibility to cytolysis, in their ability to present antigens, and in the induction of local immune-cell activation and patrol. Eventually, these alterations may culminate in either the destruction, or escape and proliferation, of the tumor. We studied the effects of the ECM and its components in a "naive" form or following binding of the inflammatory cytokines interferon gamma (IFNgamma) and tumor necrosis factor alpha (TNFalpha) on the surface expression of human leukocyte antigen (HLA) class-I, HLA class-II (HLA-DR), and intracellular adhesion molecule-1 (ICAM-1), on nonmalignant and malignant thyroid cells. The basal expression of HLA class-I molecules was not significantly changed either by naive ECM and its components or by ECM-bound cytokines. ECM synergized with IFNgamma and TNFalpha in inducing HLA-DR molecules on nonmalignant and malignant thyrocytes, with higher HLA-DR levels on the malignant cells. The laminin component, in particular, synergized with IFNgamma. Basal ICAM-1 expression on nonneoplastic cells was not significantly affected by the cytokines when grown in the absence of ECM, but was significantly upregulated when cells were cultured on ECM. In contrast, in malignant thyrocyte cultures, ECM significantly attenuated IFNgamma- and TNFalpha-mediated enhancement of ICAM-1 expression. We concluded that signals derived from ECM-embedded cytokines participate in the regulation of key thyroid cell surface molecules and, thus, may affect the final outcome of human thyroid malignancies. PMID:11128721

  11. Hepatitis B Surface Antigen S Gene is an Effective Carrier Molecule for Developing GnRH DNA Immunocastration Vaccine in Mice.

    Science.gov (United States)

    Han, Y G; Ye, W J; Liu, G Q; Jiang, X P; Ijaz, N; Zhao, J Y; Tesema, B

    2016-06-01

    Relatively molecular mass of GnRH antigens is small and hence needs to couple to a large carrier molecule to enhance its immunogenicity. This study investigated whether hepatitis B surface antigen S (HBsAg-S) gene can be used as an effective carrier molecule for developing GnRH DNA immunocastration vaccine. Two copies of human GnRH gene were fused with HBsAg-S gene for constructing a recombinant plasmid pVAX-HBsAg-S-2GnRH that coded for 27 kDa target fusion protein. Ten male mice were divided into two equal groups, treatment and control. The vaccine (50 μg/mice) prepared in saline solution was injected into male mice at weeks 0, 1, 2, 4 and 7 of the experiment. Vaccine's efficacy was evaluated in terms of GnRH-specific IgG antibody response, plasma testosterone levels, testicular weight and extent of the testicular tissue damage. The specific anti-GnRH antibody titre in vaccinated animals was significantly higher than in controls in only 4th week of immunization (p vaccinated animals showed lower testicular weight than those of the controls (p vaccinated animals was suppressed. In conclusion, in this study, the engineered plasmid to be used as a GnRH DNA vaccine induced antibody response and suppressed spermatogenesis in mice. This suggests that HBsAg-S gene can be an effective carrier molecule for developing GnRH DNA immunocastration vaccine when relatively molecular mass of the aimed antigens is small. PMID:27157596

  12. Sequence Variation and Immunologic Cross-Reactivity among Babesia bovis Merozoite Surface Antigen 1 Proteins from Vaccine Strains and Vaccine Breakthrough Isolates

    Science.gov (United States)

    LeRoith, Tanya; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Hines, Stephen A.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The Babesia bovis merozoite surface antigen 1 (MSA-1) is an immunodominant membrane glycoprotein that is the target of invasion-blocking antibodies. While antigenic variation has been demonstrated in MSA-1 among strains from distinct geographical areas, the extent of sequence variation within a region where it is endemic and the effect of variation on immunologic cross-reactivity have not been assessed. In this study, sequencing of MSA-1 from two Australian B. bovis vaccine strains and 14 breakthrough isolates from vaccinated animals demonstrated low sequence identity in the extracellular region of the molecule, ranging from 19.8 to 46.7% between the T vaccine strain and eight T vaccine breakthrough isolates, and from 18.7 to 99% between the K vaccine strain and six K vaccine breakthrough isolates. Although MSA-1 amino acid sequence varied substantially among strains, overall predicted regions of hydrophilicity and hydrophobicity in the extracellular domain were conserved in all strains examined, suggesting a conserved functional role for MSA-1 despite sequence polymorphism. Importantly, the antigenic variation created by sequence differences resulted in a lack of immunologic cross-reactivity among outbreak strains using sera from animals infected with the B. bovis vaccine strains. Additionally, sera from cattle hyperinfected with the Mexico strain of B. bovis and shown to be clinically immune did not cross-react with MSA-1 from any other isolate tested. The results indicate that isolates of B. bovis capable of evading vaccine-induced immunity contain an msa-1 gene that is significantly different from the msa-1 of the vaccine strain, and that the difference can result in a complete lack of cross-reactivity between MSA-1 from vaccine and breakthrough strains in immunized animals. PMID:16113254

  13. Three-Dimensional Structure and Biophysical Characterization of Staphylococcus aureus Cell Surface Antigen-Manganese Transporter MntC

    Energy Technology Data Exchange (ETDEWEB)

    Gribenko, Alexey; Mosyak, Lidia; Ghosh, Sharmistha; Parris, Kevin; Svenson, Kristine; Moran, Justin; Chu, Ling; Li, Sheng; Liu, Tong; Woods, Jr., Virgil L.; Jansen, Kathrin U.; Green, Bruce A.; Anderson, Annaliesa S.; Matsuka, Yury V. [Pfizer; (UCSD)

    2013-08-23

    MntC is a metal-binding protein component of the Mn2 +-specific mntABC transporter from the pathogen Staphylococcus aureus. The protein is expressed during the early stages of infection and was proven to be effective at reducing both S. aureus and Staphylococcus epidermidis infections in a murine animal model when used as a vaccine antigen. MntC is currently being tested in human clinical trials as a component of a multiantigen vaccine for the prevention of S. aureus infections. To better understand the biological function of MntC, we are providing structural and biophysical characterization of the protein in this work. The three-dimensional structure of the protein was solved by X-ray crystallography at 2.2 Å resolution and suggests two potential metal binding modes, which may lead to reversible as well as irreversible metal binding. Precise Mn2 +-binding affinity of the protein was determined from the isothermal titration calorimetry experiments using a competition approach. Differential scanning calorimetry experiments confirmed that divalent metals can indeed bind to MntC reversibly as well as irreversibly. Finally, Mn2 +-induced structural and dynamics changes have been characterized using spectroscopic methods and deuterium–hydrogen exchange mass spectroscopy. Results of the experiments show that these changes are minimal and are largely restricted to the structural elements involved in metal coordination. Therefore, it is unlikely that antibody binding to this antigen will be affected by the occupancy of the metal-binding site by Mn2 +.

  14. A reusable localized surface plasmon resonance biosensor for quantitative detection of serum squamous cell carcinoma antigen in cervical cancer patients based on silver nanoparticles array

    Directory of Open Access Journals (Sweden)

    Zhao Q

    2014-02-01

    Full Text Available Qianying Zhao,1 Ruiqi Duan,1 Jialing Yuan,1 Yi Quan,1 Huan Yang,2 Mingrong Xi1 1Department of Gynecology and Obstetrics, West China Second University Hospital, Sichuan University, 2State Key Laboratory of Optical Technologies for Micro-fabrication, Institute of Optics and Electronics, Chinese Academy of Science, Chengdu, Sichuan, People's Republic of China Abstract: Squamous cell carcinoma antigen (SCCa, as a tumor biomarker, plays an important role in adjuvant diagnosis, treatment evaluation, and prognosis prediction for cervical cancer patients. Localized surface plasmon resonance (LSPR technique based on noble metal nanoparticles bypasses the disadvantages of traditional testing strategies, in terms of free-labeling, short assay time, good sensitivity, and selectivity. Herein, we develop a novel and reusable LSPR biosensor for the detection of SCCa. First, a triangle-shaped silver nanoparticle array was fabricated using the nanosphere lithography method. Next, we investigated and verified the feasibility of amino coupling method using 11-mercaptoundecanoic acid (MUA to form a functionalized chip surface with monoclonal anti-SCCa antibodies on the silver nanoparticles for distinct detection of SCCa. Different concentrations of SCCa were successfully tested in both buffer and human serum by the ultrasensitive and specific LSPR system, with a linear quantitative detection range of 0.1–1,000 pM under optimal conditions. With appropriate regeneration solution, for example 50 mM glycine-HCl (pH 2.0, the LSPR biosensor featured effective fabrication reproducibility, which reduced both production cost and testing time. Our study represents the first application of the LSPR biosensor in cervical cancer, and demonstrates that the rapid, simple, and reusable nanochip can serve as a potential alternative for clinical serological diagnosis of SCCa in cervical cancer patients. Keywords: localized surface plasmon resonance, nanotechnology, biosensor

  15. The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major

    DEFF Research Database (Denmark)

    Kemp, M; Handman, E; Kemp, K;

    1998-01-01

    The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune...... to cutaneous leishmaniasis. Peripheral blood mononuclear cells from Sudanese individuals with a past history of self-healing cutaneous leishmaniasis proliferated vigorously in response to PSA-2 isolated from Leishmania major, whereas the antigen did not activate cells from presumably unexposed Danes...... and that these cells were the major source of interferon-gamma. The results show that Th1-like cells recognising PSA-2 are expanded during infection by L. major and that they maintain their Th1-like cytokine profile upon reactivation in vitro. Since immunity to cutaneous leishmaniasis is mediated by antigen...

  16. Construction, expression and characterization of the engineered antibody against tumor surface antigen, p185c-erbB-2

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The c-erbB-2 proto-oncogene encodes a 185kDa protein p185, which belongs to epidermal growth factorreceptor family. Amplification of this gene has been shown to correlate with poor clinical prognosis forcertain cancer patients. The monoclonal antibody A21 which directed against p185 specifically inhibitsproliferation of tumor cells overexpressing p185, hence allows it to be a candidate for targeted therapy. Inorder to overcome several drawbacks of murine MAb, we cloned its VH and VL genes and constructed thesingle-chain Fv (scFv) through a peptide linker. The recombinant scFvA21 was expressed in Escherichiacoli and purified by the affinity column. Subsequently it was characterized by ELISA, Western blot, cellimmunohistochemistry and FACS. All these assays showed the binding activity to extracellular domain(ECD) of p185. Based on those properties of scFvA21, we further constructed the scFv-Fc fusion moleculewith a homodimer form and the recombinant product was expressed in mammalian cells. In a series ofsubsequent analysis this fusion protein showed identical antigen binding site and activity with the parentantibody. These anti-p185 engineered antibodies have promised to be further modified as a tumor targetingdrugs, with a view of application in the diagnosis and treatment of human breast cancer.

  17. Prevalence of hepatitis B surface antigen & its subtypes in high risk group subjects & voluntary blood donors in Bombay.

    Science.gov (United States)

    Elavia, A J; Banker, D D

    1991-09-01

    HBsAg positive subjects belonging to high risk groups and voluntary blood donors were analysed for prevalence of HBsAg among various groups of subjects for ascertaining the carrier status among the voluntary blood donors, HBsAg subtype distribution, and association of HBsAg with blood groups and caste or religion. The prevalence of HBsAg varied from 2.02 per cent in voluntary blood donors to 58.38 per cent in patients of acute viral hepatitis. 70.5 per cent subjects had subtype 'ay' while 23.9 per cent of the subjects had subtype 'ad'. We also found compound 'ady' subtype in 5.6 per cent of our subjects. HBsAg/adr, a subtype not usually prevalent in India, was found in 30 of the 90 'ad' sera. Co-occurrence of HBsAg and anti-HBs was noted in 9 subjects. Homotypic anti-HBs was found to occur together mainly in voluntary blood donors, while heterotypic anti-HBs was found to occur together mainly multi-transfused patients. There was no significant correlation between HBsAg and blood group antigens and a relatively higher incidence of HBsAg among the Jain community was observed.

  18. Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Staalsoe, Trine; Shulman, Caroline E; Bulmer, Judith N;

    2004-01-01

    BACKGROUND: Pregnancy-associated malaria caused by Plasmodium falciparum adherence to chondroitin sulfate A in the placental intervillous space is a major cause of low birthweight and maternal anaemia in areas of endemic P falciparum transmission. Adhesion-blocking antibodies that specifically...... recognise parasite-encoded variant surface antigens (VSA) are associated with resistance to pregnancy-associated malaria. We looked for a possible relation between VSA-specific antibody concentrations, placental infection, and protection from low birthweight and maternal anaemia. METHODS: We used flow...... cytometry to measure VSA-specific IgG concentrations in plasma samples taken during child birth from 477 Kenyan women selected from a cohort of 910 women on the basis of HIV-1 status, gravidity, and placental histology. We measured VSA expressed by one placental P falciparum isolate and two isolates...

  19. Fabrication of fiber-optic localized surface plasmon resonance sensor and its application to detect antibody-antigen reaction of interferon-gamma

    Science.gov (United States)

    Jeong, Hyeon-Ho; Erdene, Norov; Lee, Seung-Ki; Jeong, Dae-Hong; Park, Jae-Hyoung

    2011-12-01

    A fiber-optic localized surface plasmon (FO LSPR) sensor was fabricated by gold nanoparticles (Au NPs) immobilized on the end-face of an optical fiber. When Au NPs were formed on the end-face of an optical fiber by chemical reaction, Au NPs aggregation occurred and the Au NPs were immobilized in various forms such as monomers, dimers, trimers, etc. The component ratio of the Au NPs on the end-face of the fabricated FO LSPR sensor was slightly changed whenever the sensors were fabricated in the same condition. Including this phenomenon, the FO LSPR sensor was fabricated with high sensitivity by controlling the density of Au NPs. Also, the fabricated sensors were measured for the resonance intensity for the different optical systems and analyzed for the effect on sensitivity. Finally, for application as a biosensor, the sensor was used for detecting the antibody-antigen reaction of interferon-gamma.

  20. Breaking tolerance in hepatitis B surface antigen (HBsAg) transgenic mice by vaccination with cross-reactive, natural HBsAg variants

    DEFF Research Database (Denmark)

    Schirmbeck, Reinhold; Dikopoulos, Nektarios; Kwissa, Marcin;

    2003-01-01

    Processing exogenous hepatitis B surface antigen (HBsAg) of the hepatitis B virus (HBV) generates the K(b)-binding S(208-215) epitope 1; processing endogenous HBsAg generates the K(b)-binding S(190-197) epitope 2. Cross-reactive CD8(+) T cell responses were primed to epitope 1 but not epitope 2......-tg mice by HBsAg(adw2); these specific CD8(+) T cells cross-reacted with epitope 1 processed from the transgene-encoded HBsAg(ayw). The liver of vaccinated HBsAg(ayw) transgenic mice showed severe histopathology and contained functional (IFNgamma-producing), cross-reactive CD8(+) T cells, and vaccinated...... HBs-tg mice showed reduced antigenemia. Hence, vaccination with natural HBsAg variants from different HBV sero/genotypes can prime cross-reactive, specific CD8(+) T cell immunity that breaks tolerance to HBsAg....

  1. Translational Enhancer of Tobacco mosaic virus Enhancing Expression of Hepatitis B Surface Antigen in Transgenic Panax ginseng C. A. Meyer Callus

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The 5'-nontranslated leader(omega sequence) of Tobacco mosaic virus(TMV) was used as a translational enhancer sequence in the expression of the hepatitis B surface antigen(HBsAg) gene in transgenic ginseng callus cultures.The adr subtype HBsAg gene was placed under the control of the Cauliflower mosaic virus(CaMV) 35S promoter linking to the TMV leader sequence. The antisense omega sequence was used in a control construct. The resulting constructs cloned in the binary vector pBI121 were used to transform the ginseng callus tissue via the Agrobacterium-mediated procedure. The integration and expression of the HBsAg gene were evaluated by PCR and western blot, respectively. Enzyme-linked immunoassays(ELISA) using a monoclonal antibody directed against human serum-derived HBsAg revealed a three to four-fold enhanced expression of HBsAg in ginseng cells conferred by the TMV omega element.

  2. Curcumin induced nanoscale CD44 molecular redistribution and antigen-antibody interaction on HepG2 cell surface

    Energy Technology Data Exchange (ETDEWEB)

    Wang Mu [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Ruan Yuxia [Department of Ophthalmology, The First Affiliated Hospital, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Xing Xiaobo; Chen Qian; Peng, Yuan [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Cai Jiye, E-mail: tjycai@jnu.edu.cn [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China)

    2011-07-04

    Graphical abstract: Highlights: > In this study, we investigate the changes of CD44 expression and distribution on HepG2 cells after curcumin treatment. > We find curcumin is able to change the morphology and ultrastructure of HepG2 cells. > Curcumin can reduce the expression of CD44 molecules and induce the nanoscale molecular redistribution on cell surface. > The binding force between CD44-modified AFM tip and the HepG2 cell surface decreases after curcumin-treatment. - Abstract: The cell surface glycoprotein CD44 was implicated in the progression, metastasis and apoptosis of certain human tumors. In this study, we used atomic force microscope (AFM) to monitor the effect of curcumin on human hepatocellular carcinoma (HepG2) cell surface nanoscale structure. High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with curcumin. The membrane average roughness increased (10.88 {+-} 4.62 nm to 129.70 {+-} 43.72 nm) and the expression of CD44 decreased (99.79 {+-} 0.16% to 75.14 {+-} 8.37%). Laser scanning confocal microscope (LSCM) imaging showed that CD44 molecules were located on the cell membrane. The florescence intensity in control group was weaker than that in curcumin treated cells. Most of the binding forces between CD44 antibodies and untreated HepG2 cell membrane were around 120-220 pN. After being incubated with curcumin, the major forces focused on 70-150 pN (10 {mu}M curcumin-treated) and 50-120 pN (20 {mu}M curcumin-treated). These results suggested that, as result of nanoscale molecular redistribution, changes of the cell surface were in response to external treatment of curcumin. The combination of AFM and LSCM could be a powerful method to detect the distribution of cell surface molecules and interactions between molecules and their ligands.

  3. Mapping Antigenic Sites of an Immunodominant Surface Lipoprotein of Mycoplasma agalactiae, AvgC, with the Use of Synthetic Peptides

    OpenAIRE

    Santona, Antonella; Carta, Franco; Fraghí, Peppinetta; Turrini, Franco

    2002-01-01

    As a first step toward the design of an epitope vaccine to prevent contagious agalactia, the strongly immunogenic 55-kDa protein of Mycoplasma agalactiae was studied and found to correspond to the AvgC protein encoded by the avgC gene. The avg genes of M. agalactiae, which encode four variable surface lipoproteins, display a significant homology to the vsp (variable membrane surface lipoproteins) genes of the bovine pathogen Mycoplasma bovis at their promoter region as well as their N-terminu...

  4. Virus-like particle production with yeast: ultrastructural and immunocytochemical insights into Pichia pastoris producing high levels of the Hepatitis B surface antigen

    Directory of Open Access Journals (Sweden)

    Adnan Ahmad

    2011-06-01

    Full Text Available Abstract Background A protective immune response against Hepatitis B infection can be obtained through the administration of a single viral polypeptide, the Hepatitis B surface antigen (HBsAg. Thus, the Hepatitis B vaccine is generated through the utilization of recombinant DNA technology, preferentially by using yeast-based expression systems. However, the polypeptide needs to assemble into spherical particles, so-called virus-like particles (VLPs, to elicit the required protective immune response. So far, no clear evidence has been presented showing whether HBsAg assembles in vivo inside the yeast cell into VLPs or later in vitro during down-stream processing and purification. Results High level production of HBsAg was carried out with recombinant Pichia pastoris using the methanol inducible AOX1 expression system. The recombinant vaccine was isolated in form of VLPs after several down-stream steps from detergent-treated cell lysates. Search for the intracellular localization of the antigen using electron microscopic studies in combination with immunogold labeling revealed the presence of HBsAg in an extended endoplasmic reticulum where it was found to assemble into defined multi-layered, lamellar structures. The distance between two layers was determined as ~6 nm indicating that these lamellas represent monolayers of well-ordered HBsAg subunits. We did not find any evidence for the presence of VLPs within the endoplasmic reticulum or other parts of the yeast cell. Conclusions It is concluded that high level production and intrinsic slow HBsAg VLP assembly kinetics are leading to retention and accumulation of the antigen in the endoplasmic reticulum where it assembles at least partly into defined lamellar structures. Further transport of HBsAg to the Golgi apparatus is impaired thus leading to secretory pathway disfunction and the formation of an extended endoplasmic reticulum which bulges into irregular cloud-shaped formations. As VLPs were

  5. Curcumin induced nanoscale CD44 molecular redistribution and antigen-antibody interaction on HepG2 cell surface

    International Nuclear Information System (INIS)

    Graphical abstract: Highlights: → In this study, we investigate the changes of CD44 expression and distribution on HepG2 cells after curcumin treatment. → We find curcumin is able to change the morphology and ultrastructure of HepG2 cells. → Curcumin can reduce the expression of CD44 molecules and induce the nanoscale molecular redistribution on cell surface. → The binding force between CD44-modified AFM tip and the HepG2 cell surface decreases after curcumin-treatment. - Abstract: The cell surface glycoprotein CD44 was implicated in the progression, metastasis and apoptosis of certain human tumors. In this study, we used atomic force microscope (AFM) to monitor the effect of curcumin on human hepatocellular carcinoma (HepG2) cell surface nanoscale structure. High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with curcumin. The membrane average roughness increased (10.88 ± 4.62 nm to 129.70 ± 43.72 nm) and the expression of CD44 decreased (99.79 ± 0.16% to 75.14 ± 8.37%). Laser scanning confocal microscope (LSCM) imaging showed that CD44 molecules were located on the cell membrane. The florescence intensity in control group was weaker than that in curcumin treated cells. Most of the binding forces between CD44 antibodies and untreated HepG2 cell membrane were around 120-220 pN. After being incubated with curcumin, the major forces focused on 70-150 pN (10 μM curcumin-treated) and 50-120 pN (20 μM curcumin-treated). These results suggested that, as result of nanoscale molecular redistribution, changes of the cell surface were in response to external treatment of curcumin. The combination of AFM and LSCM could be a powerful method to detect the distribution of cell surface molecules and interactions between molecules and their ligands.

  6. Simian and Human Immunodeficiency Virus Nef Proteins Use Different Surfaces To Downregulate Class I Major Histocompatibility Complex Antigen Expression

    OpenAIRE

    Swigut, Tomek; Iafrate, A. John; Muench, Jan; Kirchhoff, Frank; Skowronski, Jacek

    2000-01-01

    Simian immunodeficiency virus (SIV) and human immunodeficiency virus type 1 (HIV-1) Nef proteins are related regulatory proteins that share several functions, including the ability to downregulate class I major histocompatibility complex (MHC) and CD4 expression on the cell surface and to alter T-cell-receptor-initiated signal transduction in T cells. We compared the mechanisms used by SIV mac239 Nef and HIV-1 Nef to downregulate class I MHC and found that the ability of SIV Nef to downregula...

  7. Surface antigenic profiling of stem cells from human omentum fat in comparison with subcutaneous fat and bone marrow

    OpenAIRE

    Dhanasekaran, M.; Indumathi, S.; Kanmani, A.; Poojitha, R.; Revathy, K. M.; Rajkumar, J. S.; D.Sudarsanam

    2012-01-01

    Omentum fat derived stem cells have emerged as an alternative and accessible therapeutic tool in recent years in contrast to the existing persuasive sources of stem cells, bone marrow and subcutaneous adipose tissue. However, there has been a scanty citation on human omentum fat derived stem cells. Furthermore, identification of specific cell surface markers among aforesaid sources is still controversial. In lieu of this existing perplexity, the current research work aims at signifying omentu...

  8. Characterization of foot- and mouth disease virus antigen by surface-enhanced laser desorption ionization-time of flight-mass spectrometry in aqueous and oil-emulsion formulations

    NARCIS (Netherlands)

    Harmsen, M.M.; Jansen, J.; Westra, D.F.; Coco-Martin, J.M.

    2010-01-01

    We have used a novel method, surface-enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS), to characterize foot-and-mouth disease virus (FMDV) vaccine antigens. Using specific capture with FMDV binding recombinant antibody fragments and tryptic digestion of FMDV antig

  9. Cationic Lipid-Formulated DNA Vaccine against Hepatitis B Virus : Immunogenicity of MIDGE-Th1 Vectors Encoding Small and Large Surface Antigen in Comparison to a Licensed Protein Vaccine

    NARCIS (Netherlands)

    Endmann, Anne; Klunder, Katharina; Kapp, Kerstin; Riede, Oliver; Oswald, Detlef; Talman, Eduard G.; Schroff, Matthias; Kleuss, Christiane; Ruiters, Marcel H. J.; Juhls, Christiane

    2014-01-01

    Currently marketed vaccines against hepatitis B virus (HBV) based on the small (S) hepatitis B surface antigen (HBsAg) fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible

  10. Distinct domains of the CD3-gamma chain are involved in surface expression and function of the T cell antigen receptor

    DEFF Research Database (Denmark)

    Wegener, A M; Hou, X; Dietrich, J;

    1995-01-01

    these two subunits. To identify CD3-gamma-specific domains that are required for assembly of the complete TcR and for surface expression and function of the TcR, chimeric CD3-gamma/CD3-delta molecules were constructed and expressed in T cells devoid of endogenous CD3-gamma. Substitution of the extracellular...... that the extracellular domain of CD3-gamma plays a unique role in TcR assembly. Functional analyses of the transfectants demonstrated that the intracellular domain of CD3-gamma is required for protein kinase C-mediated down-regulation of TcR but is dispensable for the pattern of tyrosine phosphorylation observed......The T cell antigen receptor (TcR) is a multisubunit complex that consists of at least six different polypeptides. We have recently demonstrated that the CD3-delta subunit cannot substitute for the CD3-gamma subunit in TcR cell surface expression, in spite of significant amino acid homology between...

  11. Phenotypic modulation of chronic lymphocytic leukemia cells by phorbol ester: induction of IgM secretion and changes in the expression of B cell-associated surface antigens.

    Science.gov (United States)

    Gordon, J; Mellstedt, H; Aman, P; Biberfeld, P; Klein, G

    1984-01-01

    Freshly explanted neoplastic populations from 22 cases of phenotypically well-characterized chronic type B lymphocytic leukemia were studied for their capacity to respond to the phorbol ester TPA in vitro. In all but four cases the secretion of IgM was either induced or increased, often to a high level. In contrast, the export of free immunoglobulin (Ig) light chains, an almost consistent feature of the B lymphocytic leukemias, remained relatively constant after TPA treatment. Parallel changes in leukemic cell surface phenotype were probed with both "conventional" and monoclonal antibodies, revealing some modulation of markers in every case investigated. A diminution in the level of surface Ig (preferentially IgD) and the accumulation of cytoplasmic Ig observed after phorbol ester treatment were accompanied by a corresponding reduction or loss of the B1 antigen and usually of B2 when present. The most consistent change induced by TPA was the appearance of BB-1, a marker of activated B lymphocytes, which was rarely expressed on fresh leukemic cells. Another marker of activated lymphocytes, LB-1, was also often induced or increased in its expression after exposure of the cells to TPA. The magnitude of the TPA response appeared to relate to the stage of maturation arrest of the individual leukemic clones rather than to any clinical parameter explored. The significance of the findings to normal B cell differentiation and their potential clinical utility are discussed.

  12. Infection with an H2 recombinant herpes simplex virus vector results in expression of MHC class I antigens on the surfaces of human neuroblastoma cells in vitro and mouse sensory neurons in vivo.

    Science.gov (United States)

    Abendroth, A; Simmons, A; Efstathiou, S; Pereira, R A

    2000-10-01

    The majority of neurons in herpes simplex virus (HSV)-infected murine sensory ganglia are transiently induced to express MHC-I antigens at the cell surface, whereas only a minority are themselves productively infected. The aim of the current work was to determine whether MHC-I antigens can be expressed on the surfaces of infected neurons in addition to their uninfected neighbours. To address this aim a recombinant HSV type 1 strain, S-130, was used to deliver a mouse H2K(d) gene, under control of the HCMV IE-1 promoter/enhancer, into human neuroblastoma cells in vitro and mouse primary sensory neurons in vivo. S-130 expressed H2K(d) antigens on the surfaces of IMR-32 cells, a human neuroblastoma cell line that expresses very low levels of MHC-I constitutively. In K562 cells, which do not express MHC-I constitutively, H2K(d) and beta(2)-microglobulin (beta(2)m) were shown to be co-expressed at the cell surface following S-130 infection. This observation was taken as evidence that class I heavy chain (alphaC) molecules encoded by the expression cassette in the HSV genome were transported to the cell surface as stable complexes with beta(2)m. Significantly, after introduction of S-130 into flank skin, H2K(d) antigens were detected on the surfaces of primary sensory neurons in ganglia innervating the inoculation site. Our data show that HSV-infected murine primary sensory neurons and human neuroblastoma cells are capable of expressing cell-surface MHC-I molecules encoded by a transgene. From this, we infer that up-regulation of alphaC expression is, in principle, sufficient to overcome potential impediments to neuronal cell surface expression of MHC-I complexes.

  13. Human Leukocyte Antigen-Presented Macrophage Migration Inhibitory Factor Is a Surface Biomarker and Potential Therapeutic Target for Ovarian Cancer.

    Science.gov (United States)

    Patterson, Andrea M; Kaabinejadian, Saghar; McMurtrey, Curtis P; Bardet, Wilfried; Jackson, Ken W; Zuna, Rosemary E; Husain, Sanam; Adams, Gregory P; MacDonald, Glen; Dillon, Rachelle L; Ames, Harold; Buchli, Rico; Hawkins, Oriana E; Weidanz, Jon A; Hildebrand, William H

    2016-02-01

    T cells recognize cancer cells via HLA/peptide complexes, and when disease overtakes these immune mechanisms, immunotherapy can exogenously target these same HLA/peptide surface markers. We previously identified an HLA-A2-presented peptide derived from macrophage migration inhibitory factor (MIF) and generated antibody RL21A against this HLA-A2/MIF complex. The objective of the current study was to assess the potential for targeting the HLA-A2/MIF complex in ovarian cancer. First, MIF peptide FLSELTQQL was eluted from the HLA-A2 of the human cancerous ovarian cell lines SKOV3, A2780, OV90, and FHIOSE118hi and detected by mass spectrometry. By flow cytometry, RL21A was shown to specifically stain these four cell lines in the context of HLA-A2. Next, partially matched HLA-A*02:01+ ovarian cancer (n = 27) and normal fallopian tube (n = 24) tissues were stained with RL21A by immunohistochemistry to assess differential HLA-A2/MIF complex expression. Ovarian tumor tissues revealed significantly increased RL21A staining compared with normal fallopian tube epithelium (P < 0.0001), with minimal staining of normal stroma and blood vessels (P < 0.0001 and P < 0.001 compared with tumor cells) suggesting a therapeutic window. We then demonstrated the anticancer activity of toxin-bound RL21A via the dose-dependent killing of ovarian cancer cells. In summary, MIF-derived peptide FLSELTQQL is HLA-A2-presented and recognized by RL21A on ovarian cancer cell lines and patient tumor tissues, and targeting of this HLA-A2/MIF complex with toxin-bound RL21A can induce ovarian cancer cell death. These results suggest that the HLA-A2/MIF complex should be further explored as a cell-surface target for ovarian cancer immunotherapy.

  14. HBV S基因变异与临床疾病的关系%The correlationship between heptatitis B surface antigen gene mutations and clinical diseases

    Institute of Scientific and Technical Information of China (English)

    许正锯; 潘兴南; 魏开鹏; 杨环文; 李树清; 黄志杰

    2013-01-01

    Objective To investigate the correlationship between heptatitis B surface antigen gene mutations and clinical diseases in patients with chronic hepatitis B in Quanzhou area. Methods Surface gene region of 43 patients with chronic HBV infection was amplified by PCR and mutations were analyzed after sequencing. Results Among 43 chronic HBV infected patients, the distributions of genetypes were B (29/43, 67.44%) and C (14/43, 32.56%), while that of subtypes were adw (28/43, 65.12%), adr (14/43, 32.56%) and ayw (1/43, 0.02%), respectively. Total of amino acid 32 (aa) mutations of hepatitis B surface antigen (HBsAg) were observed in these patients. The most common aa mutations including sY200F, sM2131, sI126T and sF85C, which were usually found in patients with hepatitis failure. Nineteen (19/43, 44.19%) aa mutations and 12 substitutions were found in HBV major hydrophilic region. The mutation of aal26 was the most common (7/23, 30.43%) mutation in MHR region, and there after was aal40 (3/23, 13.04%). sT126I/A mutation was found in 2 (2/29, 6.90%) cases with genotype B, while sI126T mutation was found in 5 (5/14, 35.71%) cases with genotype C. The mutation rate of aal26 in patients with genetype C was significantly higher than that of genetype B (χ2= 5.753, P 0.05). The mutation rate of surface antigen gene in "a" determinant was higher in patients with liver failure than that of chronic hepatitis B (χ2= 4.268, P < 0.05). Conclusions The most common genotype of HBV in Quanzhou area are B (adw) and C (adr). Some HBV surface antigen gene mutations were correlated with HBV genotype heterogeneity, which may be correlated with serious liver disease.%目的 探讨泉州地区乙型肝炎病毒(HBV)慢性感染者HBV S基因变异与临床疾病的关系.方法 采用PCR产物直接测序技术对43例慢性HBV感染者的HBV S区进行序列测定及分析.结果 43例慢性HBV感染者中共检出基因B型29例(29/43,67.44%),C型14例(14/43,32.56%);血清学分型adw型28

  15. Cell surface expression level variation between two common Human Leukocyte Antigen alleles, HLA-A2 and HLA-B8, is dependent on the structure of the C terminal part of the alpha 2 and the alpha 3 domains

    DEFF Research Database (Denmark)

    Dellgren, Christoffer; Nehlin, Jan O; Barington, Torben

    2015-01-01

    Constitutive cell surface expression of Human Leukocyte Antigen (HLA) class I antigens vary extremely from tissue to tissue and individual antigens may differ widely in expression levels. Down-regulation of class I expression is a known immune evasive mechanism used by cancer cells and viruses....... Moreover, recent observations suggest that even minor differences in expression levels may influence the course of viral infections and the frequency of complications to stem cell transplantation. We have shown that some human multipotent stem cells have high expression of HLA-A while HLA-B is only weakly...... expressed, and demonstrate here that this is also the case for the human embryonic kidney cell line HEK293T. Using quantitative flow cytometry and quantitative polymerase chain reaction we found expression levels of endogenous HLA-A3 (median 71,204 molecules per cell) 9.2-fold higher than the expression of...

  16. Seroreactivity to a Large Panel of Field-Derived Plasmodium falciparum Apical Membrane Antigen 1 and Merozoite Surface Protein 1 Variants Reflects Seasonal and Lifetime Acquired Responses to Malaria

    Science.gov (United States)

    Bailey, Jason A.; Pablo, Jozelyn; Niangaly, Amadou; Travassos, Mark A.; Ouattara, Amed; Coulibaly, Drissa; Laurens, Matthew B.; Takala-Harrison, Shannon L.; Lyke, Kirsten E.; Skinner, Jeff; Berry, Andrea A.; Jasinskas, Algis; Nakajima-Sasaki, Rie; Kouriba, Bourema; Thera, Mahamadou A.; Felgner, Philip L.; Doumbo, Ogobara K.; Plowe, Christopher V.

    2015-01-01

    Parasite antigen diversity poses an obstacle to developing an effective malaria vaccine. A protein microarray containing Plasmodium falciparum apical membrane antigen 1 (AMA1, n = 57) and merozoite surface protein 1 19-kD (MSP119, n = 10) variants prevalent at a malaria vaccine testing site in Bandiagara, Mali, was used to assess changes in seroreactivity caused by seasonal and lifetime exposure to malaria. Malian adults had significantly higher magnitude and breadth of seroreactivity to variants of both antigens than did Malian children. Seroreactivity increased over the course of the malaria season in children and adults, but the difference was more dramatic in children. These results help to validate diversity-covering protein microarrays as a promising tool for measuring the breadth of antibody responses to highly variant proteins, and demonstrate the potential of this new tool to help guide the development of malaria vaccines with strain-transcending efficacy. PMID:25294612

  17. Use of radioimmune assay in investigating reagents to be used in the immunocytochemical localization of hepatitis B surface antigen in immune complexes in the kidney of patients with membranous nephropathy and Australia antigenaemia

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe-Coote, S. (South African Medical Research Council, Tygerberg (South Africa). Inst. for Electron Microscopy)

    1983-09-01

    Radioimmune assay (RIA) was used to investigate the effect of fixatives on antigenicity of the hepatitis B surface antigen (HBsAg) and the effect of pronase on the elution of antibody (Ab) from the HBsAg-Ab complex. The effect of pronase on Ab elution was also tested on sections of kidney from a patient with the immune complex disease systemic lupus erythematosus (SLE). Immunoglobulin G (IgG) was located in pronase treated and untreated sections using the indirect immunoperoxidase technique. Glutareldehyde was shown to be the fixative of choice for studies involving HBsAg. All fixatives were shown to have less effect on antigenicity at 4/sup 0/C than at room temperature. Osmium tetroxide reduced antigenicity to one-third, even at 4/sup 0/C. RIA and SLE kidney section studies showed that Ab was eluted from immune complexes by pronase. Pre-fixation of the antigen (Ag) by glutaraldehyde appears to have no effect on the final elution, although fixation after pronase treatment seemed to enhance the elution effects. The availability of an RIA kit with HBsAg- and Ab-coated beads was of great assistance in evaluating reagents to be used in immunoperoxidase studies of HBsAg in immune complexes of patients with membranous nephropathy and Australia antigenaemia.

  18. A Conserved DNA Repeat Promotes Selection of a Diverse Repertoire of Trypanosoma brucei Surface Antigens from the Genomic Archive.

    Directory of Open Access Journals (Sweden)

    Galadriel Hovel-Miner

    2016-05-01

    Full Text Available African trypanosomes are mammalian pathogens that must regularly change their protein coat to survive in the host bloodstream. Chronic trypanosome infections are potentiated by their ability to access a deep genomic repertoire of Variant Surface Glycoprotein (VSG genes and switch from the expression of one VSG to another. Switching VSG expression is largely based in DNA recombination events that result in chromosome translocations between an acceptor site, which houses the actively transcribed VSG, and a donor gene, drawn from an archive of more than 2,000 silent VSGs. One element implicated in these duplicative gene conversion events is a DNA repeat of approximately 70 bp that is found in long regions within each BES and short iterations proximal to VSGs within the silent archive. Early observations showing that 70-bp repeats can be recombination boundaries during VSG switching led to the prediction that VSG-proximal 70-bp repeats provide recombinatorial homology. Yet, this long held assumption had not been tested and no specific function for the conserved 70-bp repeats had been demonstrated. In the present study, the 70-bp repeats were genetically manipulated under conditions that induce gene conversion. In this manner, we demonstrated that 70-bp repeats promote access to archival VSGs. Synthetic repeat DNA sequences were then employed to identify the length, sequence, and directionality of repeat regions required for this activity. In addition, manipulation of the 70-bp repeats allowed us to observe a link between VSG switching and the cell cycle that had not been appreciated. Together these data provide definitive support for the long-standing hypothesis that 70-bp repeats provide recombinatorial homology during switching. Yet, the fact that silent archival VSGs are selected under these conditions suggests the 70-bp repeats also direct DNA pairing and recombination machinery away from the closest homologs (silent BESs and toward the rest of

  19. Antibody response to a major human Pneumocystis carinii surface antigen in patients without evidence of immunosuppression and in patients with suspected atypical pneumonia

    DEFF Research Database (Denmark)

    Lundgren, Bettina; Lebech, M; Lind, K;

    1993-01-01

    IgG and IgM antibodies to a purified human Pneumocystis carinii surface antigen (gp95) were measured in 694 serum specimens from two different population groups using an EIA technique. In a population of 441 patients with no evidence of immunosuppression, the percentage of persons positive for Ig......G antibodies to gp95 was significantly lower in the age group 1 to 9 years (30%, 23/77) compared to persons 10 to 19 years old (56%, 49/88). In the age group 1 to 14 years there was a significant correlation between the percentage of persons with IgG antibodies to gp95 and age. In 106 consecutive patients...... under evaluation due to atypical pneumonia, 76 patients showed no change in the titre of antibodies to Legionella spp. or Mycoplasma pneumoniae in two consecutive serum samples. Three of these 76 patients (4%) demonstrated an increase in the level of IgG antibodies to gp95 in the paired samples. One...

  20. Hepatitis B vaccination coverage and risk factors associated with incomplete vaccination of children born to hepatitis B surface antigen-positive mothers, Denmark, 2006 to 2010.

    Science.gov (United States)

    Kunoee, Asja; Nielsen, Jens; Cowan, Susan

    2016-01-01

    In Denmark, universal screening of pregnant women for hepatitis B has been in place since November 2005, with the first two years as a trial period with enhanced surveillance. It is unknown what the change to universal screening without enhanced surveillance has meant for vaccination coverage among children born to hepatitis B surface antigen (HBsAg)-positive mothers and what risk factors exist for incomplete vaccination. This retrospective cohort study included 699 children of mothers positive for HBsAg. Information on vaccination and risk factors was collected from central registers. In total, 93% (651/699) of the children were vaccinated within 48 hours of birth, with considerable variation between birthplaces. Only 64% (306/475) of the children had received all four vaccinations through their general practitioner (GP) at the age of two years, and 10% (47/475) of the children had received no hepatitis B vaccinations at all. Enhanced surveillance was correlated positively with coverage of birth vaccination but not with coverage at the GP. No or few prenatal examinations were a risk factor for incomplete vaccination at the GP. Maternity wards and GPs are encouraged to revise their vaccination procedures and routines for pregnant women, mothers with chronic HBV infection and their children.

  1. Hepatitis B virus surface antigen and anti-hepatitis C virus rapid tests underestimate hepatitis prevalence among HIV-infected patients

    DEFF Research Database (Denmark)

    Hønge, Bo Langhoff; Jespersen, S; Medina, C;

    2014-01-01

    OBJECTIVES: In the case of coinfection with HIV and hepatitis B virus (HBV) and/or hepatitis C virus (HCV), hepatic disease progression is often accelerated, with higher rates of liver cirrhosis and liver-related mortality. We aimed to evaluate the performance of the rapid tests used routinely...... to detect HBV surface antigen (HBsAg) and anti-HCV among HIV-infected patients in Guinea-Bissau. METHODS: Blood samples from HIV-infected patients in Guinea-Bissau were stored after testing for HBsAg and anti-HCV with rapid tests. Samples were subsequently re-tested for HBsAg and anti-HCV in Denmark....... RESULTS: Two rapid tests were used in Guinea-Bissau: HBsAg Strip Ref 2034 (VEDA.LAB, Alençon, France; sensitivity 62.3%; specificity 99.2%) and HEPA-SCAN (Bhat Bio-Tech, Bangalore, India; sensitivity 57.1%; specificity 99.7%). In the two tests the ability to obtain the correct outcome depended...

  2. Stable solid-phase Rh antigen.

    Science.gov (United States)

    Yared, M A; Moise, K J; Rodkey, L S

    1997-12-01

    Numerous investigators have attempted to isolate the Rh antigens in a stable, immunologically reactive form since the discovery of the Rh system over 56 years ago. We report here a successful and reproducible approach to solubilizing and adsorbing the human Rh antigen(s) to a solid-phase matrix in an antigenically active form. Similar results were obtained with rabbit A/D/F red blood cell antigens. The antigen preparation was made by dissolution of the red blood cell membrane lipid followed by fragmentation of the residual cytoskeleton in an EDTA solution at low ionic strength. The antigenic activity of the soluble preparations was labile in standard buffers but was stable in zwitterionic buffers for extended periods of time. Further studies showed that the antigenic activity of these preparations was enhanced, as was their affinity for plastic surfaces, in the presence of acidic zwitterionic buffers. Adherence to plastic surfaces at low pH maintained antigenic reactivity and specificity for antibody was retained. The data show that this approach yields a stable form of antigenically active human Rh D antigen that could be used in a red blood cell-free assay for quantitative analysis of Rh D antibody and for Rh D antibody immunoadsorption and purification.

  3. Diversity of Sarcocystis spp shed by opossums in Brazil inferred with phylogenetic analysis of DNA coding ITS1, cytochrome B, and surface antigens.

    Science.gov (United States)

    Valadas, Samantha Y O B; da Silva, Juliana I G; Lopes, Estela Gallucci; Keid, Lara B; Zwarg, Ticiana; de Oliveira, Alice S; Sanches, Thaís C; Joppert, Adriana M; Pena, Hilda F J; Oliveira, Tricia M F S; Ferreira, Helena L; Soares, Rodrigo M

    2016-05-01

    Although few species of Sarcocystis are known to use marsupials of the genus Didelphis as definitive host, an extensive diversity of alleles of surface antigen genes (sag2, sag3, and sag4) has been described in samples of didelphid opossums in Brazil. In this work, we studied 25 samples of Sarcocystis derived from gastrointestinal tract of opossums of the genus Didelphis by accessing the variability of sag2, sag3, sag4, gene encoding cytochrome b (cytB) and first internal transcribed spacer (ITS1). Reference samples of Sarcocystis neurona (SN138) and Sarcocystis falcatula (SF1) maintained in cell culture were also analyzed. We found four allele variants of cytB, seven allele variants of ITS1, 10 allele variants of sag2, 13 allele variants of sag3, and 6 allele variants of sag4. None of the sporocyst-derived sequences obtained from Brazilian opossums revealed 100% identity to SN138 at cytB gene, nor to SN138 or SF1 at ITS1 locus. In addition, none of the sag alleles were found identical to either SF1 or SN138 homologous sequences, and a high number of new sag allele types were found other than those previously described in Brazil. Out of ten sag2 alleles, four are novel, while eight out of 13 sag3 alleles are novel and one out of six sag4 alleles is novel. Further studies are needed to clarify if such a vast repertoire of allele variants of Sarcocystis is the consequence of re-assortments driven by sexual exchange, in order to form individuals with highly diverse characteristics, such as pathogenicity, host spectrum, among others or if it only represents allele variants of different species with different biological traits.

  4. Evaluation of the performance of four methods for detection of hepatitis B surface antigen and their application for testing 116,455 specimens.

    Science.gov (United States)

    Liu, Can; Chen, Tianbin; Lin, Jinpiao; Chen, Huijuan; Chen, Jing; Lin, Sheng; Yang, Bin; Shang, Hongyan; Ou, Qishui

    2014-02-01

    Hepatitis B surface antigen (HBsAg) is a crucial serum marker for the diagnosis of hepatitis B virus (HBV) infection. It is imperative to compare test results from different detection methods based on different principles. Four methods, chemiluminescent microparticle immunoassay (CMIA), electrochemiluminescent immunoassay (ECLIA), enzyme-linked immunosorbent assay (ELISA) and golden immunochromato-graphic assay (GICA) were applied to test the HBsAg level in 250 specimens. According to the EP12-A2 and EP15-A2 documents from Clinical and Laboratory Standards Institute (CLSI), the concentration at which repeated results are 50% positive (C50) of HBsAg detected by CMIA, ECLIA, ELISA and GICA was 0.05, 0.08, 0.15 and 15.0IU/ml, respectively. When the detection concentration of HBsAg was 0.5IU/ml, the imprecision degree of CMIA, ECLIA and ELISA was 8.1%, 5.9% and 14.9% respectively. When detecting high HBsAg level (≥20.0IU/ml) and HBsAg negative specimens, the consistency of the four methods was high, while for the low level (0.05-20.0IU/ml), the consistency was poor (except for the CMIA and ECLIA, Pevaluation of the four methods in qualitative diagnosis of HBsAg level in the 116,455 specimens, there was no significant discrepancy among CMIA, CMIA and ECLIA, however, GICA was significantly different from the other 3 methods. Compared with CMIA, the false negative rate of ECLIA, ELISA and GICA was 0.2%, 1.3% and 12.3% respectively. In conclusion, GICA was only suitable for the preliminary screening of HBsAg positive individuals and ELISA can be applied to the qualitative diagnosis of HBsAg. Both CMIA and ECLIA were suitable for the quantitative determination of HBsAg.

  5. Simple high-cell density fed-batch technique for high-level recombinant protein production with Pichia pastoris: Application to intracellular production of Hepatitis B surface antigen

    Directory of Open Access Journals (Sweden)

    Ross Anton

    2009-02-01

    Full Text Available Abstract Background Hepatitis B is a serious global public health concern. Though a safe and efficacious recombinant vaccine is available, its use in several resource-poor countries is limited by cost. We have investigated the production of Hepatitis B virus surface antigen (HBsAg using the yeast Pichia pastoris GS115 by inserting the HBsAg gene into the alcohol oxidase 1 locus. Results Large-scale production was optimized by developing a simple fed-batch process leading to enhanced product titers. Cells were first grown rapidly to high-cell density in a batch process using a simple defined medium with low salt and high glycerol concentrations. Induction of recombinant product synthesis was carried out using rather drastic conditions, namely through the addition of methanol to a final concentration of 6 g L-1. This methanol concentration was kept constant for the remainder of the cultivation through continuous methanol feeding based on the on-line signal of a flame ionization detector employed as methanol analyzer in the off-gas stream. Using this robust feeding protocol, maximum concentrations of ~7 grams HBsAg per liter culture broth were obtained. The amount of soluble HBsAg, competent for assembly into characteristic virus-like particles (VLPs, an attribute critical to its immunogenicity and efficacy as a hepatitis B vaccine, reached 2.3 grams per liter of culture broth. Conclusion In comparison to the highest yields reported so far, our simple cultivation process resulted in an ~7 fold enhancement in total HBsAg production with more than 30% of soluble protein competent for assembly into VLPs. This work opens up the possibility of significantly reducing the cost of vaccine production with implications for expanding hepatitis B vaccination in resource-poor countries.

  6. Purification of hepatitis B surface antigen virus-like particles from recombinant Pichia pastoris and in vivo analysis of their immunogenic properties.

    Science.gov (United States)

    Gurramkonda, Chandrasekhar; Zahid, Maria; Nemani, Satish Kumar; Adnan, Ahmad; Gudi, Satheesh Kumar; Khanna, Navin; Ebensen, Thomas; Lünsdorf, Heinrich; Guzmán, Carlos A; Rinas, Ursula

    2013-12-01

    Following earlier studies on high-level intracellular production of hepatitis B surface antigen (HBsAg) using recombinant Pichia pastoris, we present here in detail an enhanced method for the purification of recombinant HBsAg virus-like particles (VLPs). We have screened various detergents for their ability to promote the solubilization of recombinant intracellular HBsAg. In addition, we have analyzed the effect of cell disruption and extraction regarding their impact on the release of HBsAg. Our results show that introduction of the mild nonionic detergent Tween 20 in the initial process of cell lysis at ∼600bars by high pressure homogenization leads to the best results. The subsequent purification steps involved polyethylene glycol precipitation of host cell contaminants, hydrophobic adsorption of HBsAg to colloidal silica followed by ion-exchange chromatography and either isopycnic density ultracentrifugation or size exclusion chromatography for the recovery of the VLPs. After final KSCN treatment and dialysis, a total yield of ∼3% with a purity of >99% was reached. The pure protein was characterized by electron microscopy, showing the presence of uniform VLPs which are the pre-requisite for immunogenicity. The intramuscular co-administration of HBsAg VLPs, with either alum or a PEGylated-derivative of the toll-like receptor 2/6 agonist MALP-2, to mice resulted in the elicitation of significantly higher HBsAg-specific IgG titers as well as a stronger cellular immune response compared to mice vaccinated with a gold standard vaccine (Engerix™). These results show that P. pastoris derived HBsAg VLPs exhibit a high potential as a superior biosimilar vaccine against hepatitis B. PMID:24141044

  7. DNA-based vaccination induces humoral and cellular immune responses against hepatitis B virus surface antigen in mice without activation of Cmyc

    Institute of Scientific and Technical Information of China (English)

    Lian San Zhao; Shan Qin; Tao You Zhou; Hong Tang; Li Liu; Bing Jun Lei

    2000-01-01

    AIM To develop a safe and effective DNA vaccine for inducing humoral and cellular immunological responses against hepatitis B virus surface antigen (HBsAg). METHODS BALB/c mice were inoculated with NV-HB/s, a recombinant plasmid that had been inserted S gene of hepatitis B virus genome and could express HBsAg in eukaryotes. HBsAg expression was measured by ABC immunohistochemical assay, generation of anti-HBs by ELISA and cytotoxic T lymphocyte (CTL), by MTT method, existence of vaccine DNA by Southern blot hybridization and activation of oncogene C-myc by in situ hybridization.RESULTS With NV-HB/s vaccination by intramuscular injection, anti-HBs was initially positive 2 weeks after inoculation while all mice tested were HBsAg positive in the muscles. The titers and seroconversion rate of anti-HBs were steadily increasing as time went on and were dose-dependent. All the mice inoculated with 100 μg NV-HB/ s were anti-HBs positive one month after inoculation, the titer was 1:1024 or more. The humoral immune response was similar induced by either intramuscular or intradermal injection. CTL activities were much stronger (45.26%) in NV-HB/s DNA immunized mice as compared with those (only 6%) in plasmaderived HBsAg vaccine immunized mice. Two months after inoculation, all muscle samples were positive by Southern-blot hybridization for NV-HB/s DNA detection, but decreased to 25%and all were undetectable by in situ hybridization after 6 months. No oncogene Cmyc activation was found in the muscle of inoculation site. CONCLUSION NV-HB/s could generate humoral and cellular immunological responses against HBsAg that had been safely expressed in situ by NV-HB/s vaccination.

  8. Immunogenicity and safety of Advax™, a novel polysaccharide adjuvant based on delta inulin, when formulated with hepatitis B surface antigen: a randomized controlled Phase 1 study.

    Science.gov (United States)

    Gordon, David; Kelley, Peter; Heinzel, Susanne; Cooper, Peter; Petrovsky, Nikolai

    2014-11-12

    There is a need for additional safe and effective human vaccine adjuvants. Advax™ is a novel adjuvant produced from semi-crystalline particles of delta inulin. In animal studies Advax enhanced humoral and cellular immunity to hepatitis B surface antigen (HBsAg) without inducing local or systemic reactogenicity. This first-in-man Phase 1 clinical trial tested the safety and tolerability of three intramuscular doses of HBsAg formulated with Advax in a group of healthy adult subjects. Advax was well tolerated with injection site pain scores not significantly different to subjects receiving HBsAg alone and no adverse events were reported in subjects that received Advax. Seroprotection and HBsAb geometric mean titers (GMT) after three immunizations were higher in the Advax 5mg (seroprotection 5/6, 83.3%, GMT 40.7, 95% CI 11.9-139.1) and 10mg (seroprotection 4/5, 80%, GMT 51.6, 95% CI 10.0-266.2) groups versus HBsAg alone (seroprotection 1/5, 20%, GMT 4.1, 95% CI 1.3-12.8). Similarly the proportion of subjects with positive CD4 T-cell responses to HBsAg was higher in the Advax 5mg (4/6, 67%) and Advax 10mg (4/5, 80%) groups versus HBsAg alone (1/5, 20%). These results confirm the safety, tolerability and immunogenicity of Advax adjuvant observed in preclinical studies. Advax may represent a suitable replacement for alum adjuvants in prophylactic human vaccines subject to confirmation of current results in larger studies. Australia and New Zealand Clinical Trial Registry: ACTRN12607000598482.

  9. Plasmids enriched with CpG motifs activate human peripheral blood mononuclear cells in vitro and enhance th-1 immune responses to hepatitis B surface antigen in mice.

    Science.gov (United States)

    Chen, Zhihui; Cao, Jie; Liao, Xiaoling; Ke, Jinshan; Zhu, Shiying; Zhao, Ping; Qi, Zhongtian

    2011-06-01

    T helper-1 (Th-1)-type immune responses play an important role in viral clearance during infection with hepatitis B virus (HBV). Unmethylated CpG motifs present in bacterial DNA can activate toll-like receptor 9 (TLR9) signals and act as potent adjuvants to induce Th-1-type immune responses. Here, a mini-plasmid with 812 base pairs in length was constructed and used as a vector to prepare a series of plasmids containing 3-21 copies of D-type CpG motifs. In vitro, these CpG-enriched plasmids strongly stimulated proliferation of human peripheral blood mononuclear cells (PBMCs) and enhanced secretion of interferon-γ (IFN-γ) and interleukin-12 (IL-12). The responses of the PBMCs from healthy individuals to the plasmids were stronger than those obtained from HBV-infected individuals. Contrary to the strong Th-2-biased response induced by surface antigen of hepatitis B virus (HBsAg) plus alum adjuvant, immunization of BALB/c mice with HBsAg plus these plasmids induced a strong Th-1-biased response. The plasmids increased the titers of HBsAg-specific total immunoglobulin G (IgG) and IgG(2a). HBsAg-specific IL-2 and IFN-γ production and cytotoxic activity were also enhanced in the presence of the plasmids. The strength of the immune responses positively correlated with the number of CpG motifs in the plasmids. These results indicate that the use of CpG-enriched plasmids as an adjuvant to recombinant HBsAg could provide a promising and cost-effective approach for the development of efficacious therapeutic vaccines against HBV infection. PMID:21668361

  10. Molecular characterization of a variant virus that caused de novo hepatitis B without elevation of hepatitis B surface antigen after chemotherapy with rituximab.

    Science.gov (United States)

    Miyagawa, Masami; Minami, Masahito; Fujii, Kota; Sendo, Rei; Mori, Kojiro; Shimizu, Daisuke; Nakajima, Tomoaki; Yasui, Kohichiroh; Itoh, Yoshito; Taniwaki, Masafumi; Okanoue, Takeshi; Yoshikawa, Toshikazu

    2008-12-01

    Hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg)-negative patients following treatment with rituximab has been reported increasingly. The aim of this study was to investigate the molecular mechanisms underlying HBV reactivation in an HBsAg-negative patient. HBV was reactivated in a 75-year-old man following chemotherapy with rituximab, without elevation of HBsAg. The patient's full-length HBV genome was cloned and the entire sequence was determined. Transfection studies were performed in vitro using recombinant wild-type HBV (wild-type), the patient's HBV (patient), and two chimeric HBV constructs, in which the preS/S region of the patient and wild-type virus had been exchanged with one another. Secreted HBsAg and intra- and extra-cellular HBV DNA were measured. The number of amino acid substitutions in HBV from this patient was much higher than in previous reports of HBV mutants, such as occult HBV and vaccine escape HBV mutants. Levels of HBsAg and HBV DNA production in vitro were significantly lower in the patient compared to wild-type transfections. From analyses of the chimeric constructs, the altered preS/S region was responsible mainly for this impairment. These results show that highly mutated HBV can reactivate after chemotherapy with rituximab, despite an unusually large number of mutations, resulting in impaired viral replication in vitro. Severe immune suppression, probably caused by rituximab, may permit reactivation of highly mutated HBV. These findings have important clinical implications for the prevention and management of HBV reactivation and may explain partially the mechanism of recent, unusual cases of HBV reactivation. PMID:19040281

  11. Seroprevalence of Hepatitis B surface antigen, antibodies to the Hepatitis C virus, and human immunodeficiency virus in a hospital-based population in Jaipur, Rajasthan

    Directory of Open Access Journals (Sweden)

    Sood Smita

    2010-01-01

    Full Text Available Background: Hepatitis B, hepatitis C, and HIV infections are a serious global and public health problem. To assess the magnitude and dynamics of disease transmission and for its prevention and control, the study of its seroprevalence is important. A private hospital catering to the needs of a large population represents an important center for serological surveys. Available data, at Rajasthan state level, on the seroprevalence of these bloodborne pathogens is also very limited. Objective: A study was undertaken to estimate the seroprevalence of hepatitis B surface antigen (HBsAg and antibodies to hepatitis C (anti-HCV Ab and human immunodeficiency virus (anti-HIV Ab in both the sexes and different age groups in a hospital-based population in Jaipur, Rajasthan. Materials and Methods: Serum samples collected over a period of 14 months from patients attending OPDs and admitted to various IPDs of Fortis Escorts Hospital, Jaipur, were subjected within the hospital-based lab for the detection of HBsAg and anti-HCV Ab and anti-HIV Ab using rapid card tests. This was followed by further confirmation of all reactive samples by a microparticle enzyme immunoassay (Abbott AxSYM at Super Religare Laboratories (formerly SRL Ranbaxy Reference Lab, Mumbai. Results: The seroprevalence of HBsAg was found to be 0.87%, of anti-HCV Ab as 0.28%, and of anti-HIV Ab as 0.35%. Conclusion: The study throws light on the magnitude of viral transmission in the community in the state of Rajasthan and provides a reference for future studies.

  12. Diversity of Sarcocystis spp shed by opossums in Brazil inferred with phylogenetic analysis of DNA coding ITS1, cytochrome B, and surface antigens.

    Science.gov (United States)

    Valadas, Samantha Y O B; da Silva, Juliana I G; Lopes, Estela Gallucci; Keid, Lara B; Zwarg, Ticiana; de Oliveira, Alice S; Sanches, Thaís C; Joppert, Adriana M; Pena, Hilda F J; Oliveira, Tricia M F S; Ferreira, Helena L; Soares, Rodrigo M

    2016-05-01

    Although few species of Sarcocystis are known to use marsupials of the genus Didelphis as definitive host, an extensive diversity of alleles of surface antigen genes (sag2, sag3, and sag4) has been described in samples of didelphid opossums in Brazil. In this work, we studied 25 samples of Sarcocystis derived from gastrointestinal tract of opossums of the genus Didelphis by accessing the variability of sag2, sag3, sag4, gene encoding cytochrome b (cytB) and first internal transcribed spacer (ITS1). Reference samples of Sarcocystis neurona (SN138) and Sarcocystis falcatula (SF1) maintained in cell culture were also analyzed. We found four allele variants of cytB, seven allele variants of ITS1, 10 allele variants of sag2, 13 allele variants of sag3, and 6 allele variants of sag4. None of the sporocyst-derived sequences obtained from Brazilian opossums revealed 100% identity to SN138 at cytB gene, nor to SN138 or SF1 at ITS1 locus. In addition, none of the sag alleles were found identical to either SF1 or SN138 homologous sequences, and a high number of new sag allele types were found other than those previously described in Brazil. Out of ten sag2 alleles, four are novel, while eight out of 13 sag3 alleles are novel and one out of six sag4 alleles is novel. Further studies are needed to clarify if such a vast repertoire of allele variants of Sarcocystis is the consequence of re-assortments driven by sexual exchange, in order to form individuals with highly diverse characteristics, such as pathogenicity, host spectrum, among others or if it only represents allele variants of different species with different biological traits. PMID:26905780

  13. BIOCHEMICAL AND IMMUNOLOGICAL CHARACTERIZATION OF THE 200kD SCHISTOSOMULUM SURFACE ANTIGEN COMMON TO SCHISTOSOMA MANSONI AND SCHISTOSOMA JAPONICUM%曼氏和日本血吸虫童虫体表200kD共同抗原的生化与免疫学特性

    Institute of Scientific and Technical Information of China (English)

    易新元; 周金春; 王庆林

    2000-01-01

    Objective To study the biochemecal and immunological characterization of the 200 kD schistosomulum surface antigen Method and results A very high molecular weight schistosomulum surface antigen of Mr>200kD was identified and characterized using monoclonal antibodies. Carbohydrate modification experiments followed by radioimmunobinding assays demonstrated that the epitope recognised by the mAbs on this antigen was carbohydrate in nature, while protein digestion experiments followed by SDS-PAGE indicated that this antigen also contained protein. Immunoprecipitation of 125I-labelled cercarial, schistosomulum, adult worm and miracidial surface antigens followed by gel analysis showed the carbohydrate epitope to be present on 5 cercarial, 2 schistosomulum and 5 miracidial surface molecules, and suggested a possible ecological function involved in adapting the parasite to the aquatic free-living stages of its life cycle and possibly also in protecting the early schistosomula from host immune damage. The 5 cercarial surfacs antigens proved to be associated with the CHR, since all the mAbs which recognised those antigens could induce a strong CHR. A kinetic investigation of the carbohydrate epitope on schistosomula of different ages demonstrated a gradual and possibly irreversible loss during the culture period. The epitope completely disappeared from the surface of adult worms. Conclusion To demonstrate an epitope common to a number of surface molecules of various developmental stages of schistosome and therefore explains the immunological cross - reactivity among different stages at the molecular level.

  14. Characterization of sporozoite surface antigens of Plasmodium falciparum, using monoclonal antibodies. Part of a coordinated programme on the preparation of irradiated vaccines against some human diseases

    International Nuclear Information System (INIS)

    Sporozoites are considered as a source of potential vaccine. Characterization of their antigens is therefore important and can be achieved by monoclonal antibodies. The purpose of this project is to study the production of monoclonal antibodies against sporozoites of P. falciparum. Various infections of mosquitoes were carried out during the period 1981-1982 to obtain antigens for the production of hybridomas. Hybridomas were produced from mice immunized through the bites of infected mosquitoes and by intravenous inoculation. The anti-sporozoite activity of the hybridomas was tested by an immunofluorescent antibody test using P. falciparum sporozoites as antigens. Positive immunofluorescence was seen in hybridoma cell lines tested with P. falciparum, whereas negative results were obtained when the cell lines were cross-reacted with other human species (P. vivax) and with a rodent malaria parasite (P. berghei)

  15. Virosomes for antigen and DNA delivery

    NARCIS (Netherlands)

    Daemen, T; de Mare, A; Bungener, L; de Jonge, J; Huckriede, A; Wilschut, J

    2005-01-01

    Specific targeting and delivery as well as the display of antigens on the surface of professional antigen-presenting cells (APCs) are key issues in the design and development of new-generation vaccines aimed at the induction of both humoral and cell-mediated immunity. Prophylactic vaccination agains

  16. Inhibition of Viability, Proliferation, Cytokines Secretion, Surface Antigen Expression, and Adipogenic and Osteogenic Differentiation of Adipose-Derived Stem Cells by Seven-Day Exposure to 0.5 T Static Magnetic Fields

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-01-01

    Full Text Available After seven-day exposure to 0.5-Tesla Static Magnetic Field (SMF, Adipose-derived Stem Cells (ASCs and those labeled by superparamagnetic iron oxide (SPIO nanoparticles were examined for viability by methyl thiazol tetrazolium (MTT assay, proliferation by cell counting and bromodeoxyuridine (BrdU incorporation, DNA integrity by single cell gel electrophoresis, surface antigen by flow cytometry analysis, and the expression of cytokines and genetic markers by reverse transcription-PCR and underwent adipogenic and osteogenic differentiation assessed by quantifying related specific genes expression. The SMF slightly reduced cell viability and proliferation and inhibited the expression of CD49d, CD54, and CD73 but did not damage DNA integrity. The SMF slightly downregulated the expression of cytokines including Vascular Endothelial Growth Factor (VEGF, Insulin-like Growth Factor-1 (IGF-1, Transforming Growth Factor Beta 1 (TGF-β1, genetic markers comprising Stem Cell Antigen-1 (Sca1, Octamer-4 (Oct-4, ATP-binding Cassette Subfamily B Member 1 (ABCB1, adipogenic marker genes containing Lipoprotein Lipase (LPL, Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ, and osteogenic marker genes including Secreted Phosphor-protein 1 (SPP1 and Osterix (OSX. Exposure to 0.5 T SMF for seven days inhibited viability, proliferation, surface antigen expression, cytokine secretion, stem cell genetic marker expression, and adipogenic and osteogenic differentiation but did not affect the DNA integrity in ASCs with or without SPIO labeling.

  17. Transplacentally acquired maternal antibody against hepatitis B surface antigen in infants and its influence on the response to hepatitis B vaccine.

    Directory of Open Access Journals (Sweden)

    Zhiqun Wang

    Full Text Available BACKGROUND: Passively acquired maternal antibodies in infants may inhibit active immune responses to vaccines. Whether maternal antibody against hepatitis B surface antigen (anti-HBs in infants may influence the long-term immunogenicity of hepatitis B vaccine remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: Totally 338 pairs of mothers and children were enrolled. All infants were routinely vaccinated against hepatitis B based on 0-, 1- and 6-month schedule. We characterized the transplacental transfer of maternal anti-HBs, and compared anti-HBs response in children of mothers with or without anti-HBs. In a prospective observation, all 63 anti-HBs positive mothers transferred anti-HBs to their infants; 84.1% of the infants had higher anti-HBs concentrations than their mothers. One and half years after vaccination with three doses of hepatitis B vaccine, the positive rate and geometric mean concentration (GMC of anti-HBs in 32 infants with maternal anti-HBs were comparable with those in 32 infants without maternal antibody (90.6% vs 87.5%, P = 0.688, and 74.5 vs 73.5 mIU/ml, P = 0.742, respectively. In a retrospective analysis, five and half years after vaccination with three doses vaccine, the positive rates of anti-HBs in 88 children of mothers with anti-HBs ≥1000 mIU/ml, 94 children of mothers with anti-HBs 10-999 mIU/ml, and 61 children of mothers with anti-HBs <10 mIU/ml were 72.7%, 69.2%, and 63.9% (P = 0.521, respectively; anti-HBs GMC in these three groups were 38.9, 43.9, and 31.7 mIU/ml (P = 0.726, respectively. CONCLUSIONS/SIGNIFICANCE: The data demonstrate that maternal anti-HBs in infants, even at high concentrations, does not inhibit the long-term immunogenicity of hepatitis B vaccine. Thus, current hepatitis B vaccination schedule for infants will be still effective in the future when most infants are positive for maternal anti-HBs due to the massive vaccination against hepatitis B.

  18. Long-term effect of interferon plus ribavirin on hepatitis B surface antigen seroclearance in patients dually infected with hepatitis B and C viruses.

    Directory of Open Access Journals (Sweden)

    Ming-Lun Yeh

    Full Text Available BACKGROUND: Interferon-α/ribavirin combination therapy might promote hepatitis B surface antigen (HBsAg seroclearance in patients dually infected with hepatitis B and C viruses (HBV/HCV, but the long-term effect remains unclear. We aimed to investigate the rate of and the factors associated with HBsAg seroclearance during long-term follow-up after interferon-α/ribavirin combination therapy in HBV/HCV dually-infected patients. METHODOLOGY/PRINCIPAL FINDINGS: Eighty-one patients who received interferon-α/ribavirin combination therapy for 24 weeks with a follow-up period of >24 weeks were enrolled. HBV serological markers and HBV DNA were determined every 6 months. Early and late HBsAg seroclearance were defined as HBsAg loss in less or more than 6 months after end-of-treatment, respectively. Fifteen (18.5% patients had HBsAg seroclearance during a mean follow-up period of 3.4 (0.5-5.1 years. The 5-year cumulative incidence was 25.6%. Baseline cirrhosis and HBV DNA negativity 1 year after end-of-treatment were independently predictive of HBsAg seroclearance with an odds ratio (OR, 95% confidence intervals (CI of 16.6, 1.8-153 and 9.2, 1.4-62.1, respectively, by Cox regression hazard analysis. Four patients developed early and 11 developed late HBsAg seroclearance, respectively. Cox regression hazard analysis showed no factor was associated with early HBsAg seroclearance, whilst HBV DNA negativity 1 year after end-of-treatment was the only significant factor predicting late HBsAg loss (OR, 43.0; CI, 2.5-745. Five patients had HBsAg seroconversion with a 5-year cumulative incidence of 8.3%. HBV DNA negativity at baseline and one year after EOT had a trend for HBsAg seroconversion. HCV response did not correlate to HBsAg loss. CONCLUSIONS: We demonstrated that interferon-α/ribavirin had long-term effect on HBsAg seroclearance in dually HBV/HCV-infected patients. Baseline cirrhosis and seroclearance of HBV DNA 1 year after end-of-treatment were

  19. A new trivalent SnSAG surface antigen chimera for efficient detection of antibodies against Sarcocystis neurona and diagnosis of equine protozoal myeloencephalitis.

    Science.gov (United States)

    Yeargan, Michelle; de Assis Rocha, Izabela; Morrow, Jennifer; Graves, Amy; Reed, Stephen M; Howe, Daniel K

    2015-05-01

    Enzyme-linked immunosorbent assays (ELISAs) based on the SnSAG surface antigens of Sarcocystis neurona provide reliable detection of infection by the parasite. Moreover, accurate serodiagnosis of equine protozoal myeloencephalitis (EPM) is achieved with the SnSAG ELISAs by measuring antibodies in serum and cerebrospinal fluid (CSF) to reveal active infection in the central nervous system. Two independent ELISAs based on recombinant (r)SnSAG2 or a chimeric fusion of SnSAG3 and SnSAG4 (rSnSAG4/3) are currently used together for EPM serodiagnosis to overcome varied antibody responses in different horses. To achieve reliable antibody detection with a single ELISA instead of 2 separate ELISAs, rSnSAG2 was fused with rSnSAG4/3 into a single trivalent protein, designated rSnSAG2/4/3. Paired serum and CSF from 163 horses were tested with all 3 ELISAs. When the consensus antibody titers obtained with the rSnSAG2 and rSnSAG4/3 ELISAs were compared to the single SAG2/4/3 ELISA titers, Spearman rank correlation coefficients of ρ = 0.74 and ρ = 0.90 were obtained for serum and CSF, respectively, indicating strong agreement between the tests. When the rSnSAG2 and rSnSAG4/3 consensus serum-to-CSF titer ratio was compared to the rSnSAG2/4/3 serum-to-CSF titer ratio, the Spearman correlation coefficient was ρ = 0.87, again signifying strong agreement. Importantly, comparing the diagnostic interpretation of the serum-to-CSF titer ratios yielded a Cohen kappa value of 0.77. These findings suggest that the single ELISA based on the trivalent rSnSAG2/4/3 will provide serologic and diagnostic results that are highly comparable to the consensus of the 2 independent ELISAs based on rSnSAG2 and rSnSAG4/3. PMID:25943129

  20. Improved cell mediated immune responses after successful re-vaccination of non-responders to the hepatitis B virus surface antigen (HBsAg) vaccine using the combined hepatitis A and B vaccine.

    Science.gov (United States)

    Nyström, Jessica; Cardell, Kristina; Björnsdottir, Thora Björg; Fryden, Aril; Hultgren, Catharina; Sällberg, Matti

    2008-11-01

    We successfully re-vaccinated hepatitis B virus (HBV) vaccine non-responders using a double dose of the combined hepatitis A virus (HAV) and HBV vaccine. The hope was to improve priming of hepatitis B surface antigen (HBsAg)-specific cell mediated immune response (CMI) by an increased antigen dose and a theoretical adjuvant-effect from the local presence of a HAV-specific CMI. A few non-responders had a detectable HBsAg-specific CMI before re-vaccination. An in vitro detectable HBsAg-specific CMI was primed equally effective in non-responders (58%) as in first time vaccine recipients (68%). After the third dose a weak, albeit significant, association was observed between the magnitude of HBsAg-specific proliferation and anti-HBs levels. This regimen improves the priming of HBsAg-specific CMIs and antibodies.

  1. Mapping epitopes and antigenicity by site-directed masking

    Science.gov (United States)

    Paus, Didrik; Winter, Greg

    2006-06-01

    Here we describe a method for mapping the binding of antibodies to the surface of a folded antigen. We first created a panel of mutant antigens (-lactamase) in which single surface-exposed residues were mutated to cysteine. We then chemically tethered the cysteine residues to a solid phase, thereby masking a surface patch centered on each cysteine residue and blocking the binding of antibodies to this region of the surface. By these means we mapped the epitopes of several mAbs directed to -lactamase. Furthermore, by depleting samples of polyclonal antisera to the masked antigens and measuring the binding of each depleted sample of antisera to unmasked antigen, we mapped the antigenicity of 23 different epitopes. After immunization of mice and rabbits with -lactamase in Freund's adjuvant, we found that the antisera reacted with both native and denatured antigen and that the antibody response was mainly directed to an exposed and flexible loop region of the native antigen. By contrast, after immunization in PBS, we found that the antisera reacted only weakly with denatured antigen and that the antibody response was more evenly distributed over the antigenic surface. We suggest that denatured antigen (created during emulsification in Freund's adjuvant) elicits antibodies that bind mainly to the flexible regions of the native protein and that this explains the correlation between antigenicity and backbone flexibility. Denaturation of antigen during vaccination or natural infections would therefore be expected to focus the antibody response to the flexible loops. backbone flexibility | Freund's adjuvant | conformational epitope | antisera

  2. Binding of antibodies to the extractable nuclear antigens SS-A/Ro and SS-B/La is induced on the surface of human keratinocytes by ultraviolet light (UVL): Implications for the pathogenesis of photosensitive cutaneous lupus

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, F.; Kashihara-Sawami, M.; Lyons, M.B.; Norris, D.A. (Univ. of Colorado School of Medicine, Denver (USA))

    1990-01-01

    Autoantibodies to the non-histone nucleoprotein antigens SS-A/Ro, SS-B/La, and RNP are highly associated with photosensitive cutaneous lupus erythematosus (LE). In order to better understand the potential mechanisms of ultraviolet (UV) light on photosensitivity in patients with cutaneous LE, we designed immunopathologic in vitro and in vivo experiments to evaluate the effects of UV on the binding of such autoantibodies to the surface of human keratinocytes, one major target of immunologic damage in photosensitive LE. Short-term 2% paraformaldehyde fixation of suspensions of cultured human keratinocytes previously incubated with monospecific antiserum probes enabled the detection of ENA expression on the cell surface by flow-cytometry analysis. UVB light (280-320 nm) induced the binding of monospecific antibody probes for SS-A/Ro and SS-B/La on keratinocytes in a dose-dependent pattern with maximal induction observed at the dose of 200 mJ/cm2 UVB. Binding of SS-A/Ro, SS-B/La, and RNP antibody was augmented strongly, but binding of anti-Sm was very weak. In contrast, UVA (320-400 nm) light had no effect on the induction of binding of these antibody probes. Identical results were seen by standard immunofluorescence techniques. Hydroxyurea-treated keratinocytes showed similar induction of those antigens by UVB irradiation, which suggested that ENA expression on cultured keratinocytes by UVB were cell-cycle independent. Tunicamycin, an inhibitor of glycosylation of proteins, reduced UVB light effect on the SS-A/Ro and SS-B/La antigen's expression. These in vitro FACS analyses revealed that ENA augmentation on the keratinocyte cell surface was dose dependent, UVB dependent, glycosylation dependent, and cell-cycle independent. In vivo ENA augmentation on the keratinocyte surface was examined in suction blister epidermal roofs.

  3. Properties of glycolipid-enriched membrane rafts in antigen presentation.

    Science.gov (United States)

    Rodgers, William; Smith, Kenneth

    2005-01-01

    Presentation of antigen to T cells represents one of the central events in the engagement of the immune system toward the defense of the host against pathogens. Accordingly, understanding the mechanisms by which antigen presentation occurs is critical toward our understanding the properties of host defense against foreign antigen, as well as insight into other features of the immune system, such as autoimmune disease. The entire antigen-presentation event is complex, and many features of it remain poorly understood. However, recent studies have provided evidence showing that glycolipid-enriched membrane rafts are important for efficient antigen presentation; the studies suggest that one such function of rafts is trafficking of antigen-MHC II complexes to the presentation site on the surface of the antigen-presenting cell. Here, we present a critical discussion of rafts and their proposed functions in antigen presentation. Emerging topics of rafts and antigen presentation that warrant further investigation are also highlighted.

  4. In vitro binding of anthrax protective antigen on bacteriophage T4 capsid surface through Hoc-capsid interactions: A strategy for efficient display of large full-length proteins

    International Nuclear Information System (INIS)

    An in vitro binding system is described to display large full-length proteins on bacteriophage T4 capsid surface at high density. The phage T4 icosahedral capsid features 155 copies of a nonessential highly antigenic outer capsid protein, Hoc, at the center of each major capsid protein hexon. Gene fusions were engineered to express the 83-kDa protective antigen (PA) from Bacillus anthracis fused to the N-terminus of Hoc and the 130-kDa PA-Hoc protein was expressed in Escherichia coli and purified. The purified PA-Hoc was assembled in vitro on hoc - phage particles. Binding was specific, stable, and of high affinity. This defined in vitro system allowed manipulation of the copy number of displayed PA and imposed no significant limitation on the size of the displayed antigen. In contrast to in vivo display systems, the in vitro approach allows all the capsid binding sites to be occupied by the 130-kDa PA-Hoc fusion protein. The PA-T4 particles were immunogenic in mice in the absence of an adjuvant, eliciting strong PA-specific antibodies and anthrax lethal toxin neutralizing antibodies. The in vitro display on phage T4 offers a novel platform for potential construction of customized vaccines against anthrax and other infectious diseases

  5. Histocompatibility antigen test

    Science.gov (United States)

    ... more common in certain autoimmune diseases . For example, HLA-B27 antigen is found in many people (but not ... More Ankylosing spondylitis Autoimmune disorders Bone marrow transplant HLA-B27 antigen Kidney transplant Reactive arthritis Update Date 2/ ...

  6. EXPRESSION OF HUMAN α-GALACTOSIDASE AND α1,2-FUCOSYL-TRANSFERASE GENES MODIFIES THE CELL SURFACE GALα1,3GAL ANTIGEN AND CONFERS RESISTANCE TO HUMAN SERUM-MEDIATED CYTOLYSIS

    Institute of Scientific and Technical Information of China (English)

    贾延军; 任会明; 高新; 季守平; 杨军; 刘泽鹏; 李素波; 章扬培

    2004-01-01

    Objective To explore the strategies which reduce the amount of xenoantigen Galα1, 3 Gal. Methods Human α-galactosidase gene and α 1,2-fucosyltransferase gene were transferred into cultured porcine vascular endothelial cells PEDSV.15 and human α-galactosidase transgenic mice were produced. The Galα 1,3Gal on the cell surface and susceptibility of cells to human antibody-mediated lysis were analyzed. Results Human α-galactosidase gene alone reduced 78% of Galα1,3Gal on PEDSV.15 cell surface while human α-galactosidase combined with α 1,2-fucosyltransferase genes removed Galα 1,3Gal completely. Decrease of Galα1,3Gal could reduce susceptibility of cells to human antibody-mediated lysis, especially during co-expression of α-galactosidase gene and α1,2-fucosyltransferase gene. RT-PCR indicated positive human α-galactosidase gene expression in all organs of positive human α-galactosidase transgenic F1 mice including heart, liver, kidney, lung, and spleen, the amount of Galα1,3Gal antigens on which was reduced largely. 58% of spleen cells from F1 mice were destroyed by complement-mediated lysis compared with 24% of those from normal mice. Conclusions Human α-galactosidase gene and α1,2-fucosyltransferase gene effectively reduce the expression of Galα1,3Gal antigens on endothelial cell surface and confers resistance to human serummediated cytolysis. The expression of human α-galactosidase in mice can also eliminate the Galα1,3Gal antigens in most tissues and decrease the susceptibility of spleen cells to human serum-mediated cytolysis.

  7. Expression of the T1 (CD5, p67) surface antigen in B-CLL and B-NHL and its correlation with other B-cell differentiation markers.

    Science.gov (United States)

    Delia, D; Bonati, A; Giardini, R; Villa, S; De Braud, F; Cattoretti, G; Rilke, F

    1986-01-01

    The T1 surface antigen (CD5,p67) expression on blood lymphocytes (PBL) and lymphoid cells from lymph node biopsies (LN) from 31 patients with B-cell chronic lymphocytic leukemia (B-CLL) and 79 with B non-Hodgkin lymphoma (B-NHL), was detected in 25 B-CLL (80 per cent) and in 11 B-NHL (13 per cent) belonging to the following histologic subtypes: lymphocytic of CLL type (DLWD) one case, lymphoplasmacytoid (DLWD) four cases, centrocytic (DLPD) five cases, immunoblastic (DH) one case. All B-CLL and the T1 + B-NHL were also tested with monoclonal antibodies against the Common Acute Lymphoblastic Leukemia Antigen, B cells (FMC7, FMC8, BA1, Y29-55), T cells (OKT11a), HLA-DR and HLA-DQ monomorphic determinants. All the B-CLL and the T1+ B-NHL were CALLA-, BA1+, Y29.55+. FMC7+ cells were detected in large numbers six B-CLL (three T1+ and three T1-) and in four centrocytic lymphomas. FMC8 reacted with 70 per cent of leukemias (where it stained 30 per cent of neoplastic cells) and with 8/9 T+ B-NHL. HLA-DR and HLA-DQ molecules were detected in 100 per cent and 90 per cent of cases respectively. In vitro treatment of HLA-DQ- or T1- B-CLL with phorbol ester TPA led to the expression of these antigens as well as of the receptors for Interleukin 2 and MLR3 activation antigen. Surface membrane Ig (SIg) was detected in 79 per cent of cases, its density measured by FACS analysis varied, even markedly, from case to case. Among the B-CLL, cells with high SIg content were either T1+ or T1- and more likely FMC7+. The SIg- cases were seven B-CLL (five T1+ and two T1-) and two B-NHL, in which, however, cytoplasmic IgM was detected. This study reveals the existence of four major B-CLL subgroups: T1- SIg-, T1+ SIg+, T1+ SIg+, T1- SIg+. It also indicates that the T1 antigen may be transitionally present during B-cell differentiation and that its expression may precede that of SIg as supported by the in vitro studies. In addition, the finding that some B-NHL are T1+ suggests that they derive

  8. Comparative Analysis on Hepatitis B Surface Antigen through Different Detecting Methods%使用不同方法检测乙肝表面抗原的对比分析

    Institute of Scientific and Technical Information of China (English)

    陈开兰; 黄仕辉

    2013-01-01

      目的:分析化学发光法(微粒子酶免法)与酶联免疫吸附实验(ELISA)及胶体金免疫沉析法检测乙肝表面抗原的差异性。方法:利用雅培i2000化学发光分析仪测定病人标本,记录乙肝表面抗原的定量结果,将同样的标本用酶联免疫吸附实验及胶体金检测,记录检测结果,经统计学处理,对三种方法的测定结果进行比较。结果:三种方法测定乙肝表面抗原的结果存在差异,化学发光法的阳性检出率较ELISA法及胶体金免疫沉析法高。结论:对ELISA法及胶体金免疫沉析法检测乙肝表面抗原处于临界状态的标本,应使用化学发光法检测,以提高结果的准确性,更好的为临床提供诊断依据。%  Objective:Analysis of chemiluminescence (microparticle enzyme immunoassay method) and enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation, analysis of coloidal gold was detected difference between hepatitis B surface antigen.Methods: Abbott i2000 using chemiluminescence analyzer patient specimens. Record the results of the quantitative hepatitis B surface antigen, Wil have the same specimens by enzyme-linked immunosorbent assay and coloidal gold detection,Record test results, Statistical analysis,Determination of the three methods were compared.Results:Three Methods for measuring the results of hepatitis B surface antigen differences,Chemiluminescence than the positive rate of ELISA ,and immunogold method with high precipitation..Conclusion:On ELISA, and immune precipitation of coloidal gold assay of hepatitis B surface antigen in the critical state of the specimens,Chemiluminescence detection should be used to improve the accuracy of the results,the better the basis for the clinical diagnosis.

  9. Simple high-cell density fed-batch technique for high-level recombinant protein production with Pichia pastoris: Application to intracellular production of Hepatitis B surface antigen

    OpenAIRE

    Ross Anton; Lünsdorf Heinrich; Gäbel Thomas; Adnan Ahmad; Gurramkonda Chandrasekhar; Nemani Satish; Swaminathan Sathyamangalam; Khanna Navin; Rinas Ursula

    2009-01-01

    Abstract Background Hepatitis B is a serious global public health concern. Though a safe and efficacious recombinant vaccine is available, its use in several resource-poor countries is limited by cost. We have investigated the production of Hepatitis B virus surface antigen (HBsAg) using the yeast Pichia pastoris GS115 by inserting the HBsAg gene into the alcohol oxidase 1 locus. Results Large-scale production was optimized by developing a simple fed-batch process leading to enhanced product ...

  10. Whole-Blood Counting Immunoassay as a Short-Turnaround Test for Detection of Hepatitis B Surface Antigen, Anti-Hepatitis C Virus Antibodies, and Anti-Treponema pallidum Antibodies

    OpenAIRE

    Kudo, Toyoichiro; Kido, Aiko; Nishiyama, Yukiko; Koganeya, Hiroshi; Okuda, Takako; Nabeshima, Motoshige; Iinuma, Yoshitsugu; Ichiyama, Satoshi

    2004-01-01

    Whole-blood samples were used for a counting immunoassay (CIA) with the aim of developing a short- turnaround test. After optimization of the CIA, hepatitis B surface antigen (HBsAg), anti-hepatitis C virus antibodies (anti-HCV), and anti-Treponema pallidum antibodies (anti-TP) were detected as efficiently as by an enzyme immunoassay (EIA) with serum samples. The correlations between whole-blood CIA and serum EIA were 99.8, 97.1, and 99.4% for HBsAg, anti-HCV, and anti-TP, respectively. Whole...

  11. Comparative Analysis on Hepatitis B Surface Antigen through Different Detecting Methods%使用不同方法检测乙肝表面抗原的对比分析

    Institute of Scientific and Technical Information of China (English)

    陈开兰; 黄仕辉

    2013-01-01

      Objective:Analysis of chemiluminescence (microparticle enzyme immunoassay method) and enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation, analysis of coloidal gold was detected difference between hepatitis B surface antigen.Methods: Abbott i2000 using chemiluminescence analyzer patient specimens. Record the results of the quantitative hepatitis B surface antigen, Wil have the same specimens by enzyme-linked immunosorbent assay and coloidal gold detection,Record test results, Statistical analysis,Determination of the three methods were compared.Results:Three Methods for measuring the results of hepatitis B surface antigen differences,Chemiluminescence than the positive rate of ELISA ,and immunogold method with high precipitation..Conclusion:On ELISA, and immune precipitation of coloidal gold assay of hepatitis B surface antigen in the critical state of the specimens,Chemiluminescence detection should be used to improve the accuracy of the results,the better the basis for the clinical diagnosis.%  目的:分析化学发光法(微粒子酶免法)与酶联免疫吸附实验(ELISA)及胶体金免疫沉析法检测乙肝表面抗原的差异性。方法:利用雅培i2000化学发光分析仪测定病人标本,记录乙肝表面抗原的定量结果,将同样的标本用酶联免疫吸附实验及胶体金检测,记录检测结果,经统计学处理,对三种方法的测定结果进行比较。结果:三种方法测定乙肝表面抗原的结果存在差异,化学发光法的阳性检出率较ELISA法及胶体金免疫沉析法高。结论:对ELISA法及胶体金免疫沉析法检测乙肝表面抗原处于临界状态的标本,应使用化学发光法检测,以提高结果的准确性,更好的为临床提供诊断依据。

  12. Development of an in-house enzyme-linked immunosorbent assay based on surface whole cell antigen for diagnosis of Helicobacter pylori infection in patients with gastroduodenal ulcer disease.

    Science.gov (United States)

    Aziz, Faisal; Sherwani, Sikander Khan; Akhtar, Syed Shakeel; Kazmi, Shahana Urooj

    2014-01-01

    Helicobacter pylori (H. pylori) is a causative agent of gastritis, gastroduodenal ulcers and gastric adenocarcinoma. More than 50% world population is colonized by H. pylori, which is closely related to the chronic gastritis and gastric ulcer infection. In this study, a total of 214 gastritis patient's serum samples were screened for anti-H. pylori IgG antibody. A 96-well plate coated with 20 μg/ml antigen and hundred-fold diluted patient's serum was allowed to react. After extensive washing with buffer, 1:2,500 diluted conjugated secondary antibody was added. Later substrate was added to observe positivity by measuring the intensity of color. Statistical analyses were performed, and p value of <0.01 was taken as significant; 84% male patients and 89% female patients, respectively, tested positive for H. pylori, while agewise distribution was 35-45 years males (40%) and 35-55 years females (52%) were found highest number of H. pylori infected patients. In-house ELISA based on surface whole cell antigen (wELISA) showed a sensitivity of 93%, specificity of 100%, accuracy 94% and κ value 0.86 with significant correlation R-0.77020; p < 0.0001. We conclude that H. pylori local isolates surface antigen was satisfactory for diagnosis as different parameters were adjusted according to the local H. pylori isolates. Fluctuations in serum antibody titer predict the variation in an individual's response of the host against H. pylori. In-house wELISA could provide a reliable and a clinically useful method for the diagnosis of H. pylori infection in patients of Karachi, Pakistan.

  13. The severity of chorioamnionitis in pregnant sheep is associated with in vivo variation of the surface-exposed multiple-banded antigen/gene of Ureaplasma parvum.

    Science.gov (United States)

    Knox, Christine L; Dando, Samantha J; Nitsos, Ilias; Kallapur, Suhas G; Jobe, Alan H; Payton, Diane; Moss, Timothy J M; Newnham, John P

    2010-09-01

    Ureaplasma species are the bacteria most frequently isolated from human amniotic fluid in asymptomatic pregnancies and placental infections. Ureaplasma parvum serovars 3 and 6 are the most prevalent serovars isolated from men and women. We hypothesized that the effects on the fetus and chorioamnion of chronic ureaplasma infection in amniotic fluid are dependent on the serovar, dose, and variation of the ureaplasma multiple-banded antigen (MBA) and mba gene. We injected high- or low-dose U. parvum serovar 3, serovar 6, or vehicle intra-amniotically into pregnant ewes at 55 days of gestation (term = 150 days) and examined the chorioamnion, amniotic fluid, and fetal lung tissue of animals delivered by cesarean section at 125 days of gestation. Variation of the multiple banded antigen/mba generated by serovar 3 and serovar 6 ureaplasmas in vivo were compared by PCR assay and Western blot. Ureaplasma inoculums demonstrated only one (serovar 3) or two (serovar 6) MBA variants in vitro, but numerous antigenic variants were generated in vivo: serovar 6 passage 1 amniotic fluid cultures contained more MBA size variants than serovar 3 (P = 0.005), and ureaplasma titers were inversely related to the number of variants (P = 0.025). The severity of chorioamnionitis varied between animals. Low numbers of mba size variants (five or fewer) within amniotic fluid were associated with severe inflammation, whereas the chorioamnion from animals with nine or more mba variants showed little or no inflammation. These differences in chorioamnion inflammation may explain why not all women with in utero Ureaplasma spp. experience adverse pregnancy outcomes.

  14. The Severity of Chorioamnionitis in Pregnant Sheep Is Associated with In Vivo Variation of the Surface-Exposed Multiple-Banded Antigen/Gene of Ureaplasma parvum1

    Science.gov (United States)

    Knox, Christine L.; Dando, Samantha J.; Nitsos, Ilias; Kallapur, Suhas G.; Jobe, Alan H.; Payton, Diane; Moss, Timothy J.M.; Newnham, John P.

    2010-01-01

    Ureaplasma species are the bacteria most frequently isolated from human amniotic fluid in asymptomatic pregnancies and placental infections. Ureaplasma parvum serovars 3 and 6 are the most prevalent serovars isolated from men and women. We hypothesized that the effects on the fetus and chorioamnion of chronic ureaplasma infection in amniotic fluid are dependent on the serovar, dose, and variation of the ureaplasma multiple-banded antigen (MBA) and mba gene. We injected high- or low-dose U. parvum serovar 3, serovar 6, or vehicle intra-amniotically into pregnant ewes at 55 days of gestation (term = 150 days) and examined the chorioamnion, amniotic fluid, and fetal lung tissue of animals delivered by cesarean section at 125 days of gestation. Variation of the multiple banded antigen/mba generated by serovar 3 and serovar 6 ureaplasmas in vivo were compared by PCR assay and Western blot. Ureaplasma inoculums demonstrated only one (serovar 3) or two (serovar 6) MBA variants in vitro, but numerous antigenic variants were generated in vivo: serovar 6 passage 1 amniotic fluid cultures contained more MBA size variants than serovar 3 (P = 0.005), and ureaplasma titers were inversely related to the number of variants (P = 0.025). The severity of chorioamnionitis varied between animals. Low numbers of mba size variants (five or fewer) within amniotic fluid were associated with severe inflammation, whereas the chorioamnion from animals with nine or more mba variants showed little or no inflammation. These differences in chorioamnion inflammation may explain why not all women with in utero Ureaplasma spp. experience adverse pregnancy outcomes. PMID:20519696

  15. PreS1 epitope recognition in newborns after vaccination with the third-generation Sci-B-Vac™ vaccine and their relation to the antibody response to hepatitis B surface antigen

    Directory of Open Access Journals (Sweden)

    Madalinski Kazimierz

    2009-01-01

    Full Text Available Abstract Background Sci-B-Vac™ is a recombinant, hepatitis B vaccine derived from a mammalian cell line and containing hepatitis B surface antigen (HBsAg as well as preS1 and preS2 antigens. Few studies have been performed on the antibody responses to preS1 in relation to the antibody to hepatitis B surface antigen (anti-HBs response during immunisation of healthy children with preS-containing vaccines. Results In this study 28 healthy newborns were randomly selected to receive either 2.5 ug or 5.0 ug of the Sci-B-Vac vaccine. Children received three doses of vaccine according to a 0-, 1-, 6-month scheme. Antibodies against the S-protein and three synthetic peptides mimicking three B-cell preS1 epitopes, (21–32 amino acid epitope, (32–47 amino acid epitope and the C-terminal (amino acid epitope 94–117 were determined at 6 and 9 months. Fourteen (50% of the 28 newborns had detectable levels of anti-preS1 (21–32 antibodies; 15 (54% were anti-preS1 (32–47 reactive and 12 (43% were anti-preS1 (94–117 reactive at 6 or 9 months after initiation of the vaccination. Significantly higher levels of anti-HBs were observed in the sera of patients with detectable anti-preS1 (32–47 reactivity (24 550 ± 7375 IU/L, mean ± SEM as compared with the non-reactive sera (5991 ± 1530 IU/L, p Conclusion Recognition of several preS1 epitopes, and in particular, the epitope contained within the second half of the hepatocyte binding site localised in the hepatitis B surface protein of the third-generation hepatitis B vaccine is accompanied by a more pronounced antibody response to the S-gene-derived protein in healthy newborns.

  16. Antigenic Variation in Plasmodium falciparum.

    Science.gov (United States)

    Petter, Michaela; Duffy, Michael F

    2015-01-01

    Plasmodium falciparum is the protozoan parasite that causes most malaria-associated morbidity and mortality in humans with over 500,000 deaths annually. The disease symptoms are associated with repeated cycles of invasion and asexual multiplication inside red blood cells of the parasite. Partial, non-sterile immunity to P. falciparum malaria develops only after repeated infections and continuous exposure. The successful evasion of the human immune system relies on the large repertoire of antigenically diverse parasite proteins displayed on the red blood cell surface and on the merozoite membrane where they are exposed to the human immune system. Expression switching of these polymorphic proteins between asexual parasite generations provides an efficient mechanism to adapt to the changing environment in the host and to maintain chronic infection. This chapter discusses antigenic diversity and variation in the malaria parasite and our current understanding of the molecular mechanisms that direct the expression of these proteins. PMID:26537377

  17. Studies on mechanism of Sialy Lewis-X antigen in liver metastases of human colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Xiao Wei Li; Yan Qing Ding; Jun Jie Cai; Shao Qing Yang; Lian Bing An; Dong Fang Qiao

    2001-01-01

    @@INTRODUCTION Sialyl Lewis-X antigen ,correlated with carcinoma, is a group of carbohydrate antigen containing oligosaccharide expressed of embryonic tisue and glycoproteins on cell surface of embryonic tissue[1].The SLeX antigen located on cell surface is synthesized principally by two enzymes ,al ,3fucosyltransfrease and a2, 3sialyctransferase.In adults ,SLeX antigen is expressed principally on the surfaces of granulocytic cells and some tumor cells .

  18. In vitro selection of Plasmodium falciparum 3D7 for expression of variant surface antigens associated with severe malaria in African children

    DEFF Research Database (Denmark)

    Staalsoe, Trine; Nielsen, Morten A; Vestergaard, Lasse S;

    2003-01-01

    ) in older semi-immune children. Establishment of the genetic mechanism underlying changes in VSA expression in response to in vitro selective pressure is now possible because of the availability of the entire genomic sequence of the P. falciparum clone 3D7. As a first step towards direct molecular...... identification of VSASM-encoding genes in 3D7, we report here a method of enforcing expression of VSASM-like antigens in this parasite clone by a novel selection method using plasma from semi-immune children with low VSAUM-specific, but high VSASM-specific, IgG reactivity. In addition to the resulting increase...... in VSA-specific IgG recognition, VSASM-expressing 3D7(3D7-Dodowa1) showed reduced adhesion to CD36. Finally, levels of IgG specific for the VSA expressed by 3D7-Dodowa1 were uniformly higher than those of IgG with specificity for VSA expressed by the unselected 3D7 in plasma samples from geographically...

  19. Prevalence and chemotherapy-induced reactivation of occult hepatitis B virus among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma: Significance of hepatitis B core antibodies screening

    International Nuclear Information System (INIS)

    Background: Occult hepatitis B infection (OBI) is characterized by negative hepatitis B surface antigen (HBsAg) and detectable hepatitis B virus (HBV)-DNA in the liver and/or serum, with or without hepatitis B core antibody (anti-HBc). Anti-HBc is the most sensitive marker of previous HBV. HBV reactivation in patients under immunosuppressive treatment is life-threatening, occurring in both overt and occult HBV especially in hematological malignancies. Aim of the work: To evaluate the prevalence and chemotherapy-induced reactivation of OBI among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma (DLBCL) patients and to determine the significance of anti-HBc screening among this group of patients before receiving chemotherapy. Patients and methods: This cross-sectional study included 72 DLBCL patients negative for HBsAg, HBsAb and hepatitis C virus antibodies (anti-HCV). Patients were subjected to investigations including anti-HBc. All patients underwent alanine transaminase (ALT) monitoring before each cycle of chemotherapy and monthly for 12 months after the end of chemotherapy. Patients with suspected OBI were tested for HBV-DNA using real-time polymerase chain reaction (PCR). Results: Anti-HBc was detected in 10 of 72 HBsAg negative sera (13.89%) (95% confidence interval 6.9-22.2%). Five of the 10 anti-HBc positive patients in this study had OBI reactivation. Conclusion: The study concluded that anti-HBc screening is mandatory before chemotherapy. HBsAg-negative/anti-HBc-positive patients should be closely observed for signs of HBV reactivation through the regular monitoring of ALT. Prophylaxis lamivudine is recommended for anti-HBc positive patients before chemotherapy.

  20. Cloning and expression of merozoite surface antigen 2 locus(MSA-2c) of Babesia bovis isolated in Xinjiang and antigenicity of its recombinant protein%牛巴贝斯虫新疆株MSA-2c基因的克隆表达及其重组蛋白免疫原性

    Institute of Scientific and Technical Information of China (English)

    简子健; 袁江玲; 马素贞; 黄家雨; 沈炯玉

    2009-01-01

    本试验将新疆株牛巴贝斯虫的MSA-2c基因克隆,并构建重组质粒pGEX-4T-2/MSA-2c.利用大肠杆菌原核表达系统进行外源蛋白的表达,并成功诱导出GST-MSA-2c融合蛋白.通过优化诱导条件,得到了较高的可溶性表达;利用亲和层析技术纯化后的重组蛋白皮下免疫试验小鼠.间接ELISA检测发现,免疫接种56 d后,抗重组蛋白的抗体效价达到1∶220 000以上.用获得的抗血清进行Western-blot试验,可获得清晰的免疫反应条带.结果表明,本试验所表达的MSA-2c蛋白与文献报道的目的蛋白相符,并具有免疫原性.同时本试验也为建立以MSA-2c重组蛋白作为抗原的血清学诊断体系奠定了基础.%The merozoite surface antigen 2 locus gene(MSA-2c) of Babesia bovis found in Xinjiang was cloned and ligated into pGEX-4T-2 to construct a recombinant plasmid,pGEX-4T-2/MSA-2c.A fusion protein,GST-MSA-2c,was successfully expressed through prokaryotic expression system in E.coli.The high quantity of soluble expression was obtained by improving the induction conditions.The recombinant protein purified by affinity chromatography was inoculated into mice subcutaneously.The antibody titers of the recombinant protein in murine sera were above 1∶220 000 at 56 days postinoculation by indirect ELISA.The antisera were then examined by Western-blot and a clear reaction strip was found.The results showed that of the expressed MSA-2c protein was identified with interest protein reported in records,and was highly immunogenic(antigenic).It laysa foundation of construction serologically diagnostic system using MSA-2c recombinant protein as a diagnostic antigen.

  1. Antigenic presentation of heterologous epitopes engineered into the outer surface-exposed helix 4 loop region of human papillomavirus L1 capsomeres

    Directory of Open Access Journals (Sweden)

    Murata Yoshihiko

    2009-06-01

    Full Text Available Abstract Background Human papillomavirus (HPV L1 capsid proteins can self-assemble into pentamers (capsomeres that are immunogenic and can elicit neutralizing antibodies. Structural modelling of L1 inter-pentameric interactions predicts that helix 4 (h4 of each of the five L1 monomers project laterally and outwards from the pentamer. We sought to utilize HPV L1 capsomeres as a vaccine platform by engineering heterologous epitopes within L1 derivatives deleted for h4 domain. Results We used baculovirus – infected Trichoplusia ni cells and ultracentrifugation to synthesize and purify three 16L1 derivatives: one bearing a short deletion (amino acids 404–436 encompassing the h4 domain, and two others, each bearing a conserved neutralizing epitope of the human respiratory syncytial virus (RSV fusion (F protein (residues 255–278 and 423–436 that was substituted for the deleted L1 h4 domain residues. Each of the three capsomere derivatives was recognized by anti-L1 antibodies, while two bearing the RSV F-derived moieties were recognized by anti-RSV F antibodies. All three L1 derivatives formed ring-like structures that were similar in morphology and size to those described for native 16L1 capsomeres. When injected into mice, each of the capsomere derivatives was immunogenic with respect to L1 protein, and immunization with chimeric L1-RSV F pentamers resulted in RSV non-neutralizing antisera that recognized purified RSV F protein in immunoblots. Conclusion HPV L1 monomers bearing heterologous epitopes within the L1 h4 region can self-assemble into capsomeres that elicit antibody response against such non-HPV encoded epitopes. Thus, the L1 h4 region can function as a novel antigen display site within the L1 pentamer, which in turn may serve as a potential vaccine template.

  2. Tresyl-Based Conjugation of Protein Antigen to Lipid Nanoparticles Increases Antigen Immunogencity

    Science.gov (United States)

    Jain, Anekant; Yan, Weili; Miller, Keith R.; O'Carra, Ronan; Woodward, Jerold G.; Mumper, Russell J.

    2010-01-01

    The present studies were aimed at investigating the engineering of NPs with protein-conjugated-surfactant at their surface. In order to increase the immunogenicity of a protein antigen, Brij 78 was functionalized by tresyl chloride and then further reacted with the primary amine of the model proteins ovalbumin (OVA) or horseradish peroxide (HRP). The reaction yielded Brij 78-OVA and Brij 78-HRP conjugates which were then used directly to form NP-OVA or NP-HRP using a one-step warm oil-in-water microemulsion precursor method with emulsifying wax as the oil phase, and Brij 78 and the Brij 78-OVA or Brij 78-HRP conjugate as surfactants. Similarly, Brij 700 was conjugated to HIV p24 antigen to yield Brij 700-p24 conjugate. The utility of these NPs for enhancing the immune responses to protein-based vaccines was evaluated in vivo using ovalbumin (OVA) as model protein and p24 as a relevant HIV antigen. In separate in vivo studies, female BALB/c mice were immunized by subcutaneous (s.c.) injection with NP-OVA and NP-p24 formulations along with several control formulations. These results suggested that with multiple antigens, covalent attachment of the antigen to the NP significantly enhanced antigen-specific immune responses. This facile covalent conjugation and incorporation method may be utilized to further incorporate other protein antigens, even multiple antigens, into an enhanced vaccine delivery system. PMID:20837122

  3. Tresyl-based conjugation of protein antigen to lipid nanoparticles increases antigen immunogenicity.

    Science.gov (United States)

    Jain, Anekant; Yan, Weili; Miller, Keith R; O'Carra, Ronan; Woodward, Jerold G; Mumper, Russell J

    2010-11-30

    The present studies were aimed at investigating the engineering of NPs with protein-conjugated-surfactant at their surface. In order to increase the immunogenicity of a protein antigen, Brij 78 was functionalized by tresyl chloride and then further reacted with the primary amine of the model proteins ovalbumin (OVA) or horseradish peroxide (HRP). The reaction yielded Brij 78-OVA and Brij 78-HRP conjugates which were then used directly to form NP-OVA or NP-HRP using a one-step warm oil-in-water microemulsion precursor method with emulsifying wax as the oil phase, and Brij 78 and the Brij 78-OVA or Brij 78-HRP conjugate as surfactants. Similarly, Brij 700 was conjugated to HIV p24 antigen to yield Brij 700-p24 conjugate. The utility of these NPs for enhancing the immune responses to protein-based vaccines was evaluated in vivo using ovalbumin (OVA) as model protein and p24 as a relevant HIV antigen. In separate in vivo studies, female BALB/c mice were immunized by subcutaneous (s.c.) injection with NP-OVA and NP-p24 formulations along with several control formulations. These results suggested that with multiple antigens, covalent attachment of the antigen to the NP significantly enhanced antigen-specific immune responses. This facile covalent conjugation and incorporation method may be utilized to further incorporate other protein antigens, even multiple antigens, into an enhanced vaccine delivery system. PMID:20837122

  4. Protamine-based nanoparticles as new antigen delivery systems.

    Science.gov (United States)

    González-Aramundiz, José Vicente; Peleteiro Olmedo, Mercedes; González-Fernández, África; Alonso Fernández, María José; Csaba, Noemi Stefánia

    2015-11-01

    The use of biodegradable nanoparticles as antigen delivery vehicles is an attractive approach to overcome the problems associated with the use of Alum-based classical adjuvants. Herein we report, the design and development of protamine-based nanoparticles as novel antigen delivery systems, using recombinant hepatitis B surface antigen as a model viral antigen. The nanoparticles, composed of protamine and a polysaccharide (hyaluronic acid or alginate), were obtained using a mild ionic cross-linking technique. The size and surface charge of the nanoparticles could be modulated by adjusting the ratio of the components. Prototypes with optimal physicochemical characteristics and satisfactory colloidal stability were selected for the assessment of their antigen loading capacity, antigen stability during storage and in vitro and in vivo proof-of-concept studies. In vitro studies showed that antigen-loaded nanoparticles induced the secretion of cytokines by macrophages more efficiently than the antigen in solution, thus indicating a potential adjuvant effect of the nanoparticles. Finally, in vivo studies showed the capacity of these systems to trigger efficient immune responses against the hepatitis B antigen following intramuscular administration, suggesting the potential interest of protamine-polysaccharide nanoparticles as antigen delivery systems.

  5. Comparison of the binding properties of the mushroom Marasmius oreades lectin and Griffonia simplicifolia I-B isolectin to alphagalactosyl carbohydrate antigens in the surface phase

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Winter, Harry C; Goldstein, Irwin J

    2004-01-01

    The binding of two alpha-galactophilic lectins, Marasmius oreades agglutinin (MOA), and Griffonia simplicifolia I isolectin B(4) (GS I-B(4)) to neoglycoproteins and natural glycoproteins were compared in a surface phase assay. Neoglycoproteins carrying various alpha-galactosylated glycans and lam...

  6. Targeted disruption of a ring-infected erythrocyte surface antigen (RESA)-like export protein gene in Plasmodium falciparum confers stable chondroitin 4-sulfate cytoadherence capacity

    DEFF Research Database (Denmark)

    Goel, Suchi; Muthusamy, Arivalagan; Miao, Jun;

    2014-01-01

    parasite proteins, including KAHRP and PfEMP3, play important roles in the cytoadherence by mediating the clustering of PfEMP1 in rigid knoblike structures on the infected erythrocyte surface. The lack of a subtelomeric region of chromosome 2 that contains kahrp and pfemp3 causes reduced cytoadherence...

  7. Removing N-Terminal Sequences in Pre-S1 Domain Enhanced Antibody and B-Cell Responses by an HBV Large Surface Antigen DNA Vaccine

    OpenAIRE

    Guohong Ge; Shixia Wang; Yaping Han; Chunhua Zhang; Shan Lu; Zuhu Huang

    2012-01-01

    Although the use of recombinant hepatitis B virus surface (HBsAg) protein vaccine has successfully reduced global hepatitis B infection, there are still a number of vaccine recipients who do not develop detectable antibody responses. Various novel vaccination approaches, including DNA vaccines, have been used to further improve the coverage of vaccine protection. Our previous studies demonstrated that HBsAg-based DNA vaccines could induce both humoral and CMI responses in experimental animal ...

  8. The Plasmodium falciparum merozoite surface protein-1 19 KD antibody response in the Peruvian Amazon predominantly targets the non-allele specific, shared sites of this antigen

    Directory of Open Access Journals (Sweden)

    Silva Claudia

    2010-01-01

    Full Text Available Abstract Background Plasmodium falciparum re-emerged in Iquitos, Peru in 1994 and is now hypoendemic (P. falciparum infections can be followed using this population dynamic. Previous work demonstrated a strong association between this population's antibody response to PfMSP1-19KD and protection against febrile illness and parasitaemia. Therefore, some selection for PfMSP1-19KD allelic diversity would be expected if the protection is to allele-specific sites of PfMSP1-19KD. Here, the potential for allele-specific polymorphisms in this population is investigated, and the allele-specificity of antibody responses to PfMSP1-19KD are determined. Methods The 42KD region in PfMSP1 was genotyped from 160 individual infections collected between 2003 and 2007. Additionally, the polymorphic block 2 region of Pfmsp1 (Pfmsp1-B2 was genotyped in 781 infection-months to provide a baseline for population-level diversity. To test whether PfMSP1-19KD genetic diversity had any impact on antibody responses, ELISAs testing IgG antibody response were performed on individuals using all four allele-types of PfMSP1-19KD. An antibody depletion ELISA was used to test the ability of antibodies to cross-react between allele-types. Results Despite increased diversity in Pfmsp1-B2, limited diversity within Pfmsp1-42KD was observed. All 160 infections genotyped were Mad20-like at the Pfmsp1-33KD locus. In the Pfmsp1-19KD locus, 159 (99.4% were the Q-KSNG-F haplotype and 1 (0.6% was the E-KSNG-L haplotype. Antibody responses in 105 individuals showed that Q-KNG and Q-TSR alleles generated the strongest immune responses, while Q-KNG and E-KNG responses were more concordant with each other than with those from Q-TSR and E-TSR, and vice versa. The immuno-depletion ELISAs showed all samples responded to the antigenic sites shared amongst all allelic forms of PfMSP1-19KD. Conclusions A non-allele specific antibody response in PfMSP1-19KD may explain why other allelic forms have not

  9. Expression of Hepatitis B virus surface antigen (HBsAg from genotypes A, D and F and influence of amino acid variations related or not to genotypes on HBsAg detection

    Directory of Open Access Journals (Sweden)

    Natalia M. Araujo

    2009-08-01

    Full Text Available The impact of hepatitis B virus (HBV genotypes on the sensitivity of surface antigen (HBsAg detection assays has been poorly investigated. Here, plasmids carrying consensus or variant coding sequences for HBV surface proteins from genotypes A, D and F, were constructed. HBsAg levels were evaluated in medium and extracts of transfected CHO cells by a commercial polyclonal-based assay. We show that HBsAg detection values of consensus forms from genotypes D and F were, respectively, 37% and 30% lower than those obtained by genotype A. However, the presence of two single variations, T143M in genotype A, and T125M in genotype D, produced a decrease of 44% and an increase of 34%, respectively, on HBsAg mean values in comparison with their consensus forms. In conclusion, HBsAg detection levels varied among HBV genotypes. However, unique amino acid substitutions not linked to genotypes, such as T125M and T143M described here, should have more implications in HBV immunological diagnostics than the set of variations characteristic of each HBV genotype.

  10. Antigen processing and remodeling of the endosomal pathway: requirements for antigen cross-presentation.

    Directory of Open Access Journals (Sweden)

    Ewoud Bernardus Compeer

    2012-03-01

    Full Text Available The cross-presentation of endocytosed antigen as peptide/class I MHC complexes plays a central role in the elicitation of CD8+ T cell clones that mediate anti-viral and anti-tumor immune responses. While it has been clear that there are specific subsets of professional antigen presenting cells (APC capable of antigen cross-presentation, description of mechanisms involved is still ongoing. Especially amongst dendritic cells (DC, there are specialized subsets that are highly proficient at antigen cross-presentation. We here present a focused survey on the cell biological processes in the endosomal pathway that support antigen cross-presentation. This review highlight DC-intrinsic mechanisms that facilitate the cross-presentation of endocytosed antigen, including receptor-mediated uptake, recycling and maturation including the sorting of membrane proteins, dynamic remodeling of endosomal structures and cell-surface directed endosomal trafficking. We will conclude with description of pathogen-induced deviation of endosomal processing, and discuss how immune evasion strategies pertaining endosomal trafficking may preclude antigen cross-presentation.

  11. CD40-induced aggregation of MHC class II and CD80 on the cell surface leads to an early enhancement in antigen presentation.

    Science.gov (United States)

    Clatza, Abigail; Bonifaz, Laura C; Vignali, Dario A A; Moreno, José

    2003-12-15

    Ligation of CD40 on B cells increases their ability to present Ag and to activate MHC class II (MHC-II)-restricted T cells. How this occurs is not entirely clear. In this study we demonstrate that CD40 ligation on Ag-presenting B cells (APC) for a short period between 30 min and 3 h has a rapid, augmenting effect on the ability of a B cell line and normal B cells to activate T cells. This is not due to alterations in Ag processing or to an increase in surface expression of CD80, CD86, ICAM-1, or MHC-II. This effect is particularly evident with naive, resting T lymphocytes and appears to be more pronounced under limiting Ag concentrations. Shortly after CD40 ligation on a B cell line, MHC-II and CD80 progressively accumulated in cholesterol-enriched microdomains on the cell surface, which correlated with an initial enhancement in their Ag presentation ability. Moreover, CD40 ligation induced a second, late, more sustained enhancement of Ag presentation, which correlates with a significant increase in CD80 expression by APC. Thus, CD40 signaling enhances the efficiency with which APC activate T cells by at least two related, but distinct, mechanisms: an early stage characterized by aggregation of MHC-II and CD80 clusters, and a late stage in which a significant increase in CD80 expression is observed. These results raise the possibility that one important role of CD40 is to contribute to the formation of the immunological synapse on the APC side.

  12. Molecular cloning of cDNA for the human tumor-associated antigen CO-029 and identification of related transmembrane antigens

    Energy Technology Data Exchange (ETDEWEB)

    Szala, S.; Kasai, Yasushi; Steplewski, Z.; Rodeck, U.; Koprowski, H.; Linnenbach, A.J. (Wistar Inst. of Anatomy and Biology, Philadelphia, PA (USA))

    1990-09-01

    The human tumor-associated antigen CO-029 is a monoclonal antibody-defined cell surface glycoprotein of 27-34 kDa. By using the high-efficiency COS cell expression system, a full-length cDNA clone for CO-029 was isolated. When transiently expressed in COS cells, the cDNA clone directed the synthesis of an antigen reactive to monoclonal antibody CO-029 in mixed hemadsorption and immunoblot assays. Sequence analysis revealed that CO-029 belongs to a family of cell surface antigens that includes the melanoma-associated antigen ME491, the leukocyte cell surface antigen CD37, and the Sm23 antigen of the parasitic helminth Schistosoma mansoni. CO-029 and ME491 antigen expression and the effect of their corresponding monoclonal antibodies on cell growth were compared in human tumor cell lines of various histologic origins.

  13. Screening of hepatocyte proteins binding with C‑terminally truncated surface antigen middle protein of hepatitis B virus (MHBst167) by a yeast two‑hybrid system.

    Science.gov (United States)

    Li, Zhi Qun; Linghu, Enqiang; Jun, Wan; Cheng, Jun

    2014-09-01

    The function of middle hepatitis B surface protein C‑terminally truncated at amino acid position 167 (MHBst167) is not currently clear. This study aimed to screen and identify the proteins that interact with MHBst167 in hepatocytes using a yeast two‑hybrid system, and to explore the effects of MHBst167 in the development of hepatocellular carcinoma and precancerous diseases of the liver. The MHBst167 gene was amplified by polymerase chain reaction (PCR) and cloned into a pGEM‑T vector. The target region was sequenced and the constructed bait plasmid, pGBKT7‑MHBst167, was transformed into AH109 yeast cells. The transformed AH109 cells were then mated with Y187 yeast cells containing the fetal liver cDNA library plasmid using a yeast two‑hybrid system. The false positives were eliminated and the true positive clones were selected by PCR and sequencing analysis. The pGBKT7‑MHBst167 bait plasmid was successfully constructed and 66 clones grew in the selective synthetic defined media lacking leucine, tryptophan, histidine and adenine. Fifty‑two clones were identified following X‑α‑Gal selection and segregation analysis. Seven proteins were found to be expressed that could interact with MHBst167 in hepatocytes by the yeast two‑hybrid system. These results have provided novel insights into the biological functions of MHBst167.

  14. Antigen-Antibody Interaction Database (AgAbDb): a compendium of antigen-antibody interactions.

    Science.gov (United States)

    Kulkarni-Kale, Urmila; Raskar-Renuse, Snehal; Natekar-Kalantre, Girija; Saxena, Smita A

    2014-01-01

    Antigen-Antibody Interaction Database (AgAbDb) is an immunoinformatics resource developed at the Bioinformatics Centre, University of Pune, and is available online at http://bioinfo.net.in/AgAbDb.htm. Antigen-antibody interactions are a special class of protein-protein interactions that are characterized by high affinity and strict specificity of antibodies towards their antigens. Several co-crystal structures of antigen-antibody complexes have been solved and are available in the Protein Data Bank (PDB). AgAbDb is a derived knowledgebase developed with an objective to compile, curate, and analyze determinants of interactions between the respective antigen-antibody molecules. AgAbDb lists not only the residues of binding sites of antigens and antibodies, but also interacting residue pairs. It also helps in the identification of interacting residues and buried residues that constitute antibody-binding sites of protein and peptide antigens. The Antigen-Antibody Interaction Finder (AAIF), a program developed in-house, is used to compile the molecular interactions, viz. van der Waals interactions, salt bridges, and hydrogen bonds. A module for curating water-mediated interactions has also been developed. In addition, various residue-level features, viz. accessible surface area, data on epitope segment, and secondary structural state of binding site residues, are also compiled. Apart from the PDB numbering, Wu-Kabat numbering and explicit definitions of complementarity-determining regions are provided for residues of antibodies. The molecular interactions can be visualized using the program Jmol. AgAbDb can be used as a benchmark dataset to validate algorithms for prediction of B-cell epitopes. It can as well be used to improve accuracy of existing algorithms and to design new algorithms. AgAbDb can also be used to design mimotopes representing antigens as well as aid in designing processes leading to humanization of antibodies. PMID:25048123

  15. Enhanced specific immune responses by CpG DNA in mice immunized with recombinant hepatitis B surface antigen and HB vaccine

    Directory of Open Access Journals (Sweden)

    Wang Xingtai

    2011-02-01

    Full Text Available Abstract Background Hepatitis B vaccine adjuvant, alum, is generally used for vaccination although it does not stimulate Th1 immunity and 10% of the population has low or no antibody response. Efforts have been continued to find more efficient vaccine adjuvants for better antibody response as well as stimulation of Th1 immunity. Methods CpG DNA was used as an adjuvant for recombinant HBsAg to immunize 6- to 8-week-old female BALB/c mice with or without alum for different dosages. The production of HBsAb, CD80 and CD86 from dendritic cells, and cytokines IL-10, IL12, etc., were analyzed and compared for the performance of immunization. Results 5-20 μg CpG DNA had the best co-stimulation effect of HBsAb serum conversion for mice vaccinated with recombinant expressed HBsAg. The mice vaccinated with recombinant 20 μg CpG DNA and regular vaccine (containing alum adjuvant had the highest concentration of antibody production. IL-12b, IL-12a and IL10 mRNA reached to the peak level between 3 and 6 hours after the CpG DNA induction in splenocytes. The expression levels of CD80 and CD86 leucocyte surface molecules were increased with 20 μg CpG DNA alone or with 20 μg CpG DNA and 4 μg HBsAg. Conclusions Our results confirmed the adjuvant effect of CpG DNA for HBsAg in the mouse model. The increase of IL10 and IL12 production suggested the involvement of Th1 cell activation. The activation of CD80 and CD86 molecules by CpG-ODN might be part of the mechanism of T/B cells coordination and the enhancement of recombinant HBsAg induced immune response.

  16. Improved humoral and cellular immune responses against the gp120 V3 loop of HIV-1 following genetic immunization with a chimeric DNA vaccine encoding the V3 inserted into the hepatitis B surface antigen

    DEFF Research Database (Denmark)

    Fomsgaard, A; Nielsen, H V; Bryder, K;

    1998-01-01

    -2d-restricted cytotoxic T lymphocyte (CTL) epitope. In an attempt to improve the immunogenicity of V3 in DNA vaccines, a plasmid expressing MN V3 as a fusion protein with the highly immunogenic middle (pre-S2 + S) surface antigen of hepatitis B virus (HBsAg) was constructed. Epidermal inoculation......The gp120-derived V3 loop of HIV-1 is involved in co-receptor interaction, it guides cell tropism, and contains an epitope for antibody neutralization. Thus, HIV-1 V3 is an attractive vaccine candidate. The V3 of the MN strain (MN V3) contains both B- and T-cell epitopes, including a known mouse H...... by gene gun was used for genetic immunization in a mouse model. Antibody and CTL responses to MN V3 and HBsAg were measured and compared with the immune responses obtained after vaccination with plasmids encoding the complete HIV-1 MN gp160 and HBsAg (pre-S2 + S), respectively. DNA vaccination...

  17. Improved humoral and cellular immune response against the gp120 V3 loop of HIV-1 following genetic immunization with a chimeric DNA vaccine encoding the V3 inserted into the hepatites B surface antigen

    DEFF Research Database (Denmark)

    Fomsgaard, A.; Nielsen, H.V.; Bryder, K.;

    1998-01-01

    -2d-restricted cytotoxic T lymphocyte (CTL) epitope. In an attempt to improve the immunogenicity of V3 in DNA vaccines, a plasmid expressing MN V3 as a fusion protein with the highly immunogenic middle (pre-S2+S) surface antigen of hepatitis B virus (HBsAg) was constructed. Epidermal inoculation......The gp120-derived V3 loop of HIV-1 is involved in co-receptor interaction, it guides cell tropism, and contains an epitope for antibody neutralization. Thus, HIV-1 V3 is an attractive vaccine candidate. The V3 of the MN strain (MN V3) contains both B- and T-cell epitopes, including a known mouse H...... by gene gun was used for genetic immunization in a mouse model. Antibody and CTL responses to MN V3 and HBsAg were measured and compared with the immune responses obtained after vaccination with plasmids encoding the complete HIV-1 MN gp160 and HBsAg (pre-S2+S), respectively. DNA vaccination with the HIV...

  18. Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine.

    Directory of Open Access Journals (Sweden)

    Anne Endmann

    Full Text Available Currently marketed vaccines against hepatitis B virus (HBV based on the small (S hepatitis B surface antigen (HBsAg fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

  19. Advances in the study of multivalent recombinant DNA vaccines utilizing the hepatitis B virus surface antigen gene%乙肝表面抗原载体多价重组核酸疫苗研究进展

    Institute of Scientific and Technical Information of China (English)

    肖婷; 郭根灵; 辛宪云; 魏庆宽

    2012-01-01

    研究表明,乙肝病毒的包膜蛋白HBsAg不仅可以作为疫苗的理想候选分子,还可作为基因工程疫苗的理想载体,用来成功构建多种重组核酸疫苗.本文概述了以乙肝表面抗原为载体,重组或联合其他病毒、寄生虫、细胞因子等其他基因制作多价核酸疫苗的研究进展.%Studies have shown that hepatitis B virus envelope protein HBsAg can be used as an ideal candidate molecule for vaccines and also as an ideal vehicle for genetically engineered vaccines to successfully build a variety of recombinant DNA vaccines. This article provides an overview of advances in recombinant DNA vaccines prepared by using hepatitis B virus surface antigen as a carrier to restructure or join it to other viruses, parasites, cell factors, or other genes.

  20. Antigen sampling in the fish intestine.

    Science.gov (United States)

    Løkka, Guro; Koppang, Erling Olaf

    2016-11-01

    Antigen uptake in the gastrointestinal tract may induce tolerance, lead to an immune response and also to infection. In mammals, most pathogens gain access to the host though the gastrointestinal tract, and in fish as well, this route seems to be of significant importance. The epithelial surface faces a considerable challenge, functioning both as a barrier towards the external milieu but simultaneously being the site of absorption of nutrients and fluids. The mechanisms allowing antigen uptake over the epithelial barrier play a central role for maintaining the intestinal homeostasis and regulate appropriate immune responses. Such uptake has been widely studied in mammals, but also in fish, a number of experiments have been reported, seeking to reveal cells and mechanisms involved in antigen sampling. In this paper, we review these studies in addition to addressing our current knowledge of the intestinal barrier in fish and its anatomical construction. PMID:26872546

  1. Results from tandem Phase 1 studies evaluating the safety, reactogenicity and immunogenicity of the vaccine candidate antigen Plasmodium falciparum FVO merozoite surface protein-1 (MSP142 administered intramuscularly with adjuvant system AS01

    Directory of Open Access Journals (Sweden)

    Otsyula Nekoye

    2013-01-01

    Full Text Available Abstract Background The development of an asexual blood stage vaccine against Plasmodium falciparum malaria based on the major merozoite surface protein-1 (MSP1 antigen is founded on the protective efficacy observed in preclinical studies and induction of invasion and growth inhibitory antibody responses. The 42 kDa C-terminus of MSP1 has been developed as the recombinant protein vaccine antigen, and the 3D7 allotype, formulated with the Adjuvant System AS02A, has been evaluated extensively in human clinical trials. In preclinical rabbit studies, the FVO allele of MSP142 has been shown to have improved immunogenicity over the 3D7 allele, in terms of antibody titres as well as growth inhibitory activity of antibodies against both the heterologous 3D7 and homologous FVO parasites. Methods Two Phase 1 clinical studies were conducted to examine the safety, reactogenicity and immunogenicity of the FVO allele of MSP142 in the adjuvant system AS01 administered intramuscularly at 0-, 1-, and 2-months: one in the USA and, after evaluation of safety data results, one in Western Kenya. The US study was an open-label, dose escalation study of 10 and 50 μg doses of MSP142 in 26 adults, while the Kenya study, evaluating 30 volunteers, was a double-blind, randomized study of only the 50 μg dose with a rabies vaccine comparator. Results In these studies it was demonstrated that this vaccine formulation has an acceptable safety profile and is immunogenic in malaria-naïve and malaria-experienced populations. High titres of anti-MSP1 antibodies were induced in both study populations, although there was a limited number of volunteers whose serum demonstrated significant inhibition of blood-stage parasites as measured by growth inhibition assay. In the US volunteers, the antibodies generated exhibited better cross-reactivity to heterologous MSP1 alleles than a MSP1-based vaccine (3D7 allele previously tested at both study sites. Conclusions Given that the primary

  2. Murine antigen-induced arthritis.

    NARCIS (Netherlands)

    Berg, W.B. van den; Joosten, L.A.B.; Lent, P.L.E.M. van

    2007-01-01

    Antigen induced arthritis is a unilateral T-cell driven model caused by direct injection of an antigen into the knee joint of a FCA preimmunized animal. The chronicity is determined by antigen retention in avascular structures of the joint through charge mediated binding or antibody mediated trappin

  3. Transplacentally acquired antibodies against hepatitis B surface antigen in full term infants%足月新生儿母源性抗-HBs及其亚型的特性

    Institute of Scientific and Technical Information of China (English)

    武巧珍; 胡娅莉; 周乙华; 王志群; 陈建琴; 叶晓东; 蒋红

    2008-01-01

    Objective To analyze the correlation of the concentration of antibodies against hepatitis B surface antigen (anti-HBs) between normal full term pregnant women and their newborns.Methods Sixty-three paired serum samples from infants and their anti-HBs positive mothers,who delivered in the Affiliated Drum Tower Hospital of Nanjing Medical University School from Dec.2006 to Feb.2007,were quantitatively tested for anti-HBs by AxSYM AUSAB immunoassay.Subclasses of anti-HBs IgG were analyzed.The neutralizing activity of maternal anti-HBs in infants was assessed by surrogate assay. Results All infants born to anti-HBs positive mothers were also seropositive.Anti-HBs 1evels in infants were correlated with the maternal concentration(rs=0.976,P<0.01),and majority of the infants had higher concentrations than their mothers(195.4 mIU/ml vs 141.6 mIU/ml,P<0.01).The mean half-life of maternal anti-HBs in infants was estimated to be 41 days.Anti-HBs IgGl subclass was predominantly in infants,which was in agreement with that in their mothers.Transplacentally transferred anti-HBs in infants efficiently bound the hepatitis B surface antigen derived from hepatitis B patients. Conclusions Anti-HBs IgG carl efficiently transfer through the placenta.Infants born to anti-HBs positive mothers may be immune to hepatitis B virus in the early life of several months.%目的 分析了解足月新生儿母源性乙型肝炎表面抗体(抗-HBs)及其亚型的特性.方法 2006年12月至2007年02月在南京大学附属鼓楼医院住院分娩的单胎足月孕妇及其新生儿为研究对象,AxSYM全自动免疫分析仪定量检测63例抗-HBs阳性的单胎足月孕妇及其新生儿脐血婴儿和1月龄时的血清抗-HBs浓度,用固相酶联免疫法检测孕妇和脐血中抗-HBs 4种IgG亚型的含量,及其中和乙型肝炎患者血清中HBsAg的能力.结果 63例抗-HBs阳性孕妇分娩的新生儿脐血抗-HBs均为阳性,几何平均浓度为195.4 mIU/ml,

  4. Mosaic VSGs and the scale of Trypanosoma brucei antigenic variation.

    Directory of Open Access Journals (Sweden)

    James P J Hall

    Full Text Available A main determinant of prolonged Trypanosoma brucei infection and transmission and success of the parasite is the interplay between host acquired immunity and antigenic variation of the parasite variant surface glycoprotein (VSG coat. About 0.1% of trypanosome divisions produce a switch to a different VSG through differential expression of an archive of hundreds of silent VSG genes and pseudogenes, but the patterns and extent of the trypanosome diversity phenotype, particularly in chronic infection, are unclear. We applied longitudinal VSG cDNA sequencing to estimate variant richness and test whether pseudogenes contribute to antigenic variation. We show that individual growth peaks can contain at least 15 distinct variants, are estimated computationally to comprise many more, and that antigenically distinct 'mosaic' VSGs arise from segmental gene conversion between donor VSG genes or pseudogenes. The potential for trypanosome antigenic variation is probably much greater than VSG archive size; mosaic VSGs are core to antigenic variation and chronic infection.

  5. Expression and immunoactivity of chimeric particulate antigens of receptor binding site-core antigen of hepatitis B virus

    Institute of Scientific and Technical Information of China (English)

    Hai-Jie Yang; Ning-Shao Xia; Min Chen; Tong Cheng; Shui-Zhen He; Shao-Wei Li; Bao-Quan Guan; Zi-Heng Zhu; Ying Gu; Jun Zhang

    2005-01-01

    AIM: To improve the immunogenicity of receptor binding site of hepatitis B virus (HBV) on preS1 antigen using HBV core antigen as an immuno-carrier.METHODS: One to 6 tandem copies of HBV preS1 (21-47)fragment were inserted into HBcAg at the sites of aa 78 and 82, and expressed in E. coli. ELISA, Western blot and animal immunization were used to analyze the antigenicity and immmunogenicity of purified particulate antigens. The ability to capture HBV by antibodies elicited by chimeric partides was detected with immuno-capture PCR.RESULTS: Recombinant antigens CⅠ, CⅡ, CⅢ carrying 1-3 copies of HBV preS1 (21-47) individually could form viruslike particles (VLPs), similar to HBcAg in morphology. But recombinant antigens carrying 4-6 copies of HBV preS1 (21-47) were poorly expressed in E.coli. Chimeric antigens were lacking of immunoreactivity with anti-HBc monoclonal antibodies (McAbs), but still reserved good immunoreactivity with anti-HBe McAbs. CⅠ, CⅡ, CⅢ could strongly react with anti-preS1 McAb, suggesting that preS1 (21-47) fragment was well exposed on the surface of chimeric VLPs. Three chimeric VLP antigens (CⅠ, CⅡ and CⅢ) could stimulate mice to produce high-level antibody responses, and their immunogenicity was stronger than non-particulate antigen 21-47*6, containing 6 copies of preS1 (21-47). Mouse antibodies to CⅠ, CⅡ and CⅢ were able to capture HBV virions in immuno-capture PCR assay in vitro.CONCLUSION: Chimeric particulate antigens of receptor binding site-core antigen of HBV can elicit strong antibody responses to preS1. They have a potential to be developed into prophylactic or therapeutic vaccines against HBV infection.

  6. Antigenic variation with a twist--the Borrelia story.

    Science.gov (United States)

    Norris, Steven J

    2006-06-01

    A common mechanism of immune evasion in pathogenic bacteria and protozoa is antigenic variation, in which genetic or epigenetic changes result in rapid, sequential shifts in a surface-exposed antigen. In this issue of Molecular Microbiology, Dai et al. provide the most complete description to date of the vlp/vsp antigenic variation system of the relapsing fever spirochaete, Borrelia hermsii. This elaborate, plasmid-encoded system involves an expression site that can acquire either variable large protein (vlp) or variable small protein (vsp) surface lipoprotein genes from 59 different archival copies. The archival vlp and vsp genes are arranged in clusters on at least five different plasmids. Gene conversion occurs through recombination events at upstream homology sequences (UHS) found in each gene copy, and at downstream homology sequences (DHS) found periodically among the vlp/vsp archival genes. Previous studies have shown that antigenic variation in relapsing fever Borrelia not only permits the evasion of host antibody responses, but can also result in changes in neurotropism and other pathogenic properties. The vlsE antigenic variation locus of Lyme disease spirochaetes, although similar in sequence to the relapsing fever vlp genes, has evolved a completely different antigenic variation mechanism involving segmental recombination from a contiguous array of vls silent cassettes. These two systems thus appear to represent divergence from a common precursor followed by functional convergence to create two distinct antigenic variation processes. PMID:16796669

  7. Carcino-Embryonic Antigen

    International Nuclear Information System (INIS)

    Tumour marker analysis has increased our understanding of the presence of tumours in the body. Carcino-embryonic antigen, CEA, is one of the best studied tumour markers and has proved an ideal diagnostic adjuvant. It has helped in quantifying the amount of disease present in a patient and thence to make accurate prognosis on the various diagnosed ailments. At UCH, it is observed that there is an increase in cancer related ailments and therefore the need for early diagnosis is more compelling in our environment to mitigate future cost of managing advanced manifestation

  8. Cancer testis antigen and immunotherapy

    Directory of Open Access Journals (Sweden)

    Krishnadas DK

    2013-04-01

    Full Text Available Deepa Kolaseri Krishnadas, Fanqi Bai, Kenneth G Lucas Department of Pediatrics, Division of Hematology/Oncology, University of Louisville, KY, USA Abstract: The identification of cancer testis (CT antigens has been an important advance in determining potential targets for cancer immunotherapy. Multiple previous studies have shown that CT antigen vaccines, using both peptides and dendritic cell vaccines, can elicit clinical and immunologic responses in several different tumors. This review details the expression of melanoma antigen family A, 1 (MAGE-A1, melanoma antigen family A, 3 (MAGE-A3, and New York esophageal squamous cell carcinoma-1 (NY-ESO-1 in various malignancies, and presents our current understanding of CT antigen based immunotherapy. Keywords: cancer testis antigens, immunotherapy, vaccine

  9. Human leucocyte antigens in tympanosclerosis.

    Science.gov (United States)

    Dursun, G; Acar, A; Turgay, M; Calgüner, M

    1997-02-01

    This study was designed to evaluate the association between certain HLA antigens and tympanosclerosis. The serum concentrations of HLA antigens were measured by a microlymphocytotoxicity technique in patients with tympanosclerosis and compared with a healthy control group. The serum levels of HLA-B35 and -DR3 were significantly higher in the patients with tympanosclerosis. This result suggests that certain types of HLA antigens may play an important role as an indicator or mediator in the pathogenesis of tympanosclerosis. PMID:9088683

  10. Clinical Research of Enzyme Linked Immunosorbent Assay for The Detection of Hepatitis B Virus Surface Antigen False Positive%酶联免疫法检测HBsAg假阳性临床研究

    Institute of Scientific and Technical Information of China (English)

    张海军

    2013-01-01

    目的:研究分析酶联免疫法(ELISA)检测乙肝病毒表面抗原(HBsAg)的假阳性情况.方法:对酶联免疫法检测HBsAg结果为阳性的1500例血清标本用金标法验证,并用化学发光仪微粒子捕捉免疫发光法(MEIA)定量检测HBsAg的含量,以确认酶联免疫法检测结果的假阳性.结果:1500例酶联免疫法检测HBsAg阳性的血清标本,其中1479例为真阳性,真阳性率为98.6%(1479/1500);21例为假阳性,假阳性率为1.4%(21/1500).结论:酶联免疫法检测HBsAg有一定的假阳性,临床检测时应高度注意,避免错报误诊.%Objective: To study enzyme linked immunosorbent assay ( ELISA ) in detecting hepatitis B virus surface antigen ( HBsAg ) of the false positive cases. Method: ELISA for detection of HBsAg results for 1500 cases with positive serum samples using the colloidal gold method validation, and using chemical luminous instrument microparticle enzyme lmmunoassay ( MEIA ) for quantitative detection of HBsAg content, to confirm the enzyme-linked immunosorbent assay for detection of false positive results. Result: 1500 cases of enzyme-linked immunosorbent assay for detection of HBsAg positive serum samples, including 1479 cases of true positive, true positive rate was 98. 6% ( 1479/1500 ); 21 were false positive, false positive rate was 1. 4% ( 21/1500 ). Conclusion: Enzyme-linked immunosorbent assay for detection of HBsAg have false positive, clinical test should be highly attention, avoid the error diagnosis.

  11. Prevalence of Serologic Hepatitis B Markers in Blood Donors From Puebla, Mexico: The Association of Relatively High Levels of Anti-Core Antibodies With the Detection of Surface Antigen and Genomic DNA

    Directory of Open Access Journals (Sweden)

    Sosa-Jurado

    2016-06-01

    Full Text Available Background The hepatitis B virus (HBV causes chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. Surface antigen (HBsAg detection is a definitive test that can confirm HBV infection, while the presence of antibodies against the core protein (anti-HBc suggests either a previous or ongoing infection or occult hepatitis B infection (OBI. Objectives The aim of the present study was to determine the prevalence of anti-HBc and HBsAg in blood donors. Further, the study aimed to estimate the anti-HBc level at which HBV DNA is detected in putative OBI cases, as well as to search for mutations in the “a” determinant associated with the non-detection of HBsAg in serum. Patients and Methods We conducted a cross-sectional study from 2003–2009. The study included 120,552 blood donors from the state of Puebla, Mexico. Different commercial systems based on microparticles (enzymatic (MEIA or chemiluminescent (CMIA were used to determine the HBsAg and anti-HBc levels. For the detection of HBV DNA, a nested polymerase chain reaction (nested PCR was used and the genotypes were determined using Sanger sequencing. Results Of the 120,552 blood donors, 1437 (1.19%, 95% CI: 1.12 - 1.26 were reactive to anti-HBc, while 82 (0.066%, 95% CI: 0.053 - 0.079 were reactive to HBsAg. Some 156 plasma samples collected in 2009 from anti-HBc-positive/HBsAg-negative blood donors were submitted for HBV DNA detection in a search for probable OBI. Viral DNA was detected in 27/156 (17.3%, 95% CI: 11.5 - 23.1. Our results show an association between HBV DNA or HBsAg and anti-HBc S/CO levels ≥ 4.0. All DNA samples were identified as genotype H and some “a” determinant mutations were identified, although none corresponded to mutations previously reported to hinder the detection of HBsAg by commercial immunoassays. Conclusions We observed that as the anti-HBc levels increase, there is a higher prevalence of the viral protein HBsAg in blood donors. Samples testing

  12. Evaluation of modified ELISA method to detect Hepatitis B surface antigen in saliva specimens%ELISA 检测唾液中乙肝表面抗原方法的优化与评价

    Institute of Scientific and Technical Information of China (English)

    张进

    2012-01-01

      目的优化用于检测唾液中乙肝表面抗原的 ELISA 法,并对其进行评价.方法对 ELISA 的不同条件:样品类型、加样体积和孵育温度及时间进行优化,筛选最佳条件;并采用三种不同的临界值计算方法,判断最佳临界值.结果采用优化后方法,47例血清阳性对应的唾液样品中,44例检测结果为阳性;68例血清阴性对应的唾液样品中,63例检测结果为阴性.血清和唾液样品检测结果的一致性比较高,κ指数为0.87.且该方法的特异度和敏感度分别达到92.6%和93.6%.结论优化后的 ELISA 方法在唾液样品的乙肝表面抗原检测中具有潜在的应用价值.%  Objective To evaluated a modified ELISA method for detecting the Hepatitis B surface antigen (HBsAg) in saliva samples. Meyhods Optimized the different conditions, including sample type, sample volume and incubation condition, to screen the best condition. Three different methods to calculate cut-off value was evaluated to screen the most acceptable. Results HBsAg was detected in 44 saliva samples out of 47 paired positive serum specimens and not detected in 63 saliva samples out of 68 matched negative serum samples by the optimized ELISA assay. There was excelent agreement between the results for the serum and saliva specimens and the kappa value was 0.87 for saliva specimens. Using an optimized protocol, the sensitivities and specificities were 93.6% and 92.6%, respectively. Conclusion Our data showed a significant promise for the use of the modified commercial ELISA in saliva sample for Hepatitis B virus infection surveilance.

  13. Association between Hepatitis B Virus Chronic Infection and Mutations of Surface Antigen Gene%乙型肝炎病毒慢性感染与其表面抗原基因突变的相关性

    Institute of Scientific and Technical Information of China (English)

    王卫华; 宋建新

    2013-01-01

    目的 基于一个完整的乙型肝炎病毒(HBV)感染自然史的4个时期(免疫耐受期、免疫清除期、不活动期和HBeAg阴性肝炎阶段),研究HBV表面抗原各抗原表位的免疫逃逸突变分布.方法 收集280例患者的临床资料及血清标本,按照HBV自然史的不同时期分为4组,提取DNA并荧光定量,通过巢式PCR扩增HBV表面基因序列,以PCR产物作为模板进行DNA测序.分析比较4组乙肝表面抗原中辅助性T细胞(Th)表位、细胞毒性T淋巴细胞(CTL)表位及B细胞抗原表位的突变差异.结果 Th抗原表位突变中,4组间比较具有差异的是17-31、37-51、67-81等区域,CTL抗原表位突变中具有差异的是14-22、41-49等区域,在B细胞抗原表位区域发现了Q101K、P120S、T126S、Q129H、M133L、M133I、和M133T等7个乙肝表面抗原免疫逃逸突变.结论在HBV感染自然史中,表面抗原突变的累积发生在免疫清除期,突变的产生有利于HBV逃避免疫系统的攻击.%Objective To investigate the distribution of the immune escape mutations of hepatitis B virus surface antigen across the natural history of hepatitis B virus infection. Methods A total of 280 patients were divided into four groups according to the natural history of hepatitis B virus infection. DNA was extracted ,and the gene sequences of hepatitis B virus surface autigen were amplified by using nested PCR. The PCR product served as a template for DNA sequencing. The differences of mutations in epitopes of helper T cells (Th) ,cytotoxic T lymphocytes (CTL ) and B cells were analyzed. Results Among the four groups ,there were significant differences in mutations of epitopes of Th at regions of 17-31 ,37-51 ,67-81 ,and in mutations of epitopes of CTL at regions of 14-22 and 41-49 among the four groups. Immune escape mutations of hepatitis B virus surface an -tigen were found in epitopes of B cells in all four groups , namely Q101K, P120S , T126S , Q129H , M133L,M133I and M133T

  14. The immunization effects of HBV core antigen and surface antigen fusion protein in mice%乙型肝炎病毒核心抗原与表面抗原"a"决定簇融合疫苗的免疫效果

    Institute of Scientific and Technical Information of China (English)

    李磊; 田拥军; 沈鸿; 赵西平; 杨东亮

    2009-01-01

    目的 评价乙型肝炎病毒核心蛋白作为类病毒颗粒载体融合表面抗原"a"决定簇的基因疫苗和蛋白疫苗的免疫效果,为寻求有效的慢性乙型肝炎治疗性疫苗奠定基础.方法 体外分别扩增编码乙型肝炎病毒HBsAg 100~162 aa部分、HBcAg 1~78 aa部分和HBcAg 83~144aa的基因序列,目的 基因连接后定向克隆到真核表达载体pcDNA3的多克隆位点内.将嵌合基因亚克隆到原核表达载体,诱导表达并纯化获得融合蛋白.分别用真核表达质粒和纯化融合蛋白免疫BALB/c小鼠,加强免疫并定期采血,检测血清中特异性抗体并进行淋巴细胞增殖实验以评价体液和细胞免疫应答效果.实验结果进行重复测量资料的方差分析和单向方差分析. 结果嵌合基因免疫后可以产生有效的抗-HBs"体液免疫"应答,免疫0、2、4、6、8、10、12,14周时的S/N值分别为1.05±0.20、2.69±0.38、4.48±0.50、6.61±0.49、6.95±0.19、7.43±0.31、8.11±0.14、7.43±0.31,F值分别为1202.021和200.059,P<0.01.未引起明显的抗-HBc"体液免疫"应答却获得了明显的HBcAg特异性细胞免疫应答.融合蛋白免疫后也能获得有效的抗-HBs"体液免疫"应答,但针对HacAg的体液应答却较强;可以产生较强的HBcAg特异性增殖反应,而没有明显的HBsAg特异性增殖反应.嵌合基因免疫组较融合蛋白组的细胞免疫应答明显增强,体液免疫应答相对较弱. 结论 以该乙型肝炎病毒核心蛋白为载体的包含HBsAg"a"决定簇的融合基因疫苗相对于其融合蛋白具有良好的细胞和体液免疫效果.%Objective To evaluate the immunization effects of HBV core antigen and surface antigen fusion protein. Methods The DNA fragments encoding HBsAg 100-162 aa; HBcAg 1-78 aa and HBcAg 83-144 aa were PCR-amplified, and then cloned into pcDNA3 plasmid. The chimeric gene was subcloned into the prokaryotic vector, pRSET-B. The E.coli expressed recombinant protein

  15. Class II-targeted antigen is superior to CD40-targeted antigen at stimulating humoral responses in vivo.

    Science.gov (United States)

    Frleta, D; Demian, D; Wade, W F

    2001-02-01

    We examined the efficacy of using monoclonal antibodies to target antigen (avidin) to different surface molecules expressed on antigen presenting cells (APC). In particular, we targeted CD40 to test whether the "adjuvant" properties of CD40 signaling combined with targeted antigen would result in enhanced serologic responses. We targeted avidin to class II as a positive control and to CD11c as a negative control. These surface proteins represent an ensemble of surface molecules that signal upon ligation and that are expressed on professional APC, in particular dendritic cells (DC). We observed that targeting class II molecules on APC was superior to targeting CD40, or CD11c. However, CD40 and CD11c could function as targets for antigen bound monoclonal antibodies under certain conditions. Interestingly, inclusion of anti-CD40 mAb with the targeting anti-class II-targeted antigens negatively affects humoral response, suggesting that CD40 signaling under certain conditions may suppress processing and/or presentation of targeted antigen. PMID:11360928

  16. A highly sensitive method for quantitation of mast cell surface antigen-1%肥大细胞表面抗原-1高灵敏度定量分析法的建立

    Institute of Scientific and Technical Information of China (English)

    陈洪淼; 宋振镇; 陈壮荔; 王振; 胡国鹏; 冯魏

    2012-01-01

    Mast cell plays a pivotal role in type I allergy, innate immunity, chronic inflammation and tissue remodeling. The recently cloned mast cell surface antigen-1 (MASA-1) protein is mainly expressed on the surface of activated mast cells, and is useful in the determination of the activation status of mast cells. The aim of this study is to develop a rapid and sensitive method for fhe quantitation of MASA-I. Based previously prepared a mouse monoclonal antibody against human MASA-1, we optimized the conditions including coating concentration, temperature and incubation time, and finally established a sandwich ELISA with a sensitivity of 0.5 ng/ml. By using this method, the MASA-1 levels in the bronchoalveolar lavage fluid of patients with respiratory system disorders are measured to be within the range of 0-130 ng/ml. The MASA-1 level correlates with the cell number of MASA-1 -positive cells, but not with that of cells stained by toluidine blue. Compared with the cell staining technique, the ELISA system is more rapid and accurate, and allows handling of large number of same samples in parallel, therefore is applicable in both research study and clinical test relating to mast cell.%目的 建立肥大细胞表面抗原-1 (MASA- 1)的高灵敏度定量分析方法.方法 首先制备抗人MASA-1的单克隆抗体,然后结合先前制备的多克隆抗体,通过优化包被浓度、温度和反应时间等条件.建立夹心酶联免疫定量方法 结果 成功制备了特异性高的小鼠抗人MASA-1的单克隆抗体;夹心ELISA法的检测灵敏度可达0.5 ng/ml.利用该法测出各种呼吸系统疾病病人的肺清洗液中的MASA-1含量为0~130 ng/ml.MASA-1的浓度与甲苯胺蓝染色阳性细胞数之间不存在相关关系,但与MASA-1染色阳性细胞数之间呈显著正相关关系.结论 相对于MASA-1细胞染色法,本研究开发的酶联免疫法具有快速、准确及能同时分析大量样品的优点,有助于肥大细胞的实验室研究和临床检测.

  17. Antigen antibody interactions

    CERN Document Server

    DeLisi, Charles

    1976-01-01

    1. 1 Organization of the Immune System One of the most important survival mechanisms of vertebrates is their ability to recognize and respond to the onslaught of pathogenic microbes to which they are conti- ously exposed. The collection of host cells and molecules involved in this recognition­ 12 response function constitutes its immune system. In man, it comprises about 10 cells 20 (lymphocytes) and 10 molecules (immunoglobulins). Its ontogenic development is c- strained by the requirement that it be capable of responding to an almost limitless variety of molecular configurations on foreign substances, while simultaneously remaining inert to those on self components. It has thus evolved to discriminate, with exquisite precision, between molecular patterns. The foreign substances which induce a response, called antigens, are typically large molecules such as proteins and polysaccharides. The portions of these with which immunoglobulins interact are called epitopes or determinants. A typical protein epitope m...

  18. A study of the efficacy and safety of using hepatitis B surface antigen-positive donors for liver transplantation%乙型肝炎表面抗原阳性供肝在肝移植中的应用

    Institute of Scientific and Technical Information of China (English)

    鞠卫强; 何晓顺; 王东平; 邓荣海; 巫林伟; 郭志勇; 朱晓峰; 黄洁夫

    2012-01-01

    Objective To evaluate the outcomes of liver transplant recipients who received liver allografts from hepatitis B surface antigen (HBsAg)-positive donors.Methods The medical records of 23 male patients (median age,42.5 years; range: 29-61) who received HBsAg-(+) liver allografts in our organ transplant center were retrospectively analyzed.All patients had confirmed diagnosis of end-stage liver disease (ESLD) secondary to hepatitis B virus (HBV) infection,including 13 HBsAg(+)/HBeAg(-)/HBcAb(+) cases and 10 HBsAg(+)/HBeAb(+)/HBcAb(+) cases.After transplantation,all patients were administered oral entecavir and intravenous anti-hepatitis B immunoglobulin (HBIG) (2000 IU/d during the first week),along with a steroid-free immune suppression regimen.HBV-related antigen and antibody and HBV DNA were detected on post-transplantation days 1,7,14,21,and 30.The liver allografts were monitored by ultrasound imaging.After discharge,monthly follow-up recorded liver function,renal function,acute rejection,infections,vascular complications,biliary complications,HBV recurrence,cancer recurrence,and patient survival.Two of the recipients died from severe perioperative pneumonia.The remaining 21 recipients were followed-up for 10-38 months,and all 21 patients remained HBsAg(+).One recipient developed biliary ischemia and required a second liver transplantation at five months after the primary transplantation.Three recipients (all primary) died from tumor recurrence at 9,14,and 18 months post-transplantation,respectively.All other recipients survived and had acceptably low HBV DNA copy levels.Color Doppler imaging showed good graft function and normal texture.The patient and graft survival rotes were 78.3% (18/23) and 73.9% (17/23),respectively.The recurrence rote of HBV infection was 100% (23/23).In surviving patients,no liver function abnormality,graft loss,or death was found to be related to the recurrence of HBV infection.Conclusion Liver transplantation using HBsAg(+) liver

  19. Production of schistosome antigens for immunodiagnosis and vaccines: the role of recombinant DNA technology

    International Nuclear Information System (INIS)

    A major problem to confront biochemists studying the immunology of parasitic infection is a paucity of the organisms themselves. Conventional biochemical techniques for the isolation and purification of individual antigens are inappropriate. This problem has been alleviated by the application of recombinant DNA technology. It is now possible to produce large quantities of individual antigens by cloning the corresponding genes into plasmids (or other vectors) and subsequent expression in bacteria. Antigens produced in this way may provide the basis of a specific diagnostic test and vaccines. This paper describes the identification of cDNA clones of Schistosoma mansoni which encode a major egg antigen and schistosomula surface antigens. These antigens are thought to be species specific and may form the basis of a diagnostic test. The schistosomula antigens are also possible candidates for inclusion in an experimental vaccine against infection with S. mansoni. (author)

  20. [Antigenic response against PPD and antigen 60 in tubercular patients: single antigen versus the combined test].

    Science.gov (United States)

    Máttar, S; Broquetas, J M; Gea, J; Aran, X; el-Banna, N; Sauleda, J; Torres, J M

    1992-05-01

    We analyze serum samples from 70 patients with pulmonary tuberculosis and 50 healthy individuals. The antigenic activity (IgG) against protein purified antigen (PPD) and antigen 60 (A60) from M. tuberculosis. Thirteen patients were also HIV infected, and three patients had AIDS defined by the presence of disseminated tuberculosis. The test using antigen alone showed a 77% sensitivity and 74% specificity when PPD is used. When A60 was used, both values improved (81% sensitivity, 94% specificity). The use of a combined test (PPD and A60) improves the sensitivity (89%) but reduces the specificity (82%). The HIV infected patients showed similar responses to those of other patients. The combined use of different antigens might be useful for diagnosing tuberculosis. PMID:1390996

  1. 我国孕妇乙肝表面抗原阳性率的Meta分析%Meta-analysis on the positive rate of hepatitis B surface antigen among pregnant women in China

    Institute of Scientific and Technical Information of China (English)

    石果; 张顺祥

    2013-01-01

    Objective To systematically evaluate the national positive rate of hepatitis B surface antigen (HB-sAg) among pregnant women in China by meta-analysis. Methods Publications regarding the positive rate of HBsAg among pregnant women between 2002 and 2012 were extracted from China National Knowledge Infra-structure (CNK1). Chinese science & technology journal database (VIP) , Wanfang database and PubMed, The Mcta positive rate was estimated using generic inverse variance model and the random effect model provid-ed by MetaAnalyst software. Results Thirty-five papers were retrieved with a total sample size of 224 029. The weighted positive rate was 7. 91 % (95% Cl: 7. 78%-8. 03%) estimated by generic inverse variance model and 7. 60% (95% CI: 6. 50%-8. 70%) by the random effect model provided by MetaAnalyst software. Be-cause of the heterogeneity of included studies, the result acquired by MetaAnalyst software was more accurate. Conclusions The result of the meta-analysis is almost consistent with the result of national epidemiological survey, indicating that Meta analysis is reliable, which provides key parameter for making strategies to prevent maternal-infantile transmission.%目的 采用Meta分析系统评价我国孕妇2002 2012年乙肝表面抗原(HBsAg)阳性率情况.方法 系统检索中国期刊全文数据库(CNKI)、维普中文科技期刊全文数据库和万方数据资源系统及PubMed中2002年1月至2012年1月发表的有关中国孕妇HBsAg阳性率的研究报道,分别用广义倒方差模型及MetaAnalyst3.13软件提供的随机效应模型估计孕妇HBsAg合并阳性率.结果 共纳入文献35篇,总样本量224029例,经广义倒方差模型加权合并后的阳性率为7.91% (95%CI:7.78%~8.03%),MetaAnalyst合并后的阳性率7.6% (95%CI:6.5%~8.7%),因纳入研究结果具有异质性,采用MetaAnalyst提供的随机效应模型获得的结果更为合适,即我国孕妇HBsAg阳性率加权合并值为7.60%,95

  2. 乙型肝炎病毒表面抗原特异性结合肽的筛选与鉴定%Screening and identification of HBV surface antigen specific binding peptide

    Institute of Scientific and Technical Information of China (English)

    孙鸣; 马智勇; 黄朝阳; 胡斌; 沈关心

    2014-01-01

    Objective To select and identify the peptide that specifically binds with HBV surface antigen (HB-sAg) .Methods HBsAg dereved from yeast was coated on milipore plate ,phage was added to screen peptide ran-domly .After four rounds of screening ,15 phage clones were selected randomly ,the phage DNA were extracted and sequenced .And their affinities were identified by the sandwich ELISA ,the specificity was identified by the does de-pendent binding test and competitive inhibition test .Results After four rounds screening ,a predominant phage clone No .3 was obtained which could comparatively strong bind with HBsAg ,and this clone displayed a peptide sequence of SSYAPYVWQPIA .HBsAg dose dependent binding test and competitive inhibition test showed that No .3 binding with HBsAg was specific .Conclusion Peptides specifically binding to HBsAg could be obtained through the screen-ing of phage display peptide library .These peptides may be used in target gene therapy of hepatitis B .It will provide experiment foundation of target gene therapy of HBV infection .%目的:筛选并鉴定与乙型肝炎病毒表面抗原(HBsAg )特异性结合的多肽。方法将酵母表达的HBsAg包被在微孔板上,加入噬菌体进行随机肽库筛选,经过4轮筛选后,随机挑取15个克隆进行DNA测序,并通过夹心ELISA方法鉴定其亲和力,采用剂量依赖结合实验和竞争抑制实验检测其与 HBsAg结合的特异性。结果经过4轮筛选,得到一优势克隆No .3,展示肽段为SSYAPYVWQPIA ,与 HBsAg有较强的亲和力,剂量依赖结合实验和竞争抑制实验证明克隆No .3与HBsAg的结合是特异性的。结论利用噬菌体展示肽库技术可以获得HBsAg特异性结合肽,此多肽可以作为靶向分子用于乙型肝炎的基因治疗,为乙型肝炎的靶向基因治疗奠定实验基础。

  3. 乙型肝炎表面抗原弱反应性标本检测及解决方法%Detection and Solution of Hepatitisb Surface Antigen Weak Reactive Specimens

    Institute of Scientific and Technical Information of China (English)

    沈芸; 方晓慧; 姜利; 张进; 陈晓斌

    2015-01-01

    目的探讨乙型肝炎表面抗原(HBsAg)弱反应性标本的检测及解决方法。方法酶联免疫吸附实验(ELISA)法筛查出本院2011年~2012年间39例HBsAg弱反应性标本如下:①S/CO值0.6~1.3,11例;②S/CO值1.3~2.5,15例;③S/CO值2.5~5.0;13例,以上标本均做酶联免疫吸附试验(ELISA),美国雅培公司ARCHITECTi2000SR仪器定量及雅培确认实验,并比较结果的差异。结果本研究结果可见:①11例S/CO值在0.6~1.3区间,ELISA检测阳性6例,阴性5例;雅培发光定量和确认实验检测阳性5例,阴性6例,差异有统计学意义(<0.05);②15例S/CO值在1.3~2.5区间,ELISA检测阳性13例,雅培发光定量和确认实验检测阳性13例;③13例S/CO值在2.5~5.0区间,ELISA检测阳性15例,雅培发光定量和确认实验检测阳性15例。结论 ELISA检验HBsAg容易出现假阳性,临床对于ELISA结果有怀疑的应进行确认试验验证,以保证检验结果的可靠性。%Objective To evaluate the detection and solution of hepatitis surface antigen weak reactive specimens.Methods We picked up 39 weak reactive samples of HBsAg From 2011 to 2012 by Enzyme-linked immunosorbent assay(ELISA) as fol own:①S/CO 0.6~1.3,11 cases;②S/CO 1.3~2.5,13 cases;③S/CO 2.5~5.0,15 cases,retested the above samples by ELISA and Abbot ARCHITECT i2000SR quantitative confirmation experiment ,then compare the dif erence between the results.Results From this study,we got fol owing.Results ①11cases of S/CO values in the 0.6 to 1.3 range, ELISA tested positive in 6 cases,negative 5 cases;Abbot luminescence assay quantification and confirmation tested positive in 5 cases,negative 6 cases,between which the dif erence was statistical y significant( <0.05).②15 cases of S/CO values ??in the 1.3 to 2.5 range,ELISA tested positive in 13 cases,Abbot luminous quantitative and experimental tested positive in 13 cases.③13cases of S/CO values in the 2.5 to 5.0 range

  4. ELISA检测唾液中乙型肝炎表面抗原方法的优化与评价%Evaluation of modified ELISA method to detect Hepatitis B surface antigen in saliva specimens

    Institute of Scientific and Technical Information of China (English)

    张进

    2013-01-01

    目的探讨优化用于检测唾液中乙型肝炎表面抗原的 ELISA法,并对其进行评价。方法对 ELISA的不同条件:样品类型、加样体积和孵育温度及时间进行优化,筛选最佳条件;并采用3种不同的临界值计算方法,判断最佳临界值。结果不做任何处理的唾液样品可直接用于检测(P=0.100),50μL唾液样品与100、150μL加样体积检测结果比较差异无统计学意义(P=0.070)。采用25℃孵育18 h的优化方法检测的结果和对应血清的检测结果相关性最好,优化后唾液检测乙型肝炎表面抗原方法的特异性和敏感性分别达92.6%和93.6%。结论优化后的 ELISA方法在唾液样品的乙型肝炎表面抗原检测中具有潜在的应用价值。%Objective To evaluated a modified ELISA method for detecting the Hepatitis B surface antigen(HBsAg)in saliva samples.Methods Optimized the different conditions,including sample type,sample volume and incubation condition,to screen the best condition.Three different methods to calculate cut-off value was evaluated to screen the most acceptable.Results The non-processed saliva sample can be used directly for detection(P=0.100).Test results of different sample volume was no significant difference(P=0.070).HBsAg was detected in 44 saliva samples out of 47 paired positive serum specimens and not detected in 63 saliva samples out of 68 matched negative serum samples by the optimized ELISA assay.There was excellent agreement between the results for the serum and saliva specimens and the kappa value was 0.87 for saliva specimens.Using an optimized protocol,the sensitivities and specificities were 93.6% and 92.6%,respectively.Conclusion Our data showed a significant promise for the use of the modified commercial ELISA in saliva sample for Hepatitis B virus infection surveillance.

  5. COLONOSCOPY AND CARCINOEMBRYONIC ANTIGEN VARIATIONS

    Directory of Open Access Journals (Sweden)

    Rita G SOUSA

    2014-03-01

    Full Text Available Context Colonoscopy is essential for synchronous and metachronous cancer detection. Carcinoembryonic antigen is a colorectal cancer tumor marker, important as a follow-up tool in patients with previous colorectal cancer. False-positive carcinoembryonic antigen elevation results in multiples exams and in patient anxiety. In literature, there is reference to transient carcinoembryonic antigen increase with colonoscopy. Objective To evaluate the influence of bowel preparation and colonoscopy in carcinoembryonic antigen blood levels. Methods We prospectively studied subjects that underwent routine colonoscopy in our institution. Blood samples were collected (1 before bowel cleaning, (2 before colonoscopy and (3 immediately after colonoscopy. Blood carcinoembryonic antigen levels were determined by “Sandwich” immunoassay. The statistical methods used were the paired t-test and ANOVA. Results Thirty-seven patients (22M/15F were included; age range 28-84 (mean 56 years. Mean carcinoembryonic antigen values were 1.9, 2 and 1.8 for (1, (2 and (3, respectively. An increase in value (2 compared with (1 was observed in 20/37 patients (P = 0.018, mainly in younger patients and in patients requiring more endoluminal interventions. In 29/37 patients, the CEA value decreased from (2 to (3 (P = 1.3x10-7. Conclusions A trend for carcinoembryonic antigen increase after bowel cleaning was observed, especially in younger patients and in patients with more endoluminal interventions, but without clinical meaning.

  6. Comparable quality attributes of hepatitis E vaccine antigen with and without adjuvant adsorption-dissolution treatment.

    Science.gov (United States)

    Zhang, Yue; Li, Min; Yang, Fan; Li, Yufang; Zheng, Zizheng; Zhang, Xiao; Lin, Qingshan; Wang, Ying; Li, Shaowei; Xia, Ningshao; Zhang, Jun; Zhao, Qinjian

    2015-01-01

    Most vaccines require adjuvants for antigen stabilization and immune potentiation. Aluminum-based adjuvants are the most widely used adjuvants for human vaccines. Previous reports demonstrated the preservation of antigen conformation and other antigen characteristics after recovery from adjuvanted Hepatitis B and human papillomavirus vaccines. In this study, we used a combination of various physiochemical and immunochemical methods to analyze hepatitis E vaccine antigen quality attributes after recovery from adjuvants. All biochemical and biophysical methods showed similar characteristics of the p239 protein after recovery from adjuvanted vaccine formulation compared to the antigen in solution which never experienced adsorption/desorption process. Most importantly, we demonstrated full preservation of key antigen epitopes post-recovery from adjuvanted vaccine using a panel of murine monoclonal antibodies as exquisite probes. Antigenicity of p239 was probed with a panel of 9 mAbs using competition/blocking ELISA, surface plasmon resonance and sandwich ELISA methods. These multifaceted analyses demonstrated the preservation of antigen key epitopes and comparable protein thermal stability when adsorbed on adjuvants or of the recovered antigen post-dissolution treatment. A better understanding of the antigen conformation in adjuvanted vaccine will enhanced our knowledge of antigen-adjuvant interactions and facilitate an improved process control and development of stable vaccine formulation.

  7. Hu Ly-m5: a unique antigen physically associated with HLA molecules.

    Science.gov (United States)

    Sparrow, R L; McKenzie, I F

    1983-05-01

    A new human cell surface antigen (Hu Ly-m5) detected by a murine monoclonal antibody (E4.3) is described. The tissue distribution of the Hu Ly-m5 antigen is similar to the HLA antigens (with which it was initially confused) but it is not present on all bone marrow cells nor the U266 myeloma, and is expressed on the HLA-negative K562 cell line. Nevertheless, the Hu Ly-m5 antigen has some affinity for HLA molecules as the two entities cocap and the Hu Ly-m5 antigen copurifies with the HLA antigens on an anti-beta 2-microglobulin immunoabsorbent column; however, the antigen complexes did not withstand the procedures used for coprecipitation. Despite their similarities, the Hu Ly-m5 and HLA antigens are distinct molecular entities--Hu Ly-m5 consists of two bands of apparent molecular weight 69 and 60 K while HLA is comprised of the 43 and 12 K bands of the HLA heavy chain and beta 2-microglobulin, respectively. The function of the Hu Ly-m5 antigen is unknown, but no involvement in the cytotoxic T-lymphocyte response to influenza virus-infected cells could be demonstrated. The two properties described (apparent molecular weight and physical association with the HLA antigens) suggests that the Hu Ly-m5 antigen may be a viral-encoded protein.

  8. Protective efficacy of vaccination with Neospora caninum multiple recombinant antigens against experimental Neospora caninum infection

    OpenAIRE

    Cho, Jung-Hwa; Chung, Woo-Suk; Song, Kyoung-Ju; Na, Byoung-kuk; Kang, Seung-Won; Song, Chul-Yong; Kim, Tong-Soo

    2005-01-01

    Protective efficacy of vaccination with Neospora caninum multiple recombinant antigens against N. caninum infection was evaluated in vitro and in vivo. Two major immunodominant surface antigens (NcSAG1 and NcSRS2) and two dense granule proteins (NcDG1 and NcDG2) of N. caninum tachyzoites were expressed in E. coli, respectively. An in vitro neutralization assay using polyclonal antisera raised against each recombinant antigen showed inhibitory effects on the invasion of N. caninum tachyzoites ...

  9. Enhancing the recognition of tumor associated antigens

    OpenAIRE

    Restifo, Nicholas P; Irvine, Kari R.; Minev, Boris R.; Taggarse, Akash S.; McFariand, Barbra J.; Wang, Michael

    1994-01-01

    Activated CD8+ T cells (TCD8+) can directly recognize malignant cells because processed fragments of tumor associated antigens (TAA), 8-10 amino acids in length and complexed with MHC class I molecules, are displayed on tumor cell surfaces. Tumor cells have been genetically modified in a variety of ways in efforts to enhance the immune recognition of TAA. An alternative strategy is the expression of TAA in recombinant or synthetic form. This has been made possible by the recent cloning of TAA...

  10. STUDY ON MECHANISM OF MODIFICATION OF HLA ANTIGEN CAMOUFLAGED BY DIVERSE mPEGs

    Institute of Scientific and Technical Information of China (English)

    张印则; 周华友; 兰炯采; 李伟; 张志欣; 章扬培

    2004-01-01

    Objective To study mechanism of various effects of HLA antigen camouflaged by different mPEGs. Methods Effects of the modification of HLA antigen camouflaged by various mPEGs were detected by microlymphocytotoxicity test. The ability of modification was detected by SDS-PAGE. The mechanism of the modification was depicted by the three-dimensional structure of HLA antigen. Results The specific reaction between HLA-A2 antigen and its antibody were completely blocked by mPEG-BTC and mPEG-SPA. mPEG-MAL did not camouflage HLA antigen. The diversity of the modification of HLA antigen camouflaged by varied mPEGs was closely associated with the amides displayed on the surface of HLA antigen. Conclusion Only the amides which were exposed to the surface of HLA antigen can be camouflaged by mPEG. The amides on the surface of three-dimensional structure of HLA-A2 antigen determine the effect of the modification by various mPEGs.

  11. Characterization of plant plasma membrane antigens: [Annual] progress report

    International Nuclear Information System (INIS)

    Protoplast plasma membranes were used to raise antibodies in mice to cell surface antigens. Monoclonal antibodies were selected from those produced and used for indirect immunofluorescence microscopic analysis of N. tabacum cells. In parallel studies cDNA expression libraries were prepared. (DT)

  12. [Farmer's lung antigens in Germany].

    Science.gov (United States)

    Sennekamp, J; Joest, M; Sander, I; Engelhart, S; Raulf-Heimsoth, M

    2012-05-01

    Recent studies suggest that besides the long-known farmer's lung antigen sources Saccharopolyspora rectivirgula (Micropolyspora faeni), Thermoactinomyces vulgaris, and Aspergillus fumigatus, additionally the mold Absidia (Lichtheimia) corymbifera as well as the bacteria Erwinia herbicola (Pantoea agglomerans) and Streptomyces albus may cause farmer's lung in Germany. In this study the sera of 64 farmers with a suspicion of farmer's lung were examined for the following further antigens: Wallemia sebi, Cladosporium herbarum, Aspergillus versicolor, and Eurotium amstelodami. Our results indicate that these molds are not frequent causes of farmer's lung in Germany. PMID:22477566

  13. The role of FcRn in antigen presentation

    Directory of Open Access Journals (Sweden)

    Kristi eBaker

    2014-08-01

    Full Text Available Immunoglobulins are unique molecules capable of simultaneously recognizing a diverse array of antigens and themselves being recognized by a broad array of receptors. The abundance specifically of the IgG subclass and the variety of signaling receptors to which it binds render this an important immunomodulatory molecule. In addition to the classical Fcγ receptors (FcγR which bind IgG at the cell surface, the neonatal Fc receptor (FcRn is a lifelong resident of the endolysosomal system of most hematopoietic cells where it determines the intracellular fate of both IgG and IgG-containing immune complexes (IgG IC. Crosslinking of FcRn by multivalent IgG IC within antigen presenting cells such as dendritic cells (DC initiates specific mechanisms which result in trafficking of the antigen-bearing IgG IC into compartments from which the antigen can successfully be processed into peptide epitopes compatible with loading onto both MHC class I and II molecules. In turn, this enables the synchronous activation of both CD4+ and CD8+ T cell responses against the cognate antigen, thereby bridging the gap between the humoral and cellular branches of the adaptive immune response. Critically, FcRn-driven T cell priming is efficient at very low doses of antigen due to the exquisite sensitivity of the IgG-mediated antigen delivery system through which it operates. FcRn-mediated antigen presentation has important consequences in tissue compartments replete with IgG and serves not only to determine homeostatic immune activation at a variety of sites but also to induce inflammatory responses upon exposure to antigens perceived as foreign. Therapeutically targeting the pathway by which FcRn enables T cell activation in response to IgG IC is thus a highly attractive prospect not only for the treatment of diseases that are driven by immune complexes but also for manipulating local immune responses against defined antigens such as those present during infections and

  14. MHC Class Ⅰ Antigen Presentation- Recently Trimmed and Well Presented

    Institute of Scientific and Technical Information of China (English)

    Barry Flutter; Bin Gao

    2004-01-01

    Presentation of antigenic peptide to T cells by major histocompatibility complex (MHC) class Ⅰ molecules is the key to the cellular immune response. Non-self intracellular proteins are processed into short peptides and transported into endoplasmic reticulum (ER) where they are assembled with class Ⅰ molecules assisted by several chaperone proteins to form trimeric complex. MHC class Ⅰ complex loaded with optimised peptides travels to the cell surface of antigen presentation cells to be recognised by T cells. The cells presenting non-self peptides are cleared by CD8 positive T cells. In order to ensure that T cells detect an infection or mutation within the target cells the process of peptide loading and class Ⅰ expression must be carefully regulated. Many of the cellular components involved in antigen processing and class Ⅰ presentation are known and their various functions are now becoming clearer. Cellular & Molecular Immunology. 2004;1(1):22-30.

  15. MHC Class I Antigen Presentation- Recently Trimmed and Well Presented

    Institute of Scientific and Technical Information of China (English)

    BarryFlutter; BinGao

    2004-01-01

    Presentation of antigenic peptide to T cells by major histocompatibility complex (MHC) class I molecules is the key to the cellular immune response. Non-self intracellular proteins are processed into short peptides and transported into endoplasmic reticulum (ER) where they are assembled with class I molecules assisted by several chaperone proteins to form trimeric complex. MHC class I complex loaded with optimised peptides travels to the cell surface of antigen presentation cells to be recognised by T cells. The cells presenting non-self peptides are cleared by CD8 positive T cells. In order to ensure that T cells detect an infection or mutation within the target cells the process of peptide loading and class I expression must be carefully regulated. Many of the cellular components involved in antigen processing and class I presentation are known and their various functions are now becoming clearer. Cellular & Molecular Immunology. 2004;1(1):22-30.

  16. Prediction of antigenic determinants of trichosanthin by molecular modeling

    Institute of Scientific and Technical Information of China (English)

    HEYONGNING; ZONGXIANGXIA; 等

    1996-01-01

    The antigenic determinants of trichosanthin were predicted by molecular modeling.First,the threedimensional structure model of the antigen-binding fragment of anti-trichosanthin immunoglobulin E was built on the basis of its amino-acid sequence and the known three-dimensional structure of an antibody with similar sequence.Secondly,the preferable antigen-antibody interactions were obtained based on the known three-dimensional structure of trichosanthin and of the hypervariable regions of anti-trichosanthin immunoglobulin E.Two regions in the molecular surface of trichosanthin were found to form extensive interactions with the hypervariable regions of the antibody and have been predicted to be the possible antigenic determinants:one is composed of two polypeptide segments,Ile201-Glu210 and Ile225-Asp229,which are close to each other in the three-dimensional structure;and the other is the segment Lys173-Thr178.The former region seems to be the more reasonable antigenic determinant than the latter one.

  17. СAPSULAR ANTIGEN OF YERSINIA PESTIS

    Directory of Open Access Journals (Sweden)

    L. A. Kadnikova

    2015-01-01

    Full Text Available Plague is a zoonosis caused by gram-negative bacteria Yersinia pestis, which, as a rule, is transmitted to humans from septicemic rodents by the bites of infected fleas. This microbe killed more people than all of the wars in the human history. Y. pestis circulation in the natural plague foci is ensured by the whole number of pathogenicity factors with differing functional orientation. This review is devoted to one of them, Y. pestis capsular antigen (F1 or Caf1. The history of its discovery and studying of its genetic control, biosynthesis, isolation and purification, and physicochemical properties are reviewed. Its roles in plague pathogenesis and its application as a main component of plague vaccines are also discussed. Y. pestis capsule under light microscopy is visually amorphous, while high-resolution electron microscopy displays the structure formed from separate fimbria-like cords up to 200 nm long, diverging from the bacterial surface in different directions. At 37°C Y. pestis produce 800–1000 times more capsular antigen than at 28°C. Genes coding for 17.6-kD Caf1 protein, which contains 170 amino acids, are located in caf1 operon of pFra plasmid. Analysis of caf1 operon nucleotide sequence testified its close phylogenetic relationship with the gene clusters coding for pilus adhesins that were secreted with the help of chaperone/usher systems in enterobacteria including six additional adhesins in Y. pestis. Y. pestis multiplication within macrophages is the obligatory stage of plague pathogenesis, and the plague pathogen virulence correlates not with resistance to phagocyte ingesting but with bacterial ability to survive and multiply within phagolysosomes of phagocytes due to neutralization of antibacterial functions of eukaryotic cells. The capsule formed out of the Caf1 aggregates protects Y. pestis from ingestion by naïve host’s phagocytes and prevents from initiation of the alternative pathway of the complement system

  18. Natural selection promotes antigenic evolvability

    NARCIS (Netherlands)

    Graves, C.J.; Ros, V.I.D.; Stevenson, B.; Sniegowski, P.D.; Brisson, D.

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide

  19. Oncogenic cancer/testis antigens

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Andersen, Mads H; Ditzel, Henrik J

    2015-01-01

    /testis antigens are immunogenic, highly cancer-specific, and frequently expressed in various types of cancer, which make them promising candidate targets for cancer immunotherapy, including cancer vaccination and adoptive T-cell transfer with chimeric T-cell receptors. Our current understanding of tumor...

  20. Biological function and molecular mapping of M antigen in yeast phase of Histoplasma capsulatum.

    Directory of Open Access Journals (Sweden)

    Allan Jefferson Guimarães

    Full Text Available Histoplasmosis, due to the intracellular fungus Histoplasma capsulatum, can be diagnosed by demonstrating the presence of antibodies specific to the immunodominant M antigen. However, the role of this protein in the pathogenesis of histoplasmosis has not been elucidated. We sought to structurally and immunologically characterize the protein, determine yeast cell surface expression, and confirm catalase activity. A 3D-rendering of the M antigen by homology modeling revealed that the structures and domains closely resemble characterized fungal catalases. We generated monoclonal antibodies (mAbs to the protein and determined that the M antigen is present on the yeast cell surface and in cell wall/cell membrane preparations. Similarly, we found that the majority of catalase activity was in extracts containing fungal surface antigens and that the M antigen is not significantly secreted by live yeast cells. The mAbs also identified unique epitopes on the M antigen. The localization of the M antigen to the cell surface of H. capsulatum yeast and the characterization of the protein's major epitopes have important implications since it demonstrates that although the protein may participate in protecting the fungus against oxidative stress it is also accessible to host immune cells and antibody.

  1. [Mucose associated lymphoid tissue. Antigen presenting cells].

    Science.gov (United States)

    Luzardo-Baptista, Mario J; Luzardo, José Rafael

    2013-12-01

    We studied samples of normal and abnormal human mucosae, including oral tissue and uterine cervix, using electron microscopy. Special attention was given to the functions and mechanisms of defense carried out by the epithelial (EC) and dendritic cells (DC). Activated epithelial cells posses the capacity to uptake and process antigens, in order to present them, subsequently, to the dendritic cells. The structures and elements of the cells intervening on this function are: micropinocytic vesicles, multivesicular bodies, lysosomes, phagosomes, clathrin-covered vesicles, dense granules covered by a unit membrane, granules with onion likes leaves, microbodies, and dense granules with acid phosphatase activity. When they first arrive within the epithelial layers, the DC are clear with long cytoplasmic projections, which later become short, and the density of their cytoplasm increases. They possess mycropinocytic vesicles, some clathrine-covered vesicles, lysososmes and Birbeck granules. At this moment, they are known as Langerhans cells. EC and DC present many surface folds rich in micropynocytic vesicles. Between EC and DC there are many contacts (close junctions or tight junctions), through which antigens, phagocitized and processed by the EC, are given to the DC. These cells join them to major histocompatibility complex molecules or to other molecules with similar functions (CD1). Then the Langerhans cells travel to the lymphatic node to activate T cells and continue the immunologic task. So, in this way, both the EC and the DC are a link between the natural and the acquired immunological mechanisms. PMID:24502183

  2. Tresyl-Based Conjugation of Protein Antigen to Lipid Nanoparticles Increases Antigen Immunogencity

    OpenAIRE

    Jain, Anekant; Yan, Weili; Keith R Miller; O'Carra, Ronan; Woodward, Jerold G.; Russell J Mumper

    2010-01-01

    The present studies were aimed at investigating the engineering of NPs with protein-conjugated-surfactant at their surface. In order to increase the immunogenicity of a protein antigen, Brij 78 was functionalized by tresyl chloride and then further reacted with the primary amine of the model proteins ovalbumin (OVA) or horseradish peroxide (HRP). The reaction yielded Brij 78-OVA and Brij 78-HRP conjugates which were then used directly to form NP-OVA or NP-HRP using a one-step warm oil-in-wate...

  3. Advances in the study of surface antigens of Toxoplasm gondii and DNA vaccines for the parasite%弓形虫主要抗原及核酸疫苗研究进展

    Institute of Scientific and Technical Information of China (English)

    白杨; 何深一

    2011-01-01

    Toxoplasma gondii is widely distributed and infection of humans and animals can have very serious consequences, so researchers from various countries have had difficulty preventing and treating toxoplasmosis. In recent years, T. Gondii DNA vaccines have made considerable progress with in-depth study of T. Gondii and advances in molecular biology. This paper reviews the state of development of DNA vaccines for T. Gondii utilizing its major membrane antigens. This paper also explores prospects for the development of T. Gondii vaccines and it discusses the advantages and disadvantages of DNA vaccines.%弓形虫分布广泛,且人畜感染弓形虫会带来很严重的后果,所以弓形虫病的防治一直困扰着各国学者.近年来,随着对弓形虫研究的深入以及分子生物学的发展,弓形虫核酸疫苗的研究也取得了较大的进展.本文综述了弓形虫主要抗原以及弓形虫核酸疫苗的研究现状,探索弓形虫疫苗的发展前景,并对核酸疫苗的优缺点进行讨论.

  4. Concepts and applications for influenza antigenic cartography

    Science.gov (United States)

    Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2011-01-01

    Influenza antigenic cartography projects influenza antigens into a two or three dimensional map based on immunological datasets, such as hemagglutination inhibition and microneutralization assays. A robust antigenic cartography can facilitate influenza vaccine strain selection since the antigenic map can simplify data interpretation through intuitive antigenic map. However, antigenic cartography construction is not trivial due to the challenging features embedded in the immunological data, such as data incompleteness, high noises, and low reactors. To overcome these challenges, we developed a computational method, temporal Matrix Completion-Multidimensional Scaling (MC-MDS), by adapting the low rank MC concept from the movie recommendation system in Netflix and the MDS method from geographic cartography construction. The application on H3N2 and 2009 pandemic H1N1 influenza A viruses demonstrates that temporal MC-MDS is effective and efficient in constructing influenza antigenic cartography. The web sever is available at http://sysbio.cvm.msstate.edu/AntigenMap. PMID:21761589

  5. Flow Cytometric Analysis of T, B, and NK Cells Antigens in Patients with Mycosis Fungoides.

    Science.gov (United States)

    Yazıcı, Serkan; Bülbül Başkan, Emel; Budak, Ferah; Oral, Barbaros; Adim, Şaduman Balaban; Ceylan Kalin, Zübeyde; Özkaya, Güven; Aydoğan, Kenan; Saricaoğlu, Hayriye; Tunali, Şükran

    2015-01-01

    We retrospectively analyzed the clinicopathological correlation and prognostic value of cell surface antigens expressed by peripheral blood mononuclear cells in patients with mycosis fungoides (MF). 121 consecutive MF patients were included in this study. All patients had peripheral blood flow cytometry as part of their first visit. TNMB and histopathological staging of the cases were retrospectively performed in accordance with International Society for Cutaneous Lymphomas/European Organization of Research and Treatment of Cancer (ISCL/EORTC) criteria at the time of flow cytometry sampling. To determine prognostic value of cell surface antigens, cases were divided into two groups as stable and progressive disease. 17 flow cytometric analyses of 17 parapsoriasis (PP) and 11 analyses of 11 benign erythrodermic patients were included as control groups. Fluorescent labeled monoclonal antibodies were used to detect cell surface antigens: T cells (CD3(+), CD4(+), CD8(+), TCRαβ(+), TCRγδ(+), CD7(+), CD4(+)CD7(+), CD4(+)CD7(-), and CD71(+)), B cells (HLA-DR(+), CD19(+), and HLA-DR(+)CD19(+)), NKT cells (CD3(+)CD16(+)CD56(+)), and NK cells (CD3(-)CD16(+)CD56(+)). The mean value of all cell surface antigens was not statistically significant between parapsoriasis and MF groups. Along with an increase in cases of MF stage statistically significant difference was found between the mean values of cell surface antigens. Flow cytometric analysis of peripheral blood cell surface antigens in patients with mycosis fungoides may contribute to predicting disease stage and progression. PMID:26788525

  6. Lung injury mediated by antibodies to endothelium. II. Study of the effect of repeated antigen-antibody interactions in rabbits tolerant to heterologous antibody.

    OpenAIRE

    Camussi, G.; Caldwell, P. R.; Andres, G.; Brentjens, J. R.

    1987-01-01

    The effect of repeated interactions of antibodies with cell surface antigens have been examined in in vitro, but not in in vivo systems. In this study are described the results of multiple antibody-cell surface antigen interactions in vivo. Rabbits were given repeated intravenous injections of goat antibodies to angiotensin converting enzyme (ACE), an antigen expressed on the surface of lung endothelial cells. For prevention of anaphylactic reactions, which would have been induced by multiple...

  7. Genome Scale Identification of Treponema pallidum Antigens

    OpenAIRE

    McKevitt, Matthew; Brinkman, Mary Beth; McLoughlin, Melanie; Perez, Carla; Howell, Jerrilyn K.; Weinstock, George M.; Norris, Steven J; Palzkill, Timothy

    2005-01-01

    Antibody responses for 882 of the 1,039 proteins in the proteome of Treponema pallidum were examined. Sera collected from infected rabbits were used to systematically identify 106 antigenic proteins, including 22 previously identified antigens and 84 novel antigens. Additionally, sera collected from rabbits throughout the course of infection demonstrated a progression in the breadth and intensity of humoral immunoreactivity against a representative panel of T. pallidum antigens.

  8. Antigen Export Reduces Antigen Presentation and Limits T Cell Control of M. tuberculosis.

    Science.gov (United States)

    Srivastava, Smita; Grace, Patricia S; Ernst, Joel D

    2016-01-13

    Persistence of Mycobacterium tuberculosis results from bacterial strategies that manipulate host adaptive immune responses. Infected dendritic cells (DCs) transport M. tuberculosis to local lymph nodes but activate CD4 T cells poorly, suggesting bacterial manipulation of antigen presentation. However, M. tuberculosis antigens are also exported from infected DCs and taken up and presented by uninfected DCs, possibly overcoming this blockade of antigen presentation by infected cells. Here we show that the first stage of this antigen transfer, antigen export, benefits M. tuberculosis by diverting bacterial proteins from the antigen presentation pathway. Kinesin-2 is required for antigen export and depletion of this microtubule-based motor increases activation of antigen-specific CD4 T cells by infected cells and improves control of intracellular infection. Thus, although antigen transfer enables presentation by bystander cells, it does not compensate for reduced antigen presentation by infected cells and represents a bacterial strategy for CD4 T cell evasion.

  9. [HLA antigens in juvenile rheumatoid arthritis].

    Science.gov (United States)

    Rumba, I V; Sochnev, A M; Kukaĭne, E M; Burshteĭn, A M; Benevolenskaia, L I

    1990-01-01

    Antigens of I class HLA system (locus A and B) were investigated in 67 patients of Latvian nationality suffering from juvenile rheumatoid arthritis (JRA). Associations of HLA antigens with juvenile rheumatoid arthritis partially coincided with the ones revealed earlier. Typing established an increased incidence of antigen B27 (p less than 0.01) and gaplotype A2, B40 (p less than 0.01). Antigen B15 possessed a protective action with respect to JRA. Interlocus combinations demonstrated a closer association with the disease than a single antigen. The authors also revealed markers of various clinico-anatomical variants of JRA.

  10. Cell wall anchoring of the Campylobacter antigens to Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Patrycja Anna Kobierecka

    2016-02-01

    Full Text Available Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein – CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type Campylobacter jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analysed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ LAB (Lactic Acid Bacteria strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered

  11. Regulation of protein synthesis and autophagy in activated dendritic cells: implications for antigen processing and presentation.

    Science.gov (United States)

    Argüello, Rafael J; Reverendo, Marisa; Gatti, Evelina; Pierre, Philippe

    2016-07-01

    Antigenic peptides presented in the context of major histocompatibility complex (MHC) molecules originate from the degradation of both self and non-self proteins. T cells can therefore recognize at the surface of surveyed cells, the self-peptidome produced by the cell itself (mostly inducing tolerance) or immunogenic peptides derived from exogenous origins. The initiation of adaptive immune responses by dendritic cells (DCs), through the antigenic priming of naïve T cells, is associated to microbial pattern recognition receptors engagement. Activation of DCs by microbial product or inflammatory cytokines initiates multiple processes that maximize DC capacity to present exogenous antigens and stimulate T cells by affecting major metabolic and membrane traffic pathways. These include the modulation of protein synthesis, the regulation of MHC and co-stimulatory molecules transport, as well as the regulation of autophagy, that, all together promote exogenous antigen presentation while limiting the display of self-antigens by MHC molecules.

  12. Toward a network model of MHC class II-restricted antigen processing

    Directory of Open Access Journals (Sweden)

    Laurence C Eisenlohr

    2013-12-01

    Full Text Available The standard model of Major Histocompatibility Complex class II (MHCII-restricted antigen processing depicts a straightforward, linear pathway: Internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4+ T cells (TCD4+. Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while proposing that MHCII processing be thought of less in terms of discrete pathways and more in terms of a network whose major and minor conduits are variable depending upon many factors, including the epitope, the nature of the antigen, the source of the antigen, and the identity of the antigen-presenting cell.

  13. Design, Expression and Identification of Specific Multi-Epitope Antigen of Campylobacter Jejuni Surface Proteins%空肠弯曲菌表面蛋白特异性多表位抗原的设计、表达与鉴定

    Institute of Scientific and Technical Information of China (English)

    欧瑜; 鄢方兵; 唐泰山; 祝长青; 蒋原; 张常印

    2012-01-01

    构建空肠弯曲菌表面蛋白特异性多表位抗原原核表达载体,并在大肠杆菌中诱导表达,免疫动物后检测其抗血清与空肠弯曲菌菌体的反应性.从空肠弯曲菌的6个表面蛋白中分析到特异性抗原表位,人工合成其串联基因片段,将其插入原核表达载体,获得重组质粒pET-32a(+ )-CJMEA-A,经IPTG诱导后表达出25k的目标蛋白,纯化后免疫新西兰大白兔,Western blot和间接ELISA检测重组蛋白抗原性和抗血清反应性.结果表明目标蛋白具有良好的反应原和免疫原性,抗血清能与菌体发生反应.其抗体可用于C.jejuni免疫磁珠和免疫胶体金等检测方法的建立.%To construct and to express the gene of specific multi-epitope antigen from Campylobacter jejuni and to detect the reactivity of its antibody to this bacteria. Firstly ,some specific antigenic determinants were obtained after 6 surface proteins of Campytobacter jejuni were analyzed. Secondly these epitopes were linked in series and its gene was synthesized. Thirdly, the recombinant plasmid pET-32a( + )-CJMEA-A was obtained when the gene was inserted into pET-32a( + ) vector. Then,after being induced by IPTG,the 25ku of fusion protein was expressed,purified and used for the immunization of rabbits. Finally,SDS-PAGE and indirect ELISA were used to detect the antigenicity of the protein and the reactivity of the antiserum. The results showed that this protein was expressed successfully;it possesses good unnuinogem'city and reactogenicity;its antiserum can react to thalli of C. Jejuni . A conclusion can be made that the antibody of this protein could be used to detect C. Jejuni by inununomagnetic beads or immune colloidal gold technique.

  14. Unpolarized release of vaccinia virus and HIV antigen by colchicine treatment enhances intranasal HIV antigen expression and mucosal humoral responses.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available The induction of a strong mucosal immune response is essential to building successful HIV vaccines. Highly attenuated recombinant HIV vaccinia virus can be administered mucosally, but even high doses of immunization have been found unable to induce strong mucosal antibody responses. In order to solve this problem, we studied the interactions of recombinant HIV vaccinia virus Tiantan strain (rVTT-gagpol in mucosal epithelial cells (specifically Caco-2 cell layers and in BALB/c mice. We evaluated the impact of this virus on HIV antigen delivery and specific immune responses. The results demonstrated that rVTT-gagpol was able to infect Caco-2 cell layers and both the nasal and lung epithelia in BALB/c mice. The progeny viruses and expressed p24 were released mainly from apical surfaces. In BALB/c mice, the infection was limited to the respiratory system and was not observed in the blood. This showed that polarized distribution limited antigen delivery into the whole body and thus limited immune response. To see if this could be improved upon, we stimulated unpolarized budding of the virus and HIV antigens by treating both Caco-2 cells and BALB/c mice with colchicine. We found that, in BALB/c mice, the degree of infection and antigen expression in the epithelia went up. As a result, specific immune responses increased correspondingly. Together, these data suggest that polarized budding limits antigen delivery and immune responses, but unpolarized distribution can increase antigen expression and delivery and thus enhance specific immune responses. This conclusion can be used to optimize mucosal HIV vaccine strategies.

  15. Rationally designed inhibitor targeting antigen-trimming aminopeptidases enhances antigen presentation and cytotoxic T-cell responses.

    Science.gov (United States)

    Zervoudi, Efthalia; Saridakis, Emmanuel; Birtley, James R; Seregin, Sergey S; Reeves, Emma; Kokkala, Paraskevi; Aldhamen, Yasser A; Amalfitano, Andrea; Mavridis, Irene M; James, Edward; Georgiadis, Dimitris; Stratikos, Efstratios

    2013-12-01

    Intracellular aminopeptidases endoplasmic reticulum aminopeptidases 1 and 2 (ERAP1 and ERAP2), and as well as insulin-regulated aminopeptidase (IRAP) process antigenic epitope precursors for loading onto MHC class I molecules and regulate the adaptive immune response. Their activity greatly affects the antigenic peptide repertoire presented to cytotoxic T lymphocytes and as a result can regulate cytotoxic cellular responses contributing to autoimmunity or immune evasion by viruses and cancer cells. Therefore, pharmacological regulation of their activity is a promising avenue for modulating the adaptive immune response with possible applications in controlling autoimmunity, in boosting immune responses to pathogens, and in cancer immunotherapy. In this study we exploited recent structural and biochemical analysis of ERAP1 and ERAP2 to design and develop phosphinic pseudopeptide transition state analogs that can inhibit this family of enzymes with nM affinity. X-ray crystallographic analysis of one such inhibitor in complex with ERAP2 validated our design, revealing a canonical mode of binding in the active site of the enzyme, and highlighted the importance of the S2' pocket for achieving inhibitor potency. Antigen processing and presentation assays in HeLa and murine colon carcinoma (CT26) cells showed that these inhibitors induce increased cell-surface antigen presentation of transfected and endogenous antigens and enhance cytotoxic T-cell responses, indicating that these enzymes primarily destroy epitopes in those systems. This class of inhibitors constitutes a promising tool for controlling the cellular adaptive immune response in humans by modulating the antigen processing and presentation pathway. PMID:24248368

  16. Differential expression of the Escherichia coli autoaggregation factor antigen 43

    DEFF Research Database (Denmark)

    Schembri, Mark; Hjerrild, Louise; Gjermansen, Morten;

    2003-01-01

    Antigen 43 (Ag43) is a self-recognizing surface adhesin found in most Escherichia coli strains. Due to its excellent cell-to-cell aggregation characteristics, Ag43 expression confers clumping and fluffing of cells and promotes biofilm formation. Ag43 expression is repressed by the cellular redox......-forming potential of E. coli. Finally, we demonstrated that Ag43-mediated cell aggregation confers significant protection against hydrogen peroxide killing....

  17. Development of antibodies to human embryonic stem cell antigens

    OpenAIRE

    Stanley Marisa; Rao Mahendra S; Olson Judith M; Cai Jingli; Taylor Eva; Ni Hsiao-Tzu

    2005-01-01

    Abstract Background Using antibodies to specific protein antigens is the method of choice to assign and identify cell lineage through simultaneous analysis of surface molecules and intracellular markers. Embryonic stem cell research can be benefited from using antibodies specific to transcriptional factors/markers that contribute to the "stemness" phenotype or critical for cell lineage. Results In this report, we have developed and validated antibodies (either monoclonal or polyclonal) specif...

  18. Viral sequestration of antigen subverts cross presentation to CD8(+ T cells.

    Directory of Open Access Journals (Sweden)

    Eric F Tewalt

    2009-05-01

    Full Text Available Virus-specific CD8(+ T cells (T(CD8+ are initially triggered by peptide-MHC Class I complexes on the surface of professional antigen presenting cells (pAPC. Peptide-MHC complexes are produced by two spatially distinct pathways during virus infection. Endogenous antigens synthesized within virus-infected pAPC are presented via the direct-presentation pathway. Many viruses have developed strategies to subvert direct presentation. When direct presentation is blocked, the cross-presentation pathway, in which antigen is transferred from virus-infected cells to uninfected pAPC, is thought to compensate and allow the generation of effector T(CD8+. Direct presentation of vaccinia virus (VACV antigens driven by late promoters does not occur, as an abortive infection of pAPC prevents production of these late antigens. This lack of direct presentation results in a greatly diminished or ablated T(CD8+ response to late antigens. We demonstrate that late poxvirus antigens do not enter the cross-presentation pathway, even when identical antigens driven by early promoters access this pathway efficiently. The mechanism mediating this novel means of viral modulation of antigen presentation involves the sequestration of late antigens within virus factories. Early antigens and cellular antigens are cross-presented from virus-infected cells, as are late antigens that are targeted to compartments outside of the virus factories. This virus-mediated blockade specifically targets the cross-presentation pathway, since late antigen that is not cross-presented efficiently enters the MHC Class II presentation pathway. These data are the first to describe an evasion mechanism employed by pathogens to prevent entry into the cross-presentation pathway. In the absence of direct presentation, this evasion mechanism leads to a complete ablation of the T(CD8+ response and a potential replicative advantage for the virus. Such mechanisms of viral modulation of antigen presentation

  19. Calorimetric comparison of the interactions between salivary proteins and Streptococcus mutans with and without antigen I/II

    NARCIS (Netherlands)

    Xu, Chun-Ping; de Belt-Gritter, Betsy van; Busscher, Henk J.; van der Mei, Henny C.; Norde, Willem

    2007-01-01

    Antigen I/II can be found on streptococcal cell surfaces and is involved in their interaction with salivary proteins. In this paper, we determine the adsorption enthalpies of salivary proteins to Streptococcus mutans LT 11 and S. mutans IB03987 with and without antigen I/II, respectively, using isot

  20. Intermolecular forces and enthalpies in the adhesion of Streptococcus mutans and antigen I/II deficient mutant to laminin films

    NARCIS (Netherlands)

    Busscher, H.J.; Belt-Gritter, van de B.; Dijkstra, R.J.B.; Norde, W.; Mei, van der H.C.

    2007-01-01

    The antigen I/II family of surface proteins is expressed by most oral streptococci, including Streptococcus mutans, and mediates specific adhesion to, among other things, salivary films and extracellular matrix proteins. In this study we showed that antigen I/II-deficient S. mutans isogenic mutant I

  1. Identification and localization of a soluble antigen, Ag2, of 136 kDa from Plasmodium falciparum in vitro cultures

    DEFF Research Database (Denmark)

    Jakobsen, P H; Grellier, P; Theander, T G;

    1991-01-01

    as a duplet with molecular masses of 136 and 120 kDa when tested by immunoblotting. Immunoprecipitation experiments on Triton X-100 extracted antigens from synchronized cultures showed that the antigen was synthesized in the schizont stage. Ag2 was located near the surface of schizonts in the parasitophorous...

  2. Impaired Antigen-Specific Immune Response to Vaccines in Children with Antibody Production Defects.

    Science.gov (United States)

    Szczawinska-Poplonyk, Aleksandra; Breborowicz, Anna; Samara, Husam; Ossowska, Lidia; Dworacki, Grzegorz

    2015-08-01

    The impaired synthesis of antigen-specific antibodies, which is indispensable for an adaptive immune response to infections, is a fundamental pathomechanism that leads to clinical manifestations in children with antibody production defects. The aim of this study was to evaluate the synthesis of antigen-specific antibodies following immunization in relation to peripheral blood B cell subsets in young children with hypogammaglobulinemia. Twenty-two children, aged from 8 to 61 months, with a deficiency in one or more major immunoglobulin classes participated in the study. Postvaccination antibodies against tetanus and diphtheria toxoids, the surface antigen of the hepatitis B virus, and the capsular Haemophilus influenzae type b polysaccharide antigen were assessed along with an immunophenotypic evaluation of peripheral blood B lymph cell maturation. A deficiency of antibodies against the tetanus toxoid was assessed in 73% of cases and that against the diphtheria toxoid was assessed in 68% of cases, whereas a deficiency of antibodies against the surface antigen of the hepatitis B virus was revealed in 59% of the children included in the study. A defective response to immunization with a conjugate vaccine with the Haemophilus influenzae type b polysaccharide antigen was demonstrated in 55% of hypogammaglobulinemic patients. Increased proportions of transitional B lymph cells and an accumulation of plasmablasts accompanied antibody deficiencies. The defective response to vaccine protein and polysaccharide antigens is a predominating disorder of humoral immunity in children with hypogammaglobulinemia and may result from a dysfunctional state of the cellular elements of the immune system. PMID:26018535

  3. Expression and characterization of a parasite-specific antigen on macrophages after infection with Leishmania donovani.

    Science.gov (United States)

    Basu, N; Kole, L; Ghosh, A; Das, P K

    1994-03-16

    A rabbit polyclonal antibody to crude soluble antigen of Leishmania donovani promastigotes recognized a determinant expressed on the surface membrane of mouse peritoneal macrophages and human monocyte derived macrophages infected in vitro. The determinant was recognized on infected macrophage surface only when F(ab')2 fragments of anti-leishmanial antiserum was employed in immunofluorescence. F(ab')2 fragments of human patient sera also could recognize the determinant. The expression of this antigen was not stage-specific for the parasite. Immunochemical analyses revealed this antigen to be of 51 kDa protein. Specific leaching of membrane proteins by trypsin showed three bands of expressed antigens of 26, 11 and 10 kDa, which in all likelihood might be arising from the 51 kDa antigen. The antigen was not expressed until 12 h of post infection, reached a maximum level at 24 h and thereafter attained a steady state level as studied upto 96 h of post infection. This type of antigen might have a great potential in immunodiagnostics and site-specific drug targeting. PMID:8078503

  4. Discovery of Novel Plasmodium falciparum Pre-Erythrocytic Antigens for Vaccine Development.

    Directory of Open Access Journals (Sweden)

    Joao C Aguiar

    Full Text Available Nearly 100% protection against malaria infection can be achieved in humans by immunization with P. falciparum radiation-attenuated sporozoites (RAS. Although it is thought that protection is mediated by T cell and antibody responses, only a few of the many pre-erythrocytic (sporozoite and liver stage antigens that are targeted by these responses have been identified.Twenty seven P. falciparum pre-erythrocytic antigens were selected using bioinformatics analysis and expression databases and were expressed in a wheat germ cell-free protein expression system. Recombinant proteins were recognized by plasma from RAS-immunized subjects, and 21 induced detectable antibody responses in mice and rabbit and sera from these immunized animals were used to characterize these antigens. All 21 proteins localized to the sporozoite: five localized to the surface, seven localized to the micronemes, cytoplasm, endoplasmic reticulum or nucleus, two localized to the surface and cytoplasm, and seven remain undetermined. PBMC from RAS-immunized volunteers elicited positive ex vivo or cultured ELISpot responses against peptides from 20 of the 21 antigens.These T cell and antibody responses support our approach of using reagents from RAS-immunized subjects to screen potential vaccine antigens, and have led to the identification of a panel of novel P. falciparum antigens. These results provide evidence to further evaluate these antigens as vaccine candidates.ClinicalTrials.gov NCT00870987 ClinicalTrials.gov NCT00392015.

  5. Discovery of Novel Plasmodium falciparum Pre-Erythrocytic Antigens for Vaccine Development

    Science.gov (United States)

    Aguiar, Joao C.; Bolton, Jessica; Wanga, Joyce; Sacci, John B.; Iriko, Hideyuki; Mazeika, Julie K.; Han, Eun-Taek; Limbach, Keith; Patterson, Noelle B.; Sedegah, Martha; Cruz, Ann-Marie; Tsuboi, Takafumi; Hoffman, Stephen L.; Carucci, Daniel; Hollingdale, Michael R.; Villasante, Eileen D.; Richie, Thomas L.

    2015-01-01

    Background Nearly 100% protection against malaria infection can be achieved in humans by immunization with P. falciparum radiation-attenuated sporozoites (RAS). Although it is thought that protection is mediated by T cell and antibody responses, only a few of the many pre-erythrocytic (sporozoite and liver stage) antigens that are targeted by these responses have been identified. Methodology Twenty seven P. falciparum pre-erythrocytic antigens were selected using bioinformatics analysis and expression databases and were expressed in a wheat germ cell-free protein expression system. Recombinant proteins were recognized by plasma from RAS-immunized subjects, and 21 induced detectable antibody responses in mice and rabbit and sera from these immunized animals were used to characterize these antigens. All 21 proteins localized to the sporozoite: five localized to the surface, seven localized to the micronemes, cytoplasm, endoplasmic reticulum or nucleus, two localized to the surface and cytoplasm, and seven remain undetermined. PBMC from RAS-immunized volunteers elicited positive ex vivo or cultured ELISpot responses against peptides from 20 of the 21 antigens. Conclusions These T cell and antibody responses support our approach of using reagents from RAS-immunized subjects to screen potential vaccine antigens, and have led to the identification of a panel of novel P. falciparum antigens. These results provide evidence to further evaluate these antigens as vaccine candidates. Trial Registration ClinicalTrials.gov NCT00870987 ClinicalTrials.gov NCT00392015 PMID:26292257

  6. Proteomic selection of immunodiagnostic antigens for Trypanosoma congolense.

    Directory of Open Access Journals (Sweden)

    Jennifer R Fleming

    2014-06-01

    Full Text Available Animal African Trypanosomosis (AAT presents a severe problem for agricultural development in sub-Saharan Africa. It is caused by several trypanosome species and current means of diagnosis are expensive and impractical for field use. Our aim was to discover antigens for the detection of antibodies to Trypanosoma congolense, one of the main causative agents of AAT. We took a proteomic approach to identify potential immunodiagnostic parasite protein antigens. One hundred and thirteen proteins were identified which were selectively recognized by infected cattle sera. These were assessed for likelihood of recombinant protein expression in E. coli and fifteen were successfully expressed and assessed for their immunodiagnostic potential by ELISA using pooled pre- and post-infection cattle sera. Three proteins, members of the invariant surface glycoprotein (ISG family, performed favorably and were then assessed using individual cattle sera. One antigen, Tc38630, evaluated blind with 77 randomized cattle sera in an ELISA assay gave sensitivity and specificity performances of 87.2% and 97.4%, respectively. Cattle immunoreactivity to this antigen diminished significantly following drug-cure, a feature helpful for monitoring the efficacy of drug treatment.

  7. Distinct H-2-linked regulation of T-cell responses to the pre-S and S regions of the same hepatitis B surface antigen polypeptide allows circumvention of nonresponsiveness to the S region.

    OpenAIRE

    Milich, D R; McNamara, M K; A. McLachlan; Thornton, G B; Chisari, F V

    1985-01-01

    Recently, additional polypeptide components of the surface envelope of hepatitis B virus (HBV) have been identified. The pre-S(1) and pre-S(2) regions of the HBV genome encode NH2-terminal amino acid residues that together with the S-gene product (25 kDa) comprise polypeptides of 33 kDa and 39 kDa. The possible immunopathologic significance of these larger polypeptides and their relevance to vaccine development prompted us to examine the murine immune response to pre-S(2)-encoded determinants...

  8. A simple and safe method for single HLA-antigen-typing by a solid phase assay.

    Science.gov (United States)

    Häcker-Shahin, B; Giannitsis, D J

    1991-01-01

    A rapid solid phase assay for detection of single HLA-antigens on platelets was developed. The platelets were attached to the surface of polystyrene microtitre plate wells by means of a sodium carbonate buffer and centrifugation. Uncovered areas were blocked by a gelatin blocking buffer. After incubation with commercially available anti-HLA-sera the bound anti-HLA-specific antibodies directed against HLA-antigens present on the platelets were made visible by anti-IgG-coated indicator red cells and a brief centrifugation. A positive result, meaning the presence of an HLA-antigen, was indicated by a slight red cell adherence over the reaction surface. In the absence of the HLA-antigen no binding occurred and the indicator red cells formed a small red disc-like pellet.

  9. A Novel Treponema pallidum Antigen, TP0136, Is an Outer Membrane Protein That Binds Human Fibronectin▿

    OpenAIRE

    Brinkman, Mary Beth; McGill, Melanie A.; Pettersson, Jonas; Rogers, Arthur; Matějková, Petra; Šmajs, David; Weinstock, George M.; Norris, Steven J; Palzkill, Timothy

    2008-01-01

    The antigenicity, structural location, and function of the predicted lipoprotein TP0136 of Treponema pallidum subsp. pallidum were investigated based on previous screening studies indicating that anti-TP0136 antibodies are present in the sera of syphilis patients and experimentally infected rabbits. Recombinant TP0136 (rTP0136) protein was purified and shown to be strongly antigenic during human and experimental rabbit infection. The TP0136 protein was exposed on the surface of the bacterial ...

  10. Levels of Antibody against 11 Staphylococcus aureus Antigens in a Healthy Population ▿

    OpenAIRE

    Colque-Navarro, Patricia; Jacobsson, Gunnar; Andersson, Rune; Flock, Jan-Ingmar; Möllby, Roland

    2010-01-01

    Serum samples from 151 healthy individuals aged from 15 to 89 years were investigated by enzyme-linked immunosorbent assay (ELISA) for IgG levels against 11 different purified antigens from Staphylococcus aureus. Surface antigens, such as teichoic acid, clumping factors A and B, and bone sialoprotein binding protein, and extracellular proteins, such as alpha-toxin, lipase, enterotoxin A, toxic shock syndrome toxin, scalded-skin syndrome toxin, fibrinogen binding protein, and extracellular adh...

  11. Transgenic lettuce seedlings carrying hepatitis B virus antigen HBsAg

    OpenAIRE

    Jackson Marcondes; Ekkehard Hansen

    2008-01-01

    The obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. Here we report a strategy for genetic transformation of lettuce plants (Lactuca sativa L.) using the surface antigen HBsAg of hepatitis B virus. Transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. Genetic transformation process was acquired by cocultivation of cotyledons wit...

  12. PolysacDB: A Database of Microbial Polysaccharide Antigens and Their Antibodies

    OpenAIRE

    Abhijit Aithal; Arun Sharma; Shilpy Joshi; Raghava, Gajendra P S; Varshney, Grish C.

    2012-01-01

    Vaccines based on microbial cell surface polysaccharides have long been considered as attractive means to control infectious diseases. To realize this goal, detailed systematic information about the antigenic polysaccharide is necessary. However, only a few databases that provide limited knowledge in this area are available. This paper describes PolysacDB, a manually curated database of antigenic polysaccharides. We collected and compiled comprehensive information from literature and web reso...

  13. The Comparative Research of the Effect for Colloidal Gold Method and ELISA in the Detection of Hepatitis B Surface Antigen%胶体金法与ELISA对乙型肝炎标志物检测效果的比较研究

    Institute of Scientific and Technical Information of China (English)

    陈敏

    2012-01-01

    目的 进一步比较胶体金法与ELISA对乙型肝炎标志物检测的实际效果.方法 选取2011年10月1日-2012年6月30日间体检和门诊的524例患者的资料为研究对象进行了回顾性分析,524例患者运用胶体金法与ELISA法进行了检测,对相关检测结果进行了比较分析.结果 ①胶体金法与ELISA法检测HBsAg结果差异无统计学意义(P>0.05),两组方法HBsAg检测结果的符合率为97.14%.②胶体金法与ELISA法检测抗-HBs结果差异具有统计学意义(P<0.05),两组方法抗-HBs检测结果的符合率为79.20%.结论 ELISA对乙型肝炎标志物的检测效果优于胶体金法.%Objective To further compare the actual effect for colloidal gold method and ELISA in the detection of hepatitis B surface antigen. Methods The clinical data for 524 patients for medical examinations and outpatient from October 1,2011 to June 30,2012 was taken for comparison and analysis. Results ①The difference of the detection result for colloidal gold method and ELISA in HBsAg was not significant,and P >0. 05,there was no significant difference between the two groups. The coincidence rate for the two methods in the detection of HBsAg was 97. 14%. ②The difference of the result for colloidal gold method and ELISA in the detection of anti-HBs was significant, and P < 0. 05, the differences were with a statistically significance. The coincidence rate for the two methods of anti-HBs test results was 79. 20% . Conclusion In the process of the clinical detection of hepatitis B surface antigen by ELISA, the detection effect was better.

  14. Antigen Incorporation on Cryptosporidium parvum Oocyst Walls

    OpenAIRE

    Entrala Emilio; Sbihi Younes; Sánchez-Moreno Manuel; Mascaró Carmen

    2001-01-01

    Cryptosporidium parvum oocysts are the infective stages responsible for transmission and survival of the organism in the environment. In the present work we show that the oocyst wall, far from being a static structure, is able to incorporate antigens by a mechanism involving vesicle fusion with the wall, and the incorporation of the antigen to the outer oocyst wall. Using immunoelectron microscopy we show that the antigen recognized by a monoclonal antibody used for diagnosis of cryptosporidi...

  15. Histocompatibility antigens in coal miners with pneumoconiosis.

    OpenAIRE

    Soutar, C A; Coutts, I.; Parkes, W R; Dodi, I. A.; Gauld, S; Castro, J E; Turner-Warwick, M

    1983-01-01

    Twenty-five histocompatibility antigens have been measured in 100 coal miners with pneumoconiosis attending a pneumoconiosis medical panel and the results compared with a panel of 200 normal volunteers not exposed to dust. Chest radiographs were read independently by three readers according to the ILO U/C classification. On a combined score, 40 men were thought to have simple pneumoconiosis and 60 men complicated pneumoconiosis. The number of antigens tested and associations between antigens ...

  16. Molecular cloning of complementary DNAs encoding the heavy chain of the human 4F2 cell-surface antigen: a type II membrane glycoprotein involved in normal and neoplastic cell growth

    International Nuclear Information System (INIS)

    Complementary DNA (cDNA) clones encoding the heavy chain of the heterodimeric human membrane glycoprotein 4F2 have been isolated by immunoscreening of a λgt11 expression library. The identity of these clones has been confirmed by hybridization to RNA and DNA prepared from mouse L-cell transfectants, which were produced by whole cell gene transfer and selected for cell-surface expression of the human 4F2 heavy chain. DNA sequence analysis suggest that the 4F2 heavy-chain cDNAs encode an approximately 526-amino acid type II membrane glycoprotein, which is composed of a large C-terminal extracellular domain, a single potential transmembrane region, and a 50-81 amino acid N-terminal intracytoplasmic domain. Southern blotting experiments have shown that the 4F2 heavy-chain cDNAs are derived from a single-copy gene that has been highly conserved during mammalian evolution

  17. Phosphine-free synthesis of high-quality reverse type-I ZnSe/CdSe core with CdS/Cd{sub x}Zn{sub 1-x}S/ZnS multishell nanocrystals and their application for detection of human hepatitis B surface antigen

    Energy Technology Data Exchange (ETDEWEB)

    Shen Huaibin; Niu Jin Zhong; Xu Shasha; Zhou Changhua; Li Linsong [Key Laboratory for Special Functional Materials, Henan University, Kaifeng 475004 (China); Yuan Hang; Ma Lan, E-mail: malan@sz.tsinghua.edu.cn, E-mail: lsli@henu.edu.cn [Life Science Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2011-09-16

    Highly photoluminescent (PL) reverse type-I ZnSe/CdSe nanocrystals (NCs) and ZnSe/CdSe/CdS/Cd{sub x}Zn{sub 1-x}S/ZnS core/multishell NCs were successfully synthesized by a phosphine-free method. By this low-cost, 'green' synthesis route, more than 10 g of high-quality ZnSe/CdSe/CdS/Cd{sub x}Zn{sub 1-x}S/ZnS NCs were synthesized in a large scale synthesis. After the overgrowth of a CdS/Cd{sub x}Zn{sub 1-x}S/ZnS multishell on ZnSe/CdSe cores, the PL quantum yields (QYs) increased from 28% to 75% along with the stability improvement. An amphiphilic oligomer was used as a surface coating agent to conduct a phase transfer experiment, core/multishell NCs were dissolved in water by such surface modification and the QYs were still kept above 70%. The as-prepared water dispersible ZnSe/CdSe/CdS/Cd{sub x}Zn{sub 1-x}S/ZnS core/multishell NCs not only have high fluorescence QYs but also are extremely stable in various physiological conditions. Furthermore, a biosensor system (lateral flow immunoassay system, LFIA) for the detection of human hepatitis B surface antigen (HBsAg) was developed by using this water-soluble core/multishell NCs as a fluorescent label and a nitrocellulose filter membrane for lateral flow. The result showed that such ZnSe/CdSe/CdS/Cd{sub x}Zn{sub 1-x}S/ZnS core/multishell NCs were excellent fluorescent labels to detect HBsAg. The sensitivity of HBsAg detection could reach as high as 0.05 ng ml{sup -1}.

  18. Phosphine-free synthesis of high-quality reverse type-I ZnSe/CdSe core with CdS/CdxZn1 - xS/ZnS multishell nanocrystals and their application for detection of human hepatitis B surface antigen

    Science.gov (United States)

    Shen, Huaibin; Yuan, Hang; Niu, Jin Zhong; Xu, Shasha; Zhou, Changhua; Ma, Lan; Li, Lin Song

    2011-09-01

    Highly photoluminescent (PL) reverse type-I ZnSe/CdSe nanocrystals (NCs) and ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs were successfully synthesized by a phosphine-free method. By this low-cost, 'green' synthesis route, more than 10 g of high-quality ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS NCs were synthesized in a large scale synthesis. After the overgrowth of a CdS/CdxZn1 - xS/ZnS multishell on ZnSe/CdSe cores, the PL quantum yields (QYs) increased from 28% to 75% along with the stability improvement. An amphiphilic oligomer was used as a surface coating agent to conduct a phase transfer experiment, core/multishell NCs were dissolved in water by such surface modification and the QYs were still kept above 70%. The as-prepared water dispersible ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs not only have high fluorescence QYs but also are extremely stable in various physiological conditions. Furthermore, a biosensor system (lateral flow immunoassay system, LFIA) for the detection of human hepatitis B surface antigen (HBsAg) was developed by using this water-soluble core/multishell NCs as a fluorescent label and a nitrocellulose filter membrane for lateral flow. The result showed that such ZnSe/CdSe/CdS/CdxZn1 - xS/ZnS core/multishell NCs were excellent fluorescent labels to detect HBsAg. The sensitivity of HBsAg detection could reach as high as 0.05 ng ml - 1.

  19. Mechanisms of Antigen Adsorption Onto an Aluminum-Hydroxide Adjuvant Evaluated by High-Throughput Screening.

    Science.gov (United States)

    Jully, Vanessa; Mathot, Frédéric; Moniotte, Nicolas; Préat, Véronique; Lemoine, Dominique

    2016-06-01

    The adsorption mechanism of antigen on aluminum adjuvant can affect antigen elution at the injection site and hence the immune response. Our aim was to evaluate adsorption onto aluminum hydroxide (AH) by ligand exchange and electrostatic interactions of model proteins and antigens, bovine serum albumin (BSA), β-casein, ovalbumin (OVA), hepatitis B surface antigen, and tetanus toxin (TT). A high-throughput screening platform was developed to measure adsorption isotherms in the presence of electrolytes and ligand exchange by a fluorescence-spectroscopy method that detects the catalysis of 6,8-difluoro-4-methylumbelliferyl phosphate by free hydroxyl groups on AH. BSA adsorption depended on predominant electrostatic interactions. Ligand exchange contributes to the adsorption of β-casein, OVA, hepatitis B surface antigen, and TT onto AH. Based on relative surface phosphophilicity and adsorption isotherms in the presence of phosphate and fluoride, the capacities of the proteins to interact with AH by ligand exchange followed the trend: OVA electrostatic attractions governing the interactions between an antigen adsorbed onto aluminum-containing adjuvant. PMID:27238481

  20. Serum antibodies to whole-cell and recombinant antigens of Borrelia burgdorferi in cottontail rabbits.

    Science.gov (United States)

    Magnarelli, Louis A; Norris, Steven J; Fikrig, Erol

    2012-01-01

    Archived serum samples, from 95 eastern cottontail rabbits (Sylvilagus floridanus) captured in New York, New York, USA and Millbrook, New York, USA, during 1985-86, were analyzed in solid-phase enzyme-linked immunosorbent assays (ELISA) for total and class-specific immunoglobulin (Ig) M antibodies to whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37, or VlsE) during different seasons, but there was no reactivity to outer surface protein (Osp)A or OspB. Seventy-six of the 102 sera (75%) analyzed were reactive with one or more of the antigens; 61 of the positive samples (80%) reacted to whole-cell antigens, followed by results for the p35 (58%, 44/76), VlsE (43%, 33/76), and p37 (29%, 22/ 76) antigens. Fifty-eight sera (76%) contained antibodies to the VlsE or p35 antigens with or without reactivity to whole-cell antigens. High antibody titers (≥1:2,560) recorded for 52 sera indicate robust antibody production. In analyses for IgM antibodies in an ELISA containing whole-cell antigens, there were 30 positive sera; titers ranged from 1:160 to 1:640. There was minimal cross-reactivity when rabbit antisera to Treponema pallidum or four serovars of Leptospira interrogans were screened against B. burgdorferi antigens. Based on more-specific results, VlsE and p35 antigens appear to be useful markers for detecting possible B. burgdorferi infections. PMID:22247369

  1. Proteome sampling by the HLA class I antigen processing pathway.

    Directory of Open Access Journals (Sweden)

    Ilka Hoof

    Full Text Available The peptide repertoire that is presented by the set of HLA class I molecules of an individual is formed by the different players of the antigen processing pathway and the stringent binding environment of the HLA class I molecules. Peptide elution studies have shown that only a subset of the human proteome is sampled by the antigen processing machinery and represented on the cell surface. In our study, we quantified the role of each factor relevant in shaping the HLA class I peptide repertoire by combining peptide elution data, in silico predictions of antigen processing and presentation, and data on gene expression and protein abundance. Our results indicate that gene expression level, protein abundance, and rate of potential binding peptides per protein have a clear impact on sampling probability. Furthermore, once a protein is available for the antigen processing machinery in sufficient amounts, C-terminal processing efficiency and binding affinity to the HLA class I molecule determine the identity of the presented peptides. Having studied the impact of each of these factors separately, we subsequently combined all factors in a logistic regression model in order to quantify their relative impact. This model demonstrated the superiority of protein abundance over gene expression level in predicting sampling probability. Being able to discriminate between sampled and non-sampled proteins to a significant degree, our approach can potentially be used to predict the sampling probability of self proteins and of pathogen-derived proteins, which is of importance for the identification of autoimmune antigens and vaccination targets.

  2. A computational framework for influenza antigenic cartography.

    Directory of Open Access Journals (Sweden)

    Zhipeng Cai

    Full Text Available Influenza viruses have been responsible for large losses of lives around the world and continue to present a great public health challenge. Antigenic characterization based on hemagglutination inhibition (HI assay is one of the routine procedures for influenza vaccine strain selection. However, HI assay is only a crude experiment reflecting the antigenic correlations among testing antigens (viruses and reference antisera (antibodies. Moreover, antigenic characterization is usually based on more than one HI dataset. The combination of multiple datasets results in an incomplete HI matrix with many unobserved entries. This paper proposes a new computational framework for constructing an influenza antigenic cartography from this incomplete matrix, which we refer to as Matrix Completion-Multidimensional Scaling (MC-MDS. In this approach, we first reconstruct the HI matrices with viruses and antibodies using low-rank matrix completion, and then generate the two-dimensional antigenic cartography using multidimensional scaling. Moreover, for influenza HI tables with herd immunity effect (such as those from Human influenza viruses, we propose a temporal model to reduce the inherent temporal bias of HI tables caused by herd immunity. By applying our method in HI datasets containing H3N2 influenza A viruses isolated from 1968 to 2003, we identified eleven clusters of antigenic variants, representing all major antigenic drift events in these 36 years. Our results showed that both the completed HI matrix and the antigenic cartography obtained via MC-MDS are useful in identifying influenza antigenic variants and thus can be used to facilitate influenza vaccine strain selection. The webserver is available at http://sysbio.cvm.msstate.edu/AntigenMap.

  3. A computational framework for influenza antigenic cartography.

    Science.gov (United States)

    Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2010-10-07

    Influenza viruses have been responsible for large losses of lives around the world and continue to present a great public health challenge. Antigenic characterization based on hemagglutination inhibition (HI) assay is one of the routine procedures for influenza vaccine strain selection. However, HI assay is only a crude experiment reflecting the antigenic correlations among testing antigens (viruses) and reference antisera (antibodies). Moreover, antigenic characterization is usually based on more than one HI dataset. The combination of multiple datasets results in an incomplete HI matrix with many unobserved entries. This paper proposes a new computational framework for constructing an influenza antigenic cartography from this incomplete matrix, which we refer to as Matrix Completion-Multidimensional Scaling (MC-MDS). In this approach, we first reconstruct the HI matrices with viruses and antibodies using low-rank matrix completion, and then generate the two-dimensional antigenic cartography using multidimensional scaling. Moreover, for influenza HI tables with herd immunity effect (such as those from Human influenza viruses), we propose a temporal model to reduce the inherent temporal bias of HI tables caused by herd immunity. By applying our method in HI datasets containing H3N2 influenza A viruses isolated from 1968 to 2003, we identified eleven clusters of antigenic variants, representing all major antigenic drift events in these 36 years. Our results showed that both the completed HI matrix and the antigenic cartography obtained via MC-MDS are useful in identifying influenza antigenic variants and thus can be used to facilitate influenza vaccine strain selection. The webserver is available at http://sysbio.cvm.msstate.edu/AntigenMap.

  4. Measurements in international units of antibody to hepatitis B surface antigen(anti-HBs) after immunization with a yeast-derived, subtype adr hepatitis B vaccine are considerably different between chemiluminescent immunoassay (CLIA) and chemiluminescent enzyme immunoassay (CLEIA).

    Science.gov (United States)

    Ogata, Norio

    2006-04-01

    The worldwide consensus of the minimum protective anti-HBs level against HBV infection is 10 mIU/mL on assays standardized by the World Health Organization (WHO) reference preparations. To investigate whether this value could be applied to recipients of yeast-derived recombinant HB vaccine containing the major surface protein of subtype adr (Bimmugen, Astellas Pharmaceutical, Tokyo), we compared anti-HBs measurements between chemiluminescent immunoassay (CLIA) (Architect Ausab, Abbott Japan, Tokyo) and chemiluminescent enzyme immunoassay (CLEIA) (Lumipulse Forte, Fujirebio, Tokyo) in given serum samples obtained from the vaccinees. The vaccine and the two assay methods are currently in a wide use in Japan. The study included 300 medical students who completed a standard vaccination course (0, 1 and 6 months). Serum samples obtained 1 month or 13 months after completing the vaccination were simultaneously tested for anti-HBs by CLIA and CLEIA. In 147 samples with quantifiable values on both CLIA and CLEIA (10 to 1000 mIU/mL) the geometric mean titer on CLEIA (225.0 mIU/mL) was significantly higher than that on CLIA (94.5 mIU/mL) (p < 0.0001). Of 26 subjects with CLIA measurements below 10 mIU/mL, 15 samples (57.7%) showed CLEIA measurements more than 10 mIU/mL. Thus, in the subtype adr-vaccinees CLEIA demonstrated considerably high serum anti-HBs measurements compared to CLIA and discordance in determining critical anti-HBs level of 10 mIU/mL was observed in more than half the samples. This suggests that the minimum HBV-protective anti HBs titer of 10 mIU/mL is difficult to be introduced to Japan where subtype adr-HB vaccines or -HBV infection are prevalent, unless characteristics of assay methods are carefully evaluated.

  5. Benchtop Antigen Detection Technique using Nanofiltration and Fluorescent Dyes

    Science.gov (United States)

    Scardelletti, Maximilian C.; Varaljay, Vanessa

    2009-01-01

    The designed benchtop technique is primed to detect bacteria and viruses from antigenic surface marker proteins in solutions, initially water. This inclusive bio-immunoassay uniquely combines nanofiltration and near infrared (NIR) dyes conjugated to antibodies to isolate and distinguish microbial antigens, using laser excitation and spectrometric analysis. The project goals include detecting microorganisms aboard the International Space Station, space shuttle, Crew Exploration Vehicle (CEV), and human habitats on future Moon and Mars missions, ensuring astronaut safety. The technique is intended to improve and advance water contamination testing both commercially and environmentally as well. Lastly, this streamlined technique poses to greatly simplify and expedite testing of pathogens in complex matrices, such as blood, in hospital and laboratory clinics.

  6. HBsAg阳性母亲所生婴儿联合免疫后乙型肝炎表面抗体的动态变化%Combined immunoprophylaxis induces changes in anti-hepatitis B surface protein titer in infants born to mothers with positivity for hepatitis B surface antigen

    Institute of Scientific and Technical Information of China (English)

    王静; 冯玉岭; 刘明晖; 白云; 冯达红; 袁宁霞; 杜冬青; 冯卫红; 刘红莉

    2013-01-01

    Objective To conduct a prospective randomized controlled trial of infants born to hepatitis B virus (HBV) surface antigen (HBsAg)-positive mothers in order to investigate the dynamic changes in the titer of anti-HBV surface protein (HBS) induced by treatment with combined immunoprophylaxis (200 IU hepatitis B immunoglobulin (HBIG) and 5 or 10 μg yeast recombinant hepatitis B vaccine),to compare the protective effect of 5 and 10 μg hepatitis B vaccine,and to provide an immunization strategy,monitoring mode and booster immunization schedule for the high-risk group.Methods Two-hundred-and-sixty-nine infants born to HBsAg positive mothers were given combined immunoprophylaxis at birth,and the venous blood samples (at birth,and 1,7 and 12 months) were tested for HBV DNA load,and HBsAg and anti-HBS titers.Results The overall 1-year protective rate of combined immunoprophylaxis was 95.9%.There was no significant difference between the infectious rates of infants given the 5 μg or the 10 μg hepatitis B vaccine (x2 =0.876,P =0.377).The geometric mean titers (GMTs) of anti-HBS were 144.1 mIU/ml at 1-month old and 564.9 mIU/ml at the age of 7 months old (the highest point),but declined to 397.6 mIU/ml at the age of 12 months old.The rate of infants with anti-HBS titer < 100 mIU/ml was 20.9%,and that of< 10 mIU/ml was 7.4% at 7-month-old; the rate of infants with anti-HBS titer < 100 mIU/ml increased to 30.2% and that of < 10 mIU/ml increased to 15.9% at 12-monthold.At 7-month-old,the GMT of the 10 μg vaccine group was higher than that of the 5 μg vaccine group (675.3 mIU/ml vs.25.0 mIU/ml,P =0.001) and the rate of infants with anti-HBS titer < 10 mIU/ml was significantly lower in the 10 μg vaccine group (2.3% vs.12.6%,P =0.002); at 12-month-old,the rate of infants with anti-HBS titer < 100 mIU/ml was also significantly lower in the 10 μg group (20.6% vs.40.2%,P =0.001).Conclusion Combined immunoprophylaxis is therapeutically efficacious

  7. Gold nanoparticle-based fluorescence immunoassay for malaria antigen detection.

    Science.gov (United States)

    Guirgis, Bassem S S; Sá e Cunha, Cláudia; Gomes, Inês; Cavadas, Miguel; Silva, Isabel; Doria, Gonçalo; Blatch, Gregory L; Baptista, Pedro V; Pereira, Eulália; Azzazy, Hassan M E; Mota, Maria M; Prudêncio, Miguel; Franco, Ricardo

    2012-01-01

    The development of rapid detection assays for malaria diagnostics is an area of intensive research, as the traditional microscopic analysis of blood smears is cumbersome and requires skilled personnel. Here, we describe a simple and sensitive immunoassay that successfully detects malaria antigens in infected blood cultures. This homogeneous assay is based on the fluorescence quenching of cyanine 3B (Cy3B)-labeled recombinant Plasmodium falciparum heat shock protein 70 (PfHsp70) upon binding to gold nanoparticles (AuNPs) functionalized with an anti-Hsp70 monoclonal antibody. Upon competition with the free antigen, the Cy3B-labeled recombinant PfHsp70 is released to solution resulting in an increase of fluorescence intensity. Two types of AuNP-antibody conjugates were used as probes, one obtained by electrostatic adsorption of the antibody on AuNPs surface and the other by covalent bonding using protein cross-linking agents. In comparison with cross-linked antibodies, electrostatic adsorption of the antibodies to the AuNPs surfaces generated conjugates with increased activity and linearity of response, within a range of antigen concentration from 8.2 to 23.8 μg.mL(-1). The estimated LOD for the assay is 2.4 μg.mL(-1) and the LOQ is 7.3 μg.mL(-1). The fluorescence immunoassay was successfully applied to the detection of antigen in malaria-infected human blood cultures at a 3% parasitemia level, and is assumed to detect parasite densities as low as 1,000 parasites.μL(-1).

  8. Protein antigen delivery by gene gun-mediated epidermal antigen incorporation (EAI).

    Science.gov (United States)

    Scheiblhofer, Sandra; Ritter, Uwe; Thalhamer, Josef; Weiss, Richard

    2013-01-01

    The gene gun technology can not only be employed for efficient transfer of gene vaccines into upper layers of the skin, but also for application of protein antigens. As a tissue rich in professional antigen presenting cells, the skin represents an attractive target for immunizations. In this chapter we present a method for delivery of the model antigen ovalbumin into the skin of mice termed epidermal antigen incorporation and describe in detail how antigen-specific proliferation in draining lymph nodes can be followed by flow cytometry.

  9. Conjugating influenza a (H1N1) antigen to n-trimethylaminoethylmethacrylate chitosan nanoparticles improves the immunogenicity of the antigen after nasal administration.

    Science.gov (United States)

    Liu, Qingfeng; Zheng, Xiaoyao; Zhang, Chi; Shao, Xiayan; Zhang, Xi; Zhang, Qizhi; Jiang, Xinguo

    2015-11-01

    As one of the most serious infectious respiratory diseases, influenza A (H1N1) is a great threat to human health, and it has created an urgent demand for effective vaccines. Nasal immunization can induce both systemic and mucosal immune responses against viruses, and it can serve as an ideal route for vaccination. However, the low immunogenicity of antigens on nasal mucosa is a high barrier for the development of nasal vaccines. In this study, we covalently conjugated an influenza A (H1N1) antigen to the surface of N-trimethylaminoethylmethacrylate chitosan (TMC) nanoparticles (H1N1-TMC/NP) through thioester bonds to increase the immunogenicity of the antigen after nasal administration. SDS-PAGE revealed that most of the antigen was conjugated on TMC nanoparticles, and an in vitro biological activity assay confirmed the stability of the antigen after conjugation. After three nasal immunizations, the H1N1-TMC/NP induced significantly higher levels of serum IgG and mucosal sIgA compared with free antigen. A hemagglutination inhibition assay showed that H1N1-TMC/NP induced much more protective antibodies than antigen-encapsulated nanoparticles or alum-precipitated antigen (I.M.). In the mechanistic study, H1N1-TMC/NP was shown to stimulate macrophages to produce IL-1β and IL-6 and to stimulate spleen lymphocytes to produce IL-2 and IFN-γ. These results indicated that H1N1-TMC/NP may be an effective vaccine against influenza A (H1N1) viruses for use in nasal immunization.

  10. Effect of anticancer therapy on Tn antigen exposure on the leucocyte membranes in patients with leukemia

    Directory of Open Access Journals (Sweden)

    G. S. Maslak

    2014-08-01

    Full Text Available Tn-antigen (Thomsen-nouvelle antigen is tumor-associated carbohydrate antigen with only one GalNAc residue attached to serine or threonine of polypeptide chain. There is not enough data about the expression of this glycotope in hematologic processes. But the correlations between increasing Tn-antigen expression on the cell surface and tumor growth progression, invasion, and activation of cell migration are well known. Therefore, the currently important area of modern research is studying of the impact of anticancer therapy by expression of this carbohydrate antigen in the onco-proliferative process. There are two types of cytostatic therapies in clinical hospitals of Ukraine: COP-therapy (cyclophosphamide, vincristine, prednisone and FC-therapy (fludarabine, cyclophosphamide, which are the most popular due to their effectiveness and low price. The aim of our study was to investigate Tn-antigen exposure on the surface of lymphocytes, monocytes and granulocytes in polycythemia vera and subleukemic myelosis; to examine the influence of COP- and FC-therapies on Tn-antigen exponation in patients with chronic lymphocytic leukemia. The objects of the study were blood cells of patients with chronic lymphocytic leukemia (n = 25, polycythemia vera (n = 15 and subleukemic myelosis (n = 15 aged 58–66 years. Healthy hematologic volunteers (n = 15 aged 55 to 65 years were in the control group. Lymphocytes of patients with chronic lymphocytic leukemia (n = 25 were also studied after the chemotherapy treatment of patients divided into two groups: those who took COP-therapy (n = 13; and those who treated with FC-therapy (n = 12. Tn-antigen exposure on lymphocytes, monocytes and granulocytes was investigated by Beckman Сoulter EPICS flow cytometer with primary monoclonal Tn-antigen anybodies (Institute of Immunology, Moscow, Russia and secondary fluorescein isothiocyanate labeled antybodies (Millipore, USA. The number of dead cells was monitored by binding

  11. [Blood groups - minuses and pluses. Do the blood group antigens protect us from infectious diseases?].

    Science.gov (United States)

    Czerwiński, Marcin

    2015-06-25

    Human blood can be divided into groups, which is a method of blood classification based on the presence or absence of inherited erythrocyte surface antigens that can elicit immune response. According to the International Society of Blood Transfusion, there are 341 blood group antigens collected in 35 blood group systems. These antigens can be proteins, glycoproteins or glycosphingolipids, and function as transmembrane transporters, ion channels, adhesion molecules or receptors for other proteins. The majority of blood group antigens is present also on another types of cells. Due to their localization on the surface of cells, blood group antigens can act as receptors for various pathogens or their toxins, such as protozoa (malaria parasites), bacteria (Helicobacter pylori, Vibrio cholerae and Shigella dysenteriae) and viruses (Noroviruses, Parvoviruses, HIV). If the presence of group antigen (or its variant which arised due to mutation) is beneficial for the host (e.g. because pathogens are not able to bind to the cells), the blood group may become a selection trait, leading to its dissemination in the population exposed to that pathogen. There are thirteen blood group systems that can be related to pathogen resistance, and it seems that the particular influence was elicit by malaria parasites. It is generally thought that the high incidence of blood groups such as O in the Amazon region, Fy(a-b-) in Africa and Ge(-) in Papua-New Guinea is the result of selective pressure from malaria parasite. This review summarizes the data about relationship between blood groups and resistance to pathogens.

  12. Non-cytolytic antigen clearance in DNA-vaccinated mice with electropotation

    Institute of Scientific and Technical Information of China (English)

    Jin-liang PENG; Yong-gang ZHAO; Jun-hua MAI; Wen-ka PANG; Wei GUO; Guang-ming CHEN; Guo-yu MO; Gui-rong RAO; Yu-hong XU

    2007-01-01

    Aim: To explore the potential of electroporation (EP)-mediated hepatitis B virus (HBV) DNA vaccination for the treatment of chronic HBV infection. Methods: BALB/c mice were vaccinated with HBV DNA vaccine encoding for the HBV preS2-S antigen, combined with or without EP. HBV surface antigen expression plasmid was administered into mice liver via a hydrodynamic injection to mimic HBV infection. The clearance of antigen in the serum and liver was detected by ELISA assay and immunohistochemical staining. The histopathology of the liver tissues was examined by HE staining and serum alanine aminotransferase assay.Results: The immunogenicity ofHBV DNA vaccine encoding for the HBV preS2-S antigen can be improved by EP-mediated vaccine delivery. The elicited immune responses can indeed reduce the expression of HBV surface antigen (HBsAg) in hepatocytes of the mouse model that was transfected to express HBsAg using the hydrodynamic injection method. The antigen clearance process did not cause significant toxicity to liver tissue, suggesting a non-cytolytic mechanism. Conclusion: The EP-aided DNA vaccination may have potential in mediating viral clearance in chronic hepatitis B patients.

  13. Expression and Purification of a Novel Computationally Designed Antigen for Simultaneously Detection of HTLV-1 and HBV Antibodies.

    Directory of Open Access Journals (Sweden)

    Hafez Heydari Zarnagh

    2015-04-01

    Full Text Available Computational tools are reliable alternatives to laborious work in chimeric protein design. In this study, a chimeric antigen was designed using computational techniques for simultaneous detection of anti-HTLV-I and anti-HBV in infected sera. Databases were searched for amino acid sequences of HBV/HLV-I diagnostic antigens. The immunodominant fragments were selected based on propensity scales. The diagnostic antigen was designed using these fragments. Secondary and tertiary structures were predicted and the B-cell epitopes were mapped on the surface of built model. The synthetic DNA coding antigen was sub-cloned into pGS21a expression vector. SDS-PAGE analysis showed that glutathione fused antigen was highly expressed in E. coli BL21 (DE3 cells. The recombinant antigen was purified by nickel affinity chromatography. ELISA results showed that soluble antigen could specifically react with the HTLV-I and HBV infected sera. This specific antigen could be used as suitable agent for antibody-antigen based screening tests and can help clinicians in order to perform quick and precise screening of the HBV and HTLV-I infections.

  14. Further characterization of filarial antigens by SDS polyacrylamide gel electrophoresis

    OpenAIRE

    Dissanayake, S.; Galahitiyawa, S. C.; Ismail, M. M.

    1983-01-01

    SDS (sodium dodecyl sulfate)-polyacrylamide gel electrophoresis of an antigen isolated from sera of Wuchereria bancrofti-infected patients and Setaria digitata antigen SD2-4 is reported. Both antigens showed carbohydrate (glycoprotein) staining. The W. bancrofti antigen had an apparent relative molecular mass of 35 000 while the S. digitata antigen SD2-4 migrated at the marker dye position on SDS-polyacrylamide gel electrophoresis. SDS treatment of these antigens did not abolish the precipita...

  15. Flow Cytometric Analysis of T, B, and NK Cells Antigens in Patients with Mycosis Fungoides

    Directory of Open Access Journals (Sweden)

    Serkan Yazıcı

    2015-01-01

    Full Text Available We retrospectively analyzed the clinicopathological correlation and prognostic value of cell surface antigens expressed by peripheral blood mononuclear cells in patients with mycosis fungoides (MF. 121 consecutive MF patients were included in this study. All patients had peripheral blood flow cytometry as part of their first visit. TNMB and histopathological staging of the cases were retrospectively performed in accordance with International Society for Cutaneous Lymphomas/European Organization of Research and Treatment of Cancer (ISCL/EORTC criteria at the time of flow cytometry sampling. To determine prognostic value of cell surface antigens, cases were divided into two groups as stable and progressive disease. 17 flow cytometric analyses of 17 parapsoriasis (PP and 11 analyses of 11 benign erythrodermic patients were included as control groups. Fluorescent labeled monoclonal antibodies were used to detect cell surface antigens: T cells (CD3+, CD4+, CD8+, TCRαβ+, TCRγδ+, CD7+, CD4+CD7+, CD4+CD7−, and CD71+, B cells (HLA-DR+, CD19+, and HLA-DR+CD19+, NKT cells (CD3+CD16+CD56+, and NK cells (CD3−CD16+CD56+. The mean value of all cell surface antigens was not statistically significant between parapsoriasis and MF groups. Along with an increase in cases of MF stage statistically significant difference was found between the mean values of cell surface antigens. Flow cytometric analysis of peripheral blood cell surface antigens in patients with mycosis fungoides may contribute to predicting disease stage and progression.

  16. Meningococcal vaccine antigen diversity in global databases.

    Science.gov (United States)

    Brehony, Carina; Hill, Dorothea M; Lucidarme, Jay; Borrow, Ray; Maiden, Martin C

    2015-01-01

    The lack of an anti-capsular vaccine against serogroup B meningococcal disease has necessitated the exploration of alternative vaccine candidates, mostly proteins exhibiting varying degrees of antigenic variation. Analysis of variants of antigen-encoding genes is facilitated by publicly accessible online sequence repositories, such as the Neisseria PubMLST database and the associated Meningitis Research Foundation Meningococcus Genome Library (MRF-MGL). We investigated six proposed meningococcal vaccine formulations by deducing the prevalence of their components in the isolates represented in these repositories. Despite high diversity, a limited number of antigenic variants of each of the vaccine antigens were prevalent, with strong associations of particular variant combinations with given serogroups and genotypes. In the MRF-MGL and globally, the highest levels of identical sequences were observed with multicomponent/multivariant vaccines. Our analyses further demonstrated that certain combinations of antigen variants were prevalent over periods of decades in widely differing locations, indicating that vaccine formulations containing a judicious choice of antigen variants have potential for long-term protection across geographic regions. The data further indicated that formulations with multiple variants would be especially relevant at times of low disease incidence, as relative diversity was higher. Continued surveillance is required to monitor the changing prevalence of these vaccine antigens. PMID:26676305

  17. [Immunoglobulin genes encoding antibodies directed to oncodevelopmental carbohydrate antigens].

    Science.gov (United States)

    Zenita, K; Yago, K; Fujimoto, E; Kannagi, R

    1990-07-01

    We investigated the immunoglobulin genes which encode the variable region of the monoclonal antibodies directed to the onco-developmental carbohydrate antigens such SSEA-1, fucosyl SSEA-1, SSEA-3 and SSEA-4. The VH region of these antibodies was preferentially encoded by the gene members of the X24, VH7183 and Q52 families, the families which are known to be located at the 3'-end region of the murine germ line VH gene. This result is interesting particularly when considering that the members of the 3'-end VH families are known to be preferentially expressed in embryonic B lymphocytes by an intrinsic genetic program. The comparative study of the nucleic acid sequences of mRNAs encoding these antibodies and the sequences of the corresponding germ line VH genes disclosed that the sequences encoding the antibodies contain no mutation from the germ line VH genes, or contain only a few somatic mutations, which are thought to be insignificant for the reactivity of the antibodies to the nominal antigens. These results imply that some of the embryonic B lymphocytes that express the unmutated germ line VH genes of the 3'-end families can be reactive with embryonic carbohydrate antigens, albeit rearranged with appropriate D-JH gene segments, and coupled with proper light chains. The VH region of the syngenic monoclonal anti-idiotypic antibodies directed to these anti-carbohydrate antibodies were also encoded preferentially by the members of the 3'-end VH families. We propose here that a part of the virgin embryonic B lymphocytes, which express the antibody encoded by the gene members of the 3'-end VH families at the cell surface, will be stimulated by the embryonic carbohydrate antigens which are abundantly present in the internal milieu of the embryo. The clonally expanded B lymphocytes, in turn, will facilitate the proliferation of other populations of embryonic B lymphocytes expressing the corresponding anti-idiotypic antibodies, which are also encoded by the gene members

  18. Cloning and expression of the tumor-associated antigen L6.

    OpenAIRE

    Marken, J S; Schieven, G L; Hellström, I; Hellström, K E; Aruffo, A

    1992-01-01

    The L6 cell surface antigen, which is highly expressed on lung, breast, colon, and ovarian carcinomas, has attracted attention as a therapeutic target for murine monoclonal antibodies and their humanized counterparts. Its molecular nature has, however, remained elusive. Here we describe the expression cloning of a cDNA encoding the L6 antigen. COS cells transfected with this cDNA direct the expression of an approximately 24-kDa surface protein that reacts with the two anti-L6 monoclonal antib...

  19. Monoclonal antibodies to antigens on human neutrophils, activated T lymphocytes, and acute leukemia blast cells

    Energy Technology Data Exchange (ETDEWEB)

    Miterev, G.Yu.; Burova, G.F.; Puzhitskaya, M.S.; Danilevich, S.V.; Bulycheva, T.I.

    1987-11-01

    The authors describe the production of two mouse hybridomas secreting monoclonal antibodies to antigenic determinants of the surface membranes of human neutrophils, activated T lymphocytes, and acute leukemic blast cells. The degree of lymphocyte stimulation was estimated from incorporation of /sup 3/H-thymidine with parallel microculture. Monoclonal antibodies of supernatants of hybridoma cultures shown here reacted in both immunofluorescence test and cytotoxicity test with surface membrane antigens on the majority of neutrophils and PHA-activated peripheral blood lymphocytes from healthy subjects, but did not give positive reactions with unactivated lymphocytes, adherent monocytes, erythrocytes, and alloantigen-stimulated lymphocytes.

  20. ROLE OF PERIPHERAL LYMPHOCYTES SIALYL LEWIS(X) (CD15s)ANTIGEN BEFORE AND AFTER KIDNEY TRANSPLANTATION

    Institute of Scientific and Technical Information of China (English)

    Pan Xiaoming; Wang Yong; Xue Wujun; Tian Puxun

    2006-01-01

    Objective To investigate the role of peripheral lymphocytes Sialyl Lewis(x) (CD15s) antigen before and after kidney transplantation. Methods Flow cytometry technique was applied to examine the expression of peripheral lymphoid cell surface CD15s antigen after renal transplantation, and to evaluate various therapeutic regimen. Results The statistic analysis results of peripheral lymphoid cell surface CD15s antigen expression level showed that there was significant difference among the patients with acute rejection, long-term dialysis and with normal renal function post-transplant; significant difference of CD15s expression level between group of rejection and infection; no significant difference of CD15s expression among the different groups treated by various therapeutic regimens. Conclusion The different therapeutic regimen has no influence to CD15s expression; Detection of peripheral lymphoid cell surface CD15s antigen expression periodically, intelligently make convenience to understand suitable status of immunosuppression.

  1. Rabies virus glycoprotein as a carrier for anthrax protective antigen

    International Nuclear Information System (INIS)

    Live viral vectors expressing foreign antigens have shown great promise as vaccines against viral diseases. However, safety concerns remain a major problem regarding the use of even highly attenuated viral vectors. Using the rabies virus (RV) envelope protein as a carrier molecule, we show here that inactivated RV particles can be utilized to present Bacillus anthracis protective antigen (PA) domain-4 in the viral membrane. In addition to the RV glycoprotein (G) transmembrane and cytoplasmic domains, a portion of the RV G ectodomain was required to express the chimeric RV G anthrax PA on the cell surface. The novel antigen was also efficiently incorporated into RV virions. Mice immunized with the inactivated recombinant RV virions exhibited seroconversion against both RV G and anthrax PA, and a second inoculation greatly increased these responses. These data demonstrate that a viral envelope protein can carry a bacterial protein and that a viral carrier can display whole polypeptides compared to the limited epitope presentation of previous viral systems

  2. Transplant immuno-diagnostics: crossmatch and antigen detection.

    Science.gov (United States)

    South, Andrew M; Grimm, Paul C

    2016-06-01

    Identifying and monitoring donor-directed anti-human leukocyte antigen antibodies are a rapidly evolving area of solid organ transplantation. Donor-specific antibodies dictate pre-transplant donor choice and donor-recipient matching and underlie much acute and chronic allograft rejection and loss. The evolution of available technology has driven this progress. Early, labor-intensive, whole-cell assays based on complement-dependent cytotoxicity suffered from poor sensitivity and specificity, technical challenges and lack of precision. Sequential improvement in assay performance included anti-human immunoglobulin-enhanced, complement-dependent cytotoxicity techniques followed by cell-based flow cytometry. However, variable specificity and sensitivity inherent in cell-based testing continued to limit flow cytometry. The introduction of solid-phase assays led to a second revolution in histocompatibility testing with the use of purified antigens bound to artificial surfaces rather than whole cells. These techniques augmented sensitivity and specificity to detect even low-titer antibodies to previously undetected antigens. Identification of complement-activating antibodies is being introduced, but current technology is in the developmental stage. While the detection of alloantibodies has improved dramatically, our comprehension of their importance remains imperfect. Variability in methodology and a lack of standardization limits the clinical application of these tests. In spite of the hurdles that remain, antibody-mediated rejection has become a key target to improve graft survival. PMID:26139577

  3. Antigen incorporation on Cryptosporidium parvum oocyst walls

    Directory of Open Access Journals (Sweden)

    Entrala Emilio

    2001-01-01

    Full Text Available Cryptosporidium parvum oocysts are the infective stages responsible for transmission and survival of the organism in the environment. In the present work we show that the oocyst wall, far from being a static structure, is able to incorporate antigens by a mechanism involving vesicle fusion with the wall, and the incorporation of the antigen to the outer oocyst wall. Using immunoelectron microscopy we show that the antigen recognized by a monoclonal antibody used for diagnosis of cryptosporidiosis (Merifluor®, Meridian Diagnostic Inc. could be found associated with vesicles in the space between the sporozoites and the oocysts wall, and incorporated to the outer oocyst wall by an unknown mechanism.

  4. Expression of Tac antigen component of bovine interleukin-2 receptor in different leukocyte populations infected with Theileria parva or Theileria annulata

    OpenAIRE

    Dobbelaere, D A; Prospero, T D; Roditi, I J; Kelke, C; Baumann, I.; Eichhorn, M; Williams, R O; Ahmed, J. S.; Baldwin, C L; Clevers, J.C.

    1990-01-01

    The Tac antigen component of the bovine interleukin-2 receptor was expressed as a Cro-beta-galactosidase fusion protein in Escherichia coli and used to raise antibodies in rabbits. These antibodies were used for flow cytofluorimetric analysis to investigate the expression of Tac antigen in a variety of Theileria parva-infected cell lines and also in three Theileria annulata-infected cell lines. Cells expressing Tac antigen on their surface were found in all T. parva-infected cell lines tested...

  5. Kinetics of antibody-induced modulation of respiratory syncytial virus antigens in a human epithelial cell line

    Directory of Open Access Journals (Sweden)

    Gómez-Garcia Beatriz

    2007-07-01

    Full Text Available Abstract Background The binding of viral-specific antibodies to cell-surface antigens usually results in down modulation of the antigen through redistribution of antigens into patches that subsequently may be internalized by endocytosis or may form caps that can be expelled to the extracellular space. Here, by use of confocal-laser-scanning microscopy we investigated the kinetics of the modulation of respiratory syncytial virus (RSV antigen by RSV-specific IgG. RSV-infected human epithelial cells (HEp-2 were incubated with anti-RSV polyclonal IgG and, at various incubation times, the RSV-cell-surface-antigen-antibody complexes (RSV Ag-Abs and intracellular viral proteins were detected by indirect immunoflourescence. Results Interaction of anti-RSV polyclonal IgG with RSV HEp-2 infected cells induced relocalization and aggregation of viral glycoproteins in the plasma membrane formed patches that subsequently produced caps or were internalized through clathrin-mediated endocytosis participation. Moreover, the concentration of cell surface RSV Ag-Abs and intracellular viral proteins showed a time dependent cyclic variation and that anti-RSV IgG protected HEp-2 cells from viral-induced death. Conclusion The results from this study indicate that interaction between RSV cell surface proteins and specific viral antibodies alter the expression of viral antigens expressed on the cells surface and intracellular viral proteins; furthermore, interfere with viral induced destruction of the cell.

  6. Expression of Hepatitis B Surface Antigen Gene in Ginseng Cells

    Institute of Scientific and Technical Information of China (English)

    YU Hai-peng; XUE Yan; AN Wei; LIU Dan; HAO Shu-mei; SHENG Jun

    2009-01-01

    The recombinant plasmid pBIBSa containing the HBsAg DNA fragment was transferred into Agrobacte-rium tumefaciens strain LBA4404 directly. Ginseng cells were transfected with A. Tumefaciens carrying pBIBSa and the ginseng cell lines carrying HBsAg-S gene were obtained. The presence of target gene in the transfect cells was confirmed by PCR and RT-PCR. A clear band at the site of 700 bp was observed by agarose electrophoresis analysis of the samples containing the target gene. HBsAg expressed by the transgenic ginseng cells was detected by Western blot. Maximum expression levels of 184 ng HBsAg/g FW and 0. 009% of the total soluble proteins were observed by ELISA. HBsAg in ginseng cells was located both on the cell membrane and in the nuclei.

  7. Variant surface antigens, virulence genes and the pathogenesis of malaria

    DEFF Research Database (Denmark)

    Deitsch, Kirk W; Hviid, Lars

    2004-01-01

    The first Molecular Approaches to Malaria meeting was held 2-5 February 2000 in Lorne, Australia. Following the meeting, Brian Cooke, Mats Wahlgren and Ross Coppel predicted that research into the molecular details of the mechanisms behind sequestration of parasitized erythrocytes would "become i......". We contemplate on these statements, following the recent second Molecular Approaches to Malaria meeting, which was held at the same venue on 2-5 February 2004....

  8. Prokaryotic expression of surface membrane antigen SAG1 gene from Toxoplasma Gondii and the diagnostic value of the recombinant protein%弓形虫膜表面抗原SAG1基因的原核表达及重组蛋白的免疫诊断价值

    Institute of Scientific and Technical Information of China (English)

    王朝兰; 汤冬生; 姚湧; 汪学龙; 王业梅

    2011-01-01

    目的 探讨重组弓形虫膜表面抗原SAG1基因的表达产物-原核表达蛋白(rSAG1)用于弓形虫病的免疫诊断价值.方法 用异丙基-B-D-硫代吡喃半乳糖苷(IPTG)诱导大肠埃希菌重组质粒pET28a-SAG1(pET28a-SAG1/BL21)表达,纯化重组pET28a-SAG1/BL21弓形虫膜表面抗原SAG1基因表达产物;用弓形虫缓殖子感染的鼠血清、正常鼠血清和10例弓形虫患者血清为一抗,基因表达产物rSAG1用免疫印迹法进行鉴定,比较rSAG1在弓形虫病免疫诊断中的价值.结果 纯化重组弓形虫膜表面抗原SAG1基因后获得了相对分子质量约38.5×103的表达产物rSAG1;表面抗原SAG1可被弓形虫缓殖子感染的鼠血清所识别;10例弓形虫患者血清在免疫印迹诊断中,有4例出现了弓形虫膜表面抗原SAG1基因表达产物rSAG1.结论 rSAG1具备一定的弓形虫病的免疫诊断价值.%Objective To investigate the diagnostic value of the recombinant surface antigen 1 (rSAG1) in immunodiagnosis of toxoplasmosis. Methods Isopropyl β-D- 1 -thio-galaetopyranoside (IPTG) was used to induce the expression of recombinant plasmid pET28a-SAG1 of Escherich coli(pET28a-SAG1/BL21 ). The expression products (rSAG1) of pET28a-SAG1/BL21 were identified by Western blotting. The serum of mice infected with Toxoplasma gondii tachyzoites, normal mouse serum and the serum from 10 toxoplasma gondii patients were used as primary anti-Toxoplasma gondii antibodies, and the rSAG1 gene products were identified by Western blotting, by which the diagnostic value of rSAG1 in Toxoplasmosis was compared. Results After induction and purification, rSAG1 protein was obtained and its relative molecular mass was 38.5 × 103. The fusion protein could be recognized by the serum of mouse infected with Toxoplasma gondii tachyzoites, rSAG1 of expression products of surface membrane antigen SAG1 gene from Toxoplasma Gondii could be detected in 4 cases from 10 patients by Westem blotting.Conclusion The r

  9. Highly Sensitive Nanoparticle-based Multifunctional Biosensor for Antigen Detection

    Science.gov (United States)

    Siavoshi, Salome

    Precise and selective positioning of nanoparticles gives rise to many applications where assembly of nano building blocks with different biological or chemical functionalization is necessary. One remarkable application is the simultaneous early detection of multiple biomarkers in the field of miniaturized multiplex biosensors. To enable multiplex detection of antigens, nanoparticles with various antibody coatings can be selectively assembled in trenches on different regions on a biochip so that they bind selectively to the specific antigen of interest. The presented work utilizes electric field assisted assembly techniques to assemble nanoparticles with various surface functionalization and coatings. Nanoparticles are assembled into pre-fabricated via and trench patterns generated on a PMMA coated gold surface, using electron-beam lithography. Two techniques have been developed for selective assembly of nanoparticles: sequential size-selective directed assembly and sequential site-selective assembly. Both selective assembly techniques provide fast and reproducible assembly over large areas while achieving high yield. The sequential size-selective assembly is a template-assisted technique where the selectivity is achieved by controlling the size of the nanopatterns and the size of the nanoparticles. The possibility of particle detachment and the factors affecting the sorting efficiency for this technique is studied. We show that a complete sorting can be achieved when the size of the vias is close to the diameter of the nanoparticles and the size distribution of the chosen nanoparticles do not overlap. In the site-selective assembly, the selectivity is achieved by having electrically isolated sites (regions) on the same chip. Electrophoresis is performed for each region in a step by step process. Selective assembly results, for up to four nanoparticles with various coating/functionalization are presented using the site-selective assembly technique. We use the

  10. 慢性乙型肝炎患者血清表面抗原与抗体同时阳性结果分析%Analysis of coexistence of hepatitis B surface antigen and anti - HBs antibodies in patients with chronic hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    陈天宝; 范公忍; 李娟; 胡学玲

    2011-01-01

    Objective:To study the relationship between concurrence mode of hepatitis B surface antigen and anti - HBs antibodies in patients with chronic hepatitis B virus infection and HBV DNA. Methods :Serological diagnosis for HBV infection was detected by VITROS Eci/ECiQ immunodiagnostic systems and HBV DNA viral load was quantified by using the commercially a-vailable real -time fluorescence quantitative kit ( PG Biotech). Results:Among the 5717 patients monitored at our hospital, 248 (4.34% ) have been identified as carrying both HBsAg and anti - HBs antibodies. In which, the majority appeared with HBV DNA at the same time. Conclusion: Coexistence of HBsAg and anti - HBs is not rare. HBV DNA concentration is an important parameter to diagnose and treat patients with simultaneous positive for HBsAg and anti - HBs antibodies.%目的:探讨乙型肝炎患者HBsAg和抗HBs共存模式及与HBV DNA的关系.方法:采用增强化学发光法检测血清乙肝标志物,并采用荧光定量PCR法检测HBV DNA.结果:5717例慢性乙肝患者检测出HBsAg和抗HBs双阳性248例,占4.34%,其中多数与HBV DNA同时出现.结论:HBsAg和抗HBs同时阳性并不少见,慢性乙肝患者出现抗HBs,不完全代表病毒复制终止,需结合HBV DNA定量综合分析.

  11. Optimisation of immuno-gold nanoparticle complexes for antigen detection

    OpenAIRE

    Van Der Heide, Susan; RUSSELL, David

    2016-01-01

    The aim of this investigation was to define the optimum method of binding antibodies to the surface of gold nanoparticles (AuNPs) and then to apply the optimised antibody-functionalised AuNPs for the detection of a target antigen. A detailed investigation of three different techniques for the functionalisation of AuNPs with anti-cocaine antibody and methods for the subsequent characterisation of the antibody-functionalised AuNP are reported. The addition of anti-cocaine antibody onto the AuNP...

  12. Prostate-specific antigen (PSA) blood test

    Science.gov (United States)

    Prostate-specific antigen; Prostate cancer screening test; PSA ... PSA testing is an important tool for detecting prostate cancer, but it is not foolproof. Other conditions can cause a rise in PSA, including: A larger prostate ...

  13. Mapping Epitopes on a Protein Antigen by the Proteolysis of Antigen-Antibody Complexes

    Science.gov (United States)

    Jemmerson, Ronald; Paterson, Yvonne

    1986-05-01

    A monoclonal antibody bound to a protein antigen decreases the rate of proteolytic cleavage of the antigen, having the greatest effect on those regions involved in antibody contact. Thus, an epitope can be identified by the ability of the antibody to protect one region of the antigen more than others from proteolysis. By means of this approach, two distinct epitopes, both conformationally well-ordered, were characterized on horse cytochrome c.

  14. Tales of Antigen Evasion from CAR Therapy.

    Science.gov (United States)

    Sadelain, Michel

    2016-06-01

    Both T cells bearing chimeric antigen receptors and tumor-specific antibodies can successfully target some malignancies, but antigen escape can lead to relapse. Two articles in this issue of Cancer Immunology Research explore what effective countermeasures may prevent it. Cancer Immunol Res; 4(6); 473-473. ©2016 AACRSee articles by Zah et al., p. 498, and Rufener et al., p. 509. PMID:27252092

  15. Characterization of an antigenically distinct porcine rotavirus.

    OpenAIRE

    Bridger, J C; Clarke, I. N.; McCrae, M A

    1982-01-01

    A porcine virus with rotavirus morphology, which was antigenically unrelated to previously described rotaviruses, is described. Particles with an outer capsid layer measured 75 nm and those lacking the outer layer were 63 nm in diameter. Particles which resembled cores were also identified. The virus was shown to be antigenically distinct from other rotaviruses as judged by immunofluorescence and immune electron microscopy, and it failed to protect piglets from challenge with porcine rotaviru...

  16. A new virion precipitation test for oncovirus envelope antigens which detects common antigenic determinants in mammalian type-C viruses and Mason-Pfizer monkey virus.

    Science.gov (United States)

    Altstein, A D; Zakharova, L G; Zhdanov, V M

    1979-03-15

    A method for the study of oncovirus envelope antigens was developed, bases on the precipitation of intact virions by a double antibody technique. The amount of precipitated virus was then measured as reverse transcriptase activity. The method was designated the virion precipitation test (VPT). It has been used for titration of antibodies to envelope antigens of oncoviruses. The study of envelop antigens of 11 different oncoviruses permitted their differentiation into the following groups: (1) murine type-C viruses: (2) feline type-C viruses; (3) simian type-C viruses; (4) the RD-114/BEV group; (5) Mason-Pfizer monkey virus (M-PMV); (6) bovine leukemia virus; (7) avian type-C viruses; (8) mouse mammary tumor virus. No common antigenic determinants were detected in the last three groups. Mammalian type-C viruses (RD-114, NIH-MuLV, G-MuLV) had common antigenic determinants in the envelope, as demonstrated with an anti-RD-114 serum. Mammalian type-C viruses also shared antigenic determinants with M-PMV. The relationship of type-C viruses to M-PMV decreased in the following order: RD-114--NIH-MuLV--G-MuLV. It was also shown that the endogenous xenotropic feline RD-114 virus was more closely related to xenotropic NIH-MuLV than to ecotropic G-MuLV. The nature of the common antigenic determinants, as demonstrated by VPT on the surface of mammalian type-C viruses and M-PMV, and their significance for the concept of oncovirus evolution are discussed.

  17. Secretion, interaction and assembly of two O-glycosylated cell wall antigens from Candida albicans.

    Science.gov (United States)

    Pavia, J; Aguado, C; Mormeneo, S; Sentandreu, R

    2001-07-01

    The mechanisms of incorporation of two antigens have been determined using a monoclonal antibody (3A10) raised against the material released from the mycelial cell wall by zymolyase digestion and retained on a concanavalin A column. One of the hybridomas secreted an IgG that reacted with two bands in Western blots. Indirect immunofluorescence showed that the antigens were located on the surfaces of mycelial cells, but within the cell walls of yeasts. These antigens were detected in a membrane preparation, in the SDS-soluble material and in the material released by a 1,3-beta-glucanase and chitinase from the cell walls of yeast and mycelial cells. In the latter three samples, an additional high-molecular-mass, highly polydispersed band was also detected. Beta-elimination of each fraction resulted in the disappearance of all antigen bands, suggesting that they are highly O-glycosylated. In addition, the electrophoretic mobility of the high-molecular-mass, highly polydispersed bands increased after digestion with endoglycosidase H, indicating that they are also N-glycosylated. New antigen bands were released when remnants of the cell walls extracted with 1,3-beta-glucanase or chitinase were digested with chitinase or 1,3-beta-glucanase. These results are consistent with the notion that, after secretion, parts of the O-glycosylated antigen molecules are transferred to an N-glycosylated protein(s). This molecular complex, as well as the remaining original 70 and 80 kDa antigen molecules, next bind to 1,3-beta-glucan or chitin, probably via 1,6-beta-glucan, and, in an additional step, to chitin or 1,3-beta-glucan. This process results in the final molecular product of each antigen, and their distribution in the cell walls. PMID:11429475

  18. Sialic acid-modified antigens impose tolerance via inhibition of T-cell proliferation and de novo induction of regulatory T cells.

    Science.gov (United States)

    Perdicchio, Maurizio; Ilarregui, Juan M; Verstege, Marleen I; Cornelissen, Lenneke A M; Schetters, Sjoerd T T; Engels, Steef; Ambrosini, Martino; Kalay, Hakan; Veninga, Henrike; den Haan, Joke M M; van Berkel, Lisette A; Samsom, Janneke N; Crocker, Paul R; Sparwasser, Tim; Berod, Luciana; Garcia-Vallejo, Juan J; van Kooyk, Yvette; Unger, Wendy W J

    2016-03-22

    Sialic acids are negatively charged nine-carbon carboxylated monosaccharides that often cap glycans on glycosylated proteins and lipids. Because of their strategic location at the cell surface, sialic acids contribute to interactions that are critical for immune homeostasis via interactions with sialic acid-binding Ig-type lectins (siglecs). In particular, these interactions may be of importance in cases where sialic acids may be overexpressed, such as on certain pathogens and tumors. We now demonstrate that modification of antigens with sialic acids (Sia-antigens) regulates the generation of antigen-specific regulatory T (Treg) cells via dendritic cells (DCs). Additionally, DCs that take up Sia-antigen prevent formation of effector CD4(+) and CD8(+)T cells. Importantly, the regulatory properties endowed on DCs upon Sia-antigen uptake are antigen-specific: only T cells responsive to the sialylated antigen become tolerized. In vivo, injection of Sia-antigen-loaded DCs increased de novo Treg-cell numbers and dampened effector T-cell expansion and IFN-γ production. The dual tolerogenic features that Sia-antigen imposed on DCs are Siglec-E-mediated and maintained under inflammatory conditions. Moreover, loading DCs with Sia-antigens not only inhibited the function of in vitro-established Th1 and Th17 effector T cells but also significantly dampened ex vivo myelin-reactive T cells, present in the circulation of mice with experimental autoimmune encephalomyelitis. These data indicate that sialic acid-modified antigens instruct DCs in an antigen-specific tolerogenic programming, enhancing Treg cells and reducing the generation and propagation of inflammatory T cells. Our data suggest that sialylation of antigens provides an attractive way to induce antigen-specific immune tolerance. PMID:26941238

  19. Effective induction of naive and recall T-cell responses by targeting antigen to human dendritic cells via a humanized anti-DC-SIGN antibody.

    NARCIS (Netherlands)

    Tacken, P.J.; Vries, I.J.M. de; Gijzen, K.; Joosten, B.H.G.M.; Wu, D.; Rother, R.P.; Faas, S.J.; Punt, C.J.A.; Torensma, R.; Adema, G.J.; Figdor, C.G.

    2005-01-01

    Current dendritic cell (DC)-based vaccines are based on ex vivo-generated autologous DCs loaded with antigen prior to readministration into patients. A more direct and less laborious strategy is to target antigens to DCs in vivo via specific surface receptors. Therefore, we developed a humanized ant

  20. Intermolecular forces and enthalpies in the adhesion of Streptococcus mutans and an antigen I/II-deficient mutant to laminin films

    NARCIS (Netherlands)

    Busscher, Henk J.; van de Belt-Gritter, Betsy; Dijkstra, Rene J. B.; Norde, Willem; Petersen, Fernanda C.; Scheie, Anne A.; van der Mei, Henny C.

    2007-01-01

    The antigen I/II family of surface proteins is expressed by most oral streptococci, including Streptococcus mutans, and mediates specific adhesion to, among other things, salivary films and extracellular matrix proteins. In this study we showed that antigen I/II-deficient S. mutans isogenic mutant I

  1. Characterization of the carbohydrate components of Taenia solium oncosphere proteins and their role in the antigenicity.

    Science.gov (United States)

    Arana, Yanina; Verastegui, Manuela; Tuero, Iskra; Grandjean, Louis; Garcia, Hector H; Gilman, Robert H

    2013-10-01

    This study examines the carbohydrate composition of Taenia solium whole oncosphere antigens (WOAs), in order to improve the understanding of the antigenicity of the T. solium. Better knowledge of oncosphere antigens is crucial to accurately diagnose previous exposure to T. solium eggs and thus predict the development of neurocysticercosis. A set of seven lectins conjugates with wide carbohydrate specificity were used on parasite fixations and somatic extracts. Lectin fluorescence revealed that D-mannose, D-glucose, D-galactose and N-acetyl-D-galactosamine residues were the most abundant constituents of carbohydrate chains on the surface of T. solium oncosphere. Lectin blotting showed that posttranslational modification with N-glycosylation was abundant while little evidence of O-linked carbohydrates was observed. Chemical oxidation and enzymatic deglycosylation in situ were performed to investigate the immunoreactivity of the carbohydrate moieties. Linearizing or removing the carbohydrate moieties from the protein backbones did not diminish the immunoreactivity of these antigens, suggesting that a substantial part of the host immune response against T. solium oncosphere is directed against the peptide epitopes on the parasite antigens. Finally, using carbohydrate probes, we demonstrated for the first time that the presence of several lectins on the surface of the oncosphere was specific to carbohydrates found in intestinal mucus, suggesting a possible role in initial attachment of the parasite to host cells.

  2. Identifying protective Streptococcus pyogenes vaccine antigens recognized by both B and T cells in human adults and children

    DEFF Research Database (Denmark)

    Mortensen, Rasmus; Nissen, Thomas Nørrelykke; Fredslund, Sine;

    2016-01-01

    No commercial vaccine exists against Group A streptococci (GAS; Streptococcus pyogenes) and only little is known about anti-GAS protective immunity. In our effort to discover new protective vaccine candidates, we selected 21 antigens based on an in silico evaluation. These were all well......-conserved among different GAS strains, upregulated in host-pathogen interaction studies, and predicted to be extracellular or associated with the surface of the bacteria. The antigens were tested for both antibody recognition and T cell responses in human adults and children. The antigenicity of a selected group...

  3. TH1 and TH2 responses are influenced by HLA antigens in healthy neonates vaccinated with recombinant hepatitis B vaccine.

    OpenAIRE

    Abdollah Jafarzadeh; Fazel Shokri

    2012-01-01

    The immune response to hepatitis B surface antigen (HBsAg) is influenced by several factors, of which HLA antigens and balanced secretion of Th1/Th2 cytokines play important roles. The aim of this study was to evaluate the influence of HLA antigens on cytokine secretion by HBsAg-stimulated peripheral blood mononuclear cells (PBMC) from healthy neonates vaccinated with recombinant HBsAg. PBMCs were isolated from 48 Iranian neonates vaccinated with a recombinant HBV vaccine. The cells were stim...

  4. Biochemical basis of synergy between antigen and T-helper (Th) cell-mediated activation of resting human B cells.

    OpenAIRE

    Chartash, E K; Crow, M K; Friedman, S M

    1989-01-01

    We have utilized CD23 expression as a marker for B cell activation in order to investigate the biochemical basis for synergy between antigen and T helper (Th) cells in the activation of resting human B cells. Our results confirm that while ligation of surface immunoglobulin (sIg) receptors by antigen analogues (e.g., F(ab')2 goat anti-human IgM) does not lead to CD23 expression, this stimulus markedly enhances CD23 expression induced during antigen specific Th-B cell interaction or by rIL-4. ...

  5. Improved immunogenicity of novel baculovirus-derived Theileria parva p67 subunit antigens

    NARCIS (Netherlands)

    Kaba, S.A.; Schaap, D.; Roode, E.C.; Nene, V.; Musoke, A.J.; Vlak, J.M.; Oers, van M.M.

    2004-01-01

    East Coast fever (ECF) in cattle is caused by the tick-borne protozoan parasite Theileria parva. The major sporozoite surface antigen of T parva (p67) is an important candidate for inclusion in a subunit vaccine. Recently, we reported the expression and production of different parts of p67 as fusion

  6. Antigen-43-mediated autoaggregation of Escherichia coli is blocked by fimbriation

    DEFF Research Database (Denmark)

    Hasman, Henrik; Chakraborty, Trinad; Klemm, Per

    1999-01-01

    Antigen 43 (Ag43), the product of the flu gene, is a surface-displayed autotransporter protein of Escherichia coli. Ag43 is responsible for the autoaggregation and flocculation of static liquid cultures of many E. coli strains. The expression of Ag43 has been reported to be phase variable...

  7. Increased expression of beta 2-microglobulin and histocompatibility antigens on human lymphoid cells induced by interferon

    DEFF Research Database (Denmark)

    Hokland, M; Heron, I; Berg, K

    1982-01-01

    Normal human peripheral blood lymphocytes were incubated in the presence of different concentrations of interferon for various incubation periods. Subsequently, the amount of beta 2-Microglobulin and HLA-A, B and C surface antigens was estimated by means of quantitative immunofluorescence (flow c...

  8. Immunofluorescence detection of new antigen-antibody system (delta/anti-delta) associated to hepatitis B virus in liver and in serum of HBsAg carriers.

    Science.gov (United States)

    Rizzetto, M; Canese, M G; Aricò, S; Crivelli, O; Trepo, C; Bonino, F; Verme, G

    1977-01-01

    A new antigen-antibody system associated with the hepatitis B virus and immunologically distinct from the HB surface, core, and e systems is reported. The new antigen, termed delta, was detected by direct immunofluorescence only in the liver cell nuclei of patients with HBsAg positive chronic liver disease. At present, the intrahepatic expression of HBcAg and delta antigen appears to be mutually exclusive. No ultrastructural aspect corresponding to the delta antigen could be identified under the electron microscope. delta antibody was found in the serum of chronic HBsAg carriers, with a higher prevalence in patients with liver damage. The nuclear fluorescence patterns of HBcAg and delta antigen were similar; it is only possible to discriminate between the two antigens by using the respective specific antisera. Images Figure PMID:75123

  9. A Viral Vectored Prime-Boost Immunization Regime Targeting the Malaria Pfs25 Antigen Induces Transmission-Blocking Activity

    OpenAIRE

    Goodman, Anna L.; Blagborough, Andrew M.; Sumi Biswas; Yimin Wu; Hill, Adrian V.; Sinden, Robert E.; Draper, Simon J

    2011-01-01

    The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63), human adenovirus serotype 5 (AdHu5) and modified vaccinia virus Ankara (MVA) viral vectored vaccines. Two immunizations were administered to mice in a ...

  10. Enzyme-Linked Immunosorbent Assay Employing a Recombinant Antigen for Detection of Protective Antibody against Swine Erysipelas

    OpenAIRE

    Imada, Yumiko; Mori, Yasuyuki; Daizoh, Masaji; Kudoh, Kazuma; Sakano, Tetsuya

    2003-01-01

    The specificities and sensitivities of five recombinant proteins of the surface protective antigen (SpaA) of Erysipelothrix rhusiopathiae were examined by indirect enzyme-linked immunosorbent assay (ELISA) with the aim of developing a reliable serological test for the detection of protective antibody against E. rhusiopathiae. Fully mature protein and the N-terminal 416 amino acids (SpaA416) showed sufficient antigenicities, and further examination was done with SpaA416 because of its higher y...

  11. Antigen I/II encoded by integrative and conjugative elements of Streptococcus agalactiae and role in biofilm formation.

    Science.gov (United States)

    Chuzeville, Sarah; Dramsi, Shaynoor; Madec, Jean-Yves; Haenni, Marisa; Payot, Sophie

    2015-11-01

    Streptococcus agalactiae (i.e. Group B streptococcus, GBS) is a major human and animal pathogen. Genes encoding putative surface proteins and in particular an antigen I/II have been identified on Integrative and Conjugative Elements (ICEs) found in GBS. Antigens I/II are multimodal adhesins promoting colonization of the oral cavity by streptococci such as Streptococcus gordonii and Streptococcus mutans. The prevalence and diversity of antigens I/II in GBS were studied by a bioinformatic analysis. It revealed that antigens I/II, which are acquired by horizontal transfer via ICEs, exhibit diversity and are widespread in GBS, in particular in the serotype Ia/ST23 invasive strains. This study aimed at characterizing the impact on GBS biology of proteins encoded by a previously characterized ICE of S. agalactiae (ICE_515_tRNA(Lys)). The production and surface exposition of the antigen I/II encoded by this ICE was examined using RT-PCR and immunoblotting experiments. Surface proteins of ICE_515_tRNA(Lys) were found to contribute to GBS biofilm formation and to fibrinogen binding. Contribution of antigen I/II encoded by SAL_2056 to biofilm formation was also demonstrated. These results highlight the potential for ICEs to spread microbial adhesins between species. PMID:26232503

  12. Two-dimensional periodic relief grating as a versatile platform for selective immunosorbent assay and visualizing of antigens.

    Science.gov (United States)

    Chen, Jem-Kun; Zhou, Gang-Yan; Huang, Chih-Feng; Chang, Jia-Yaw

    2013-04-24

    In this study, we fabricated a nanopillar array of silicon oxide, involving very-large-scale integration (VLSI) and reactive ion etching (RIE), as two-dimensional periodic relief gratings (2DPRGs) on Si surfaces. Antihuman ALB was successively oriented on the pillar surface of 2DPRG modified protein G as an optical detector that is specific for targeted antigen. The antibody modified 2DPRG alone produces insignificant structure change, but upon immunocapture of antigens, the antigen filling in the 2DPRG leads to a dramatic change of the pillar scale. Binding of the antibodies to the 2DPRG occurs in a way that still allows them to function and selectively bind antigen. The performance of the sensor was evaluated by capturing HRP-human ALB on the antibody-modified 2DPRG and measuring the effective refractive index (neff) resulting from the attachment of antigens. The neff values of the 2DPRG are found to relate with the pillar scale of the 2DPRG, generated by antigen coupling, resulting in color change from pure green to orange, observed by the naked eye along an incident angle of 10-20°. Moreover, we calculated the filling factors inside the 2DPRG with effective-medium theory to verify the pillar structure changes. This technique eliminates much of the surface modifications and the secondary immunochemical or enzyme-linked steps that are common in immunoassays. Such films have potential applications as optical biosensors.

  13. 酶联免疫法检测血清乙型肝炎表面抗原的空白限检出限及定量限的建立与评价%The establishment and evaluation of limit of blank, limit of detection and limit of quantitation for detection of serum hepatitis B surface antigens by enzyme-linked immunosorbent assay

    Institute of Scientific and Technical Information of China (English)

    谭丽娜; 杨泽华; 赵克斌

    2013-01-01

    Objective To explore the question of serum hepatitis B surface antigens(HBsAg) results detected by enzyme-linked immunosorbent assay(ELISA) so as to prevent undetection of weakly positive samples, and to establish limit of blank (LOB), limit of detection (LOD) and limit of quantitation (LOQ). Methods Refering to CLSI EP17-A file, the HBsAg blank sample and a series of samples with low concentrations were performed ELJSA detection. According to the distribution, the results were analyzed using the relative statistical method. ELJSA was used to detect LOB, LOD and LOQ of HBsAg. Results The results were LOB=0.117 μg/L, LOD=0.317 μg/L and LOQ= 0.500 μg/L Conclusion The LOB established by referring to CLSI EP17-file was more scientific and reasonable than that established by conventional method and thus it might satisfy the clinical lab requirements better.%目的 探讨酶联免疫吸附试验(ELISA)检测血清乙型肝炎表面抗原(HBsAg)结果检测限的问题,防止漏检弱阳性标本,建立本实验室的空白限(LOB)、检出限(LOD)及定量限(LOQ).方法 参考美国临床实验室标准化委员会(CISI)发布的《确定检测低限和定量检测限的方案》(EP17-A)文件,将HBsAg的空白样本及一系列的低浓度样本进行ELISA检测,对得到的结果根据其分布状态,采用百分位数进行统计描述,建立ELISA法检测HBsAg的空白限、检出限及定量限.结果 空白限为0.117 μg/L,检出限为0.317 μg/L,定量限为0.500μg/L.结论 参考CLSI EP17-A文件建立的检测限比常规方法建立的检测限科学合理,更能满足临床实验室的要求.

  14. 牛微小隐孢子虫表面抗原CP15基因原核表达及其表达产物的鉴定%Prokaryotic Expression and Identification of Cryptosporidium parvum Surface Antigen CP15 Gene in Escherichia coli BL21

    Institute of Scientific and Technical Information of China (English)

    满达; 兰丽; 王艳霞; 王敏; 格日勒图

    2012-01-01

    To construct a recombinant plasmid contain CP15 gene of Cryptosporidium parvumiC. parvum) and obtain re-corabinant protein. The surface antigen CP15 gene fragment of C. parvum was amplified from plasmid pMD-CP15 by PCR,and subcloned into pGEX 4T-3. The fusion express recombinant vector pGEX-CP15 was constructed in E. coli BL21. The recombinant protein was induced by 1 mmol/L IPTG and identified by SDS-PAGE and Western blotting. The CP15 gene fragment was amplified correctly as the size of gene was about 390 bp, and the recombinant plasmid pGEX-CP15 was constructed. The protein band with a molecular weight of 42 ku was detected on SDS-PAGE, which totally same with the theoretical size. The expressed protein was identified by Western blotting performed with GST serum. The fusion protein of CP15 was highly expressed in E. coli.%试验旨在构建微小隐孢子虫表面抗原CP15基因原核表达载体并获得重组CP15蛋白.试验以已知重组质粒pMDCP15为模板,PCR方法扩增出CP15基因片段,并亚克隆到pGEX4T-3,构建了在E.coli BL21中GST融合表达载体pGEX-CP15;经1 mmol/L IPTG进行诱导表达获得目的蛋白,其大小采用SDS-PAGE电泳和Western blotting进行鉴定.结果表明,扩增出约390 bp的微小隐孢子虫表面抗原CP15基因片段并成功构建pGEX-CP15质粒,表达出分子质量为42 ku的融合蛋白,与推导的理论值相符.Western blotting显示该蛋白能被GST血清识别.牛微小隐孢子虫表面抗原CP15基因在大肠杆菌中得到了高效表达.

  15. Antigenic typing Polish isolates of canine parvovirus

    Energy Technology Data Exchange (ETDEWEB)

    Mizak, B. [National Veterinary Research Institute, Pulawy (Poland); Plucienniczak, A. [Polish Academy ofd Sciences. Microbiology and Virology Center, Lodz (Poland)

    1995-12-31

    Polish strains of canine parvovirus isolated between 1982 and 1993 were examined to determine the extent to which the virus has evolved antigenically and genetically over eleven years. Two CPV isolates obtained in Warsaw in 1982 and Pulawy in 1993, were examined using monoclonal antibody typing, restriction analysis and sequencing VP-2 protein gene. Five other isolates from Warsaw and Pulawy were tested with the panel of monoclonal antibodies specific to CPV-2, CPV-2a and common for canine parvovirus, feline panleukopenia virus and milk enteritis virus. Results of the studies demonstrated that all isolates tested represented CPV-2a antigenic type. Rapid antigenic strain replacement recorded by Parrish and Senda in the U.S.A and Japan was not confirmed in Poland. (author). 30 refs, 2 tabs.

  16. Idiopathic focal segmental glomerulosclerosis and HLA antigens.

    Science.gov (United States)

    Gerbase-DeLima, M; Pereira-Santos, A; Sesso, R; Temin, J; Aragão, E S; Ajzen, H

    1998-03-01

    The objective of the present study was to investigate a possible association between HLA class II antigens and idiopathic focal segmental glomerulosclerosis (FSGS). HLA-A, -B, -DR and -DQ antigens were determined in 19 Brazilian patients (16 white subjects and three subjects of Japanese origin) with biopsy-proven FSGS. Comparison of the HLA antigen frequencies between white patients and white local controls showed a significant increase in HLA-DR4 frequency among FSGS patients (37.7 vs 17.2%, P < 0.05). In addition, the three patients of Japanese extraction, not included in the statistical analysis, also presented HLA-DR4. In conclusion, our data confirm the association of FSGS with HLA-DR4 previously reported by others, thus providing further evidence for a role of genes of the HLA complex in the susceptibility to this disease. PMID:9698788

  17. Idiopathic focal segmental glomerulosclerosis and HLA antigens

    Directory of Open Access Journals (Sweden)

    M. Gerbase-DeLima

    1998-03-01

    Full Text Available The objective of the present study was to investigate a possible association between HLA class II antigens and idiopathic focal segmental glomerulosclerosis (FSGS. HLA-A, -B, -DR and -DQ antigens were determined in 19 Brazilian patients (16 white subjects and three subjects of Japanese origin with biopsy-proven FSGS. Comparison of the HLA antigen frequencies between white patients and white local controls showed a significant increase in HLA-DR4 frequency among FSGS patients (37.7 vs 17.2%, P<0.05. In addition, the three patients of Japanese extraction, not included in the statistical analysis, also presented HLA-DR4. In conclusion, our data confirm the association of FSGS with HLA-DR4 previously reported by others, thus providing further evidence for a role of genes of the HLA complex in the susceptibility to this disease

  18. Transgenic lettuce seedlings carrying hepatitis B virus antigen HBsAg

    Directory of Open Access Journals (Sweden)

    Jackson Marcondes

    2008-12-01

    Full Text Available The obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. Here we report a strategy for genetic transformation of lettuce plants (Lactuca sativa L. using the surface antigen HBsAg of hepatitis B virus. Transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. Genetic transformation process was acquired by cocultivation of cotyledons with Agrobacterium tumefaciens harboring the recombinant plasmid. It is the first description of a lettuce Brazilian variety "Vitória de Verão" genetically modified.

  19. Identification of two germ-tube-specific cell wall antigens of Candida albicans.

    OpenAIRE

    Ponton, J; J. M. Jones

    1986-01-01

    Outer cell wall layers of intact yeast- and mycelial-phase Candida albicans B311 were extracted with dithiothreitol. Antisera against mycelial-phase organisms were absorbed with yeast-phase organisms or yeast-phase extract and used to stain Western blots of sodium dodecyl sulfate-polyacrylamide gels loaded with yeast- and mycelial-phase extracts. Autoradiography of gels loaded with extracts from organisms surface labeled with 125I was used to detect surface antigens containing proteins. Antig...

  20. Efficient production of secreted staphylococcal antigens in a non-lysing and proteolytically reduced Lactococcus lactis strain

    NARCIS (Netherlands)

    Neef, Jolanda; Koedijk, Danny G. A. M.; Bosma, Tjibbe; van Dijl, Jan Maarten; Buist, Girbe

    2014-01-01

    Cell surface-exposed and secreted proteins are attractive targets for vaccination against pathogenic gram-positive bacteria. To obtain sufficient amounts of such antigens, efficient protein production platforms are needed. In this study, a pipeline for the production and purification of surface-expo