Specificity and polyreactivity of the antibody response during natural HIV-1 infection

OpenAIRE

Wang, Xin

2006-01-01

The specificity and polyreactivity of the antibody response in natural HIV-1 infection were studied. First, to investigate the overall antibody response, overlapping linear peptides were used to screen sera taken from HIV-1-infected individuals. The polyclonal antibody response was relatively stable during long-term infection, compared with acute infection, and mostly directed against immunodominant regions. Low level, transient antibody responses were detected against membrane proximal exter...

Polyfunctional HIV-Specific Antibody Responses Are Associated with Spontaneous HIV Control.

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Margaret E Ackerman

2016-01-01

Full Text Available Elite controllers (ECs represent a unique model of a functional cure for HIV-1 infection as these individuals develop HIV-specific immunity able to persistently suppress viremia. Because accumulating evidence suggests that HIV controllers generate antibodies with enhanced capacity to drive antibody-dependent cellular cytotoxicity (ADCC that may contribute to viral containment, we profiled an array of extra-neutralizing antibody effector functions across HIV-infected populations with varying degrees of viral control to define the characteristics of antibodies associated with spontaneous control. While neither the overall magnitude of antibody titer nor individual effector functions were increased in ECs, a more functionally coordinated innate immune-recruiting response was observed. Specifically, ECs demonstrated polyfunctional humoral immune responses able to coordinately recruit ADCC, other NK functions, monocyte and neutrophil phagocytosis, and complement. This functionally coordinated response was associated with qualitatively superior IgG3/IgG1 responses, whereas HIV-specific IgG2/IgG4 responses, prevalent among viremic subjects, were associated with poorer overall antibody activity. Rather than linking viral control to any single activity, this study highlights the critical nature of functionally coordinated antibodies in HIV control and associates this polyfunctionality with preferential induction of potent antibody subclasses, supporting coordinated antibody activity as a goal in strategies directed at an HIV-1 functional cure.

SINGLE CHAIN VARIABLE FRAGMENTS OF ANTIBODIES AGAINST DIPHTHERIA TOXIN B-SUBUNIT ISOLATED FROM PHAGE DISPLAY HUMAN ANTIBODY LIBRARY

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Oliinyk O. S.

2014-02-01

Full Text Available Diphtheria toxin is an exoantigen of Corynebacterium diphtheriae that inhibits protein synthesis and kills sensitive cells. The aim of this study was to obtain human recombinant single-chain variable fragment (scFv antibodies against receptor-binding B subunit of diphtheria toxin. 12 specific clones were selected after three rounds of a phage display naїve (unimmunized human antibody library against recombinant B-subunit. scFv DNA inserts from these 12 clones were digested with MvaI, and 6 unique restriction patterns were found. Single-chain antibodies were expressed in Escherichia coli XL1-blue. The recombinant proteins were characterized by immunoblotting of bacterial extracts and detection with an anti-E-tag antibody. The toxin B-subunit-binding function of the single-chain antibody was shown by ELISA. The affinity constants for different clones were found to be from 106 to 108 М–1. Due to the fact, that these antibody fragments recognized epitopes in the receptor-binding Bsubunit of diphtheria toxin, further studies are interesting to evaluate their toxin neutralization properties and potential for therapeutic applications. Obtained scFv-antibodies can also be used for detection and investigation of biological properties of diphtheria toxin.

When is affect variability bad for health? The association between affect variability and immune response to the influenza vaccination.

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Jenkins, Brooke N; Hunter, John F; Cross, Marie P; Acevedo, Amanda M; Pressman, Sarah D

2018-01-01

This study addresses methodological and theoretical questions about the association between affect and physical health. Specifically, we examine the role of affect variability and its interaction with mean levels of affect to predict antibody (Ab) levels in response to an influenza vaccination. Participants (N=83) received the vaccination and completed daily diary measures of affect four times a day for 13days. At one and four months post-vaccination, blood was collected from the participants to assess Ab levels. Findings indicate that affect variability and its interaction with mean levels of affect predict an individual's immune response. Those high in mean positive affect (PA) who had more PA variability were more likely to have a lower Ab response in comparison to those who had high mean PA and less PA variability. Although it did not interact with mean negative affect (NA), NA variability on its own was associated with Ab response, whereby those with less NA variability mounted a more robust immune response. Affect variability is related to immune response to an influenza vaccination and, in some cases, interacts with mean levels of affect. These oscillations in affective experiences are critical to consider in order to unpack the intricacies of how affect influences health. These findings suggest that future researchers should consider the important role of affect variability on physical health-relevant outcomes as well as examine the moderating effect of mean affect levels. Copyright © 2017 Elsevier Inc. All rights reserved.

Structure-Based Design of Hepatitis C Virus Vaccines That Elicit Neutralizing Antibody Responses to a Conserved Epitope

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Pierce, Brian G.; Boucher, Elisabeth N.; Piepenbrink, Kurt H.; Ejemel, Monir; Rapp, Chelsea A.; Thomas, William D.; Sundberg, Eric J.; Weng, Zhiping; Wang, Yang; Diamond, Michael S.

2017-08-09

Despite recent advances in therapeutic options, hepatitis C virus (HCV) remains a severe global disease burden, and a vaccine can substantially reduce its incidence. Due to its extremely high sequence variability, HCV can readily escape the immune response; thus, an effective vaccine must target conserved, functionally important epitopes. Using the structure of a broadly neutralizing antibody in complex with a conserved linear epitope from the HCV E2 envelope glycoprotein (residues 412 to 423; epitope I), we performed structure-based design of immunogens to induce antibody responses to this epitope. This resulted in epitope-based immunogens based on a cyclic defensin protein, as well as a bivalent immunogen with two copies of the epitope on the E2 surface. We solved the X-ray structure of a cyclic immunogen in complex with the HCV1 antibody and confirmed preservation of the epitope conformation and the HCV1 interface. Mice vaccinated with our designed immunogens produced robust antibody responses to epitope I, and their serum could neutralize HCV. Notably, the cyclic designs induced greater epitope-specific responses and neutralization than the native peptide epitope. Beyond successfully designing several novel HCV immunogens, this study demonstrates the principle that neutralizing anti-HCV antibodies can be induced by epitope-based, engineered vaccines and provides the basis for further efforts in structure-based design of HCV vaccines.

IMPORTANCEHepatitis C virus is a leading cause of liver disease and liver cancer, with approximately 3% of the world's population infected. To combat this virus, an effective vaccine would have distinct advantages over current therapeutic options, yet experimental vaccines have not been successful to date, due in part to the virus's high sequence variability leading to immune escape. In this study, we rationally designed several vaccine immunogens based on the structure of a conserved epitope that

Radiosensitivity of antibody responses and radioresistant secondary tetanus antitoxin responses

International Nuclear Information System (INIS)

Stoner, R.; Terres, G.; Cottier, H.; Hess, M.

1976-01-01

Primary tetanus antitoxin responses were increasingly repressed in mice when gamma radiation doses of 100 to 400 rads were delivered by whole-body exposure prior to immunization with fluid tetanus toxoid (FTT). Nearly normal secondary antitoxin responses were obtained in mice exposed to 600 rads of gamma radiation 4 days after secondary antigenic stimulation with FTT. A rapid transition from radiosensitivity of the antibody-forming system on days 1 to 3 was followed by relative radioresistance on day 4 after the booster injection of toxoid. Studies on lymphoid cellular kinetics in popliteal lymph nodes after injection of 3 H--thymidine ( 3 H--TdR) and incorporation of 3 H--L-histidine into circulating antitoxin were carried out. Analysis of tritium radioactivity in antigen--antibody precipitates of serums 2 hr after injection of the labeled amino acid revealed maximum incorporation into antibody around day 7 after the booster in nonirradiated controls and about day 12, i.e., 8 days after irradiation, in experimental mice. The shift from radiosensitivity to relative radioresistance was attributed to a marked peak of plasma-cell proliferation in the medulla of lymph nodes on day 3. Many medullary plasma cells survived and continued to proliferate after exposure to radiation. Germinal centers were destroyed by radiation within 1 day. Since antibody formation continued after exposure to radiation and after the loss of germinal centers, this supports the view that germinal-center cells were involved more in the generation of memory cells than in antibody synthesis

[Screening serum response special antibodies of U251 cell line from surface display phage antibody library].

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Yu, Min; Tan, De-Yong; Qian, Wei; Lai, Jian-Hua; Sun, Gui-Lin

2004-05-01

U251 cell is a sensitive cell line to serum, which stops at G0 phase of cell cycle in no-serum medium, and recovers growth when the serum is added into no-serum medium. The cell can express corresponding proteins in different phase of cell cycle. Therefore it is very signification for the study of cell cycle regulation mechanism that explores these proteins. In this paper, the mouse antibody phage display library was added into the bottle in which the serum starvation U251 cells had been cultured, and the special antibody phages were absorbed. Then the absorbed antibody phages were amplified by adding E. coli TG1 and helper phage M13K07. Amplified antibody phages were added into bottle in which the serum cultured cell after serum starvation (follow named as serum recovered cells) were incubated, so that the cell absorbed the no-special antibody phages for the serum starvation cell and the special antibody phages were in supernatant. The remaining no-special antibody phages in the supernatant were discarded by repeating above program 3-4 times. The pure special antibody phages were gotten, and amplified by adding the host cell E. coli TG1 and helper phage M13K07. Then the host bacterium infected special antibody phage was spread on the plate medium with ampicillin, and the monoclonal antibody phages were gotten. Using same as above program, the monoclonal antibody phages absorbed specially for serum recovered U251 cells were obtained when the serum recovered cells instead of serum starvation cells and serum starvation cells instead of serum recovered cells. In this study, ninety-six positive monoclonal antibody phages that absorbed specially the serum starvation cells and eighty-two positive monoclonal antibody phages that absorbed specially the serum recovered cells were obtained. By using cell immunochemistry assay, two special signification antibodies were obtained. one (No.11) was the strong response in serum starvation cells, the other (No.2) was the strong

Protection against Syphilis Correlates with Specificity of Antibodies to the Variable Regions of Treponema pallidum Repeat Protein K

OpenAIRE

Morgan, Cecilia A.; Lukehart, Sheila A.; Van Voorhis, Wesley C.

2003-01-01

Syphilis has been recognized as a disease since the late 1400s, yet there is no practical vaccine available. One impediment to the development of a vaccine is the lack of understanding of multiple reinfections in humans despite the development of robust immune responses during the first episode. It has been shown that the Treponema pallidum repeat protein K (TprK) differs in seven discrete variable (V) regions in isolates and that the antibody response during infection is directed to these V ...

Protection against syphilis correlates with specificity of antibodies to the variable regions of Treponema pallidum repeat protein K.

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Morgan, Cecilia A; Lukehart, Sheila A; Van Voorhis, Wesley C

2003-10-01

Syphilis has been recognized as a disease since the late 1400s, yet there is no practical vaccine available. One impediment to the development of a vaccine is the lack of understanding of multiple reinfections in humans despite the development of robust immune responses during the first episode. It has been shown that the Treponema pallidum repeat protein K (TprK) differs in seven discrete variable (V) regions in isolates and that the antibody response during infection is directed to these V regions. Immunization with TprK confers significant protection against infection with the homologous strain. We hypothesize that the antigenic diversity of TprK is involved in immune evasion, which contributes to the lack of heterologous protection. Here, using the rabbit model, we show a correlation between limited heterologous protection and tprK diversity in the challenge inoculum. We demonstrate that antibody responses to the V regions of one TprK molecule show limited cross-reactivity with heterologous TprK V regions.

HIV-1 subtype C superinfected individuals mount low autologous neutralizing antibody responses prior to intrasubtype superinfection

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Basu Debby

2012-09-01

Full Text Available Abstract Background The potential role of antibodies in protection against intra-subtype HIV-1 superinfection remains to be understood. We compared the early neutralizing antibody (NAb responses in three individuals, who were superinfected within one year of primary infection, to ten matched non-superinfected controls from a Zambian cohort of subtype C transmission cases. Sequence analysis of single genome amplified full-length envs from a previous study showed limited diversification in the individuals who became superinfected with the same HIV-1 subtype within year one post-seroconversion. We hypothesized that this reflected a blunted NAb response, which may have made these individuals more susceptible to superinfection. Results Neutralization assays showed that autologous plasma NAb responses to the earliest, and in some cases transmitted/founder, virus were delayed and had low to undetectable titers in all three superinfected individuals prior to superinfection. In contrast, NAbs with a median IC50 titer of 1896 were detected as early as three months post-seroconversion in non-superinfected controls. Early plasma NAbs in all subjects showed limited but variable levels of heterologous neutralization breadth. Superinfected individuals also exhibited a trend toward lower levels of gp120- and V1V2-specific IgG binding antibodies but higher gp120-specific plasma IgA binding antibodies. Conclusions These data suggest that the lack of development of IgG antibodies, as reflected in autologous NAbs as well as gp120 and V1V2 binding antibodies to the primary infection virus, combined with potentially competing, non-protective IgA antibodies, may increase susceptibility to superinfection in the context of settings where a single HIV-1 subtype predominates.

Human antibody responses to Schistosoma mansoni: does antigen directed, isotype restriction result in the production of blocking antibodies?

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David W. Dunne

1987-01-01

Full Text Available After treatment young Kenyan schoolchildren are highly susceptible to reinfection with Schistosoma mansoni. Older children and adults are resistant to reinfection. There is no evidence that this age related resistance is due to a slow development of protective immunological mechanisms, rather, it appears that young children are susceptible because of the presence of blocking antibodies which decline with age, thus allowing the expression of protective responses. Correlations between antibody responses to different stages of the parasite life-cycle suggest that, in young children, antigen directed, isotype restriction of the response against cross-reactive polysaccharide egg antigens results in an ineffectual, or even blocking antibody response to the schistosomulum.

Clinical Manifestations of an Anti-Drug Antibody Response: Autoimmune Reactions.

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Swanson, Steven J

2014-12-01

Antibodies can be generated against a therapeutic protein upon administration to human subjects. When the therapeutic protein closely mimics one of the subject's endogenous proteins, those antibodies might bind to the endogenous protein in addition to the therapeutic protein. This scenario results when tolerance to the endogenous protein is broken. The consequences of breaking tolerance include an autoimmune response where antibodies are generated against the endogenous protein. These autoantibodies could have significant clinical relevance depending on several factors, including the redundancy of action of the endogenous protein as well as the concentration, binding affinity, and neutralizing potential of the antibodies. The consequences of a therapeutic-protein-induced autoimmune reaction can be challenging to manage as the stimulus for further perpetuation of the immune response can shift from the therapeutic protein to the endogenous protein. The potential for inducing an autoimmune response is one of the reasons that the immune response to a therapeutic protein should be monitored if it persists through the end of the study.

Antibody and B cell responses to Plasmodium sporozoites

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Johanna N Dups

2014-11-01

Full Text Available Antibodies are capable of blocking infection of the liver by Plasmodium sporozoites. Accordingly the induction of anti-sporozoite antibodies is a major aim of various vaccine approaches to malaria. In recent years our knowledge of the specificity and quantities of antibodies required for protection has been greatly expanded by clinical trials of various whole sporozoite and subunit vaccines. Moreover, the development of humanized mouse models and transgenic parasites have also aided our ability to assess the specificity of antibodies and their ability to block infection. Nonetheless, considerable gaps remain in our knowledge - in particular in understanding what antigens are recognized by infection blocking antibodies and in knowing how we can induce robust, long-lived antibody responses. Maintaining high levels of circulating antibodies is likely to be of primary importance, as antibodies must block infection in the short time it takes for sporozoites to reach the liver from the skin. It is clear that a better understanding of the development of protective B cell-mediated immunity will aid the development and refinement of malaria vaccines.

Stratification of antibody-positive subjects by antibody level reveals an impact of immunogenicity on pharmacokinetics.

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Zhou, Lei; Hoofring, Sarah A; Wu, Yu; Vu, Thuy; Ma, Peiming; Swanson, Steven J; Chirmule, Narendra; Starcevic, Marta

2013-01-01

The availability of highly sensitive immunoassays enables the detection of antidrug antibody (ADA) responses of various concentrations and affinities. The analysis of the impact of antibody status on drug pharmacokinetics (PK) is confounded by the presence of low-affinity or low-concentration antibody responses within the dataset. In a phase 2 clinical trial, a large proportion of subjects (45%) developed ADA following weekly dosing with AMG 317, a fully human monoclonal antibody therapeutic. The antibody responses displayed a wide range of relative concentrations (30 ng/mL to >13 μg/mL) and peaked at various times during the study. To evaluate the impact of immunogenicity on PK, AMG 317 concentration data were analyzed following stratification by dose group, time point, antibody status (positive or negative), and antibody level (relative concentration). With dose group as a stratifying variable, a moderate reduction in AMG 317 levels (AMG 317 levels was revealed when antibody data was stratified by both time point and antibody level. In general, high ADA concentrations (>500 ng/mL) and later time points (week 12) were associated with significantly (up to 97%) lower trough AMG 317 concentrations. The use of quasi-quantitative antibody data and appropriate statistical methods was critical for the most comprehensive evaluation of the impact of immunogenicity on PK.

Felix Hoppe-Seyler Lecture 1997. Protective antibody responses against viruses.

Science.gov (United States)

Zinkernagel, R M

1997-08-01

Neutralizing antibody responses against the acute cytopathic vesicular stomatitis virus (VSV) have been studied in mice to evaluate their general characteristics including specificity, self-/non-self discrimination and memory. IgM responses are generated very early, by day 3 to 4, in a T helper cell-independent fashion and without VSV having polyclonal activating capacities. The order of the glycoprotein tips on the virus envelope (multiple, 8-10 nm distance, paracrystalline) exhibiting the neutralizing determinants are key to this prompt response. These paracrystalline identical multimeric antigens are characteristic of infectious agents and are always reacted against by B cells. Self-antigens that are accessible to B cells in the intact host are either monomeric in serum or mobile multimers on cell surfaces; these configurations need contact dependent or contact independent T help, respectively. Because T help is tolerant against self-antigens, no anti-self B cell responses are usually induced against monomeric self-antigens. If collagen or DNA (rigid multimeric self-antigens) become accessible, however, they may become targets of auto-antibody responses. The antibody repertoire against VSV is partially contained in the germline and partially is generated by somatic mutation; they seem not to undergo affinity-maturation. In any case protection against lethal infection is dependent upon strictly T helper cell dependent IgG generated by day 6 to 7 and reaches a protective level of about 1-10 micrograms/ml. Interesting affinity/avidity and onrate above a minimal threshold are of no apparent advantage for protection in vivo. Maintenance of these antibody levels by antigen depots, and not the presence of memory B cells alone, is key to providing protective immunological memory. Collectively these data suggest that studying biologically important protective antibody responses may modify some of the parameters that have been defined by studying hapten specific antibody

 Variable fragments of heavy chain antibodies (VHHs: a new magic bullet molecule of medicine?

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Dorota Smolarek

2012-06-01

Full Text Available  Serum of animals belonging to the Camelidae family (camels and llamas contains fully active antibodies that are naturally devoid of light chains. Variable domains derived from heavy chain antibodies (hcAb called VHHs or nanobodies™ can bind antigens as effectively as full-length antibodies and are easy to clone and express. Because of their potential, VHHs are being intensively studied as potential therapeutic, diagnostic and imaging tools. The paper reviews the molecular background of heavy chain antibodies and describes methods of obtaining recombinant fragments of heavy chain antibodies as well as their therapeutic, diagnostic and other applications.

Human antibody and antigen response to IncA antibody of Chlamydia trachomatis.

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Tsai, P Y; Hsu, M C; Huang, C T; Li, S Y

2007-01-01

The high prevalence of C. trachomatis worldwide has underscored the importance of identifying specific immunogenic antigens in facilitating diagnosis as well as vaccine development. The aim of this study is to evaluate IncA antibody and antigen production in natural human infections. Our temporal expression study showed that IncA transcription and protein expression could be detected as early as 4 hours after the start of infection. Antibody responses could be detected in urine and genital swab samples from C. trachomatis-positive patients. It is especially interesting to note that the IncA antigen could be detected in urine. In conclusion, we have identified IncA as an important antigen in human. The potential applicability of the IncA antibody or antigen in the diagnosis as well as to vaccine development for C. trachomatis is also discussed.

Antibody response to pneumococcal vaccine in patients with early stage Hodgkin's disease

DEFF Research Database (Denmark)

Frederiksen, B; Specht, L; Henrichsen, J

1989-01-01

response to pneumococcal type antigens was similar in healthy adults and in patients with early stage HD before therapy. After treatment, postvaccination antibody response became negligible. Even up to 7 years after cessation of therapy patients were not able to raise a significant antibody response....

Insight into the potential for DNA idiotypic fusion vaccines designed for patients by analysing xenogeneic anti-idiotypic antibody responses

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Forconi, Francesco; King, Catherine A; Sahota, Surinder S; Kennaway, Christopher K; Russell, Nigel H; Stevenson, Freda K

2002-01-01

DNA vaccines induce immune responses against encoded proteins, and have clear potential for cancer vaccines. For B-cell tumours, idiotypic (Id) immunoglobulin encoded by the variable region genes provides a target antigen. When assembled as single chain Fv (scFv), and fused to an immunoenhancing sequence from tetanus toxin (TT), DNA fusion vaccines induce anti-Id antibodies. In lymphoma models, these antibodies have a critical role in mediating protection. For application to patients with lymphoma, two questions arise: first, whether pre-existing antibody against TT affects induction of anti-scFv antibodies; second, whether individual human scFv fusion sequences are able to fold consistently to generate antibodies able to recognize private conformational Id determinants expressed by tumour cells. Using xenogeneic vaccination with scFv sequences from four patients, we have shown that pre-existing anti-TT immunity slows, but does not prevent, anti-Id antibody responses. To determine folding, we have monitored the ability of nine DNAscFv–FrC patients' vaccines to induce xenogeneic anti-Id antibodies. Antibodies were induced in all cases, and were strikingly specific for each patient's immunoglobulin with little cross-reactivity between patients, even when similar VH or VL genes were involved. Blocking experiments with human serum confirmed reactivity against private determinants in 26–97% of total antibody. Both immunoglobulin G1 (IgG1) and IgG2a subclasses were present at 1·3 : 1–15 : 1 consistent with a T helper 2-dominated response. Xenogeneic vaccination provides a simple route for testing individual patients' DNAscFv–FrC fusion vaccines, and offers a strategy for production of anti-Id antibodies. The findings underpin the approach of DNA idiotypic fusion vaccination for patients with B-cell tumours. PMID:12225361

Development of Broadly Neutralizing Antibody Mimitopes for Characterization of CRF01_AE HIV-1 Antibody Responses

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Jesse V. Schoen

2017-10-01

Full Text Available Mapping humoral immune responses to HIV-1 over the course of natural infection is important in understanding epitope exposure in relation to elicitation of broadly neutralizing antibodies (bNAbs, which is considered imperative for effective vaccine design. When analyzing HIV-specific immune responses, the antibody binding profiles may be a correlate for functional antibody activity. In this study, we utilized phage display technology to identify novel mimitopes that may represent Env epitope structures bound by bNAbs directed at V1V2 and V3 domains, CD4 binding site (CD4bs and the membrane proximal external region (MPER of Env. Mimitope sequence motifs were determined for each bNAb epitope. Given the ongoing vaccine development efforts in Thailand, these mimitopes that represent CD4bs and MPER epitopes were used to map immune responses of HIV-1 CRF01_AE-infected individuals with known neutralizing responses from two distinct time periods, 1996-98 and 2012-15. The more contemporary cohort showed an increase in binding breadth with binding observed for all MPER and CD4bs mimitopes, while the older cohort showed only 75% recognition of the CD4bs mimitopes and no MPER mimotope binding. Furthermore, mimitope binding profiles correlated significantly with magnitude (p=0.0036 and breadth (p=0.0358 of neutralization of a multi-subtype Tier 1 panel of pseudoviruses. These results highlight the utility of this mimitope mapping approach for detecting human plasma IgG-specificities that target known neutralizing antibody epitopes, and may also provide an indication of the plasticity of antibody binding within HIV-1 Env neutralization determinants.

Modular Construction of Large Non-Immune Human Antibody Phage-Display Libraries from Variable Heavy and Light Chain Gene Cassettes.

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Lee, Nam-Kyung; Bidlingmaier, Scott; Su, Yang; Liu, Bin

2018-01-01

Monoclonal antibodies and antibody-derived therapeutics have emerged as a rapidly growing class of biological drugs for the treatment of cancer, autoimmunity, infection, and neurological diseases. To support the development of human antibodies, various display techniques based on antibody gene repertoires have been constructed over the last two decades. In particular, scFv-antibody phage display has been extensively utilized to select lead antibodies against a variety of target antigens. To construct a scFv phage display that enables efficient antibody discovery, and optimization, it is desirable to develop a system that allows modular assembly of highly diverse variable heavy chain and light chain (Vκ and Vλ) repertoires. Here, we describe modular construction of large non-immune human antibody phage-display libraries built on variable gene cassettes from heavy chain and light chain repertoires (Vκ- and Vλ-light can be made into independent cassettes). We describe utility of such libraries in antibody discovery and optimization through chain shuffling.

Porcine humoral immune responses to multiple injections of murine monoclonal antibodies

DEFF Research Database (Denmark)

Lohse, Louise; Nielsen, Jens; Kamstrup, Søren

2005-01-01

In humans and cattle, multiple injections of murine monoclonal antibodies (m-mAbs) induce anti-mouse antibody responses. The objectives of the present. study were to investigate whether a similar response could be seen when pigs were subjected to m-mAb therapy, and to study the kinetics of such a...

The antibody response against human and chimeric anti-TNF therapeutic antibodies primarily targets the TNF binding region

NARCIS (Netherlands)

van Schie, K. A.; Hart, M. H.; de Groot, E. R.; Kruithof, S.; Aarden, L. A.; Wolbink, G. J.; Rispens, T.

2015-01-01

In a subset of patients, anti tumour necrosis factor (TNF) therapeutic antibodies are immunogenic, resulting in the formation of antidrug antibodies (ADAs). Neutralising ADAs compete with TNF for its binding site and reduces the effective serum concentration, causing clinical non-response. It is

Vaccination of horses with Lyme vaccines for dogs induces short-lasting antibody responses.

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Guarino, Cassandra; Asbie, Sanda; Rohde, Jennifer; Glaser, Amy; Wagner, Bettina

2017-07-24

Borrelia burgdorferi can induce Lyme disease. Approved Lyme vaccines for horses are currently not available. In an effort to protect horses, veterinarians are using Lyme vaccines licensed for dogs. However, data to assess the response of horses to, or determine the efficacy of this off-label vaccine use are missing. Here, antibodies against outer surface protein A (OspA), OspC, and OspF were quantified in diagnostic serum submissions from horses with a history of vaccination with canine Lyme vaccines. The results suggested that many horses respond with low and often short-lasting antibody responses. Subsequently, four experimental vaccination trials were performed. First, we investigated antibody responses to three canine vaccines in B. burgdorferi-naïve horses. One killed bacterin vaccine induced antibodies against OspC. OspA antibodies were low for all three vaccines and lasted less than 16weeks. The second trial tested the impact of the vaccine dose using the OspA/OspC inducing bacterin vaccine in horses. A 2mL dose produced higher OspA and OspC antibody values than a 1mL dose. However, the antibody response again quickly declined, independent of dose. Third, the horses were vaccinated with 2 doses of a recombinant OspA vaccine. Previous vaccination and/or environmental exposure enhanced the magnitude and longevity of the OspA antibody response to about 20weeks. Last, the influence of intramuscular versus subcutaneous vaccine administration was investigated for the recombinant OspA vaccine. OspA antibody responses were not influenced by injection route. The current work highlights that commercial Lyme vaccines for dogs induce only transient antibody responses in horses which can also be of low magnitude. Protection from infection with B. burgdorferi should not be automatically assumed after vaccinating horses with Lyme vaccines for dogs. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Dual antibody therapy to harness the innate anti-tumor immune response to enhance antibody targeting of tumors.

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Chester, Cariad; Marabelle, Aurelien; Houot, Roch; Kohrt, Holbrook E

2015-04-01

Cancer immunotherapy is a rapidly evolving field that offers a novel paradigm for cancer treatment: therapies focus on enhancing the immune system's innate and adaptive anti-tumor response. Early immunotherapeutics have achieved impressive clinical outcomes and monoclonal antibodies are now integral to therapeutic strategies in a variety of cancers. However, only recently have antibodies targeting innate immune cells entered clinical development. Innate immune effector cells play important roles in generating and maintaining antitumor immunity. Antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) are important innate immune mechanisms for tumor eradication. These cytolytic processes are initiated by the detection of a tumor-targeting antibody and can be augmented by activating co-stimulatory pathways or blocking inhibitory signals on innate immune cells. The combination of FDA-approved monoclonal antibodies with innate effector-targeting antibodies has demonstrated potent preclinical therapeutic synergy and early-phase combinatorial clinical trials are ongoing. Copyright © 2015 Elsevier Ltd. All rights reserved.

High-throughput sequencing of natively paired antibody chains provides evidence for original antigenic sin shaping the antibody response to influenza vaccination.

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Tan, Yann-Chong; Blum, Lisa K; Kongpachith, Sarah; Ju, Chia-Hsin; Cai, Xiaoyong; Lindstrom, Tamsin M; Sokolove, Jeremy; Robinson, William H

2014-03-01

We developed a DNA barcoding method to enable high-throughput sequencing of the cognate heavy- and light-chain pairs of the antibodies expressed by individual B cells. We used this approach to elucidate the plasmablast antibody response to influenza vaccination. We show that >75% of the rationally selected plasmablast antibodies bind and neutralize influenza, and that antibodies from clonal families, defined by sharing both heavy-chain VJ and light-chain VJ sequence usage, do so most effectively. Vaccine-induced heavy-chain VJ regions contained on average >20 nucleotide mutations as compared to their predicted germline gene sequences, and some vaccine-induced antibodies exhibited higher binding affinities for hemagglutinins derived from prior years' seasonal influenza as compared to their affinities for the immunization strains. Our results show that influenza vaccination induces the recall of memory B cells that express antibodies that previously underwent affinity maturation against prior years' seasonal influenza, suggesting that 'original antigenic sin' shapes the antibody response to influenza vaccination. Published by Elsevier Inc.

Heritability of antibody isotype and subclass responses to Plasmodium falciparum antigens.

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Nancy O Duah

2009-10-01

Full Text Available It is important to understand the extent to which genetic factors regulate acquired immunity to common infections. A classical twin study design is useful to estimate the heritable component of variation in measurable immune parameters.This study assessed the relative heritability of different plasma antibody isotypes and subclasses (IgG1, IgG2, IgG3, IgG4, IgM, IgA and IgE naturally acquired to P. falciparum blood stage antigens AMA1, MSP1-19, MSP2 (two allelic types and MSP3 (two allelic types. Separate analyses were performed on plasma from 213 pairs of Gambian adult twins, 199 child twin pairs sampled in a dry season when there was little malaria transmission, and another set of 107 child twin pairs sampled at the end of the annual wet season when malaria was common. There were significantly positive heritability (h(2 estimates for 48% (20/42 of the specific antibody assays (for the seven isotypes and subclasses to the six antigens tested among the adults, 48% (20/42 among the children in the dry season and 31% (13/42 among the children in the wet season. In children, there were significant heritability estimates for IgG4 reactivity against each of the antigens, and this subclass had higher heritability than the other subclasses and isotypes. In adults, 75% (15/20 of the significantly heritable antigen-specific isotype responses were attributable to non-HLA class II genetic variation, whereas none showed a significant HLA contribution.Genome-wide approaches are now warranted to map the major genetic determinants of variable antibody isotype and subclass responses to malaria, alongside evaluation of their impact on infection and disease. Although plasma levels of IgG4 to malaria antigens are generally low, the exceptionally high heritability of levels of this subclass in children deserves particular investigation.

Oral antibiotics enhance antibody responses to keyhole limpet hemocyanin in orally but not muscularly immunized chickens.

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Murai, Atsushi; Kitahara, Kazuki; Okumura, Shouta; Kobayashi, Misato; Horio, Fumihiko

2016-02-01

Recent studies have emphasized the crucial role of gut microbiota in triggering and modulating immune response. We aimed to determine whether the modification of gut microbiota by oral co-administration of two antibiotics, ampicillin and neomycin, would lead to changes in the antibody response to antigens in chickens. Neonatal chickens were given or not given ampicillin and neomycin (0.25 and 0.5 g/L, respectively) in drinking water. At 2 weeks of age, the chicks were muscularly or orally immunized with antigenic keyhole limpet hemocyanin (KLH), and then serum anti-KLH antibody levels were examined by ELISA. In orally immunized chicks, oral antibiotics treatment enhanced antibody responses (IgM, IgA, IgY) by 2-3-fold compared with the antibiotics-free control, while the antibiotics did not enhance antibody responses in the muscularly immunized chicks. Concomitant with their enhancement of antibody responses, the oral antibiotics also lowered the Lactobacillus species in feces. Low doses of antibiotics (10-fold and 100-fold lower than the initial trial), which failed to change the fecal Lactobacillus population, did not modify any antibody responses when chicks were orally immunized with KLH. In conclusion, oral antibiotics treatment enhanced the antibody response to orally exposed antigens in chickens. This enhancement of antibody response was associated with a modification of the fecal Lactobacillus content, suggesting a possible link between gut microbiota and antibody response in chickens. © 2015 Japanese Society of Animal Science.

Smoking and periodontal disease: discrimination of antibody responses to pathogenic and commensal oral bacteria.

Science.gov (United States)

Hayman, L; Steffen, M J; Stevens, J; Badger, E; Tempro, P; Fuller, B; McGuire, A; Al-Sabbagh, Mohanad; Thomas, M V; Ebersole, J L

2011-04-01

Smoking is an independent risk factor for the initiation, extent and severity of periodontal disease. This study examined the ability of the host immune system to discriminate commensal oral bacteria from pathogens at mucosal surfaces, i.e. oral cavity. Serum immunoglobulin (Ig)G antibody reactive with three pathogenic and five commensal oral bacteria in 301 current smokers (age range 21-66 years) were examined by enzyme-linked immunosorbent assay. Clinical features of periodontal health were used as measures of periodontitis. Antibody to the pathogens and salivary cotinine levels were related positively to disease severity; however, the antibody levels were best described by the clinical disease unrelated to the amount of smoking. The data showed a greater immune response to pathogens than commensals that was related specifically to disease extent, and most noted in black males. Significant correlations in individual patient responses to the pathogens and commensals were lost with an increasing extent of periodontitis and serum antibody to the pathogens. Antibody to Porphyromonas gingivalis was particularly distinct with respect to the discriminatory nature of the immune responses in recognizing the pathogens. Antibody responses to selected pathogenic and commensal oral microorganisms differed among racial groups and genders. The antibody response to the pathogens was related to disease severity. The level of antibody to the pathogens, and in particular P. gingivalis, was correlated with disease severity in black and male subsets of patients. The amount of smoking did not appear to impact directly serum antibody levels to these oral bacteria. © 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.

Equine allogeneic bone marrow-derived mesenchymal stromal cells elicit antibody responses in vivo.

Science.gov (United States)

Pezzanite, Lynn M; Fortier, Lisa A; Antczak, Douglas F; Cassano, Jennifer M; Brosnahan, Margaret M; Miller, Donald; Schnabel, Lauren V

2015-04-12

This study tested the hypothesis that Major Histocompatibility Complex (MHC) incompatible equine mesenchymal stromal cells (MSCs) would induce cytotoxic antibodies to donor MHC antigens in recipient horses after intradermal injection. No studies to date have explored recipient antibody responses to allogeneic donor MSC transplantation in the horse. This information is critical because the horse is a valuable species for assessing the safety and efficacy of MSC treatment prior to human clinical application. Six MHC heterozygote horses were identified as non-ELA-A2 haplotype by microsatellite typing and used as allogeneic MHC-mismatched MSC recipients. MHC homozygote horses of known ELA-A2 haplotype were used as MSC and peripheral blood leukocyte (PBL) donors. One MHC homozygote horse of the ELA-A2 haplotype was the recipient of ELA-A2 donor MSCs as an MHC-matched control. Donor MSCs, which were previously isolated and immunophenotyped, were thawed and culture expanded to achieve between 30x10(6) and 50x10(6) cells for intradermal injection into the recipient's neck. Recipient serum was collected and tested for the presence of anti-donor antibodies prior to MSC injection and every 7 days after MSC injection for the duration of the 8-week study using the standard two-stage lymphocyte microcytotoxicity dye-exclusion test. In addition to anti-ELA-A2 antibodies, recipient serum was examined for the presence of cross-reactive antibodies including anti-ELA-A3 and anti-RBC antibodies. All MHC-mismatched recipient horses produced anti-ELA-A2 antibodies following injection of ELA-A2 MSCs and developed a wheal at the injection site that persisted for the duration of the experiment. Anti-ELA-A2 antibody responses were varied both in terms of strength and timing. Four recipient horses had high-titered anti-ELA-A2 antibody responses resulting in greater than 80% donor PBL death in the microcytotoxicity assays and one of these horses also developed antibodies that cross

The association of heavy and light chain variable domains in antibodies: implications for antigen specificity.

KAUST Repository

Chailyan, Anna

2011-06-28

The antigen-binding site of immunoglobulins is formed by six regions, three from the light and three from the heavy chain variable domains, which, on association of the two chains, form the conventional antigen-binding site of the antibody. The mode of interaction between the heavy and light chain variable domains affects the relative position of the antigen-binding loops and therefore has an effect on the overall conformation of the binding site. In this article, we analyze the structure of the interface between the heavy and light chain variable domains and show that there are essentially two different modes for their interaction that can be identified by the presence of key amino acids in specific positions of the antibody sequences. We also show that the different packing modes are related to the type of recognized antigen.

Kinetics of circulating antibody response to Trichomonas vaginalis: clinical and diagnostic implications.

Science.gov (United States)

Ton Nu, Phuong Anh; Rappelli, Paola; Dessì, Daniele; Nguyen, Vu Quoc Huy; Fiori, Pier Luigi

2015-12-01

Persistence of antibodies against pathogens after antimicrobial treatment is a marker of therapy failure or evolution to a chronic infection. The kinetics of antibody production decrease following antigen elimination is highly variable, and predicting the duration of soluble immunity in infectious diseases is often impossible. This hampers the development and use of immunoassays for diagnostic and seroepidemiological purposes. In the case of Trichomonas vaginalis infection, the kinetics of antibody levels decrease following therapy has never been studied. We thus investigated the clearance of circulating anti-T. vaginalis IgGs after pharmacological treatment in patients affected by trichomoniasis. 18 female patients affected by acute trichomoniasis were enrolled in this study. After metronidazole therapy administration, subjects were followed up monthly up to 5 months, and serum levels of anti-T. vaginalis IgGs were measured by ELISA. We showed that a successful therapy is characterised by a relatively fast decline of specific antibodies, until turning into negative by ELISA in 1-3 months. In a few patients we observed that the persistence of anti-T. vaginalis antibodies was associated with an evolution to chronic infection, which may be due to treatment failure or to reinfection by untreated sexual partners. Our results describe the direct correlation between the decline of a specific humoral anti-T. vaginalis response and an effective antimicrobial therapy. These findings may facilitate the follow-up approach to circumvent limitations in developing new diagnostic tools and techniques routinely used in microbiology laboratories to assess the presence of T. vaginalis in clinical samples. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

PF4-HIT antibody (KKO) complexes activate broad innate immune and inflammatory responses.

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Haile, Lydia A; Rao, Roshni; Polumuri, Swamy K; Arepally, Gowthami M; Keire, David A; Verthelyi, Daniela; Sommers, Cynthia D

2017-11-01

Heparin-induced thrombocytopenia (HIT) is an immune-mediated complication of heparin anticoagulation therapy resulting in thrombocytopenia frequently accompanied by thrombosis. Current evidence suggests that HIT is associated with antibodies developed in response to multi-molecular complexes formed by platelet factor 4 (PF4) bound to heparin or cell surface glycosaminoglycans. These antibody complexes activate platelets and monocytes typically through FcγRIIA receptors increasing the production of PF4, inflammatory mediators, tissue factor and thrombin. The influence of underlying events in HIT including complex-induced pro-inflammatory cell activation and structural determinants leading to local inflammatory responses are not fully understood. The stoichiometry and complex component requirements were determined by incubating fresh peripheral blood mononuclear cells (PBMC) with different concentrations of unfractionated heparin (H), low molecular weight heparin (LMWH), PF4- and anti-PF4-H complex antibodies (KKO). Cytokine mRNA or protein were measured by qRT-PCR or Meso Scale Discovery technology, respectively. Gene expression profile analysis for 594 genes was performed using Nanostring technology and analyzed using Ingenuity Pathway Analysis software. The data show that antibodies magnify immune responses induced in PBMCs by PF4 alone or in complex with heparin or LMWH. We propose that following induction of HIT antibodies by heparin-PF4 complexes, binding of the antibodies to PF4 is sufficient to induce a local pro-inflammatory response which may play a role in the progression of HIT. In vitro assays using PBMCs may be useful in characterizing local inflammatory and innate immune responses induced by HIT antibodies in the presence of PF4 and different sources of heparins. The findings and conclusions in this article are solely the responsibility of the authors and are not being formally disseminated by the Food and Drug Administration. Thus, they should not be

Severe antiphospholipid antibody syndrome - response to plasmapheresis and rituximab.

Science.gov (United States)

Gkogkolou, Paraskevi; Ehrchen, Jan; Goerge, Tobias

2017-09-01

Antiphospholipid antibody syndrome (APS) is a systemic autoimmune disease characterized by arterial and/or venous thrombosis, recurrent abortions and detection of antiphospholipid antibodies. In fulminant cases, involvement of multiple organs can lead to significant morbidity and even fatal outcomes, so that a rapid, interdisciplinary treatment is needed. Here, we describe the case of a 39-year-old woman with a severe hard-to-treat APS with arterial occlusion and progressive skin necrosis, who was successfully treated with a combination therapy with plasmapheresis and rituximab. The treatment led to complete remission of the skin lesions for over a year. Clinical response correlated with a long-lasting reduction of antiphospholipid antibodies and B-cell depletion. This case demonstrates the use of antiphospholipid antibodies for monitoring APS-activity and shows that this severe vascular disease requires rigorous therapeutic approaches.

Ranitidine improves postoperative suppression of antibody response to preoperative vaccination

DEFF Research Database (Denmark)

Nielsen, Hans Jørgen; Hammer, J H; Moesgaard, F

1992-01-01

The effect of the histamine-2 receptor antagonist ranitidine (100 mg intravenously every 12 hours for 72 hours) on postoperative serum antibody responses to preoperative immunization with six limit of flocculation tetanus toxoid and six limit of flocculation diphtheria toxoid was assessed...... in a double-blind, placebo-controlled randomized study in 26 patients undergoing major abdominal surgery. The preoperative antitetanus antibody level was less than 0.1 IU/ml in all patients, and they were inoculated with both antigens 48 hours before surgery. Serum samples for analysis of antitetanus toxoid...... and antidiphtheria toxoid were drawn before skin incision and on postoperative days 1, 3, 5, 7, 10, 14, 21, and 28. Ranitidine significantly increased the postoperative antibody response to tetanus toxoid, (p less than 0.01) and insignificantly increased that to diphtheria toxoid vaccination (p less than 0...

Thermodynamics of antibody-antigen interaction revealed by mutation analysis of antibody variable regions.

Science.gov (United States)

Akiba, Hiroki; Tsumoto, Kouhei

2015-07-01

Antibodies (immunoglobulins) bind specific molecules (i.e. antigens) with high affinity and specificity. In order to understand their mechanisms of recognition, interaction analysis based on thermodynamic and kinetic parameters, as well as structure determination is crucial. In this review, we focus on mutational analysis which gives information about the role of each amino acid residue in antibody-antigen interaction. Taking anti-hen egg lysozyme antibodies and several anti-small molecule antibodies, the energetic contribution of hot-spot and non-hot-spot residues is discussed in terms of thermodynamics. Here, thermodynamics of the contribution from aromatic, charged and hydrogen bond-forming amino acids are discussed, and their different characteristics have been elucidated. The information gives fundamental understanding of the antibody-antigen interaction. Furthermore, the consequences of antibody engineering are analysed from thermodynamic viewpoints: humanization to reduce immunogenicity and rational design to improve affinity. Amino acid residues outside hot-spots in the interface play important roles in these cases, and thus thermodynamic and kinetic parameters give much information about the antigen recognition. Thermodynamic analysis of mutant antibodies thus should lead to advanced strategies to design and select antibodies with high affinity. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Immune response in mice to ingested soya protein: antibody production, oral tolerance and maternal transfer

DEFF Research Database (Denmark)

Christensen, Hanne Risager; Pedersen, Susanne Brix; Frøkiær, Hanne

2004-01-01

antibody response in the offspring, bat in this case in the absence of oral tolerance. This indicates that, under certain conditions, factors involved in spontaneous antibody production can be transmitted from mother to offspring. Understanding the immune response to soya protein ingested under healthy...... by ELISA, and to the presence of oral tolerance detected as a suppressed antibody and cell-proliferation response upon immunisation with soya protein. F0 mice generated soya-specific antibodies, while oral tolerance to the same soya proteins was also clearly induced. When F0 dams were transferred to soya...

Systemic and Mucosal Antibody Responses to Soluble and Nanoparticle-Conjugated Antigens Administered Intranasally

Directory of Open Access Journals (Sweden)

Savannah E. Howe

2016-10-01

Full Text Available Nanoparticles (NPs are increasingly being used for drug delivery, as well as antigen carriers and immunostimulants for the purpose of developing vaccines. In this work, we examined how intranasal (i.n. priming followed by i.n. or subcutaneous (s.c. boosting immunization affects the humoral immune response to chicken ovalbumin (Ova and Ova conjugated to 20 nm NPs (NP-Ova. We show that i.n. priming with 20 mg of soluble Ova, a dose known to trigger oral tolerance when administered via gastric gavage, induced substantial systemic IgG1 and IgG2c, as well as mucosal antibodies. These responses were further boosted following a s.c. immunization with Ova and complete Freund’s adjuvant (Ova+CFA. In contrast, 100 µg of Ova delivered via NPs induced an IgG1-dominated systemic response, and primed the intestinal mucosa for secretion of IgA. Following a secondary s.c. or i.n. immunization with Ova+CFA or NP-Ova, systemic IgG1 titers significantly increased, and serum IgG2c and intestinal antibodies were induced in mice primed nasally with NP-Ova. Only Ova- and NP-Ova-primed mice that were s.c.-boosted exhibited substantial systemic and mucosal titers for up to 6 months after priming, whereas the antibodies of i.n.-boosted mice declined over time. Our results indicate that although the amount of Ova delivered by NPs was 1000-fold less than Ova delivered in soluble form, the antigen-specific antibody responses, both systemic and mucosal, are essentially identical by 6 months following the initial priming immunization. Additionally, both i.n.- and s.c.-boosting strategies for NP-Ova-primed mice were capable of inducing a polarized Th1/Th2 immune response, as well as intestinal antibodies; however, it is only by using a heterogeneous prime-boost strategy that long-lasting antibody responses were initiated. These results provide valuable insight for future mucosal vaccine development, as well as furthering our understanding of mucosal antibody responses.

Identification and verification of hybridoma-derived monoclonal antibody variable region sequences using recombinant DNA technology and mass spectrometry

Science.gov (United States)

Antibody engineering requires the identification of antigen binding domains or variable regions (VR) unique to each antibody. It is the VR that define the unique antigen binding properties and proper sequence identification is essential for functional evaluation and performance of recombinant antibo...

Antibody Response is More Likely to Pneumococcal Proteins Than to Polysaccharide After HIV-associated Invasive Pneumococcal Disease

DEFF Research Database (Denmark)

Kantsø, Bjørn; Green, Nicola; Goldblatt, David

2015-01-01

to at least 1 protein compared to 51% of non-IPD controls. HIV IPD cases responded to more proteins than non-IPD controls (8.6 ± 8.4 vs 4.2 ± 7.6 proteins; P = .01), and had a significantly higher probability of yielding an antibody response to the proteins PiaA, PsaA, and PcpA. Twenty-two percent of HIV......-infected individuals with IPD had a serotype-specific antibody response. Younger age at the time of IPD was the only predictor of a serotype-specific pneumococcal antibody response, whereas we did not identify predictors of a protein-specific antibody response. CONCLUSIONS: Antibody responses occurred more frequently...

Opposite effects of total lymphoid irradiation on T cell-dependent and T cell-independent antibody responses

Energy Technology Data Exchange (ETDEWEB)

Tanay, A.; Strober, S.

1984-02-01

The effect of total lymphoid irradiation (TLI) on the primary antibody response to the dinitrophenylated heterologous protein, keyhole limpet hemocyanin (DNP-KLH), in complete Freund's adjuvant (CFA), and to the trinitrophenylated polysaccharide antigen, Brucella abortus (TNP-BA), was studied in BALB/c mice. The antibody response to both antigens was diminished in comparison with nonirradiated mice when antigens were injected within 3 days after TLI. When the mice were immunized 30 days after completion of TLI the antibody response to DNP-KLH in CFA was still diminished, but the antibody response to TNP-BA was enhanced 5- to 10-fold as compared with that of control animals. The opposite effect of TLI on the two antibody responses was also observed in a syngeneic primary adoptive transfer system.

Neurofilament light antibodies in serum reflect response to natalizumab treatment in multiple sclerosis.

Science.gov (United States)

Amor, Sandra; van der Star, Baukje J; Bosca, Isabel; Raffel, Joel; Gnanapavan, Sharmilee; Watchorn, Jonathan; Kuhle, Jens; Giovannoni, Gavin; Baker, David; Malaspina, Andrea; Puentes, Fabiola

2014-09-01

Increased levels of antibodies to neurofilament light protein (NF-L) in biological fluids have been found to reflect neuroinflammatory responses and neurodegeneration in multiple sclerosis (MS). To evaluate whether levels of serum antibodies against NF-L correlate with clinical variants and treatment response in MS. The autoantibody reactivity to NF-L protein was tested in serum samples from patients with relapsing-remitting MS (RRMS) (n=22) and secondary progressive MS (SPMS) (n=26). Two other cohorts of RRMS patients under treatment with natalizumab were analysed cross-sectionally (n=16) and longitudinally (n=24). The follow-up samples were taken at 6, 12, 18 and 24 months after treatment, and the NF-L antibody levels were compared against baseline levels. NF-L antibodies were higher in MS clinical groups than healthy controls and in RRMS compared to SPMS patients (ptreatment compared with baseline measurements (p=0.001). Drug efficacy in MS treatment indicates the potential use of monitoring the content of antibodies against the NF-L chain as a predictive biomarker of treatment response in MS. © The Author(s) 2014.

A residue-specific shift in stability and amyloidogenicity of antibody variable domains.

Science.gov (United States)

Nokwe, Cardine N; Zacharias, Martin; Yagi, Hisashi; Hora, Manuel; Reif, Bernd; Goto, Yuji; Buchner, Johannes

2014-09-26

Variable (V) domains of antibodies are essential for antigen recognition by our adaptive immune system. However, some variants of the light chain V domains (VL) form pathogenic amyloid fibrils in patients. It is so far unclear which residues play a key role in governing these processes. Here, we show that the conserved residue 2 of VL domains is crucial for controlling its thermodynamic stability and fibril formation. Hydrophobic side chains at position 2 stabilize the domain, whereas charged residues destabilize and lead to amyloid fibril formation. NMR experiments identified several segments within the core of the VL domain to be affected by changes in residue 2. Furthermore, molecular dynamic simulations showed that hydrophobic side chains at position 2 remain buried in a hydrophobic pocket, and charged side chains show a high flexibility. This results in a predicted difference in the dissociation free energy of ∼10 kJ mol(-1), which is in excellent agreement with our experimental values. Interestingly, this switch point is found only in VL domains of the κ family and not in VLλ or in VH domains, despite a highly similar domain architecture. Our results reveal novel insight into the architecture of variable domains and the prerequisites for formation of amyloid fibrils. This might also contribute to the rational design of stable variable antibody domains. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Analysis of the diversity of murine antibodies to dextran B1355. II. Demonstration of multiple idiotypes with variable expression in several strains

International Nuclear Information System (INIS)

Hansburg, D.; Briles, D.E.; Davie, J.M.

1977-01-01

We have developed radioimmunoassays that detect idiotypic (variable region) differences among the α(1 → 3) dextran-binding myeloma proteins U102, J558, and M104 as well as an assay that detects variable region determinants common to all three proteins. Using these assays, we have examined 7S and 19S anti-α(1 → 3) dextran antibodies induced in five murine strains of the a 1 I/sub g/C/sub H/ linkage group and the recombinant strain BAB/14. All idiotypes were expressed in both 19S and 7S antibodies from all strains, but with considerable strain-specific variability in penetrance. In two strains, one additional type of antibody, which lacked all four idiotypic determinants, generally constituted the bulk of total anti-α(1 → 3) dextran antibodies

Expression and production of llama variable heavy-chain antibody fragments (VHHs) by Aspergillus awamori

NARCIS (Netherlands)

Joosten, V.; Gouka, R.J.; Hondel, C.A.M.J.J. van den; Verrips, C.T.; Lokman, B.C.

2005-01-01

We report the expression and production of llama variable heavy-chain antibody fragments (VHHs) by Aspergillus awamori. Fragments encoding VHHs were cloned in a suitable Aspergillus expression vector and transformants secreting VHH fragments were analysed for integrated gene copy-numbers, mRNA

Ontogeny of adaptive antibody response to a model antigen in captive altricial zebra finches.

Directory of Open Access Journals (Sweden)

Tess L Killpack

Full Text Available Based on studies from the poultry literature, all birds are hypothesized to require at least 4 weeks to develop circulating mature B-cell lineages that express functionally different immunoglobulin specificities. However, many altricial passerines fledge at adult size less than four weeks after the start of embryonic development, and therefore may experience a period of susceptibility during the nestling and post-fledging periods. We present the first study, to our knowledge, to detail the age-related changes in adaptive antibody response in an altricial passerine. Using repeated vaccinations with non-infectious keyhole limpet hemocyanin (KLH antigen, we studied the ontogeny of specific adaptive immune response in altricial zebra finches Taeniopygia guttata. Nestling zebra finches were first injected at 7 days (7d, 14 days (14d, or 21 days post-hatch (21d with KLH-adjuvant emulsions, and boosted 7 days later. Adults were vaccinated in the same manner. Induced KLH-specific IgY antibodies were measured using ELISA. Comparisons within age groups revealed no significant increase in KLH-specific antibody levels between vaccination and boost in 7d birds, yet significant increases between vaccination and boost were observed in 14d, 21d, and adult groups. There was no significant difference among age groups in KLH antibody response to priming vaccination, yet KLH antibody response post-boost significantly increased with age among groups. Post-boost antibody response in all nestling age groups was significantly lower than in adults, indicating that mature adult secondary antibody response level was not achieved in zebra finches prior to fledging (21 days post-hatch in zebra finches. Findings from this study contribute fundamental knowledge to the fields of developmental immunology and ecological immunology and strengthen the utility of zebra finches as a model organism for future studies of immune ontogeny.

[Prevalence of antibodies to hepatitis A virus in healthcare workers and associated variables].

Science.gov (United States)

Carreras-Valls, Rosa; Valverde-Lozano, Judit; Benito-Carreras, Dolors; Inglés-Torruella, Joan; Vilardell-Ynaraja, Miquel; Garre-Olmo, Josep; Gil-Soto, Rosa; Escalé-Roca, Margarita

2013-01-01

Vaccination against hepatitis A is recommended in risk groups, including healthcare workers. The objective of this study was to determine the prevalence of antibodies to HAV (IgG) among workers in the healthcare setting in order to establish criteria for vaccination. A cross-sectional, analytic, observational study of 4,864 employees was undertaken in four healthcare companies in Catalonia (Spain). The variables gathered included personal data, professional category, location of employment, and serology. The overall prevalence of antibodies to HAV was 52.7%. The prevalence significantly increased with greater age. The mean age of seropositive workers was 41.5 years compared with 34.3 in workers with negative serology. The highest prevalence of antibodies was found in cleaning employees (74.2%) and catering staff (75.3%). Given the high prevalence of seronegative adults susceptible to infection and the characteristics of their professional activities, vaccination of all staff working in health institutions should be considered. Copyright © 2012 SESPAS. Published by Elsevier Espana. All rights reserved.

Antibody response to routine measles vaccination among a ...

African Journals Online (AJOL)

owner

2013-02-08

Feb 8, 2013 ... Abstract Background: Despite a global decline in mortality and morbidity from measles in the last decade, outbreaks continue to occur in some parts of the world including Nigeria. Objective: To determine antibody response to routine measles vacci- nation in Nigerian children and evaluate vaccine potency.

Duration of antibody response following vaccination against feline immunodeficiency virus.

Science.gov (United States)

Westman, Mark E; Malik, Richard; Hall, Evelyn; Harris, Matthew; Hosie, Margaret J; Norris, Jacqueline M

2017-10-01

Objectives Recently, two point-of-care (PoC) feline immunodeficiency virus (FIV) antibody test kits (Witness and Anigen Rapid) were reported as being able to differentiate FIV-vaccinated from FIV-infected cats at a single time point, irrespective of the gap between testing and last vaccination (0-7 years). The aim of the current study was to investigate systematically anti-FIV antibody production over time in response to the recommended primary FIV vaccination series. Methods First, residual plasma from the original study was tested using a laboratory-based ELISA to determine whether negative results with PoC testing were due to reduced as opposed to absent antibodies to gp40. Second, a prospective study was performed using immunologically naive client-owned kittens and cats given a primary FIV vaccination series using a commercially available inactivated whole cell/inactivated whole virus vaccine (Fel-O-Vax FIV, three subcutaneous injections at 4 week intervals) and tested systematically (up to 11 times) over 6 months, using four commercially available PoC FIV antibody kits (SNAP FIV/FeLV Combo [detects antibodies to p15/p24], Witness FeLV/FIV [gp40], Anigen Rapid FIV/FeLV [p24/gp40] and VetScan FeLV/FIV Rapid [p24]). Results The laboratory-based ELISA showed cats from the original study vaccinated within the previous 0-15 months had detectable levels of antibodies to gp40, despite testing negative with two kits that use gp40 as a capture antigen (Witness and Anigen Rapid kits). The prospective study showed that antibody testing with SNAP Combo and VetScan Rapid was positive in all cats 2 weeks after the second primary FIV vaccination, and remained positive for the duration of the study (12/12 and 10/12 cats positive, respectively). Antibody testing with Witness and Anigen Rapid was also positive in a high proportion of cats 2 weeks after the second primary FIV vaccination (8/12 and 7/12, respectively), but antibody levels declined below the level of detection in

Epstein-Barr virus but not cytomegalovirus is associated with reduced vaccine antibody responses in Gambian infants.

Directory of Open Access Journals (Sweden)

Beth Holder

2010-11-01

Full Text Available Epstein-Barr virus (EBV and cytomegalovirus (CMV are persistent herpesviruses that have various immunomodulatory effects on their hosts. Both viruses are usually acquired in infancy in Sub-Saharan Africa, a region where childhood vaccines are less effective than in high income settings. To establish whether there is an association between these two observations, we tested the hypothesis that infection with one or both viruses modulate antibody responses to the T-cell independent meningococcal polysaccharide vaccine and the T-cell dependent measles vaccines.Infection with EBV and CMV was diagnosed by the presence of virus-specific IgM in the peripheral blood or by the presence of IgG at higher levels than that found in umbilical cord blood. Anti-meningococcus IgG and IgM were quantified by ELISA. Anti-measles antibody responses were quantified by haemagglutinin antibody inhibition assay. Infants infected with EBV had reduced IgG and IgM antibody responses to meningococcal polysaccharides and to measles vaccine. Infection with CMV alone predicted no changes in the response to meningococcal polysaccharide. While CMV alone had no discernable effect on the antibody response to measles, the response of infants infected with both CMV and EBV was similar to that of infants infected with neither, suggesting that the effects of CMV infection countered the effects of EBV on measles antibody responses.The results of this exploratory study indicate that infection with EBV is associated with reduced antibody responses to polysaccharides and to measles vaccine, but suggest that the response to T-cell dependent antigens such as measles haemagglutinin may be restored by infection with CMV.

Characterization of antibody response in neuroinvasive infection caused by Toscana virus.

Science.gov (United States)

Pierro, A; Ficarelli, S; Ayhan, N; Morini, S; Raumer, L; Bartoletti, M; Mastroianni, A; Prati, F; Schivazappa, S; Cenni, P; Vocale, C; Rossini, G; Gaibani, P; Sambri, V; Landini, M P; Lewis, R E; Charrel, R N; Varani, S

2017-11-01

Among sandfly-borne pathogens, Toscana virus (TOSV) is a prominent cause of summer meningitis in Mediterranean Europe. Here, we assessed the kinetics of anti-TOSV antibodies over time in 41 patients diagnosed with TOSV meningitis or meningoencephalitis in northeastern Italy. Acute and follow-up serum samples were collected up to 20 months after diagnosis of TOSV infection and tested for the presence of specific antibody using immunoenzymatic and indirect immunofluorescence assays. In addition, maturation of anti-TOSV IgG over time was evaluated as well as production of neutralizing antibodies. Specific IgM and IgG response was present at diagnosis in 100% of patients; TOSV-specific IgM and IgG were detected in patients' sera up to 6 and 20 months after diagnosis, respectively. The avidity index (AI) increased over the first month after infection in 100% of patients and most cases exceeded 60% by Day 30 post infection. The AI subsequently plateaued then declined at 20 months after diagnosis. Finally, neutralization assay to TOSV was performed in 217 sera collected from 41 patients; 69.6% of tested samples resulted in reactive and moderate levels of neutralizing antibodies observed during all phases of infection despite high titres of total anti-TOSV IgG. Specific antibody response develops rapidly and is long-lasting for neuroinvasive TOSV infection. Serodiagnosis of neuroinvasive TOSV requires simultaneous detection of specific IgM and IgG. Moderate levels of neutralizing antibodies were maintained over the study period, while the protective role of antibodies lacking neutralizing activity is unclear and requires further evaluation. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Screening for single-chain variable fragment antibodies against multiple Cry1 toxins from an immunized mouse phage display antibody library.

Science.gov (United States)

Dong, Sa; Bo, Zongyi; Zhang, Cunzheng; Feng, Jianguo; Liu, Xianjin

2018-04-01

Single-chain variable fragment (scFv) is a kind of antibody that possess only one chain of the complete antibody while maintaining the antigen-specific binding abilities and can be expressed in prokaryotic system. In this study, scFvs against Cry1 toxins were screened out from an immunized mouse phage displayed antibody library, which was successfully constructed with capacity of 6.25 × 10 7  CFU/mL. Using the mixed and alternative antigen coating strategy and after four rounds of affinity screening, seven positive phage-scFvs against Cry1 toxins were selected and characterized. Among them, clone scFv-3H9 (MG214869) showing relative stable and high binding abilities to six Cry1 toxins was selected for expression and purification. SDS-PAGE indicated that the scFv-3H9 fragments approximately 27 kDa were successfully expressed in Escherichia coli HB2151 strain. The purified scFv-3H9 was used to establish the double antibody sandwich enzyme-linked immunosorbent assay method (DAS-ELISA) for detecting six Cry1 toxins, of which the lowest detectable limits (LOD) and the lowest quantitative limits (LOQ) were 3.14-11.07 and 8.22-39.44 ng mL -1 , respectively, with the correlation coefficient higher than 0.997. The average recoveries of Cry1 toxins from spiked rice leaf samples were ranged from 84 to 95%, with coefficient of variation (CV) less than 8.2%, showing good accuracy for the multi-residue determination of six Cry1 toxins in agricultural samples. This research suggested that the constructed phage display antibody library based on the animal which was immunized with the mixture of several antigens under the same category can be used for the quick and effective screening of generic antibodies.

Increased IgD milk antibody responses in a patient with Down's syndrome, pulmonary hemosiderosis and cor pulmonale.

Science.gov (United States)

Galant, S; Nussbaum, E; Wittner, R; DeWeck, A L; Heiner, D C

1983-10-01

IgD antibody responses to cow's milk were investigated in a two-year-old black boy with evidence of pulmonary hemosiderosis and pulmonary hypertension. Initially a broad spectrum of immunologic responses to cow's milk were observed including IgD, IgE, and precipitin antibodies. Specific IgD antibody responses to cow's milk could be modulated in terms of challenge or elimination and correlated with the clinical course. It is possible that IgD antibodies may be important in milk-related pulmonary hemosiderosis.

Role of the Antigen Capture Pathway in the Induction of a Neutralizing Antibody Response to Anthrax Protective Antigen

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Anita Verma

2018-02-01

Full Text Available Toxin neutralizing antibodies represent the major mode of protective immunity against a number of toxin-mediated bacterial diseases, including anthrax; however, the cellular mechanisms that lead to optimal neutralizing antibody responses remain ill defined. Here we show that the cellular binding pathway of anthrax protective antigen (PA, the binding component of anthrax toxin, determines the toxin neutralizing antibody response to this antigen. PA, which binds cellular receptors and efficiently enters antigen-presenting cells by receptor-mediated endocytosis, was found to elicit robust anti-PA IgG and toxin neutralizing antibody responses. In contrast, a receptor binding-deficient mutant of PA, which does not bind receptors and only inefficiently enters antigen-presenting cells by macropinocytosis, elicited very poor antibody responses. A chimeric protein consisting of the receptor binding-deficient PA mutant tethered to the binding subunit of cholera toxin, which efficiently enters cells using the cholera toxin receptor rather than the PA receptor, elicited an anti-PA IgG antibody response similar to that elicited by wild-type PA; however, the chimeric protein elicited a poor toxin neutralizing antibody response. Taken together, our results demonstrate that the antigen capture pathway can dictate the magnitudes of the total IgG and toxin neutralizing antibody responses to PA as well as the ratio of the two responses.

Idiotypes as immunogens: facing the challenge of inducing strong therapeutic immune responses against the variable region of immunoglobulins

International Nuclear Information System (INIS)

López-Requena, Alejandro; Burrone, Oscar R.; Cesco-Gaspere, Michela

2012-01-01

Idiotype (Id)-based immunotherapy has been exploited as cancer treatment option. Conceived as therapy for malignancies bearing idiotypic antigens, it has been also extended to solid tumors because of the capacity of anti-idiotypic antibodies to mimic Id-unrelated antigens. In both these two settings, efforts are being made to overcome the poor immune responsiveness often experienced when using self immunoglobulins as immunogens. Despite bearing a unique gene combination, and thus particular epitopes, it is normally difficult to stimulate the immune response against antibody variable regions. Different strategies are currently used to strengthen Id immunogenicity, such as concomitant use of immune-stimulating molecules, design of Id-containing immunogenic recombinant proteins, specific targeting of relevant immune cells, and genetic immunization. This review focuses on the role of anti-Id vaccination in cancer management and on the current developments used to foster anti-idiotypic B and T cell responses.

Idiotypes as immunogens: facing the challenge of inducing strong therapeutic immune responses against the variable region of immunoglobulins

Energy Technology Data Exchange (ETDEWEB)

López-Requena, Alejandro [Molecular Immunology Group, International Centre for Genetic Engineering and Biotechnology, Trieste (Italy); Immunobiology Division, Center of Molecular Immunology, Havana (Cuba); Bioengineering Research Institute, Biotech Pharmaceutical Co., Ltd, Beijing (China); Burrone, Oscar R.; Cesco-Gaspere, Michela, E-mail: cescogaspere@gmail.com [Molecular Immunology Group, International Centre for Genetic Engineering and Biotechnology, Trieste (Italy)

2012-11-09

Idiotype (Id)-based immunotherapy has been exploited as cancer treatment option. Conceived as therapy for malignancies bearing idiotypic antigens, it has been also extended to solid tumors because of the capacity of anti-idiotypic antibodies to mimic Id-unrelated antigens. In both these two settings, efforts are being made to overcome the poor immune responsiveness often experienced when using self immunoglobulins as immunogens. Despite bearing a unique gene combination, and thus particular epitopes, it is normally difficult to stimulate the immune response against antibody variable regions. Different strategies are currently used to strengthen Id immunogenicity, such as concomitant use of immune-stimulating molecules, design of Id-containing immunogenic recombinant proteins, specific targeting of relevant immune cells, and genetic immunization. This review focuses on the role of anti-Id vaccination in cancer management and on the current developments used to foster anti-idiotypic B and T cell responses.

Sequence variability is correlated with weak immunogenicity in Streptococcus pyogenes M protein

Science.gov (United States)

Lannergård, Jonas; Kristensen, Bodil M; Gustafsson, Mattias C U; Persson, Jenny J; Norrby-Teglund, Anna; Stålhammar-Carlemalm, Margaretha; Lindahl, Gunnar

2015-01-01

The M protein of Streptococcus pyogenes, a major bacterial virulence factor, has an amino-terminal hypervariable region (HVR) that is a target for type-specific protective antibodies. Intriguingly, the HVR elicits a weak antibody response, indicating that it escapes host immunity by two mechanisms, sequence variability and weak immunogenicity. However, the properties influencing the immunogenicity of regions in an M protein remain poorly understood. Here, we studied the antibody response to different regions of the classical M1 and M5 proteins, in which not only the HVR but also the adjacent fibrinogen-binding B repeat region exhibits extensive sequence divergence. Analysis of antisera from S. pyogenes-infected patients, infected mice, and immunized mice showed that both the HVR and the B repeat region elicited weak antibody responses, while the conserved carboxy-terminal part was immunodominant. Thus, we identified a correlation between sequence variability and weak immunogenicity for M protein regions. A potential explanation for the weak immunogenicity was provided by the demonstration that protease digestion selectively eliminated the HVR-B part from whole M protein-expressing bacteria. These data support a coherent model, in which the entire variable HVR-B part evades antibody attack, not only by sequence variability but also by weak immunogenicity resulting from protease attack. PMID:26175306

Antibody responses of ponies to initial and challenge infections of Strongylus vulgaris.

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Klei, T R; Chapman, M R; Torbert, B J; McClure, J R

1983-05-01

An indirect fluorescent antibody assay (IFA) was developed using Strongylus vulgaris third stage larvae (L3) as antigens. Observations using the IFA indicate that a species-specific antibody response to S. vulgaris L3 develops in S. vulgaris-infected ponies and that some surface L3 antigens are shared by adult worms. Sequential antibody levels against S. vulgaris were measured in strongyle-naive and in immune ponies following initial and challenge infections using the IFA and an indirect hemagglutination assay (IHA). Antibody levels measured by IFA increased faster following initial infections than did levels measured by IHA. Antibody levels appear to increase following challenge infections of immune ponies when measured with the IFA, but not with the IHA. Significant differences in antibody titers were not seen between ponies which developed colic following challenge infections and those that did not develop colic. Antibodies were not detectable in ponies unexposed to larval migrations, but which received surgical implantation of S. vulgaris adults into the cecum.

Soluble HIV-1 envelope immunogens derived from an elite neutralizer elicit cross-reactive V1V2 antibodies and low potency neutralizing antibodies.

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Sara Carbonetti

Full Text Available We evaluated four gp140 Envelope protein vaccine immunogens that were derived from an elite neutralizer, subject VC10042, whose plasma was able to potently neutralize a wide array of genetically distinct HIV-1 isolates. We sought to determine whether soluble Envelope proteins derived from the viruses circulating in VC10042 could be used as immunogens to elicit similar neutralizing antibody responses by vaccination. Each gp140 was tested in its trimeric and monomeric forms, and we evaluated two gp140 trimer vaccine regimens in which adjuvant was supplied at all four immunizations or at only the first two immunizations. Interestingly, all four Envelope immunogens elicited high titers of cross-reactive antibodies that recognize the variable regions V1V2 and are potentially similar to antibodies linked with a reduced risk of HIV-1 acquisition in the RV144 vaccine trial. Two of the four immunogens elicited neutralizing antibody responses that neutralized a wide array of HIV-1 isolates from across genetic clades, but those responses were of very low potency. There were no significant differences in the responses elicited by trimers or monomers, nor was there a significant difference between the two adjuvant regimens. Our study identified two promising Envelope immunogens that elicited anti-V1V2 antibodies and broad, but low potency, neutralizing antibody responses.

Enhanced sensitivity in detection of antiviral antibody responses using biotinylation of foot-and-mouth disease virus (FMDV) capsids

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Analysis of the immune response to infection of livestock by foot-and-mouth disease virus (FMDV) is most often reported as the serum antibody response to the virus. While measurement of neutralizing antibody has been sensitive and specific, measurements of the quality of the antibody response are le...

Enhanced sensitivity in detection of antiviral antibody responses using biotinylation of foot-and-mouth disease virus (FMDV) capsids.

Science.gov (United States)

Kenney, Mary; Waters, Ryan A; Rieder, Elizabeth; Pega, Juan; Perez-Filguera, Mariano; Golde, William T

2017-11-01

Analysis of the immune response to infection of livestock by foot-and-mouth disease virus (FMDV) is most often reported as the serum antibody response to the virus. While measurement of neutralizing antibody has been sensitive and specific, measurements of the quality of the antibody response are less robust. Determining the immunoglobulin (Ig) isotype of the serum antibody response provides a deeper understanding of the biology of the response and more sensitive methods for these assays will facilitate analyses of B cell mediated immunity. We tested the hypothesis that using the virus as the molecular probe could be achieved by adding tags to the surface of the FMDV capsid, and that would enhance sensitivity in assays for anti-FMDV antibody responses. The use of a FLAG-tagged virus in these assays failed to yield improvement whereas chemically biotinylating the virus capsid resulted in significant enhancement of the signal. Here we describe methods using biotinylated virus for measuring anti-viral antibody in serum and antibody secreting cells (ASCs) in blood that are sensitive and specific. Finally, we describe using the biotinylated virus in flow cytometry where such assays should greatly enhance the analysis of anti-virus antibody producing B cells, allowing the investigator to focus on only the FMDV specific B cells when analyzing the development of the B cell response to either infection or vaccination. Published by Elsevier B.V.

Antibody response to pneumococcal vaccine in patients with early stage Hodgkin's disease

DEFF Research Database (Denmark)

Frederiksen, B.; Specht, L.; Henrichsen, J.

1989-01-01

Antibody response to pneumococcal vaccination was studied in 76 patients with Hodgkin's disease (HD) before, during and at different time intervals after cessation of therapy. All patients were in pathological stage I and II following explorative laparatomy with splenectomy. The increase in antib......Antibody response to pneumococcal vaccination was studied in 76 patients with Hodgkin's disease (HD) before, during and at different time intervals after cessation of therapy. All patients were in pathological stage I and II following explorative laparatomy with splenectomy. The increase...

Activated human nasal epithelial cells modulate specific antibody response against bacterial or viral antigens.

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Chiou-Yueh Yeh

Full Text Available Nasal mucosa is an immune responsive organ evidenced by eliciting both specific local secretory IgA and systemic IgG antibody responses with intra-nasal administration of antigens. Nevertheless, the role of nasal epithelial cells in modulating such responses is unclear. Human nasal epithelial cells (hNECs obtained from sinus mucosa of patients with chronic rhinosinusitis were cultured in vitro and firstly were stimulated by Lactococcus lactis bacterium-like particles (BLPs in order to examine their role on antibody production. Secondly, both antigens of immunodominant protein IDG60 from oral Streptococcus mutans and hemagglutinin (HA from influenza virus were tested to evaluate the specific antibody response. Stimulated hNECs by BLPs exhibited a significant increase in the production of interleukin-6 (IL-6, and thymic stromal lymphopoietin (TSLP. Conditioned medium of stimulated hNECs has effects on enhancing the proliferation of CD4+ T cells together with interferon-γ and IL-5 production, increasing the costimulatory molecules on dendritic cells and augmenting the production of IDG60 specific IgA, HA specific IgG, IgA by human peripheral blood lymphocytes. Such production of antigen specific IgG and IgA is significantly counteracted in the presence of IL-6 and TSLP neutralizing antibodies. In conclusion, properly stimulated hNECs may impart immuno-modulatory effects on the antigen-specific antibody response at least through the production of IL-6 and TSLP.

Suppression of the immune response to ovalbumin in vivo by anti-idiotypic antibodies

International Nuclear Information System (INIS)

Grinevich, A.S.; Pinegin, B.V.

1986-01-01

Conditions of suppression of the immune response to a food allergin (ovalbumin) were studied with the aid of anti-idiotypic (AID) antibodies. Hen ovalbumin was used and the experiments were performed on mice. Antibodies were isolated from the resulting protein fractions and tested for inhibitor activity by the method of direct radioimmunologic analysis. The test system consisted of the reaction of binding the globulin fraction to the total preparation of antibodies to ovalbumin from mice and a 125 I-labeled total preparation of antibodies to ovalbumin of the same animals

Seasonal influenza vaccination is the strongest correlate of cross-reactive antibody responses in migratory bird handlers.

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Oshansky, Christine M; Wong, Sook-San; Jeevan, Trushar; Smallwood, Heather S; Webby, Richard J; Shafir, Shira C; Thomas, Paul G

2014-12-09

Avian species are reservoirs of influenza A viruses and could harbor viruses with significant pandemic potential. We examined the antibody and cellular immune responses to influenza A viruses in field or laboratory workers with a spectrum of occupational exposure to avian species for evidence of zoonotic infections. We measured the seroprevalence and T cell responses among 95 individuals with various types and degrees of prior field or laboratory occupational exposure to wild North American avian species using whole blood samples collected in 2010. Plasma samples were tested using endpoint enzyme-linked immunosorbent assay (ELISA) and hemagglutination (HA) inhibition (HAI) assays to subtypes H3, H4, H5, H6, H7, H8, and H12 proteins. Detectable antibodies were found against influenza HA antigens in 77% of individuals, while 65% of individuals tested had measurable T cell responses (gamma interferon [IFN-γ] enzyme-linked immunosorbent spot assay [ELISPOT]) to multiple HA antigens of avian origin. To begin defining the observed antibody specificities, Spearman rank correlation analysis showed that ELISA responses, which measure both head- and stalk-binding antibodies, do not predict HAI reactivities, which measure primarily head-binding antibodies. This result suggests that ELISA titers can report cross-reactivity based on the levels of non-head-binding responses. However, the strongest positive correlate of HA-specific ELISA antibody titers was receipt of seasonal influenza virus vaccination. Occupational exposure was largely uncorrelated with serological measures, with the exception of individuals exposed to poultry, who had higher levels of H7-specific antibodies than non-poultry-exposed individuals. While the cohort had antibody and T cell reactivity to a broad range of influenza viruses, only occupational exposure to poultry was associated with a significant difference in antibody levels to a specific subtype (H7). There was no evidence that T cell assays

Pre-existing neutralizing antibody mitigates B cell dysregulation and enhances the Env-specific antibody response in SHIV-infected rhesus macaques.

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Juan Pablo Jaworski

Full Text Available Our central hypothesis is that protection against HIV infection will be powerfully influenced by the magnitude and quality of the B cell response. Although sterilizing immunity, mediated by pre-formed abundant and potent antibodies is the ultimate goal for B cell-targeted HIV vaccine strategies, scenarios that fall short of this may still confer beneficial defenses against viremia and disease progression. We evaluated the impact of sub-sterilizing pre-existing neutralizing antibody on the B cell response to SHIV infection. Adult male rhesus macaques received passive transfer of a sub-sterilizing amount of polyclonal neutralizing immunoglobulin (Ig purified from previously infected animals (SHIVIG or control Ig prior to intra-rectal challenge with SHIVSF162P4 and extensive longitudinal sampling was performed. SHIVIG treated animals exhibited significantly reduced viral load and increased de novo Env-specific plasma antibody. Dysregulation of the B cell profile was grossly apparent soon after infection in untreated animals; exemplified by a ≈50% decrease in total B cells in the blood evident 2-3 weeks post-infection which was not apparent in SHIVIG treated animals. IgD+CD5+CD21+ B cells phenotypically similar to marginal zone-like B cells were highly sensitive to SHIV infection, becoming significantly decreased as early as 3 days post-infection in control animals, while being maintained in SHIVIG treated animals, and were highly correlated with the induction of Env-specific plasma antibody. These results suggest that B cell dysregulation during the early stages of infection likely contributes to suboptimal Env-specific B cell and antibody responses, and strategies that limit this dysregulation may enhance the host's ability to eliminate HIV.

Epigenetics of peripheral B cell differentiation and the antibody response

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Hong eZan

2015-12-01

Full Text Available Epigenetic modifications, such as histone post-translational modifications, DNA methylation, and alteration of gene expression by non-coding RNAs, including microRNAs (miRNAs and long non-coding RNAs (lncRNAs, are heritable changes that are independent from the genomic DNA sequence. These regulate gene activities and, therefore, cellular functions. Epigenetic modifications act in concert with transcription factors and play critical roles in B cell development and differentiation, thereby modulating antibody responses to foreign- and self-antigens. Upon antigen encounter by mature B cells in the periphery, alterations of these lymphocytes epigenetic landscape are induced by the same stimuli that drive the antibody response. Such alterations instruct B cells to undergo immunoglobulin class switch DNA recombination (CSR and somatic hypermutation (SHM, as well as differentiation to memory B cells or long-lived plasma cells for the immune memory. Inducible histone modifications, together with DNA methylation and miRNAs modulate the transcriptome, particularly the expression of activation-induced cytidine deaminase (AID, which is essential for CSR and SHM, and factors central to plasma cell differentiation, such as B lymphocyte-induced maturation protein-1 (Blimp-1. These inducible B cell-intrinsic epigenetic marks guide the maturation of antibody responses. Combinatorial histone modifications also function as histone codes to target CSR and, possibly, SHM machinery to the Ig loci by recruiting specific adaptors that can stabilize CSR/SHM factors. In addition, lncRNAs, such as recently reported lncRNA-CSR and an lncRNA generated through transcription of the S region that form G-quadruplex structures, are also important for CSR targeting. Epigenetic dysregulation in B cells, including the aberrant expression of non-coding RNAs and alterations of histone modifications and DNA methylation, can result in aberrant antibody responses to foreign antigens

Impact of a Plasmodium falciparum AMA1 vaccine on antibody responses in adult Malians.

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Alassane Dicko

2007-10-01

Full Text Available Apical Membrane Antigen 1 (AMA1 of Plasmodium falciparum merozoites is a leading blood-stage malaria vaccine candidate. Protection of Aotus monkeys after vaccination with AMA1 correlates with antibody responses.A randomized, controlled, double-blind phase 1 clinical trial was conducted in 54 healthy Malian adults living in an area of intense seasonal malaria transmission to assess the safety and immunogenicity of the AMA1-C1 malaria vaccine. AMA1-C1 contains an equal mixture of yeast-expressed recombinant proteins based on sequences from the FVO and 3D7 clones of P. falciparum, adsorbed on Alhydrogel. The control vaccine was the hepatitis B vaccine (Recombivax. Participants were enrolled into 1 of 3 dose cohorts (n = 18 per cohort and randomized 2:1 to receive either AMA1-C1 or Recombivax. Participants in the first, second, and third cohorts randomized to receive AMA1-C1 were vaccinated with 5, 20 and 80 microg of AMA1-C1, respectively. Vaccinations were administered on days 0, 28, and 360, and participants were followed until 6 months after the final vaccination. AMA1-C1 was well tolerated; no vaccine-related severe or serious adverse events were observed. AMA1 antibody responses to the 80 microg dose increased rapidly from baseline levels by days 14 and 28 after the first vaccination and continued to increase after the second vaccination. After a peak 14 days following the second vaccination, antibody levels decreased to baseline levels one year later at the time of the third vaccination that induced little or no increase in antibody levels.Although the AMA1-C1 vaccine candidate was well-tolerated and induced antibody responses to both vaccine and non-vaccine alleles, the antibody response after a third dose given at one year was lower than the response to the initial vaccinations. Additionally, post-vaccination increases in anti-AMA1 antibody levels were not associated with significant changes in in vitro growth inhibition of P. falciparum

Antibody response to equine coronavirus in horses inoculated with a bovine coronavirus vaccine.

Science.gov (United States)

Nemoto, Manabu; Kanno, Toru; Bannai, Hiroshi; Tsujimura, Koji; Yamanaka, Takashi; Kokado, Hiroshi

2017-11-17

A vaccine for equine coronavirus (ECoV) is so far unavailable. Bovine coronavirus (BCoV) is antigenically related to ECoV; it is therefore possible that BCoV vaccine will induce antibodies against ECoV in horses. This study investigated antibody response to ECoV in horses inoculated with BCoV vaccine. Virus neutralization tests showed that antibody titers against ECoV increased in all six horses tested at 14 days post inoculation, although the antibody titers were lower against ECoV than against BCoV. This study showed that BCoV vaccine provides horses with antibodies against ECoV to some extent. It is unclear whether antibodies provided by BCoV vaccine are effective against ECoV, and therefore ECoV challenge studies are needed to evaluate efficacy of the vaccine in the future.

Observed Parent-Child Relationship Quality Predicts Antibody Response to Vaccination in Children

Science.gov (United States)

O'Connor, Thomas G; Wang, Hongyue; Moynihan, Jan A; Wyman, Peter A.; Carnahan, Jennifer; Lofthus, Gerry; Quataert, Sally A.; Bowman, Melissa; Burke, Anne S.; Caserta, Mary T

2015-01-01

Background Quality of the parent-child relationship is a robust predictor of behavioral and emotional health for children and adolescents; the application to physical health is less clear. Methods We investigated the links between observed parent-child relationship quality in an interaction task and antibody response to meningococcal conjugate vaccine in a longitudinal study of 164 ambulatory 10-11 year-old children; additional analyses examine associations with cortisol reactivity, BMI, and somatic illness. Results Observed negative/conflict behavior in the interaction task predicted a less robust antibody response to meningococcal serotype C vaccine in the child over a 6 month-period, after controlling for socio-economic and other covariates. Observer rated interaction conflict also predicted increased cortisol reactivity following the interaction task and higher BMI, but these factors did not account for the link between relationship quality and antibody response. Conclusions The results begin to document the degree to which a major source of child stress exposure, parent-child relationship conflict, is associated with altered immune system development in children, and may constitute an important public health consideration. PMID:25862953

Sequence variability is correlated with weak immunogenicity in Streptococcus pyogenes M protein.

Science.gov (United States)

Lannergård, Jonas; Kristensen, Bodil M; Gustafsson, Mattias C U; Persson, Jenny J; Norrby-Teglund, Anna; Stålhammar-Carlemalm, Margaretha; Lindahl, Gunnar

2015-10-01

The M protein of Streptococcus pyogenes, a major bacterial virulence factor, has an amino-terminal hypervariable region (HVR) that is a target for type-specific protective antibodies. Intriguingly, the HVR elicits a weak antibody response, indicating that it escapes host immunity by two mechanisms, sequence variability and weak immunogenicity. However, the properties influencing the immunogenicity of regions in an M protein remain poorly understood. Here, we studied the antibody response to different regions of the classical M1 and M5 proteins, in which not only the HVR but also the adjacent fibrinogen-binding B repeat region exhibits extensive sequence divergence. Analysis of antisera from S. pyogenes-infected patients, infected mice, and immunized mice showed that both the HVR and the B repeat region elicited weak antibody responses, while the conserved carboxy-terminal part was immunodominant. Thus, we identified a correlation between sequence variability and weak immunogenicity for M protein regions. A potential explanation for the weak immunogenicity was provided by the demonstration that protease digestion selectively eliminated the HVR-B part from whole M protein-expressing bacteria. These data support a coherent model, in which the entire variable HVR-B part evades antibody attack, not only by sequence variability but also by weak immunogenicity resulting from protease attack. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Variability in response to albuminuria-lowering drugs

DEFF Research Database (Denmark)

Petrykiv, Sergei I; de Zeeuw, Dick; Persson, Frederik

2017-01-01

AIMS: Albuminuria-lowering drugs have shown different effect size in different individuals. Since urine albumin levels are known to vary considerably from day-to-day, we questioned whether the between-individual variability in albuminuria response after therapy initiation reflects a random...... variability or a true response variation to treatment. In addition, we questioned whether the response variability is drug dependent. METHODS: To determine whether the response to treatment is random or a true drug response, we correlated in six clinical trials the change in albuminuria during placebo...... or active treatment (on-treatment) with the change in albuminuria during wash-out (off-treatment). If these responses correlate during active treatment, it suggests that at least part of the response variability can be attributed to drug response variability. We tested this for enalapril, losartan...

Clinical response to adalimumab: relationship to anti-adalimumab antibodies and serum adalimumab concentrations in rheumatoid arthritis

NARCIS (Netherlands)

Bartelds, Geertje M.; Wijbrandts, Carla A.; Nurmohamed, Michael T.; Stapel, Steven; Lems, Willem F.; Aarden, Lucien; Dijkmans, Ben A. C.; Tak, Paul Peter; Wolbink, Gerrit Jan

2007-01-01

BACKGROUND: A substantial proportion of patients with rheumatoid arthritis (RA) do not respond, or lose initial response, to adalimumab treatment. One explanation for non-response is that patients develop anti-adalimumab antibodies. OBJECTIVES: To evaluate the incidence of formation of antibody

Dissection of antibody specificities induced by yellow fever vaccination.

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Oksana Vratskikh

Full Text Available The live attenuated yellow fever (YF vaccine has an excellent record of efficacy and one dose provides long-lasting immunity, which in many cases may last a lifetime. Vaccination stimulates strong innate and adaptive immune responses, and neutralizing antibodies are considered to be the major effectors that correlate with protection from disease. Similar to other flaviviruses, such antibodies are primarily induced by the viral envelope protein E, which consists of three distinct domains (DI, II, and III and is presented at the surface of mature flavivirions in an icosahedral arrangement. In general, the dominance and individual variation of antibodies to different domains of viral surface proteins and their impact on neutralizing activity are aspects of humoral immunity that are not well understood. To gain insight into these phenomena, we established a platform of immunoassays using recombinant proteins and protein domains that allowed us to dissect and quantify fine specificities of the polyclonal antibody response after YF vaccination in a panel of 51 vaccinees as well as determine their contribution to virus neutralization by serum depletion analyses. Our data revealed a high degree of individual variation in antibody specificities present in post-vaccination sera and differences in the contribution of different antibody subsets to virus neutralization. Irrespective of individual variation, a substantial proportion of neutralizing activity appeared to be due to antibodies directed to complex quaternary epitopes displayed on the virion surface only but not on monomeric E. On the other hand, DIII-specific antibodies (presumed to have the highest neutralizing activity as well as broadly flavivirus cross-reactive antibodies were absent or present at very low titers. These data provide new information on the fine specificity as well as variability of antibody responses after YF vaccination that are consistent with a strong influence of individual

Effect of partial and complete variable loop deletions of the human immunodeficiency virus type 1 envelope glycoprotein on the breadth of gp160-specific immune responses

International Nuclear Information System (INIS)

Gzyl, Jaroslaw; Bolesta, Elizabeth; Wierzbicki, Andrew; Kmieciak, Dariusz; Naito, Toshio; Honda, Mitsuo; Komuro, Katsutoshi; Kaneko, Yutaro; Kozbor, Danuta

2004-01-01

Induction of cross-reactive cellular and humoral responses to the HIV-1 envelope (env) glycoprotein was examined after DNA immunization of BALB/c mice with gp140 89.6 -derived constructs exhibiting partial or complete deletions of the V1, V2, and V3 domains. It was demonstrated that specific modification of the V3 loop (mV3) in combination with the V2-modified (mV2) or V1/V2-deleted (ΔV1/V2) region elicited increased levels of cross-reactive CD8 + T cell responses. Mice immunized with the mV2/mV3 or ΔV1/V2/mV3 gp140 89.6 plasmid DNA were greater than 50-fold more resistant to challenge with recombinant vaccinia virus (rVV) expressing heterologous env gene products than animals immunized with the wild-type (WT) counterpart. Sera from mV2/mV3- and ΔV1/V2/mV3-immunized mice exhibited the highest cross-neutralizing activity and displayed intermediate antibody avidity values which were further enhanced by challenge with rVV expressing the homologous gp160 glycoprotein. In contrast, complete deletion of the variable regions had little or no effect on the cross-reactive antibody responses. The results of these experiments indicate that the breadth of antibody responses to the HIV-1 env glycoprotein may not be increased by removal of the variable domains. Instead, partial deletions within these regions may redirect specific responses toward conserved epitopes and facilitate approaches for boosting cross-reactive cellular and antibody responses to the env glycoprotein

Immunoglobulin variable region sequences of two human monoclonal antibodies directed to an onco-developmental carbohydrate antigen, lactotetraosylceramide (LcOse4Cer).

Science.gov (United States)

Yago, K; Zenita, K; Ohwaki, I; Harada, R; Nozawa, S; Tsukazaki, K; Iwamori, M; Endo, N; Yasuda, N; Okuma, M

1993-11-01

A human monoclonal antibody, 11-50, was generated and was shown to recognize an onco-developmental carbohydrate antigen, LcOse4Cer. The isotype of this antibody was IgM, lambda, similar to the previously known human anti-LcOse4 antibodies, such as IgMWOO and HMST-1. We raised a murine anti-idiotypic antibody G3 (IgG1, kappa) against 11-50, and tested its reactivity towards the affinity purified human polyclonal anti-LcOse4 antibodies prepared from pooled human sera using a Gal beta 1-->3GlcNAc beta-immobilized column. The results indicated that at least a part of the human polyclonal anti-LcOse4 antibodies shared the G3 idiotype with 11-50. We further analyzed the sequence of variable regions of the two anti-LcOse4 antibodies, 11-50 and HMST-1. Sequence analysis of the heavy chain variable regions indicated that the VH regions of these two antibodies were highly homologous to each other (93.5% at the nucleic acid level), and these antibodies utilized the germline genes VH1.9III and hv3005f3 as the VH segments, which are closely related germline genes of the VHIII family. It was noted that these germline VH genes are frequently utilized in fetal B cells. The JH region of both antibodies was encoded by the JH4 gene. For the light chain, the V lambda segments of the two antibodies were 96.3% homologous to each other at the nucleic acid level. The V lambda segments of both antibodies showed the highest homology to the rearranged V lambda gene called V lambda II.DS among reported V lambda genes, while the exact germline V lambda genes encoding the two antibodies were not yet registered in available sequence databanks. The amino acid sequences of the J lambda segments of both antibodies were identical. These results indicate that the two human antibodies recognizing the onco-developmental carbohydrate antigen Lc4 are encoded by the same or very homologous germline genes.

Serum antibody responses in pigs trickle-infected with Ascaris and Trichuris

DEFF Research Database (Denmark)

Kringel, Helene; Thamsborg, Stig Milan; Petersen, Heidi Huus

2015-01-01

A humoral immune response following helminth infection in pigs is well documented. However, it has been difficult to confirm the existence of antibody mediated resistance against the large roundworm, Ascaris suum, and whipworm, Trichuris suis, in experimental settings by correlating worm burdens...... or egg excretion with specific antibody levels. We set out to investigate the association between worm load and T. suis and A. suum specific serum antibody levels (IgG1, IgG2 and IgA) against excretory-secretory products of adults and third stage larvae, respectively, measured at 0, 7 and 14 weeks p.......i. in a trickle-infected F1-resource-population of crossbred pigs (n=195). Furthermore, we wanted to determine the heritability of these antibody isotypes during the course of infection. Most pigs remained infected with A. suum throughout the experiment while they expelled T. suis between 7 and 14 weeks post...

Comparisons of the effect of naturally acquired maternal pertussis antibodies and antenatal vaccination induced maternal tetanus antibodies on infant's antibody secreting lymphocyte responses and circulating plasma antibody

Science.gov (United States)

The goal of this study was to explore the effects of trans-placental tetanus toxoid (TT) and pertussis (PT) antibodies on an infant's response to vaccination in the context of antenatal immunization with tetanus but not with pertussis. 38 mothers received a single dose of TT vaccine during pregnancy...

T cell regulation of the thymus-independent antibody response to trinitrophenylated-Brucella abortus (TNP-BA)

Energy Technology Data Exchange (ETDEWEB)

Tanay, A.; Strober, S.

1985-06-01

The authors have previously observed a reduction of the T cell-dependent primary antibody response to dinitrophenylated keyhole limpet hemocyanin, and an enhancement of the T cell-independent response to trinitrophenylated Brucella abortus (TNP-BA) in BALB/c mice after treatment with total lymphoid irradiation (TLI). To elucidate the relative contribution of T and B cells to the enhanced T cell-independent antibody responses after TLI, a syngeneic primary adoptive transfer system was utilized whereby irradiated hosts were reconstituted with unfractionated spleen cells or a combination of purified T and B cells from TLI-treated and untreated control mice. Antibody responses of purified splenic B cells from TLI-treated BALB/c mice (TLI/B) to TNP-BA were enhanced 10-fold as compared with those of unfractionated (UF) spleen cells or B cells from normal (NL) BALB/c mice (NL/UF and NL/B, respectively). Splenic T cells from normal animals (NL/T) suppressed the anti-TNP-BA response of TLI/B by more than 100-fold. NL/T neither suppressed nor enhanced the response of NL/B. On the other hand, T cells from TLI-treated mice (TLI/T) enhanced by 100-fold the anti-TNP-BA response of NL/B, but neither suppressed nor enhanced the response of TLI/B. Thus, T cells can regulate the T cell-independent antibody response to TNP-BA. However, experimental manipulation of the T and B cell populations is needed to demonstrate the regulatory functions.

T cell regulation of the thymus-independent antibody response to trinitrophenylated-Brucella abortus (TNP-BA)

International Nuclear Information System (INIS)

Tanay, A.; Strober, S.

1985-01-01

The authors have previously observed a reduction of the T cell-dependent primary antibody response to dinitrophenylated keyhole limpet hemocyanin, and an enhancement of the T cell-independent response to trinitrophenylated Brucella abortus (TNP-BA) in BALB/c mice after treatment with total lymphoid irradiation (TLI). To elucidate the relative contribution of T and B cells to the enhanced T cell-independent antibody responses after TLI, a syngeneic primary adoptive transfer system was utilized whereby irradiated hosts were reconstituted with unfractionated spleen cells or a combination of purified T and B cells from TLI-treated and untreated control mice. Antibody responses of purified splenic B cells from TLI-treated BALB/c mice (TLI/B) to TNP-BA were enhanced 10-fold as compared with those of unfractionated (UF) spleen cells or B cells from normal (NL) BALB/c mice (NL/UF and NL/B, respectively). Splenic T cells from normal animals (NL/T) suppressed the anti-TNP-BA response of TLI/B by more than 100-fold. NL/T neither suppressed nor enhanced the response of NL/B. On the other hand, T cells from TLI-treated mice (TLI/T) enhanced by 100-fold the anti-TNP-BA response of NL/B, but neither suppressed nor enhanced the response of TLI/B. Thus, T cells can regulate the T cell-independent antibody response to TNP-BA. However, experimental manipulation of the T and B cell populations is needed to demonstrate the regulatory functions

The impact of administration of conjugate vaccines containing cross reacting material on Haemophilus influenzae type b antibody responses in infants: A systematic review and meta-analysis of randomised controlled trials.

Science.gov (United States)

Voysey, Merryn; Sadarangani, Manish; Clutterbuck, Elizabeth; Bolgiano, Barbara; Pollard, Andrew J

2016-07-25

Protein-polysaccharide conjugate vaccines such as Haemophilus influenzae type b (Hib), meningococcal, and pneumococcal vaccine, induce immunological memory and longer lasting protection than plain polysaccharide vaccines. The most common proteins used as carriers are tetanus toxoid (TT) and cross reacting material-197 (CRM), a mutant form of diphtheria toxoid. CRM conjugate vaccines have been reported to suppress antibody responses to co-administered Hib-TT vaccine. We conducted a systematic review and meta-analysis of randomised controlled trials in which infants were randomised to receive meningococcal or pneumococcal conjugate vaccines along with Hib-TT. Trials of licensed vaccines with different carrier proteins were included for group C meningococcal (MenC), quadrivalent ACWY meningococcal (MenACWY), and pneumococcal vaccines. Twenty-three trials were included in the meta-analyses. Overall, administration of MenC-CRM in a 2 or 3 dose schedule resulted in a 45% reduction in Hib antibody concentrations (GMR 0.55, 95% CI 0.49-0.62). MenACWY-CRM boosted Hib antibody responses by 22% (GMR 1.22, 95% CI 1.06-1.41) whilst pneumococcal CRM conjugate vaccines had no impact on Hib antibody responses (GMR 0.91, 95% CI 0.68-1.22). The effect of CRM protein-polysaccharide conjugate vaccines on Hib antibody responses varies greatly between vaccines. Co-administration of a CRM conjugate vaccine can produce either positive or negative effects on Hib antibody responses. These inconsistencies suggest that CRM itself may not be the main driver of variability in Hib responses, and challenge current perspectives on this issue. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

is maintained at low densities. Here, we test the hypothesis that the presence or absence of antibodies against variant antigens on the surface of P. falciparum-infected erythrocytes protect individuals against some infectious challenges and render them susceptible to others. Plasma collected in Daraweesh...... 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...

Anti-carbamylated Protein Antibody Levels Correlate with Anti-Sa (Citrullinated Vimentin) Antibody Levels in Rheumatoid Arthritis.

Science.gov (United States)

Challener, Gregory J; Jones, Jonathan D; Pelzek, Adam J; Hamilton, B JoNell; Boire, Gilles; de Brum-Fernandes, Artur José; Masetto, Ariel; Carrier, Nathalie; Ménard, Henri A; Silverman, Gregg J; Rigby, William F C

2016-02-01

The presence of anticitrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) indicates a breach in immune tolerance. Recent studies indicate that this breach extends to homocitrullination of lysines with the formation of anti-carbamylated protein (anti-CarP) antibodies. We analyzed the clinical and serologic relationships of anti-CarP in 2 RA cohorts. Circulating levels of immunoglobulin G anti-CarP antibodies were determined by ELISA in established (Dartmouth-Hitchcock Medical Center) and early (Sherbrooke University Hospital Center) cohorts and evaluated for anticyclic citrullinated peptide antibodies (anti-CCP), specific ACPA, and rheumatoid factor (RF) levels using the Student t test and correlation analysis. We identified elevated anti-CarP antibodies titers in 47.0% of seropositive patients (Dartmouth, n = 164), with relationships to anti-CCP (p < 0.0001) and IgM-RF (p = 0.001). Similarly, 38.2% of seropositive patients from the Sherbrooke cohort (n = 171) had elevated anti-CarP antibodies; titers correlated to anti-CCP (p = 0.01) but not IgM-RF (p = 0.09). A strong correlation with anti-Sa was observed: 47.9% anti-Sa+ patients were anti-CarP antibodies+ versus only 25.4% anti-Sa- in the Sherbrooke cohort (p = 0.0002), and 62.6% anti-Sa+ patients versus 26.9% anti-Sa- were anti-CarP antibodies+ in Dartmouth (p < 0.0001). We found a more variable response for reactivity to citrullinated fibrinogen or to citrullinated peptides from fibrinogen and α enolase. In 2 North American RA cohorts, we observed a high prevalence of anti-CarP antibody positivity. We also describe a surprising and unexpected association of anti-CarP with anti-Sa antibodies that could not be explained by cross-reactivity. Further, considerable heterogeneity exists between anti-CarP reactivity and other citrullinated peptide reactivity, raising the question of how the pathogenesis of antibody responses for carbamylated proteins and citrullinated proteins may be linked in vivo.

Antibody responses in allogeneic radiation chimeras

International Nuclear Information System (INIS)

Coico, R.F.

1982-01-01

The construction of long-lived allogeneic radiation chimeras, free of graft-versus-host disease, has been achieved using serologic elimination of Thy 1 + cells from donor bone marrow. Humoral immune function was not restored in these animals as evidenced by lack of primary antibody responses to a T cell-dependent antigen, namely, sheep erythrocytes (SRBC) both in vivo and in vitro. No evidence for a suppressor cell-mediated mechanism was found. Using separated chimera spleen cell populations and specific helper cell soluble mediators, the functional capabilities of chimera B cells, T cells, and macrophages were assessed. These findings suggested that the failure of chimeras to produce antibody is not the result of impaired B cell, T cell, or macrophage function, but rather, that it is due to ineffective cellular interactions. Physiologic cellular interactions depend upon the sharing of major histocompatibility complex (MHC) determinants between interacting cells. However, the self-recognition repertoire of developing T cells may be influenced by the environment which these cells differentiate such that they learn to recognize host MHC determinants as self. These findings support the interpretation that the immunologic hyporeactivity of allogeneic bone marrow chimeras reflects the role of the host environment in restricting the interactive capabilities of donor-derived cells

A Potent Virus-Specific Antibody-Secreting Cell Response to Acute Enterovirus 71 Infection in Children.

Science.gov (United States)

Huang, Kuan-Ying Arthur; Lin, Jainn-Jim; Chiu, Cheng-Hsun; Yang, Shuan; Tsao, Kuo-Chien; Huang, Yhu-Chering; Lin, Tzou-Yien

2015-09-01

Enterovirus 71 (EV71) remains a leading pathogen for acute infectious diseases in children, especially in Asia. The cellular basis for establishing a virus-specific antibody response to acute EV71 infections is unclear in children. We studied the magnitude of virus-specific antibody-secreting B cells (ASCs) and its relationship with serological response, clinical parameters, and virological parameters among children with laboratory-confirmed EV71 infection. A potent EV71 genogroup B- and virus-specific ASC response was detected in the first week of illness among genotype B5 EV71-infected children. The cross-reactive EV71-specific ASC response to genogroup C viral antigens composed about 10% of the response. The EV71-specific ASC response in children aged ≥3 years produced immunoglobulin G predominantly, but immunoglobulin M was predominant in younger children. Proliferation marker was expressed by the majority of circulating ASCs in the acute phase of EV71 infection. Virus-specific ASC responses significantly correlated with throat viral load, fever duration, and serological genogroup-specific neutralization titer. The presence of a virus-specific ASC response serves an early cellular marker of an EV71-specific antibody response. Further detailed study of EV71-specific ASCs at the monoclonal level is crucial to delineate the specificity and function of antibody immunity in children. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Wildtype p53-specific Antibody and T-Cell Responses in Cancer Patients

DEFF Research Database (Denmark)

Pedersen, Anders Elm; Stryhn, Anette; Justesen, Sune

2011-01-01

patients. Detection of antibodies against wt p53 protein has been used as a diagnostic and prognostic marker and discovery of new T-cell epitopes has enabled design of cancer vaccination protocols with promising results. Here, we identified wt p53-specific antibodies in various cancer patients......(264-272) in breast cancer patients and against HLA-A*01:01 binding peptide wt p53(226-234) and HLA-B*07:02 binding peptide wt p53(74-82) in renal cell cancer and breast cancer patients, respectively. Finally, we analyzed antibody and T-cell responses against wt p53 15-mer peptides in patients with metastatic renal...

SINGLE DOMAIN ANTIBODIES AND BIOENGINEERING DRUGS ON THEIR BASIS: NEW OPPORTUNITIES FOR DIAGNOSTICS AND THERAPY

Directory of Open Access Journals (Sweden)

E. N. Gorshkova

2016-01-01

Full Text Available Almost 20 years ago, a unique class of antibodies devoid of L chains was discovered in Camelidae blood serum. Only one variable domain is responsible for antigen recognition in these unusual antibodies. A recombinant protein, which is analogue to such antigen-recognizing variable domain was called the single domain antibody (sdAb, “nanobody” or “nanoantibody”. The single-domain antibodies and their derivatives have been widely used in the field of biology, toxicology and medicine offering new opportunities for diagnosis and treatment of cancer, autoimmune diseases, infectious diseases, and for toxin neutralization. This review focuses on latest researches in the field and concerns some prospectives for creation of nanoantibody-based diagnostic and therapeutic drugs.

Targeting nanodisks via a single chain variable antibody - Apolipoprotein chimera

International Nuclear Information System (INIS)

Iovannisci, David M.; Beckstead, Jennifer A.; Ryan, Robert O.

2009-01-01

Nanodisks (ND) are nanometer scale complexes of phospholipid and apolipoprotein that have been shown to function as drug delivery vehicles. ND harboring significant quantities of the antifungal agent, amphotericin B, or the bioactive isoprenoid, all trans retinoic acid, have been generated and characterized. As currently formulated, ND possess limited targeting capability. In this study, we constructed a single chain variable antibody (scFv).apolipoprotein chimera and assessed the ability of this fusion protein to form ND and recognize the antigen to which the scFv is directed. Data obtained revealed that α-vimentin scFv.apolipoprotein A-I is functional in ND formation and antigen recognition, opening the door to the use of such chimeras in targeting drug-enriched ND to specific tissues.

Tofacitinib Suppresses Antibody Responses to Protein Therapeutics in Murine Hosts1

Science.gov (United States)

Onda, Masanori; Ghoreschi, Kamran; Steward-Tharp, Scott; Thomas, Craig; O’Shea, John J.; Pastan, Ira H.; FitzGerald, David J.

2014-01-01

Immunogenicity remains the ‘Achilles’ heel’ of protein-based therapeutics. Anti-drug antibodies produced in response to protein therapeutics can severely limit both the safety and efficacy of this expanding class of agent. Here we report that monotherapy of mice with tofacitinib (the Janus kinase inhibitor) quells antibody responses to an immunotoxin derived from the bacterial protein, Pseudomonas exotoxin A, as well as to the model antigen, keyhole limpet hemocyanin. Thousandfold reductions in IgG1 titers to both antigens were observed 21 days post-immunization. In fact, suppression was evident for all IgG isotypes and IgM. A reduction in IgG3 production was also noted with a thymus-independent type II antigen. Mechanistic investigations revealed that tofacitinib treatment led to reduced numbers of CD127+ pro-B cells. Furthermore, we observed fewer germinal center B cells and the impaired formation of germinal centers of mice treated with tofacitinib. Since normal immunoglobulin levels were still present during the tofacitinib treatment, this agent specifically reduced anti-drug antibodies, thus preserving the potential efficacy of biological therapeutics, including those that are used as cancer therapeutics. PMID:24890727

Antibody responses of swine following infection with Mycoplasma hyopneumoniae, M. hyorhinis, M. hyosynoviae and M. flocculare.

Science.gov (United States)

Gomes Neto, João Carlos; Strait, Erin L; Raymond, Matthew; Ramirez, Alejandro; Minion, F Chris

2014-11-07

Several mycoplasma species possessing a range of virulence have been described in swine. The most commonly described are Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycoplasma hyosynoviae, and Mycoplasma flocculare. They are ubiquitious in many pig producing areas of the world, and except for M. hyopneumoniae, commercial antibody-based assays are lacking for most of these. Antibody cross-reactivity among these four mycoplasma species is not well characterized. Recently, the use of pen-based oral fluids for herd surveillance is of increasing interest. Thus, this study sought to measure pig antibody responses and the level of cross-reactivity in serum and pen-based oral fluids after challenge with four species of swine mycoplasmas. Four groups of four mycoplasma-free growing pigs were separately inoculated with the different mycoplasma species. Pen-based oral fluids and serum samples were collected weekly until necropsy. Species-specific Tween 20 ELISAs were used to measure antibody responses along with four other commercial M. hyopneumoniae ELISAs. Animals from all groups seroconverted to the challenge species of mycoplasma and no evidence of cross-contamination was observed. A delayed antibody response was seen with all but M. hyorhinis-infected pigs. Cross-reactive IgG responses were detected in M. hyopneumoniae- and M. flocculare-infected animals by the M. hyorhinis Tween 20 ELISA, while sera from M. hyosynoviae and M. flocculare-infected pigs were positive in one commercial assay. In pen-based oral fluids, specific anti-M. hyopneumoniae IgA responses were detected earlier after infection than serum IgG responses. In summary, while some antibody-based assays may have the potential for false positives, evidence of this was observed in the current study. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of antibody response in mice against avian influenza A

Indian Academy of Sciences (India)

Home; Journals; Journal of Biosciences; Volume 39; Issue 3. Evaluation of antibody response in mice against avian influenza A (H5N1) strain neuraminidase expressed in yeast Pichia pastoris. Murugan Subathra Ponsekaran Santhakumar Mangamoori Lakshmi Narasu Syed Sultan Beevi Sunil K Lal. Articles Volume 39 ...

Relationship between exposure to vector bites and antibody responses to mosquito salivary gland extracts.

Science.gov (United States)

Fontaine, Albin; Pascual, Aurélie; Orlandi-Pradines, Eve; Diouf, Ibrahima; Remoué, Franck; Pagès, Frédéric; Fusaï, Thierry; Rogier, Christophe; Almeras, Lionel

2011-01-01

Mosquito-borne diseases are major health problems worldwide. Serological responses to mosquito saliva proteins may be useful in estimating individual exposure to bites from mosquitoes transmitting these diseases. However, the relationships between the levels of these IgG responses and mosquito density as well as IgG response specificity at the genus and/or species level need to be clarified prior to develop new immunological markers to assess human/vector contact. To this end, a kinetic study of antibody levels against several mosquito salivary gland extracts from southeastern French individuals living in three areas with distinct ecological environments and, by implication, distinct Aedes caspius mosquito densities were compared using ELISA. A positive association was observed between the average levels of IgG responses against Ae. caspius salivary gland extracts and spatial Ae. caspius densities. Additionally, the average level of IgG responses increased significantly during the peak exposure to Ae. caspius at each site and returned to baseline four months later, suggesting short-lived IgG responses. The species-specificity of IgG antibody responses was determined by testing antibody responses to salivary gland extracts from Cx. pipiens, a mosquito that is present at these three sites at different density levels, and from two other Aedes species not present in the study area (Ae. aegypti and Ae. albopictus). The IgG responses observed against these mosquito salivary gland extracts contrasted with those observed against Ae. caspius salivary gland extracts, supporting the existence of species-specific serological responses. By considering different populations and densities of mosquitoes linked to environmental factors, this study shows, for the first time, that specific IgG antibody responses against Ae. caspius salivary gland extracts may be related to the seasonal and geographical variations in Ae. caspius density. Characterisation of such immunological

Heavy chain only antibodies

DEFF Research Database (Denmark)

Moghimi, Seyed Moein; Rahbarizadeh, Fatemeh; Ahmadvand, Davoud

2013-01-01

Unlike conventional antibodies, heavy chain only antibodies derived from camel contain a single variable domain (VHH) and two constant domains (CH2 and CH3). Cloned and isolated VHHs possess unique properties that enable them to excel conventional therapeutic antibodies and their smaller antigen...

Anti-α-galactosidase A antibody response to agalsidase beta treatment

DEFF Research Database (Denmark)

Wilcox, William R; Linthorst, Gabor E; Germain, Dominique P

2012-01-01

Agalsidase beta, a form of recombinant human α-galactosidase A (αGAL), is approved for use as enzyme replacement therapy (ERT) for Fabry disease. An immunogenic response against a therapeutic protein could potentially impact its efficacy or safety. The development of anti-αGAL IgG antibodies...... was evaluated in 571 men and 251 women from the Fabry Registry who were treated with agalsidase beta. Most men developed antibodies (416 of 571, 73%), whereas most women did not (31 of 251, 12%). Women were also significantly more likely to tolerize than men; whereas 18 of 31 women tolerized (58%, 95%CI: 52......%-64%), only 47 of 416 men tolerized during the observation period (11%, 95% CI: 8%-15%). Patients who eventually tolerized had lower median peak anti-αGAL IgG antibody titers than patients who remained seropositive at their most recent assessment (400 versus 3200 in men, 200 versus 400 in women, respectively...

Use of QuantiFERON®-TB Gold in-tube culture supernatants for measurement of antibody responses.

Directory of Open Access Journals (Sweden)

Simon G Kimuda

Full Text Available QuantiFERON®-TB Gold in-tube (QFT-GIT supernatants may be important samples for use in assessment of anti-tuberculosis (TB antibodies when only limited volumes of blood can be collected and when a combination of antibody and cytokine measurements are required. These analytes, when used together, may also have the potential to differentiate active pulmonary TB (APTB from latent TB infection (LTBI. However, few studies have explored the use of QFT-GIT supernatants for investigations of antibody responses. This study determined the correlation and agreement between anti-CFP-10 and anti-ESAT-6 antibody concentrations in QFT-GIT nil supernatant and serum pairs from 68 TB household contacts. We also explored the ability of Mycobacterium tuberculosis (M.tb specific antibodies, or ratios of antibody to interferon gamma (IFN-γ in QFT-GIT supernatants, to differentiate 97 APTB cases from 58 individuals with LTBI. Sputum smear microscopy was used to define APTB, whereas the QFT-GIT and tuberculin skin test were used to define LTBI. There were strong and statistically significant correlations between anti-CFP-10 and anti-ESAT-6 antibodies in unstimulated QFT-GIT supernatants and sera (r = 0.89; p<0.0001 for both, and no significant differences in antibody concentration between them. Anti-CFP-10 & anti-ESAT-6 antibodies differentiated APTB from LTBI with sensitivities of 88.7% & 71.1% and specificities of 41.4% & 51.7% respectively. Anti-CFP-10 antibody/M.tb specific IFN-γ and anti-ESAT-6 antibody/M.tb specific IFN-γ ratios had sensitivities of 48.5% & 54.6% and specificities of 89.7% and 75.9% respectively. We conclude that QFT-GIT nil supernatants may be used in the place of sera when measuring antibody responses, reducing blood volumes needed for such investigations. Antibodies in QFT-GIT nil supernatants on their own discriminate APTB from LTBI with high sensitivity but have poor specificity, whereas the reverse is true when antibodies are used in

Shark Variable New Antigen Receptor (VNAR Single Domain Antibody Fragments: Stability and Diagnostic Applications

Directory of Open Access Journals (Sweden)

Stewart Nuttall

2013-01-01

Full Text Available The single variable new antigen receptor domain antibody fragments (VNARs derived from shark immunoglobulin new antigen receptor antibodies (IgNARs represent some of the smallest known immunoglobulin-based protein scaffolds. As single domains, they demonstrate favorable size and cryptic epitope recognition properties, making them attractive in diagnosis and therapy of numerous disease states. Here, we examine the stability of VNAR domains with a focus on a family of VNARs specific for apical membrane antigen 1 (AMA-1 from Plasmodium falciparum. The VNARs are compared to traditional monoclonal antibodies (mAbs in liquid, lyophilized and immobilized nitrocellulose formats. When maintained in various formats at 45 °C, VNARs have improved stability compared to mAbs for periods of up to four weeks. Using circular dichroism spectroscopy we demonstrate that VNAR domains are able to refold following heating to 80 °C. We also demonstrate that VNAR domains are stable during incubation under potential in vivo conditions such as stomach acid, but not to the protease rich environment of murine stomach scrapings. Taken together, our results demonstrate the suitability of shark VNAR domains for various diagnostic platforms and related applications.

Impaired antibody response causes persistence of prototypic T cell-contained virus.

Directory of Open Access Journals (Sweden)

Andreas Bergthaler

2009-04-01

Full Text Available CD8 T cells are recognized key players in control of persistent virus infections, but increasing evidence suggests that assistance from other immune mediators is also needed. Here, we investigated whether specific antibody responses contribute to control of lymphocytic choriomeningitis virus (LCMV, a prototypic mouse model of systemic persistent infection. Mice expressing transgenic B cell receptors of LCMV-unrelated specificity, and mice unable to produce soluble immunoglobulin M (IgM exhibited protracted viremia or failed to resolve LCMV. Virus control depended on immunoglobulin class switch, but neither on complement cascades nor on Fc receptor gamma chain or Fc gamma receptor IIB. Cessation of viremia concurred with the emergence of viral envelope-specific antibodies, rather than with neutralizing serum activity, and even early nonneutralizing IgM impeded viral persistence. This important role for virus-specific antibodies may be similarly underappreciated in other primarily T cell-controlled infections such as HIV and hepatitis C virus, and we suggest this contribution of antibodies be given consideration in future strategies for vaccination and immunotherapy.

Development of single chain variable fragment (scFv) antibodies against Xylella fastidiosa subsp. pauca by phage display.

Science.gov (United States)

Yuan, Qing; Jordan, Ramon; Brlansky, Ronald H; Istomina, Olga; Hartung, John

2015-10-01

Xylella fastidiosa is a member of the gamma proteobacteria. It is fastidious, insect-vectored and xylem-limited and causes a variety of diseases, some severe, on a wide range of economically important perennial crops, including grape and citrus. Antibody based detection assays are commercially available for X. fastidiosa, and are effective at the species, but not at the subspecies level. We have made a library of scFv antibody fragments directed against X. fastidiosa subsp. pauca strain 9a5c (citrus) by using phage display technology. Antibody gene repertoires were PCR-amplified using 23 primers for the heavy chain variable region (V(H)) and 21 primers for the light chain variable region (V(L)). The V(H) and V(L) were joined by overlap extension PCR, and then the genes of the scFv library were ligated into the phage vector pKM19. The library contained 1.2×10(7) independent clones with full-length scFv inserts. In each of 3cycles of affinity-selection with 9a5c, about 1.0×10(12) phage were used for panning with 4.1×10(6), 7.1×10(6), 2.1×10(7) phage recovered after the first, second and third cycles, respectively. Sixty-six percent of clones from the final library bound X. fastidiosa 9a5c in an ELISA. Some of these scFv antibodies recognized strain 9a5c and did not recognize X. fastidiosa strains that cause Pierce's disease of grapevine. Published by Elsevier B.V.

The Complexity of a Dengue Vaccine: A Review of the Human Antibody Response.

Directory of Open Access Journals (Sweden)

Jacky Flipse

Full Text Available Dengue is the most prevalent mosquito-borne viral disease worldwide. Yet, there are no vaccines or specific antivirals available to prevent or treat the disease. Several dengue vaccines are currently in clinical or preclinical stages. The most advanced vaccine is the chimeric tetravalent CYD-TDV vaccine of Sanofi Pasteur. This vaccine has recently cleared Phase III, and efficacy results have been published. Excellent tetravalent seroconversion was seen, yet the protective efficacy against infection was surprisingly low. Here, we will describe the complicating factors involved in the generation of a safe and efficacious dengue vaccine. Furthermore, we will discuss the human antibody responses during infection, including the epitopes targeted in humans. Also, we will discuss the current understanding of the assays used to evaluate antibody response. We hope this review will aid future dengue vaccine development as well as fundamental research related to the phenomenon of antibody-dependent enhancement of dengue virus infection.

The Complexity of a Dengue Vaccine: A Review of the Human Antibody Response

Science.gov (United States)

Flipse, Jacky; Smit, Jolanda M.

2015-01-01

Dengue is the most prevalent mosquito-borne viral disease worldwide. Yet, there are no vaccines or specific antivirals available to prevent or treat the disease. Several dengue vaccines are currently in clinical or preclinical stages. The most advanced vaccine is the chimeric tetravalent CYD-TDV vaccine of Sanofi Pasteur. This vaccine has recently cleared Phase III, and efficacy results have been published. Excellent tetravalent seroconversion was seen, yet the protective efficacy against infection was surprisingly low. Here, we will describe the complicating factors involved in the generation of a safe and efficacious dengue vaccine. Furthermore, we will discuss the human antibody responses during infection, including the epitopes targeted in humans. Also, we will discuss the current understanding of the assays used to evaluate antibody response. We hope this review will aid future dengue vaccine development as well as fundamental research related to the phenomenon of antibody-dependent enhancement of dengue virus infection. PMID:26065421

Circulating CXCR5+PD-1+ response predicts influenza vaccine antibody responses in young adults but not elderly adults

OpenAIRE

Herati, Ramin Sedaghat; Reuter, Morgan A.; Dolfi, Douglas V.; Mansfield, Kathleen D.; Aung, Htin; Badwan, Osama Z.; Kurupati, Raj K.; Kannan, Senthil; Ertl, Hildegund; Schmader, Kenneth E.; Betts, Michael R.; Canaday, David H.; Wherry, E. John

2014-01-01

Although influenza vaccination is recommended for all adults annually, the incidence of vaccine failure, defined as weak or absent increase in neutralizing antibody titers, is increased in the elderly compared to young adults. The T follicular helper subset of CD4 T cells (Tfh) provides B cell help in germinal centers and is necessary for class-switched antibody responses. Previous studies suggested a role for circulating T follicular helper cells (cTfh) following influenza vaccination in adu...

Characterisation of antibody responses in pigs induced by recombinant oncosphere antigens from Taenia solium.

Science.gov (United States)

Jayashi, César M; Gonzalez, Armando E; Castillo Neyra, Ricardo; Kyngdon, Craig T; Gauci, Charles G; Lightowlers, Marshall W

2012-12-14

Recombinant antigens cloned from the oncosphere life cycle stage of the cestode parasite Taenia solium (T. solium) have been proven to be effective as vaccines for protecting pigs against infections with T. solium. Previous studies have defined three different host protective oncosphere antigens, TSOL18, TSOL16 and TSOL45. In this study, we evaluated the potential for combining the antigens TSOL16 and TSOL18 as a practical vaccine. Firstly, in a laboratory trial, we compared the immunogenicity of the combined antigens (TSOL16/18) versus the immunogenicity of the antigens separately. Secondly, in a field trial, we tested the ability of the TSOL16/18 vaccine to induce detectable antibody responses in animals living under environmental stress and traditionally reared in areas where T. solium cysticercosis is endemic; and finally, we characterised the immune response of the study population. Pigs of 8-16 weeks of age were vaccinated with 200 μg each of TSOL16 and TSOL18, plus 5mg of Quil-A. Specific total IgG, IgG(1) and IgG(2) antibody responses induced by TSOL16 and TSOL18 were determined with ELISA. The immunogenicity of both antigens was retained in the combined TSOL16/18 vaccine. The combined vaccine TSOL16/18 induced detectable specific anti-TSOL18 antibody responses in 100% (113/113) and specific anti-TSOL16 in 99% (112/113) of the vaccinated animals measured at 2 weeks following the booster vaccination. From the two IgG antibody subtypes analysed we found there was stronger response to IgG(2). Copyright © 2012 Elsevier Ltd. All rights reserved.

Reliable cloning of functional antibody variable domains from hybridomas and spleen cell repertoires employing a reengineered phage display system.

Science.gov (United States)

Krebber, A; Bornhauser, S; Burmester, J; Honegger, A; Willuda, J; Bosshard, H R; Plückthun, A

1997-02-14

A prerequisite for the use of recombinant antibody technologies starting from hybridomas or immune repertoires is the reliable cloning of functional immunoglobulin genes. For this purpose, a standard phage display system was optimized for robustness, vector stability, tight control of scFv-delta geneIII expression, primer usage for PCR amplification of variable region genes, scFv assembly strategy and subsequent directional cloning using a single rare cutting restriction enzyme. This integrated cloning, screening and selection system allowed us to rapidly obtain antigen binding scFvs derived from spleen-cell repertoires of mice immunized with ampicillin as well as from all hybridoma cell lines tested to date. As representative examples, cloning of monoclonal antibodies against a his tag, leucine zippers, the tumor marker EGP-2 and the insecticide DDT is presented. Several hybridomas whose genes could not be cloned in previous experimental setups, but were successfully obtained with the present system, expressed high amounts of aberrant heavy and light chain mRNAs, which were amplified by PCR and greatly exceeded the amount of binding antibody sequences. These contaminating variable region genes were successfully eliminated by employing the optimized phage display system, thus avoiding time consuming sequencing of non-binding scFv genes. To maximize soluble expression of functional scFvs subsequent to cloning, a compatible vector series to simplify modification, detection, multimerization and rapid purification of recombinant antibody fragments was constructed.

Steroid-Responsive Epilepsia Partialis Continua with Anti-Thyroid Antibodies: A Spectrum of Hashimoto's Encephalopathy

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Hiroki Masuda

2014-05-01

Full Text Available Background: When a neuropsychiatric symptom due to encephalopathy develops in a patient with anti-thyroid antibodies, especially when the symptom is steroid-responsive, Hashimoto's encephalopathy (HE needs to be included in the differential diagnosis of the patient. Although HE is an elusive disease, it is thought to cause various clinical presentations including seizures, myoclonus, and epilepsia partialis continua (EPC. Case Report: We present the case of a 33-year-old Japanese woman who acutely developed EPC in the right hand as an isolated manifestation. A thyroid ultrasound showed an enlarged hypoechogenic gland, and a thyroid status assessment showed euthyroid with high titers of thyroid antibodies. A brain MRI revealed a nodular lesion in the left precentral gyrus. Corticosteroid treatment resulted in a cessation of the symptom. Conclusions: A precentral nodular lesion can be responsible for steroid-responsive EPC in a patient with anti-thyroid antibodies and may be caused by HE. The serial MRI findings of our case suggest the presence of primary demyelination, with ischemia possibly due to vasculitis around the demyelinating lesion.

Antibody production in response to staphylococcal MS-1 phage cocktail in patients undergoing phage therapy

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Maciej Żaczek

2016-10-01

Full Text Available In this study, we investigated the humoral immune response (through the release of IgG, IgA, and IgM antiphage antibodies to a staphylococcal phage cocktail in patients undergoing experimental phage therapy at the Phage Therapy Unit, Medical Center of the Ludwik Hirszfeld Institute of Immunology and Experimental Therapy in Wrocław, Poland. We also evaluated whether occurring antiphage antibodies had neutralizing properties towards applied phages (K rate. Among 20 examined patients receiving the MS-1 phage cocktail orally and/or locally, the majority did not show a noticeably higher level of antiphage antibodies in their sera during phage administration. Even in those individual cases with an increased immune response, mostly by induction of IgG and IgM, the presence of antiphage antibodies did not translate into unsatisfactory clinical results of phage therapy. On the other hand, a negative outcome of the treatment occurred in some patients who showed relatively weak production of antiphage antibodies before and during treatment. This may imply that possible induction of antiphage antibodies is not an obstacle to the implementation of phage therapy and support our assumption that the outcome of the phage treatment does not primarily depend on the appearance of antiphage antibodies in sera of patients during therapy. These conclusions are in line with our previous findings. The confirmation of this thesis is of great interest as regards the efficacy of phage therapy in humans.

Antibody Production in Response to Staphylococcal MS-1 Phage Cocktail in Patients Undergoing Phage Therapy.

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Żaczek, Maciej; Łusiak-Szelachowska, Marzanna; Jończyk-Matysiak, Ewa; Weber-Dąbrowska, Beata; Międzybrodzki, Ryszard; Owczarek, Barbara; Kopciuch, Agnieszka; Fortuna, Wojciech; Rogóż, Paweł; Górski, Andrzej

2016-01-01

In this study, we investigated the humoral immune response (through the release of IgG, IgA, and IgM antiphage antibodies) to a staphylococcal phage cocktail in patients undergoing experimental phage therapy at the Phage Therapy Unit, Medical Center of the Ludwik Hirszfeld Institute of Immunology and Experimental Therapy in Wrocław, Poland. We also evaluated whether occurring antiphage antibodies had neutralizing properties toward applied phages (K rate). Among 20 examined patients receiving the MS-1 phage cocktail orally and/or locally, the majority did not show a noticeably higher level of antiphage antibodies in their sera during phage administration. Even in those individual cases with an increased immune response, mostly by induction of IgG and IgM, the presence of antiphage antibodies did not translate into unsatisfactory clinical results of phage therapy. On the other hand, a negative outcome of the treatment occurred in some patients who showed relatively weak production of antiphage antibodies before and during treatment. This may imply that possible induction of antiphage antibodies is not an obstacle to the implementation of phage therapy and support our assumption that the outcome of the phage treatment does not primarily depend on the appearance of antiphage antibodies in sera of patients during therapy. These conclusions are in line with our previous findings. The confirmation of this thesis is of great interest as regards the efficacy of phage therapy in humans.

Diversity and maturation in the anti-dansyl antibody response of the Balb/C mouse

International Nuclear Information System (INIS)

Burns, F.R.

1987-01-01

Ten hybridoma cell lines that produce antibodies with specificity for the 5-dimethylaminonaphthalene-1-sulfonyl(dansyl)-lysine hapten, were studied. Single stranded cDNAs were generated by reverse transcription of the immunoglobulin (Ig) mRNAs primed by 5' P-32 labeled oligonucleotides complementary to specific regions of the Ig message. Nucleic acid sequences of 4 mu heavy chains was sufficient to reveal that the early immune response involves members of at least three distinct heavy chain variable region (V/sub H/) gene families. Nucleic acid sequences and Southern blot data from 6 gamma heavy chains reveal that the gamma response is comprised of members of only a single V/sub H/ family although representation from that family derives from at least three distinguishable germline genes. The abrupt restriction of V/sub H/ family usage at the point of class switch can not be explained on the basis of antigen driven selection or of idio-type repression. The data indicate a mechanism for preferential class switch of a particular V/sub H/ family independent of affinity considerations or repression of other idiotypes

Diversity and maturation in the anti-dansyl antibody response of the Balb/C mouse

Energy Technology Data Exchange (ETDEWEB)

Burns, F.R.

1987-01-01

Ten hybridoma cell lines that produce antibodies with specificity for the 5-dimethylaminonaphthalene-1-sulfonyl(dansyl)-lysine hapten, were studied. Single stranded cDNAs were generated by reverse transcription of the immunoglobulin (Ig) mRNAs primed by 5' P-32 labeled oligonucleotides complementary to specific regions of the Ig message. Nucleic acid sequences of 4 mu heavy chains was sufficient to reveal that the early immune response involves members of at least three distinct heavy chain variable region (V/sub H/) gene families. Nucleic acid sequences and Southern blot data from 6 gamma heavy chains reveal that the gamma response is comprised of members of only a single V/sub H/ family although representation from that family derives from at least three distinguishable germline genes. The abrupt restriction of V/sub H/ family usage at the point of class switch can not be explained on the basis of antigen driven selection or of idio-type repression. The data indicate a mechanism for preferential class switch of a particular V/sub H/ family independent of affinity considerations or repression of other idiotypes.

Antibody response to booster vaccination with tetanus and diphtheria in adults exposed to perfluorinated alkylates

DEFF Research Database (Denmark)

Kielsen, Katrine; Shamim, Zaiba; Ryder, Lars P.

2016-01-01

Recent studies suggest that exposure to perfluorinated alkylate substances (PFASs) may induce immunosuppression in humans and animal models. In this exploratory study, 12 healthy adult volunteers were recruited. With each subject, serum-PFAS concentrations were measured and their antibody responses...... prospectively followed for 30 days after a booster vaccination with diphtheria and tetanus. The results indicated that serum-PFAS concentrations were positively correlated and positively associated with age and male sex. The specific antibody concentrations in serum were increased from Day 4 to Day 10 post......-booster, after which a constant concentration was reached. Serum PFAS concentrations showed significant negative associations with the rate of increase in the antibody responses. Interestingly, this effect was particularly strong for the longer-chain PFASs. All significant associations remained significant after...

Antibody response in cattle, sheep and rats to infection with. gamma. -irradiated metacercariae of Fasciola hepatica

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Hughes, D.L.; Doy, T.G. (Agricultural Research Council, Compton (UK). Inst. for Research on Animal Diseases); Hanna, R.E.B. (Queen' s Univ., Belfast, Northern Ireland (UK))

1982-05-01

Cattle, sheep and rats were infected orally with ..gamma..-irradiated metacercariae of Fasciola hepatica, or with normal metacercariae. The antibody response was monitored in each host to metacercarial tegument (T0), juvenile tegument (T1), adult tegument (T2) and gut antigens. The response was examined at weekly intervals for cattle and sheep throughout 15 weeks of infection and four weeks after infection in rats, using an indirect fluorescent antibody labelling technique. It was found that the irradiated metacercariae engendered a normal humoral response to T0, T1 and gut antigens in all three hosts although the antibody levels were somewhat reduced due to early death or stunting of the flukes. T0 and T1 appeared to be antigenically similar. Antibodies against T2 appeared late in the animals infected with ..gamma..-irradiated metacercariae and the titres attained were considerably lower than in the controls. The T2 antigen stimulus in the animals given ..gamma..-irradiated metacercariae was probably provided by flukes which 'broke through' the developmental barrier imposed by irradiation and which were found alive at autopsy.

Antibody response in cattle, sheep and rats to infection with γ-irradiated metacercariae of Fasciola hepatica

International Nuclear Information System (INIS)

Hughes, D.L.; Doy, T.G.

1982-01-01

Cattle, sheep and rats were infected orally with γ-irradiated metacercariae of Fasciola hepatica, or with normal metacercariae. The antibody response was monitored in each host to metacercarial tegument (T0), juvenile tegument (T1), adult tegument (T2) and gut antigens. The response was examined at weekly intervals for cattle and sheep throughout 15 weeks of infection and four weeks after infection in rats, using an indirect fluorescent antibody labelling technique. It was found that the irradiated metacercariae engendered a normal humoral response to T0, T1 and gut antigens in all three hosts although the antibody levels were somewhat reduced due to early death or stunting of the flukes. T0 and T1 appeared to be antigenically similar. Antibodies against T2 appeared late in the animals infected with γ-irradiated metacercariae and the titres attained were considerably lower than in the controls. The T2 antigen stimulus in the animals given γ-irradiated metacercariae was probably provided by flukes which 'broke through' the developmental barrier imposed by irradiation and which were found alive at autopsy. (author)

The immunoglobulin class of anti-hapten antibody secreted during secondary responses in vitro and in vivo.

Science.gov (United States)

North, J R; Dresser, D W

1977-05-01

A comparison has been made of the in vitro and in vivo response of primed mouse spleen cells to the hapten DNP. The responses were analysed in terms of six classes (sub-classes) of humoral antibody directed against the cross-reacting hapten TNP. By comparison with the response in intact mice the adoptive secondary response is delayed by 3 days in addition to being somewhat lesser in magnitude. The timing of the response in vitro is similar to that observed in intact mice. The preponderant class in all three responses was gammaG1 with gammaA and gammaG3 secreting cells consistently comprising the smallest proportion of the total of antibody-secreting cells.

Kinetic and HPV infection effects on cross-type neutralizing antibody and avidity responses induced by Cervarix®

Science.gov (United States)

Kemp, Troy J.; Safaeian, Mahboobeh; Hildesheim, Allan; Pan, Yuanji; Penrose, Kerri J.; Porras, Carolina; Schiller, John T.; Lowy, Douglas R.; Herrero, Rolando; Pinto, Ligia A.

2012-01-01

Background We previously demonstrated that Cervarix® elicits antibody responses against vaccine-related types for which clinical efficacy was demonstrated (HPV-31 and -45). Here, we evaluated the kinetics of neutralization titers and avidity of Cervarix®-induced antibodies up to 36 months of follow-up in unexposed and HPV infected women. Methods A subset of women who participated in the Cost Rica HPV-16/18 Vaccine Trial had pre- and post-vaccination sera tested for antibody responses to HPV-16, -18, -31, -45, and -58 using a pseudovirion-based neutralization assay, and HPV-16 antibody avidity using an HPV-16 L1 VLP (virus-like particle)-based ELISA developed in our laboratory. Results In uninfected women, neutralizing antibody titers did not reach significance until after the 3rd dose for HPV-31 (month 12, p=0.009) and HPV-45 (month 12, p=0.003), but then persisted up to month 36 (HPV-31, p=0.01; HPV-45, p=0.002). Individuals infected with HPV-16 or HPV-31 at enrollment developed a significantly higher median antibody response to the corresponding HPV type after one dose, but there was not a difference between median titers after three doses compared to the HPV negative group. Median HPV-16 antibody avidity and titer increased over time up to month 12; however, the HPV-16 avidity did not correlate well with HPV-16 neutralizing antibody titers at each time point examined, except for month 6. The median avidity levels were higher in HPV-16 infected women at month 1 (p=0.04) and lower in HPV-16 infected women at month 12 (p=0.006) compared to the HPV negative women. Conclusions The persistence of cross-neutralization titers at month 36 suggests cross-reactive antibody responses are likely to persist long-term and are not influenced by infection status at enrollment. However, the weak correlation between avidity and neutralization titers emphasizes the need for examining avidity in efficacy studies to determine if high avidity antibodies play a critical role in

Treatment-responsive limbic encephalitis identified by neuropil antibodies: MRI and PET correlates

Science.gov (United States)

Ances, Beau M.; Vitaliani, Roberta; Taylor, Robert A.; Liebeskind, David S.; Voloschin, Alfredo; Houghton, David J.; Galetta, Steven L.; Dichter, Marc; Alavi, Abass; Rosenfeld, Myrna R.; Dalmau, Josep

2007-01-01

had dramatic clinical and neuroimaging responses to immunotherapy or tumour resection; two patients had neurological relapse and improved with immunotherapy. Overall, the phenotype associated with the novel neuropil antibodies includes dominant behavioural and psychiatric symptoms and seizures that often interfere with the evaluation of cognition and memory, and brain MRI or FDG-PET abnormalities less frequently restricted to the medial temporal lobes than in patients with classical paraneoplastic or VGKC antibodies. When compared with patients with VGKC antibodies, patients with these novel antibodies are more likely to have CSF inflammatory abnormalities and systemic tumours (teratoma and thymoma), and they do not develop SIADH-like hyponatraemia. Although most autoantigens await characterization, all share intense expression by the neuropil of hippocampus, with patterns of immunolabelling characteristic enough to suggest the diagnosis of these disorders and predict response to treatment. PMID:15888538

Immune response to pneumococcal polysaccharides 4 and 14 in elderly and young adults. I Antibody concentrations, avidity and functional activity

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Carlone George M

2005-06-01

Full Text Available Abstract Streptococcus pneumoniae is a serious worldwide pathogen and the focus of numerous vaccine development projects. Currently the most widely accepted surrogate marker for evaluating the efficacy of a given vaccine is to utilize ELISA. Measurement of antibody concentration by ELISA without reduction in cross-reactive antibodies causes an overestimation of antibody concentration and therefore protection, this is most notable in the aged, an at risk group for this infection. We compared the immune response to the pneumococcal polysaccharides (PPS 4 and 14 of 20 young to 20 elderly adults. Pre-and post-vaccination IgG antibody concentrations and antibody avidity against PPS4 and PPS14 were measured using two different enzyme-linked immunosorbant assay (ELISA absorption protocols. All sera were pre-absorbed with either cell-wall polysaccharide (CPS, or CPS and serotype 22F polysaccharide. Pre- and post-vaccination IgG antibody concentrations for serotype 4, but not 14, were significantly lowered with the additional absorption with serotype 22F polysaccharide in both age groups. Young and elderly demonstrated a significant increase from pre- to post-immunization antibody concentration, using either absorption method; and opsonophagocytic antibody titers in response to both PPS4 and PPS14. The correlation coefficients between ELISA and opsonophagocytic assays were improved by additional absorption with serotype 22F in response to serotype 4, but not serotype 14 in all age groups. Opsonophagocytic antibody titers in a sub-group of elderly (>77 years of age were significantly lower than the opsonophagocytic antibody concentrations in young adults. These results suggest the importance of eliminating cross-reactive antibodies from ELISA measurements by absorption of serum and an age-related impairment in the antibody response to pneumococcal polysaccharides.

Kinetics of Anti-Phlebotomus perniciosus Saliva Antibodies in Experimentally Bitten Mice and Rabbits.

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Inés Martín-Martín

Full Text Available Sand flies are hematophagous arthropods that act as vectors of Leishmania parasites. When hosts are bitten they develop cellular and humoral responses against sand fly saliva. A positive correlation has been observed between the number of bites and antibody levels indicating that anti-saliva antibody response can be used as marker of exposure to sand flies. Little is known about kinetics of antibodies against Phlebotomus perniciosus salivary gland homogenate (SGH or recombinant salivary proteins (rSP. This work focused on the study of anti-P. perniciosus saliva antibodies in sera of mice and rabbits that were experimentally exposed to the bites of uninfected sand flies.Anti-saliva antibodies were evaluated by ELISA and Western blot. In addition, antibody levels against two P. perniciosus rSP, apyrase rSP01B and D7 related protein rSP04 were determined in mice sera. Anti-saliva antibody levels increased along the immunizations and correlated with the number of sand fly bites. Anti-SGH antibody levels were detected in sera of mice five weeks after exposure, and persisted for at least three months. Anti-apyrase rSP01B antibodies followed similar kinetic responses than anti-SGH antibodies while rSP04 showed a delayed response and exhibited a greater variability among sera of immunized mice. In rabbits, anti-saliva antibodies appeared after the second week of exposure and IgG antibodies persisted at high levels, even 7 months post-exposure.Our results contributed to increase the knowledge on the type of immune response P. perniciosus saliva and individual proteins elicited highlighting the use of rSP01B as an epidemiological marker of exposure. Anti-saliva kinetics in sera of experimentally bitten rabbits were studied for the first time. Results with rabbit model provided useful information for a better understanding of the anti-saliva antibody levels found in wild leporids in the human leishmaniasis focus in the Madrid region, Spain.

Memory B-Cell and Antibody Responses Induced by Plasmodium falciparum Sporozoite Immunization

NARCIS (Netherlands)

Nahrendorf, W.; Scholzen, A.; Bijker, E.M.; Teirlinck, A.C.; Bastiaens, G.J.H.; Schats, R.; Hermsen, C.C.; Visser, L.G.; Langhorne, J.; Sauerwein, R.W.

2014-01-01

BACKGROUND: Immunization of healthy volunteers during receipt of chemoprophylaxis with Plasmodium falciparum sporozoites (CPS-immunization) induces sterile protection from malaria. Antibody responses have long been known to contribute to naturally acquired immunity against malaria, but their

[A case of an anti-Ma2 antibody-positive patient presenting with variable CNS symptoms mimicking multiple system atrophy with a partial response to immunotherapy].

Science.gov (United States)

Shiraishi, Wataru; Iwanaga, Yasutaka; Yamamoto, Akifumi

2015-01-01

A 70-year-old man with a 5-month history of progressive bradykinesia of the bilateral lower extremities was admitted to our hospital. At the age of 64, he underwent proximal gastrectomy for gastric cancer. He also had a history of subacute combined degeneration of the spinal cord since the age of 67, which was successfully treated with vitamin B12 therapy. Four weeks before admission to our hospital, he admitted himself to his former hospital complaining of walking difficulty. Two weeks later, however, his symptoms progressed rapidly; he was immobilized for two weeks and did not respond to the vitamin therapy. On admission to our hospital, he showed moderate paralysis of the lower extremities, cog-wheel rigidity of the four extremities, and dystonic posture of his left hand. He also showed orthostatic hypotension and vesicorectal disorders. Blood examination and cerebrospinal fluid analysis revealed no remarkable abnormalities. Electroencephalography showed frontal dominant, high voltage, sharp waves. His brain and spinal MRI revealed no notable abnormalities. We suspected autoimmune disease and commenced one course of intravenous methylprednisolone therapy, resulting in improvement of the parkinsonism and orthostatic hypotension. Based on these results, we investigated possible neural antigens and detected anti-Ma2 antibody. In addition to limbic encephalitis, anti-Ma2 antibody-positive neural disorders are characterized by rapid eye movement sleep behavior disorders or parkinsonism. Here, we report an anti-Ma2 antibody positive patient presenting variable CNS symptoms mimicking multiple system atrophy, who responded to immunotherapy.

Distinct human antibody response to the biological warfare agent Burkholderia mallei.

Science.gov (United States)

Varga, John J; Vigil, Adam; DeShazer, David; Waag, David M; Felgner, Philip; Goldberg, Joanna B

2012-10-01

The genetic similarity between Burkholderia mallei (glanders) and Burkholderia pseudomallei (melioidosis) had led to the general assumption that pathogenesis of each bacterium would be similar. In 2000, the first human case of glanders in North America since 1945 was reported in a microbiology laboratory worker. Leveraging the availability of pre-exposure sera for this individual and employing the same well-characterized protein array platform that has been previously used to study a large cohort of melioidosis patients in southeast Asia, we describe the antibody response in a human with glanders. Analysis of 156 peptides present on the array revealed antibodies against 17 peptides with a > 2-fold increase in this infection. Unexpectedly, when the glanders data were compared with a previous data set from B. pseudomallei infections, there were only two highly increased antibodies shared between these two infections. These findings have implications in the diagnosis and treatment of B. mallei and B. pseudomallei infections.

Correlated effects of selection for immunity in White Leghorn chicken lines on natural antibodies and specific antibody responses to KLH and M. butyricum

NARCIS (Netherlands)

Minozzi, G.; Parmentier, H.K.; Mignon-Grasteau, S.; Nieuwland, M.G.B.; Bed'hom, B.; Gourichon, D.; Minvielle, F.; Pinard-van der Laan, M.H.

2008-01-01

Background - The effect of selection for three general immune response traits on primary antibody responses (Ab) to Mycobacterium butyricum or keyhole limpet hemocyanin (KLH) was studied in four experimental lines of White Leghorn chicken. Birds underwent 12 generations of selection for one of three

Variability of IgM response in hepatitis C virus infection

NARCIS (Netherlands)

Zaaijer, H. L.; Mimms, L. T.; Cuypers, H. T.; Reesink, H. W.; van der Poel, C. L.; Taskar, S.; Lelie, P. N.

1993-01-01

The IgM and IgG antibody response to various hepatitis C virus (HCV) antigens was studied in 8 patients who acquired posttransfusion HCV infection. IgM anti-HCV was detectable in only 4 of these patients, coincident with (1 patient) or later than (3 patients) the IgG anti-HCV response. Seven

Neutralizing antibody response in the patients with hand, foot and mouth disease to enterovirus 71 and its clinical implications

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Zhu Liye

2011-06-01

Full Text Available Abstract Enterovirus 71 (EV71 has emerged as a significant pathogen causing large outbreaks in China for the past 3 years. Developing an EV71 vaccine is urgently needed to stop the spread of the disease; however, the adaptive immune response of humans to EV71 infection remains unclear. We examined the neutralizing antibody titers in HFMD patients and compared them to those of asymptomatic healthy children and young adults. We found that 80% of HFMD patients became positive for neutralizing antibodies against EV71 (GMT = 24.3 one day after the onset of illness. The antibody titers in the patients peaked two days (GMT = 79.5 after the illness appeared and were comparable to the level of adults (GMT = 45.2. Noticeably, the antibody response was not correlated with disease severity, suggesting that cellular immune response, besides neutralizing antibodies, could play critical role in controlling the outcome of EV71 infection in humans.

Total lymphoid irradiation reduces IgG autoantibody production and enhances specific antibody responses in NZB/NZW F1 mice

Energy Technology Data Exchange (ETDEWEB)

Farinas, M.C.; Strober, S.

1989-07-01

Thymus-independent primary antibody responses were studied in young and old (9 months) untreated and TLI-treated NZB/NZW and BALB/c mice. Untreated old NZB/NZW mice had a low primary response to Brucella abortus (BA) as compared to that of young NZB/NZW and BALB/c mice. However, TLI treatment resulted in a 130-fold increase in the IgG anti-BA primary antibody response at day 21 postimmunization, achieving similar levels to those of young NZB/NZW or nonautoimmune BALB/c mice. Anti-TNP responses to trinitrophenylated BA or Ficoll were masked by high background levels of anti-TNP antibodies. Despite the increase in the anti-BA response, spontaneous immunoglobulin secretion and autoantibody levels were markedly decreased after TLI in old NZB/NZW mice.

Total lymphoid irradiation reduces IgG autoantibody production and enhances specific antibody responses in NZB/NZW F1 mice

International Nuclear Information System (INIS)

Farinas, M.C.; Strober, S.

1989-01-01

Thymus-independent primary antibody responses were studied in young and old (9 months) untreated and TLI-treated NZB/NZW and BALB/c mice. Untreated old NZB/NZW mice had a low primary response to Brucella abortus (BA) as compared to that of young NZB/NZW and BALB/c mice. However, TLI treatment resulted in a 130-fold increase in the IgG anti-BA primary antibody response at day 21 postimmunization, achieving similar levels to those of young NZB/NZW or nonautoimmune BALB/c mice. Anti-TNP responses to trinitrophenylated BA or Ficoll were masked by high background levels of anti-TNP antibodies. Despite the increase in the anti-BA response, spontaneous immunoglobulin secretion and autoantibody levels were markedly decreased after TLI in old NZB/NZW mice

Development of an Indirect Competitive Enzyme-Linked Immunosorbent Assay for Glycocholic Acid Based on Chicken Single-Chain Variable Fragment Antibodies.

Science.gov (United States)

Cui, Xiping; Vasylieva, Natalia; Wu, Panpan; Barnych, Bogdan; Yang, Jun; Shen, Ding; He, Qiyi; Gee, Shirley J; Zhao, Suqing; Hammock, Bruce D

2017-10-17

Glycocholic acid (GCA) is an important metabolite of bile acids, whose urine levels are expected to be a specific diagnostic biomarker for hepatocellular carcinoma (HCC). A high-throughput immunoassay for determination of GCA would be of significant advantage and useful for primary diagnosis, surveillance, and early detection of HCC. Single-chain variable fragment (scFv) antibodies have several desirable characteristics and are an attractive alternative to traditional antibodies for the immunoassay. Because chicken antibodies possess single heavy and light variable functional domains, they are an ideal framework for simplified generation of recombinant antibodies for GCA detection. However, chicken scFvs have rarely been used to detect GCA. In this study, a scFv library was generated from chickens immunized with a GCA hapten coupled to bovine serum albumin (BSA), and anti-GCA scFvs were isolated by a phage-displayed method. Compared to the homologous coating antigen, use of a heterologous coating antigen resulted in about an 85-fold improvement in sensitivity of the immunoassay. This assay, under optimized conditions, had a linear range of 0.02-0.18 μg/mL, with an IC 50 of 0.06 μg/mL. The assay showed negligible cross-reactivity with various related bile acids, except for taurocholic acid. The detection of GCA from spiked human urine samples ranged from 86.7% to 123.3%. These results, combined with the advantages of scFv antibodies, indicated that a chicken scFv-based enzyme-linked immunosorbent assay is a suitable method for high-throughput screening of GCA in human urine.

An unexpected antibody response to an engineered influenza virus modifies CD8+ T cell responses.

Science.gov (United States)

Thomas, Paul G; Brown, Scott A; Yue, Wen; So, Jenny; Webby, Richard J; Doherty, Peter C

2006-02-21

The ovalbumin(323-339) peptide that binds H2I-A(b) was engineered into the globular heads of hemagglutinin (H) molecules from serologically non-cross-reactive H1N1 and H3N2 influenza A viruses, the aim being to analyze recall CD4+ T cell responses in a virus-induced respiratory disease. Prime/challenge experiments with these H1ova and H3ova viruses in H2(b) mice gave the predicted, ovalbumin-specific CD4+ T cell response but showed an unexpectedly enhanced, early expansion of viral epitope-specific CD8+ T cells in spleen and a greatly diminished inflammatory process in the virus-infected respiratory tract. At the same time, the primary antibody response to the H3N2 challenge virus was significantly reduced, an effect that has been associated with preexisting neutralizing antibody in other experimental systems. Analysis of serum from the H1ova-primed mice showed low-level binding to H3ova but not to the wild-type H3N2 virus. Experiments with CD4+ T cell-depleted and Ig-/- mice indicated that this cross-reactive Ig is indeed responsible for the modified pathogenesis after respiratory challenge. Furthermore, the effect does not seem to be virus-dose related, although it does require infection. These findings suggest intriguing possibilities for vaccination and, at the same time, emphasize that engineered modifications in viruses may have unintended immunological consequences.

A review of human anti-globulin antibody (HAGA, HAMA, HACA, HAHA) responses to monoclonal antibodies. Not four letter words.

Science.gov (United States)

Mirick, G R; Bradt, B M; Denardo, S J; Denardo, G L

2004-12-01

The United States Food and Drug Administration (FDA) has approved unconjugated monoclonal antibodies (MAbs) for immunotherapy (IT) of B-cell lymphoma, breast cancer and acute myeloid leukemia. More recently, approval has been given for conjugated ZevalinTM ((90)yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ((131)I-tositumomab, Corixa, Corp., Seattle, WA and GlaxoSmithKline, Philadelphia, PA) anti-CD20 MAbs for use in radioimmunotherapy (RIT) of non-Hodgkin's lymphoma (NHL), thus redefining the standard care of cancer patients. Because of, and despite a lack of basis for concern about allergic reactions due to human antibody responses to these foreign proteins, assays were developed to determine HAGA (human anti-globulin antibody) levels that developed in patient sera following treatment with MAbs. Strategies were also devised to ''humanize'' MAbs and to temporarily block patient immune function with drugs in order to decrease the seroconversion rates, with considerable success. On the other hand, a survival advantage has been observed in some patients who developed a HAGA following treatment. This correlates with development of an anti-idiotype antibody cascade directed toward the MAbs used to treat these patients. What follows is a selective review of HAGA and its effect on cancer treatment over the past 2 decades.

A review of human anti-globulin antibody (HAGA, HAMA, HACA, HAHA) responses to monoclonal antibodies. Not four letter words

International Nuclear Information System (INIS)

Mirick, G. R.; Bradt, B. M.; Denardo, S. J.; Denardo, G. L.

2004-01-01

The United States Food and Drugs Administration (FDA) has approved unconjugated monoclonal antibodies (MAbs) for immunotherapy (IT) of B-cell lymphoma, breast cancer and acute myeloid leukemia. More recently, approval has been given for conjugated ZevalinTM ( 9 0yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ( 1 31I-tositumomab, Corixa, Corp., Seattle, WA and GlaxoSmithKline, Philadelphia, PA) antiCD20 MAns for use in radioimmunotherapy (RIT) of non-Hodgikin's lymphoma (NHL), thus redefining the standard care of cancer patients. Because of, and despite a lack of basis for concern about allergic reactions due to human antibody responses to these foreign proteins, essays were developed to determine HAGE (human anti-globulin antibody) levels that developed in patient sera following treatment with MAbs. Strategies were also devised to humanize MAbs and to temporarily block patient immune function with drugs in order to decrease the seroconversion rates, with considerable success. On the other hand, a survival advantage has been observed in some patients who developed a HAGA following treatment. This correlates with development of an anti-idiotype antibody cascade directed toward the MAbs used to treat these patients. What follows is a selective review of HAGA and its effect on cancer treatment over the past 2 decades

HIV-1-Specific Antibody Response and Function after DNA Prime and Recombinant Adenovirus 5 Boost HIV Vaccine in HIV-Infected Subjects.

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Johannes S Gach

Full Text Available Little is known about the humoral immune response against DNA prime-recombinant adenovirus 5 (rAd5 boost HIV vaccine among HIV-infected patients on long-term suppressive antiretroviral therapy (ART. Previous studies emphasized cellular immune responses; however, current research suggests both cellular and humoral responses are likely required for a successful therapeutic vaccine. Thus, we aimed to understand antibody response and function induced by vaccination of ART-treated HIV-1-infected patients with immune recovery. All subjects participated in EraMune 02, an open-label randomized clinical trial of ART intensification followed by a six plasmid DNA prime (envA, envB, envC, gagB, polB, nefB and rAd5 boost HIV vaccine with matching inserts. Antibody binding levels were determined with a recently developed microarray approach. We also analyzed neutralization efficiency and antibody-dependent cellular cytotoxicity (ADCC. We found that the DNA prime-rAd5 boost vaccine induced a significant cross-clade HIV-specific antibody response, which correlated with antibody neutralization efficiency. However, despite the increase in antibody binding levels, the vaccine did not significantly stimulate neutralization or ADCC responses. This finding was also reflected by a lack of change in total CD4+ cell associated HIV DNA in those who received the vaccine. Our results have important implications for further therapeutic vaccine design and administration, especially in HIV-1 infected patients, as boosting of preexisting antibody responses are unlikely to lead to clearance of latent proviruses in the HIV reservoir.

Immune TB Antibody Phage Display Library as a Tool To Study B Cell Immunity in TB Infections.

Science.gov (United States)

Hamidon, Nurul Hamizah; Suraiya, Siti; Sarmiento, Maria E; Acosta, Armando; Norazmi, Mohd Nor; Lim, Theam Soon

2018-03-01

B cells and in particular antibodies has always played second fiddle to cellular immunity in regard to tuberculosis (TB). However, recent studies has helped position humoral immunity especially antibodies back into the foray in relation to TB immunity. Therefore, the ability to correlate the natural antibody responses of infected individuals toward TB antigens would help strengthen this concept. Phage display is an intriguing approach that can be utilized to study antibody-mediated responses against a particular infection via harvesting the B cell repertoire from infected individuals. The development of disease-specific antibody libraries or immune libraries is useful to better understand antibody-mediated immune responses against specific disease antigens. This study describes the generation of an immune single-chain variable fragment (scFv) library derived from TB-infected individuals. The immune library with an estimated diversity of 10 9 independent clones was then applied for the identification of monoclonal antibodies against Mycobacterium tuberculosis α-crystalline as a model antigen. Biopanning of the library isolated three monoclonal antibodies with unique gene usage. This strengthens the role of antibodies in TB immunity in addition to the role played by cellular immunity. The developed library can be applied against other TB antigens and aid antibody-derived TB immunity studies in the future.

Immune response to inactivated influenza virus vaccine: antibody reactivity with epidemic influenza B viruses of two highly distinct evolutionary lineages.

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Pyhälä, R; Kleemola, M; Kumpulainen, V; Vartiainen, E; Lappi, S; Pönkä, A; Cantell, K

1992-01-01

Vaccination of adults (healthy female employees potentially capable of transmitting influenza to high-risk persons; n = 104) in autumn 1990 with a trivalent influenza virus vaccine containing B/Yamagata/16/88 induced a low antibody response to B/Finland/150/90, a recent variant of B/Victoria/2/87-like viruses, as compared with the antibody response to B/Finland/172/91, a current variant in the lineage of B/Yamagata/16/88-like viruses. Up to the end of the epidemic season, the antibody status declined but was still significantly better than before the vaccination. The results suggest that the vaccine strain was appropriate for the outbreak of 1990 to 1991 in Finland, but may provide unsatisfactory protection against B/Victoria/2/87-like viruses. Evidence is given that use of Madin-Darby canine kidney (MDCK)-grown virus as an antigen in the haemagglutination inhibition test (HI) may provide more reliable information about the protective antibodies than use of untreated or ether-treated egg-grown viruses. Significantly higher postvaccination and postepidemic antibody titres were recorded among subjects who exhibited the antibody before vaccination than among seronegative subjects. A significantly higher response rate among initially seronegative people than among seropositive people was recorded for antibody to B/Finland/150/90, but no clear evidence was obtained that the pre-existing antibody could have had a negative effect on the antibody production.

MINOR HUMAN-ANTIBODY RESPONSE TO A MOUSE AND CHIMERIC MONOCLONAL-ANTIBODY AFTER A SINGLE IV INFUSION IN OVARIAN-CARCINOMA PATIENTS - A COMPARISON OF 5 ASSAYS

NARCIS (Netherlands)

BUIST, MR; KENEMANS, P; VANKAMP, GJ; Haisma, Hidde

The human anti-(mouse Ig) antibody (HAMA) response was measured in serum of 52 patients suspected of having ovarian carcinoma who had received an i.v. injection of either the murine monoclonal antibody (mAb) OV-TL 3 F(ab')(2) (n = 28, 1 mg) or the chimeric mouse/human mAb MOv18 (cMOv18; n = 24, 3

Quantitative and temporal analyses of murine antibody response in serum and gut secretions to infection with Giardia muris.

Science.gov (United States)

Snider, D P; Underdown, B J

1986-04-01

We analyzed the appearance and level of Giardia muris-specific antibody of immunoglobulin A (IgA), IgG, and IgM isotypes, at weekly intervals, over the course of a 7-week infection in BALB/c and C57BL/6 mice. Using sensitive immunoradiometric assays, we observed that IgA antibody was the only detectable anti-G. muris antibody in intestinal secretions throughout the course of infection. No secreted IgG or IgM anti-G. muris antibody was detected even in concentrated intestinal secretions. The expulsion of G. muris by the mice was associated closely with the appearance and increasing levels of secreted anti-G. muris IgA antibody. Both IgG and IgA serum antibody to G. muris were detected, but no serum IgM antibody was detected. Serum IgA and IgG anti-G. muris antibody remained at high levels up to 10 weeks following clearance of the parasite. An interesting observation indicated that serum IgA antibody to G. muris developed more slowly in response to infection than secreted IgA antibody. An analysis of the molecular weight distribution of total serum IgA in infected mice determined that infection produced a transient but significant shift in serum IgA to high-molecular-weight (greater than or equal to dimeric IgA) forms. The results indicate that a substantial IgA antibody response occurs in sera and in gut secretions of G. muris-resistant mice and that IgA antibody is the dominant and possibly the only effector antibody active in intestinal secretions during G. muris infection in mice.

The antibody response to well-defined malaria antigens after acute malaria in individuals living under continuous malaria transmission

DEFF Research Database (Denmark)

Petersen, E; Høgh, B; Dziegiel, M

1992-01-01

The IgG and IgM antibody responses to the C-terminal 783 amino acids of the P. falciparum glutamate-rich protein, GLURP489-1271, expressed as an E. coli fusion protein, the IgG response to a 18-mer synthetic peptide EDKNEKGQHEIVEVEEIL (GLURP899-916) representing the C-terminal repeats of GLURP......, and a synthetic peptide (EENV)6 representing the C-terminal repeats from Pf155/RESA, were investigated longitudinally in 13 children and 7 adults living under conditions of continuous, intense malaria transmission. Some subjects did not recognize the antigens after malaria infection, and in subjects recognizing...... the antigens, the responses were often short-lived. In adults, the antibody responses to the GLURP489-1271 fusion protein and the (EENV)6 peptide peaked after 2 weeks, and not all individuals responded to all antigens. The antibody response, even against large fragments of conserved antigens, is not uniformly...

Antibody responses of cervids (Cervus elaphus) following experimental Mycobacterium bovis infection and the implications for immunodiagnosis.

Science.gov (United States)

Harrington, Noel P; Surujballi, Om P; Prescott, John F; Duncan, J Robert; Waters, W Ray; Lyashchenko, Konstantin; Greenwald, Rena

2008-11-01

Captive and free-ranging wildlife animals are implicated in the maintenance and transmission of bovine tuberculosis and therefore pose a significant obstacle to eradication of the disease from domestic livestock. The current antemortem diagnostic method, the intradermal tuberculin skin test, is impractical for routine use with many wild animals. Antibody-based assays are particularly attractive because the animals are handled only once and immediate processing of the sample is not required. This report characterizes the antibody responses of red deer-elk hybrids (Cervus elaphus) against Mycobacterium bovis and subsequently evaluates the diagnostic performance of select antigens in a rapid-test format. Sequential serum samples were collected from 10 animals experimentally infected with M. bovis and 5 noninfected animals over a 7-month period postinfection (p.i.). Samples were evaluated by enzyme-linked immunosorbent assays, immunoblot analyses, and multiantigen print immunoassays for seroreactivity to mycobacterial antigens. Although all infected animals produced antibodies to M. bovis protein antigens, there was significant animal-to-animal variation in the kinetics and magnitudes of responses and the antigens recognized. The most frequently recognized antigens included MPB83, ESAT-6, CFP10, and MPB70. Responses to some antigens, such as MPB83, were consistently detected as early as 4 weeks after inoculation, whereas other antigens were detected only much later (>140 days p.i.). Antibody responses were boosted by injection of tuberculin for intradermal tuberculin skin testing. Comparison of single-antigen (fluorescence polarization assay) with multiantigen (CervidTB STAT-PAK) rapid tests demonstrated that a highly sensitive and specific serodiagnostic test for tuberculosis in cervids will require multiple and carefully selected seroreactive antigens covering a broad spectrum of antibody specificities.

Antibody Responses to Marburg Virus in Egyptian Rousette Bats and Their Role in Protection against Infection.

Science.gov (United States)

Storm, Nadia; Jansen Van Vuren, Petrus; Markotter, Wanda; Paweska, Janusz T

2018-02-10

Egyptian rousette bats (ERBs) are reservoir hosts for the Marburg virus (MARV). The immune dynamics and responses to MARV infection in ERBs are poorly understood, and limited information exists on the role of antibodies in protection of ERBs against MARV infection. Here, we determine the duration of maternal immunity to MARV in juvenile ERBs, and evaluate the duration of the antibody response to MARV in bats naturally or experimentally infected with the virus. We further explore whether antibodies in previously naturally exposed bats is fully protective against experimental reinfection with MARV. Maternal immunity was lost in juvenile ERBs by 5 months of age. Antibodies to MARV remained detectable in 67% of experimentally infected bats approximately 4 months post inoculation (p.i.), while antibodies to MARV remained present in 84% of naturally exposed bats at least 11 months after capture. Reinfection of seropositive ERBs with MARV produced an anamnestic response from day 5 p.i. Although PCR-defined viremia was present in 73.3% of reinfected ERBs, replicating virus was recovered from the serum of only one bat on day 3 p.i. The negative PCR results in the salivary glands, intestines, bladders and reproductive tracts of reinfected bats, and the apparent absence of MARV in the majority of swabs collected from these bats suggest that reinfection may only play a minor role in the transmission and maintenance of MARV amongst ERBs in nature.

Immune-mediated steroid-responsive epileptic spasms and epileptic encephalopathy associated with VGKC-complex antibodies.

Science.gov (United States)

Suleiman, Jehan; Brenner, Tanja; Gill, Deepak; Troedson, Christopher; Sinclair, Adriane J; Brilot, Fabienne; Vincent, Angela; Lang, Bethan; Dale, Russell C

2011-11-01

Autoantibodies that bind to voltage-gated potassium-channel complex proteins (VGKC-complex antibodies) occur frequently in adults with limbic encephalitis presenting with cognitive impairment and seizures. Recently, VGKC-complex antibodies have been described in a few children with limbic encephalitis, and children with unexplained encephalitis presenting with status epilepticus. We report a case of infantile-onset epileptic spasms and developmental delay compatible with epileptic encephalopathy. Our patient was a female infant, aged 4 months at presentation. She had evidence of immune activation in the central nervous system with elevated cerebrospinal fluid neopterin and mirrored oligoclonal bands, which prompted testing for autoantibodies. VGKC-complex antibodies were elevated (201 pmol/L, normalVGKC-complex antibodies might represent a marker of immune therapy responsiveness in a subgroup of patients with infantile epileptic encephalopathy. © The Authors. Developmental Medicine & Child Neurology © 2011 Mac Keith Press.

Cocoa Diet and Antibody Immune Response in Preclinical Studies

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Mariona Camps-Bossacoma

2017-06-01

Full Text Available The ability of cocoa to interact with the immune system in vitro and in vivo has been described. In the latter context, a cocoa-enriched diet in healthy rats was able to modify the immune system’s functionality. This fact could be observed in the composition and functionality of lymphoid tissues, such as the thymus, spleen, and lymph nodes. Consequently, immune effector mechanisms, such as antibody synthesis, were modified. A cocoa-enriched diet in young rats was able to attenuate the serum levels of immunoglobulin (Ig G, IgM, and IgA and also the intestinal IgM and IgA secretion. Moreover, in immunized rats, the intake of cocoa decreased specific IgG1, IgG2a, IgG2c, and IgM concentrations in serum. This immune-regulator potential was then tested in disease models in which antibodies play a pathogenic role. A cocoa-enriched diet was able to partially prevent the synthesis of autoantibodies in a model of autoimmune arthritis in rats and was also able to protect against IgE and T helper 2-related antibody synthesis in two rat models of allergy. Likewise, a cocoa-enriched diet prevented an oral sensitization process in young rats. In this review, we will focus on the influence of cocoa on the acquired branch of the immune function. Therefore, we will focus on how a cocoa diet influences lymphocyte function both in the systemic and intestinal immune system. Likewise, its potential role in preventing some antibody-induced immune diseases is also included. Although further studies must characterize the particular cocoa components responsible for such effects and nutritional studies in humans need to be carried out, cocoa has potential as a nutraceutical agent in some hypersensitivity status.

Dashboard systems: Pharmacokinetic/pharmacodynamic mediated dose optimization for monoclonal antibodies.

Science.gov (United States)

Mould, Diane R; Dubinsky, Marla C

2015-03-01

Many marketed drugs exhibit high variability in exposure and response. While these drugs are efficacious in their approved indications, finding appropriate dose regimens for individual patients is not straightforward. Similar dose adjustment problems are also seen with drugs that have a complex relationship between exposure and response and/or a narrow therapeutic window. This is particularly true for monoclonal antibodies, where prolonged dosing at a sub-therapeutic dose can also elicit anti-drug antibodies which will further compromise safety and efficacy. Thus, finding appropriate doses quickly would represent a substantial improvement in healthcare. Dashboard systems, which are decision-support tools, offer an improved, convenient means of tailoring treatment for individual patients. This article reviews the clinical need for this approach, particularly with monoclonal antibodies, the design, development, and testing of such systems, and the likely benefits of dashboard systems in clinical practice. We focus on infliximab for reference. © 2015, The American College of Clinical Pharmacology.

Immunomodulatory activity of andrographolide on macrophage activation and specific antibody response

Science.gov (United States)

Wang, Wei; Wang, Jing; Dong, Sheng-fu; Liu, Chun-hong; Italiani, Paola; Sun, Shu-hui; Xu, Jing; Boraschi, Diana; Ma, Shi-ping; Qu, Di

2010-01-01

Aim: To investigate the immunomodulatory effects of andrographolide on both innate and adaptive immune responses. Methods: Andrographolide (10 μg/mL in vitro or 1 mg/kg in vivo) was used to modulate LPS-induced classical activated (M1) or IL-4-induced alternative activated (M2) macrophages in vitro and humor immune response to HBsAg in vivo. Cytokine gene expression profile (M1 vs M2) was measured by real-time PCR, IL-12/IL-10 level was detected by ELISA, and surface antigen expression was evaluated by flow cytometry, whereas phosphorylation level of ERK 1/2 and AKT was determined by Western blot. The level of anti-HBs antibodies in HBsAg immunized mice was detected by ELISA, and the number of HBsAg specific IL-4-producing splenocyte was enumerated by ELISPOT. Results: Andrographolide treatment in vitro attenuated either LPS or IL-4 induced macrophage activation, inhibited both M1 and M2 cytokines expression and decreased IL-12/IL-10 ratio (the ratio of M1/M2 polarization). Andrographolide down-regulated the expression of mannose receptor (CD206) in IL-4 induced macrophages and major histocompability complex/costimulatory molecules (MHC I, CD40, CD80, CD86) in LPS-induced macrophages. Correspondingly, anti-HBs antibody production and the number of IL-4-producing splenocytes were reduced by in vivo administration of andrographolide. Reduced phosphorylation levels of ERK1/2 and AKT were observed in macrophages treated with andrographolide. Conclusion: Andrographolide can modulate the innate and adaptive immune responses by regulating macrophage phenotypic polarization and Ag-specific antibody production. MAPK and PI3K signaling pathways may participate in the mechanisms of andrographolide regulating macrophage activation and polarization. PMID:20139902

An efficient method for isolating antibody fragments against small peptides by antibody phage display

DEFF Research Database (Denmark)

Duan, Zhi; Siegumfeldt, Henrik

2010-01-01

We generated monoclonal scFv (single chain variable fragment) antibodies from an antibody phage display library towards three small synthetic peptides derived from the sequence of s1-casein. Key difficulties for selection of scFv-phages against small peptides were addressed. Small peptides do....... The scFvs were sequenced and characterized, and specificity was characterized by ELISA. The methods developed in this study are universally applicable for antibody phage display to efficiently produce antibody fragments against small peptides....

Antibody response to a T-cell-independent antigen is preserved after splenic artery embolization for trauma.

Science.gov (United States)

Olthof, D C; Lammers, A J J; van Leeuwen, E M M; Hoekstra, J B L; ten Berge, I J M; Goslings, J C

2014-11-01

Splenic artery embolization (SAE) is increasingly being used as a nonoperative management strategy for patients with blunt splenic injury following trauma. The aim of this study was to assess the splenic function of patients who were embolized. A clinical study was performed, with splenic function assessed by examining the antibody response to polysaccharide antigens (pneumococcal 23-valent polysaccharide vaccine), B-cell subsets, and the presence of Howell-Jolly bodies (HJB). The data were compared to those obtained from splenectomized patients and healthy controls (HC) who had been included in a previously conducted study. A total of 30 patients were studied: 5 who had proximal SAE, 7 who had distal SAE, 8 who had a splenectomy, and 10 HC. The median vaccine-specific antibody response of the SAE patients (fold increase, 3.97) did not differ significantly from that of the HC (5.29; P = 0.90); however, the median response of the splenectomized patients (2.30) did differ (P = 0.003). In 2 of the proximally embolized patients and none of the distally embolized patients, the ratio of the IgG antibody level postvaccination compared to that prevaccination was splenic immune function of embolized patients was preserved, and therefore routine vaccination appears not to be indicated. Although the median antibody responses did not differ between the patients who underwent proximal SAE and those who underwent distal SAE, 2 of the 5 proximally embolized patients had insufficient responses to vaccination, whereas none of the distally embolized patients exhibited an insufficient response. Further research should be done to confirm this finding. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Antibody responses to a major Pneumocystis carinii antigen in human immunodeficiency virus-infected patients with and without P. carinii pneumonia

DEFF Research Database (Denmark)

Lundgren, Bettina; Lundgren, Jens Dilling; Nielsen, T

1992-01-01

of pulmonary symptoms. Significantly more patients with P. carinii pneumonia (PCP) had detectable antibodies compared with HIV-infected patients without PCP and with HIV-negative controls (50 [66%] of 76 vs. 18 [34%] of 53 and 7 [35%] of 20, respectively; P less than .001), and the level of antibody response......Antibody responses to a major purified human Pneumocystis carinii surface antigen (gp95) were determined by ELISA in human immunodeficiency virus (HIV)-infected patients. Serum IgG directed against gp95 was measured in 129 consecutive HIV-infected patients who underwent bronchoscopy for evaluation...... response, compared with only 1 (3%) of 31 patients without PCP (P less than .001). This patient had PCP on the basis of clinical criteria, including response to therapy. Thus, despite severe immunosuppression, a proportion of HIV-infected patients with PCP can mount a specific IgG-mediated antibody...

A review of human anti-globulin antibody (HAGA, HAMA, HACA, HAHA) responses to monoclonal antibodies. Not four letter words

Energy Technology Data Exchange (ETDEWEB)

Mirick, G. R.; Bradt, B. M.; Denardo, S. J.; Denardo, G. L. [Calfornia Univ., Sacramento (United States). Davis Medical Center

2004-12-01

The United States Food and Drugs Administration (FDA) has approved unconjugated monoclonal antibodies (MAbs) for immunotherapy (IT) of B-cell lymphoma, breast cancer and acute myeloid leukemia. More recently, approval has been given for conjugated ZevalinTM ({sup 9}0yttrium ibritumomab tiuxetan, IDEC-Y2B8, Biogen Idec, Cambridge, MA) and BexxarTM ({sup 1}31I-tositumomab, Corixa, Corp., Seattle, WA and GlaxoSmithKline, Philadelphia, PA) antiCD20 MAns for use in radioimmunotherapy (RIT) of non-Hodgikin's lymphoma (NHL), thus redefining the standard care of cancer patients. Because of, and despite a lack of basis for concern about allergic reactions due to human antibody responses to these foreign proteins, essays were developed to determine HAGE (human anti-globulin antibody) levels that developed in patient sera following treatment with MAbs. Strategies were also devised to humanize MAbs and to temporarily block patient immune function with drugs in order to decrease the seroconversion rates, with considerable success. On the other hand, a survival advantage has been observed in some patients who developed a HAGA following treatment. This correlates with development of an anti-idiotype antibody cascade directed toward the MAbs used to treat these patients. What follows is a selective review of HAGA and its effect on cancer treatment over the past 2 decades.

Bacille Calmette-Guérin (BCG) vaccination at birth and antibody responses to childhood vaccines. A randomised clinical trial

DEFF Research Database (Denmark)

Nissen, Thomas Nørrelykke; Birk, Nina Marie; Smits, Gaby

2017-01-01

) vaccination at birth, The Danish Calmette Study, we investigated the effect of BCG at birth on the antibody response to the three routine vaccines against DiTeKiPol/Act-Hib and Prevenar 13 in a subgroup of participants. METHODS: Within 7days after birth, children were randomised 1:1 to BCG vaccination...... children (178 BCG; 122 controls), almost all children (>96%) had antibody responses above the protective levels. Overall BCG vaccination at birth did not affect the antibody level. When stratifying by 'age at randomisation' we found a possible inducing effect of BCG on antibodies against B. pertussis......-protective levels in almost all children. No overall effect of neonatal BCG vaccination was observed....

The CARD8 p.C10X mutation associates with a low anti-glycans antibody response in patients with Crohn's disease.

Science.gov (United States)

Vasseur, Francis; Sendid, Boualem; Broly, Franck; Gower-Rousseau, Corinne; Sarazin, Aurore; Standaert-Vitse, Annie; Colombel, Jean-Frederic; Poulain, Daniel; Jouault, Thierry

2013-03-18

Crohn's disease (CD) is associated with elevated anti-glycans antibody response in 60% of CD patients, and 25% of healthy first-degree relatives (HFDRs), suggesting a genetic influence for this humoral response. In mice, anti-glucan antibody response depends on the NLRP3 inflammasome. Here, we explored the effect of mutated CARD8, a component of the inflammasome, on anti-glycans antibody response in human. The association between p.C10X mutation (rs2043211) of the CARD8 gene and the levels of anti-glycans antibody response was examined in 39 CD families. The family-based QTDT association test was used to test for the genetic association between CARD8 p.C10X mutation and anti-glycan antibodies in the pedigrees. The difference in antibody responses determined by ELISA was tested in a subgroup of CD probands (one per family) and in a subgroup of HFDRs using the Wilcoxon Kruskal Wallis non-parametric test. The QTDT familial transmission tests showed that the p.C10X mutation of CARD8 was significantly associated with lower levels of antibody to mannans and glucans but not chitin (p=0.024, p=0.0028 and p=0.577, for ASCA, ALCA and ACCA, respectively). These associations were independent of NOD2 and NOD1 genetic backgrounds. The p.C10X mutation significantly associated or displayed a trend toward lower ASCA and ALCA levels (p=0.038 and p=0.08, respectively) only in the subgroup of CD probands. Such associations were not significant for ACCA levels in both subgroups of CD probands and of HFDRs. Our results show that ASCA and ALCA but not ACCA levels are under the influence of CARD8 genotype. Alteration of CARD8, a component of inflammasome, is associated with lower levels of antibodies directed to mannans and glucans at least in CD patients.

Reduced antibody responses against Plasmodium falciparum vaccine candidate antigens in the presence of Trichuris trichiura

DEFF Research Database (Denmark)

Esen, Meral; Mordmüller, Benjamin; de Salazar, Pablo Martinez

2012-01-01

BACKGROUND: Helminth infections are highly prevalent in the tropics and may have an effect on immune responses to vaccines due to their immunomodulatory effect. The prevalence of helminth infections in young children, the target group for malaria and most other vaccines, is high. Therefore we...... assessed the influence of helminth infection on vaccine-induced immune responses in a phase I clinical trial of the malaria vaccine candidate GMZ2. METHODS: Twenty Gabonese preschool-age children were vaccinated with GMZ2, a blood stage malaria vaccine candidate. Humoral immune response against the vaccine...... antigens and parasitological status were assessed. Vaccine-specific antibody concentrations and memory B-cell numbers were compared in worm infected and non-infected participants. RESULTS: Antibody response to GMZ2 was 3.4-fold (95% confidence interval: 1.6, 7.4) higher in Trichuris trichiura negative...

Kotai Antibody Builder: automated high-resolution structural modeling of antibodies.

Science.gov (United States)

Yamashita, Kazuo; Ikeda, Kazuyoshi; Amada, Karlou; Liang, Shide; Tsuchiya, Yuko; Nakamura, Haruki; Shirai, Hiroki; Standley, Daron M

2014-11-15

Kotai Antibody Builder is a Web service for tertiary structural modeling of antibody variable regions. It consists of three main steps: hybrid template selection by sequence alignment and canonical rules, 3D rendering of alignments and CDR-H3 loop modeling. For the last step, in addition to rule-based heuristics used to build the initial model, a refinement option is available that uses fragment assembly followed by knowledge-based scoring. Using targets from the Second Antibody Modeling Assessment, we demonstrate that Kotai Antibody Builder generates models with an overall accuracy equal to that of the best-performing semi-automated predictors using expert knowledge. Kotai Antibody Builder is available at http://kotaiab.org standley@ifrec.osaka-u.ac.jp. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Generation of “LYmph Node Derived Antibody Libraries” (LYNDAL) for selecting fully human antibody fragments with therapeutic potential.

Science.gov (United States)

Diebolder, Philipp; Keller, Armin; Haase, Stephanie; Schlegelmilch, Anne; Kiefer, Jonathan D; Karimi, Tamana; Weber, Tobias; Moldenhauer, Gerhard; Kehm, Roland; Eis-Hübinger, Anna M; Jäger, Dirk; Federspil, Philippe A; Herold-Mende, Christel; Dyckhoff, Gerhard; Kontermann, Roland E; Arndt, Michaela A E; Krauss, Jürgen

2014-01-01

The development of efficient strategies for generating fully human monoclonal antibodies with unique functional properties that are exploitable for tailored therapeutic interventions remains a major challenge in the antibody technology field. Here, we present a methodology for recovering such antibodies from antigen-encountered human B cell repertoires. As the source for variable antibody genes, we cloned immunoglobulin G (IgG)-derived B cell repertoires from lymph nodes of 20 individuals undergoing surgery for head and neck cancer. Sequence analysis of unselected “LYmph Node Derived Antibody Libraries” (LYNDAL) revealed a naturally occurring distribution pattern of rearranged antibody sequences, representing all known variable gene families and most functional germline sequences. To demonstrate the feasibility for selecting antibodies with therapeutic potential from these repertoires, seven LYNDAL from donors with high serum titers against herpes simplex virus (HSV) were panned on recombinant glycoprotein B of HSV-1. Screening for specific binders delivered 34 single-chain variable fragments (scFvs) with unique sequences. Sequence analysis revealed extensive somatic hypermutation of enriched clones as a result of affinity maturation. Binding of scFvs to common glycoprotein B variants from HSV-1 and HSV-2 strains was highly specific, and the majority of analyzed antibody fragments bound to the target antigen with nanomolar affinity. From eight scFvs with HSV-neutralizing capacity in vitro,the most potent antibody neutralized 50% HSV-2 at 4.5 nM as a dimeric (scFv)2. We anticipate our approach to be useful for recovering fully human antibodies with therapeutic potential.

Development of new versions of anti-human CD34 monoclonal antibodies with potentially reduced immunogenicity

International Nuclear Information System (INIS)

Qian Weizhu; Wang Ling; Li Bohua; Wang Hao; Hou Sheng; Hong Xueyu; Zhang Dapeng; Guo Yajun

2008-01-01

Despite the widespread clinical use of CD34 antibodies for the purification of human hematopoietic stem/progenitor cells, all the current anti-human CD34 monoclonal antibodies (mAbs) are murine, which have the potential to elicit human antimouse antibody (HAMA) immune response. In the present study, we developed three new mouse anti-human CD34 mAbs which, respectively, belonged to class I, class II and class III CD34 epitope antibodies. In an attempt to reduce the immunogenicity of these three murine mAbs, their chimeric antibodies, which consisted of mouse antibody variable regions fused genetically to human antibody constant regions, were constructed and characterized. The anti-CD34 chimeric antibodies were shown to possess affinity and specificity similar to that of their respective parental murine antibodies. Due to the potentially better safety profiles, these chimeric antibodies might become alternatives to mouse anti-CD34 antibodies routinely used for clinical application

The monoclonal S9.6 antibody exhibits highly variable binding affinities towards different R-loop sequences.

Directory of Open Access Journals (Sweden)

Fabian König

Full Text Available The monoclonal antibody S9.6 is a widely-used tool to purify, analyse and quantify R-loop structures in cells. A previous study using the surface plasmon resonance technology and a single-chain variable fragment (scFv of S9.6 showed high affinity (0.6 nM for DNA-RNA and also a high affinity (2.7 nM for RNA-RNA hybrids. We used the microscale thermophoresis method allowing surface independent interaction studies and electromobility shift assays to evaluate additional RNA-DNA hybrid sequences and to quantify the binding affinities of the S9.6 antibody with respect to distinct sequences and their GC-content. Our results confirm high affinity binding to previously analysed sequences, but reveals that binding affinities are highly sequence specific. Our study presents R-loop sequences that independent of GC-content and in different sequence variations exhibit either no binding, binding affinities in the micromolar range and as well high affinity binding in the nanomolar range. Our study questions the usefulness of the S9.6 antibody in the quantitative analysis of R-loop sequences in vivo.

Diagnostic and immunological aspects of the antibody response to human cytomegalvirus infection

NARCIS (Netherlands)

Middeldorp, Jaap Michiel

1985-01-01

The studies described in this thesis were initiated with three main aims: First, to develop a practical and sensitive method for serodiagnosis of Human cytomegoal virus ( CMV)-infections and to determine the relative diagnostic value of IgM and IgG antibody responses to distinct CMV-antigens.

An alphavirus vector overcomes the presence of neutralizing antibodies and elevated numbers of Tregs to induce immune responses in humans with advanced cancer.

Science.gov (United States)

Morse, Michael A; Hobeika, Amy C; Osada, Takuya; Berglund, Peter; Hubby, Bolyn; Negri, Sarah; Niedzwiecki, Donna; Devi, Gayathri R; Burnett, Bruce K; Clay, Timothy M; Smith, Jonathan; Lyerly, H Kim

2010-09-01

Therapeutic anticancer vaccines are designed to boost patients' immune responses to tumors. One approach is to use a viral vector to deliver antigen to in situ DCs, which then activate tumor-specific T cell and antibody responses. However, vector-specific neutralizing antibodies and suppressive cell populations such as Tregs remain great challenges to the efficacy of this approach. We report here that an alphavirus vector, packaged in virus-like replicon particles (VRP) and capable of efficiently infecting DCs, could be repeatedly administered to patients with metastatic cancer expressing the tumor antigen carcinoembryonic antigen (CEA) and that it overcame high titers of neutralizing antibodies and elevated Treg levels to induce clinically relevant CEA-specific T cell and antibody responses. The CEA-specific antibodies mediated antibody-dependent cellular cytotoxicity against tumor cells from human colorectal cancer metastases. In addition, patients with CEA-specific T cell responses exhibited longer overall survival. These data suggest that VRP-based vectors can overcome the presence of neutralizing antibodies to break tolerance to self antigen and may be clinically useful for immunotherapy in the setting of tumor-induced immunosuppression.

Identification and verification of hybridoma-derived monoclonal antibody variable region sequences using recombinant DNA technology and mass spectrometry.

Science.gov (United States)

Babrak, Lmar; McGarvey, Jeffery A; Stanker, Larry H; Hnasko, Robert

2017-10-01

Antibody engineering requires the identification of antigen binding domains or variable regions (VR) unique to each antibody. It is the VR that define the unique antigen binding properties and proper sequence identification is essential for functional evaluation and performance of recombinant antibodies (rAb). This determination can be achieved by sequence analysis of immunoglobulin (Ig) transcripts obtained from a monoclonal antibody (MAb) producing hybridoma and subsequent expression of a rAb. However the polyploidy nature of a hybridoma cell often results in the added expression of aberrant immunoglobulin-like transcripts or even production of anomalous antibodies which can confound production of rAb. An incorrect VR sequence will result in a non-functional rAb and de novo assembly of Ig primary structure without a sequence map is challenging. To address these problems, we have developed a methodology which combines: 1) selective PCR amplification of VR from both the heavy and light chain IgG from hybridoma, 2) molecular cloning and DNA sequence analysis and 3) tandem mass spectrometry (MS/MS) on enzyme digests obtained from the purified IgG. Peptide analysis proceeds by evaluating coverage of the predicted primary protein sequence provided by the initial DNA maps for the VR. This methodology serves to both identify and verify the primary structure of the MAb VR for production as rAb. Published by Elsevier Ltd.

Minor human antibody response to a mouse and chimeric monoclonal antibody after a single i.v. infusion in ovarian carcinoma patients: a comparison of five assays

NARCIS (Netherlands)

Buist, M. R.; Kenemans, P.; van Kamp, G. J.; Haisma, H. J.

1995-01-01

The human anti-(mouse Ig) antibody (HAMA) response was measured in serum of 52 patients suspected of having ovarian carcinoma who had received an i.v. injection of either the murine monoclonal antibody (mAb) OV-TL 3 F(ab')2 (n = 28, 1 mg) or the chimeric mouse/human mAb MOv18 (cMOv18; n = 24, 3 mg).

Antibody response in the female rabbit reproductive tract to influenza haemagglutinin encoded by a recombinant myxoma virus

International Nuclear Information System (INIS)

Gu Wenyi; Holland, Michael; Janssens, Peter; Kerr, Peter

2003-01-01

The antibody response in serum and the reproductive tract of female rabbits to a model antigen, influenza virus haemagglutinin (HA), encoded by a recombinant myxoma virus was investigated. Strong and lasting IgG antibody responses to HA were induced in serum following intradermal, intranasal, and intravaginal immunisations. HA IgG was also detected in reproductive tract fluids but was only about 1% the titer of that in serum. HA IgA was not detected in serum of any infected groups and was occasionally detected in reproductive tract fluids at a low titer only after infections through mucosal sites. HA IgM was also detected only in some of the reproductive tract fluids at very low levels. Induction of ovulation did not change these patterns and B cell homing to the reproductive tract was not profound. In contrast, HA IgG and IgM titers in ovarian follicular fluids were comparable to that in serum. These data suggest that if this virus is used to deliver an immunocontraceptive vaccine that requires a high-level antibody response, the target antigen needs to be accessible to serum antibody or in the ovary

Effects of sublethal gamma radiation on T and B cell activity in the antibody response of mice

International Nuclear Information System (INIS)

Carlson, D.E.; Lubet, R.A.

1976-01-01

The relative radiosensitivity of T and B cells was followed in sublethally irradiated mice reconstituted with bone marrow cells, thymus cells, or both, and simultaneously challenged with sheep erythrocytes. Numbers of antibody-forming cells in recipient spleens were determined on days 4 to 8. In this assay the response of mice given bone marrow cells was limited by the amount of residual T cell activity, while the response of mice given thymus cells was limited by the residual B cell activity. Although residual activity of both T and B cells was suppressed in mice given 300 to 700 rad at 80 rad/min, residual B cell activity was consistently lower in these animals. When antibody responses were initiated at intervals after irradiation, B cell activity was clearly limiting by 48 hr after 500 or 600 rad. The activity of both T and B cells was sensitive to differences in dose rate between 8 and 80 rad/min. The 4 to 7 fold dose-rate sensitivity of T cells paralleled that of differentially irradiated nonreconstituted mice. In contrast, dose-rate dependence of B cell activity varied from 10- to 20-fold between 8 and 80 rad/min. These results suggest that radiation suppression of antibody responses in mice is highly dependent upon B cell sensitivity, and that dose-rate dependence of the antibody response may be explained in large part by differential sensitivity of B cells

Naturally acquired antibody responses to recombinant Pfs230 and Pfs48/45 transmission blocking vaccine candidates.

Science.gov (United States)

Jones, Sophie; Grignard, Lynn; Nebie, Issa; Chilongola, Jaffu; Dodoo, Daniel; Sauerwein, Robert; Theisen, Michael; Roeffen, Will; Singh, Shrawan Kumar; Singh, Rajesh Kumar; Singh, Sanjay; Kyei-Baafour, Eric; Tetteh, Kevin; Drakeley, Chris; Bousema, Teun

2015-07-01

Pfs48/45 and Pfs230 are Plasmodium falciparum sexual stage proteins and promising malaria transmission-blocking vaccine candidates. Antibody responses against these proteins may be naturally acquired and target antigens may be under selective pressure. This has consequences for the future evaluation of vaccine immunogenicity and efficacy in populations naturally exposed to malaria. We determined naturally acquired antibody responses to the recombinant proteins Pfs48/45-10C and Pfs230-230CMB in children from three malaria endemic settings in Ghana, Tanzania and Burkina Faso. We also examined genetic polymorphisms in the P. falciparum gene pfs48/45. Antibody prevalence was 1.1-18.2% for 10C and 6.7-18.9% for 230CMB. In Burkina Faso we observed evidence of an age-dependent acquisition pattern for both 10C (p < 0.001) and 230CMB (p = 0.031). Membrane feeding assays on a separate dataset demonstrated an association between functional transmission reducing activity and antibody prevalence for both 10C (p = 0.017) and 230CMB (p = 0.049). 17 single nucleotide polymorphisms were found in pfs48/45 (from 126 samples), with 5 non-synonymous SNPs in the Pfs48/45 10C region. We conclude there are naturally acquired antibody responses to both vaccine candidates which have functional relevance by reducing the transmissibility of infected individuals. We identified genetic polymorphisms, in pfs48/45 which exhibited geographical specificity. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Homologous and heterologous antibody responses of mice immunized with purified feline herpesvirus type 1 and canine herpesvirus glycoproteins.

Science.gov (United States)

Limcumpao, J A; Horimoto, T; Xuan, X N; Tohya, Y; Azetaka, M; Takahashi, E; Mikami, T

1991-06-01

The three glycoproteins each of feline herpesvirus type 1 (FHV-1) and canine herpesvirus (CHV) were purified by affinity chromatography using glycoprotein-specific monoclonal antibodies and used individually or in combination in immunizing mice to determine their relative immunogenicity. All the glycoproteins induced detectable virus neutralizing antibodies to the homologous virus but FHV-1 gp143/108 and its cross-reacting counterpart, CHV gp145/112, elicited the highest titers not only to the homologous virus but to the heterologous virus as well. The production of ELISA antibodies after glycoprotein immunization was variable, while hemagglutination-inhibiting antibodies were produced by only 1 out of 10 FHV-1 gp60-inoculated mice. In general, the antibody titers induced by CHV glycoproteins were lower than those by FHV-1 glycoproteins. These results indicate that these glycoproteins may be useful as subunit vaccines against FHV-1 and CHV infections.

Treatment with belimumab in systemic lupus erythematosus does not impair antibody response to 13-valent pneumococcal conjugate vaccine.

Science.gov (United States)

Nagel, J; Saxne, T; Geborek, P; Bengtsson, A A; Jacobsen, S; Svaerke Joergensen, C; Nilsson, J-Å; Skattum, L; Jönsen, A; Kapetanovic, M C

2017-09-01

Background/purpose The objective of this study was to explore the impact of systemic lupus erythematosus and belimumab given in addition to standard of care therapy on 13-valent conjugated pneumococcal vaccine (PCV13) response. Methods Forty-seven systemic lupus erythematosus patients and 21 healthy controls were immunized with a single dose of 13-valent conjugated pneumococcal vaccine. Forty systemic lupus erythematosus patients were treated with traditional disease-modifying anti rheumatic drugs, 11 of those received belimumab in addition, and 32 patients were treated with concomitant prednisolone. Quantification of serotype specific IgG levels to 12 pneumococcal capsular polysaccharides was performed in serum taken before and four to six weeks after vaccination using multiplex fluorescent microsphere immunoassay. IgG levels against serotypes 23F and 6B were also analyzed using standard enzyme-linked immunosorbent assays. Opsonophagocytic assay was performed on serotype 23F to evaluate the functionality of the antibodies. Pre- and post-vaccination log transformed antibody levels were compared to determine the impact of systemic lupus erythematosus diagnosis and different treatments on antibody response. Results Systemic lupus erythematosus patients as a group showed lower post-vaccination antibody levels and lower fold increase of antibody levels after vaccination compared to controls ( p = 0.02 and p = 0.009, respectively). Systemic lupus erythematosus patients treated with belimumab in addition to standard of care therapy or with only hydroxychloroquine did not differ compared to controls, whereas the other treatment groups had significantly lower fold increase of post-vaccination antibody levels. Higher age was associated with lower post-vaccination antibody levels among systemic lupus erythematosus patients. Conclusion Belimumab given in addition to traditional disease-modifying anti rheumatic drugs or prednisolone did not further impair antibody

Stratification of Antibody-Positive Subjects by Antibody Level Reveals an Impact of Immunogenicity on Pharmacokinetics

OpenAIRE

Zhou, Lei; Hoofring, Sarah A.; Wu, Yu; Vu, Thuy; Ma, Peiming; Swanson, Steven J.; Chirmule, Narendra; Starcevic, Marta

2012-01-01

The availability of highly sensitive immunoassays enables the detection of antidrug antibody (ADA) responses of various concentrations and affinities. The analysis of the impact of antibody status on drug pharmacokinetics (PK) is confounded by the presence of low-affinity or low-concentration antibody responses within the dataset. In a phase 2 clinical trial, a large proportion of subjects (45%) developed ADA following weekly dosing with AMG 317, a fully human monoclonal antibody therapeutic....

Antibody response to booster vaccination with tetanus and diphtheria in adults exposed to perfluorinated alkylates.

Science.gov (United States)

Kielsen, Katrine; Shamim, Zaiba; Ryder, Lars P; Nielsen, Flemming; Grandjean, Philippe; Budtz-Jørgensen, Esben; Heilmann, Carsten

2016-01-01

Recent studies suggest that exposure to perfluorinated alkylate substances (PFASs) may induce immunosuppression in humans and animal models. In this exploratory study, 12 healthy adult volunteers were recruited. With each subject, serum-PFAS concentrations were measured and their antibody responses prospectively followed for 30 days after a booster vaccination with diphtheria and tetanus. The results indicated that serum-PFAS concentrations were positively correlated and positively associated with age and male sex. The specific antibody concentrations in serum were increased from Day 4 to Day 10 post-booster, after which a constant concentration was reached. Serum PFAS concentrations showed significant negative associations with the rate of increase in the antibody responses. Interestingly, this effect was particularly strong for the longer-chain PFASs. All significant associations remained significant after adjustment for sex and age. Although the study involved a small number of subjects, these findings of a PFAS-associated reduction of the early humoral immune response to booster vaccination in healthy adults supported previous findings of PFAS immunosuppression in larger cohorts. Furthermore, the results suggested that cellular mechanisms right after antigen exposure should be investigated more closely to identify possible mechanisms of immunosuppression from PFAS.

Rapid isolation of antibody from a synthetic human antibody library by repeated fluorescence-activated cell sorting (FACS.

Directory of Open Access Journals (Sweden)

Sung Sun Yim

Full Text Available Antibodies and their derivatives are the most important agents in therapeutics and diagnostics. Even after the significant progress in the technology for antibody screening from huge libraries, it takes a long time to isolate an antibody, which prevents a prompt action against the spread of a disease. Here, we report a new strategy for isolating desired antibodies from a combinatorial library in one day by repeated fluorescence-activated cell sorting (FACS. First, we constructed a library of synthetic human antibody in which single-chain variable fragment (scFv was expressed in the periplasm of Escherichia coli. After labeling the cells with fluorescent antigen probes, the highly fluorescent cells were sorted by using a high-speed cell sorter, and these cells were reused without regeneration in the next round of sorting. After repeating this sorting, the positive clones were completely enriched in several hours. Thus, we screened the library against three viral antigens, including the H1N1 influenza virus, Hepatitis B virus, and Foot-and-mouth disease virus. Finally, the potential antibody candidates, which show K(D values between 10 and 100 nM against the target antigens, could be successfully isolated even though the library was relatively small (∼ 10(6. These results show that repeated FACS screening without regeneration of the sorted cells can be a powerful method when a rapid response to a spreading disease is required.

Studies on the antibody response of mice and humans after immunization with potential influenza virus A (H1N1) vaccines

International Nuclear Information System (INIS)

Poumbourios, P.; Jackson, D.C.; Oxford, J.S.

1993-01-01

The antibody response of mice and adult humans to immunization with subunit vaccines derived from a pair of antigenically distinct influenza A H1N1 viruses isolate in eggs was investigated. Although the haemagglutinin molecule of each virus differed by only three amino acid residues, highly specific antibody responses were elicited in mice as determined by haemagglutination inhibition and radioimmunoprecipitation assays. Results from competitive radioimmunoassays using monoclonal antibodies of known specificity and a study of the reactivity of mouse antisera with H1N1 field strains indicated that the marked differences in the antibody responses to the two vaccines was due to an amino acid substitution in the distal tip of the haemagglutinin molecule. In contrast, cross reactive antibody responses were elicited in humans presumably due to exposure to viruses related to the candidate vaccine prior to vaccination. Although immunogenic differences are apparent in this pair of antigenically distinct viruses in naive laboratory animals, these differences are not apparent following vaccination of humans that had prior exposure to related viruses. 21 refs., 5 tabs., 4 figs

Protective immunization with B16 melanoma induces antibody response and not cytotoxic T cell response

International Nuclear Information System (INIS)

Sarzotti, M.; Sriyuktasuth, P.; Klimpel, G.R.; Cerny, J.

1986-01-01

C57BL/6 mice immunized with three intraperitoneal injections of syngeneic, irradiated B16 melanoma cells, became resistant to B16 tumor challenge. Immunized mice had high levels of serum antibody against a membrane antigen of B16 cells. The B16 antigen recognized by the anti-B16 sera formed a major band of 90 KD in gel electrophoresis. The anti-B16 antibody was partially protective when mixed with B16 cells and injected into normal recipient mice. Surprisingly, B16 resistance mice were incapable of generating cytotoxic T cells (CTL) specific for the B16 tumor. Both spleen and lymph node cell populations from immunized mice did not generate B16-specific CTL. Allogeneic mice (DBA/2 or C3H) were also unable to generate B16-specific CTL: however, alloreactive CTL produced in these strains of mice by immunization with C57BL/6 lymphocytes, did kill B16 target cells. Interestingly, spleen cells from syngeneic mice immunized with B16 tumor produced 6-fold more interleukin-2 (IL-2) than normal spleen cells, in vitro. These data suggest that immunization with B16 tumor activates a helper subset of T cells (for antibody and IL-2 production) but not the effector CTL response

Antibodies and Selection of Monoclonal Antibodies.

Science.gov (United States)

Hanack, Katja; Messerschmidt, Katrin; Listek, Martin

Monoclonal antibodies are universal binding molecules with a high specificity for their target and are indispensable tools in research, diagnostics and therapy. The biotechnological generation of monoclonal antibodies was enabled by the hybridoma technology published in 1975 by Köhler and Milstein. Today monoclonal antibodies are used in a variety of applications as flow cytometry, magnetic cell sorting, immunoassays or therapeutic approaches. First step of the generation process is the immunization of the organism with appropriate antigen. After a positive immune response the spleen cells are isolated and fused with myeloma cells in order to generate stable, long-living antibody-producing cell lines - hybridoma cells. In the subsequent identification step the culture supernatants of all hybridoma cells are screened weekly for the production of the antibody of interest. Hybridoma cells producing the antibody of interest are cloned by limited dilution till a monoclonal hybridoma is found. This is a very time-consuming and laborious process and therefore different selection strategies were developed since 1975 in order to facilitate the generation of monoclonal antibodies. Apart from common automation of pipetting processes and ELISA testing there are some promising approaches to select the right monoclonal antibody very early in the process to reduce time and effort of the generation. In this chapter different selection strategies for antibody-producing hybridoma cells are presented and analysed regarding to their benefits compared to conventional limited dilution technology.

Naturally acquired antibody responses to recombinant Pfs230 and Pfs48/45 transmission blocking vaccine candidates

DEFF Research Database (Denmark)

Jones, Sophie; Grignard, Lynn; Nebie, Issa

2015-01-01

for the future evaluation of vaccine immunogenicity and efficacy in populations naturally exposed to malaria. METHODS: We determined naturally acquired antibody responses to the recombinant proteins Pfs48/45-10C and Pfs230-230CMB in children from three malaria endemic settings in Ghana, Tanzania and Burkina Faso......OBJECTIVES: Pfs48/45 and Pfs230 are Plasmodium falciparum sexual stage proteins and promising malaria transmission-blocking vaccine candidates. Antibody responses against these proteins may be naturally acquired and target antigens may be under selective pressure. This has consequences....... We also examined genetic polymorphisms in the P. falciparum gene pfs48/45. RESULTS: Antibody prevalence was 1.1-18.2% for 10C and 6.7-18.9% for 230CMB. In Burkina Faso we observed evidence of an age-dependent acquisition pattern for both 10C (p assays...

Deciphering allogeneic antibody response against native and denatured HLA epitopes in organ transplantation.

Science.gov (United States)

Visentin, Jonathan; Guidicelli, Gwendaline; Moreau, Jean-François; Lee, Jar-How; Taupin, Jean-Luc

2015-07-01

Anti-HLA donor-specific antibodies are deleterious for organ transplant survival. Class I HLA donor-specific antibodies are identified by using the Luminex single antigen beads (LSAB) assay, which also detects anti-denatured HLA antibodies (anti-dHLAs). Anti-dHLAs are thought to be unable to recognize native HLA (nHLA) on the cell surface and therefore to be clinically irrelevant. Acid denaturation of nHLA on LSAB allows anti-dHLAs to be discriminated from anti-nHLAs. We previously defined a threshold for the ratio between mean fluorescence intensity against acid-treated (D for denaturation) and nontreated (N) LSAB, D ≥ 1.2 N identifying the anti-dHLAs. However, some anti-dHLAs remained able to bind nHLA on lymphocytes in flow cytometry crossmatches, and some anti-nHLAs conserved significant reactivity toward acid-treated LSAB. After depleting serum anti-nHLA reactivity with HLA-typed cells, we analyzed the residual LSAB reactivity toward nontreated and acid-treated LSABs, and then evaluated the ability of antibodies to recognize nHLA alleles individually. We observed that sera can contain mixtures of anti-nHLAs and anti-dHLAs, or anti-nHLAs recognizing acid-resistant epitopes, all possibly targeting the same allele(s). Therefore, the anti-HLA antibody response can be highly complex and subtle, as is the accurate identification of pathogenic anti-HLA antibodies in human serum. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative serology assays for determination of antibody responses to Ebola virus glycoprotein and matrix protein in nonhuman primates and humans.

Science.gov (United States)

Vu, Hong; Shulenin, Sergey; Grolla, Allen; Audet, Jonathan; He, Shihua; Kobinger, Gary; Unfer, Robert C; Warfield, Kelly L; Aman, M Javad; Holtsberg, Frederick W

2016-02-01

The West Africa Ebola virus disease (EVD) outbreak has reached unprecedented magnitude and caused worldwide concerns for the spread of this deadly virus. Recent findings in nonhuman primates (NHPs) demonstrate that antibodies can be protective against EVD. However, the role of antibody response in vaccine-mediated protection is not fully understood. To address these questions quantitative serology assays are needed for measurement of the antibody response to key Ebola virus (EBOV) proteins. Serology enzyme-linked immunosorbent assays (ELISA's), using a reference detection antibody, were developed in order to standardize the quantitation of antibody levels in vaccinated NHPs or in humans exposed to EBOV or immunized with an EBOV vaccine. Critical reagents were generated to support the development of the serology ELISAs. Recombinant EBOV matrix protein (VP40) was expressed in Escherichia coli and purified. Two variants of the glycoprotein (GP), the ectodomain lacking the transmembrane domain (GPΔTM), and an engineered GP lacking the mucin-like domain (GPΔmuc) were expressed and purified from mammalian cell systems. Using these proteins, three ELISA methods were developed and optimized for reproducibility and robustness, including stability testing of critical reagents. The assay was used to determine the antibody response against VP40, GPΔTM, and GPΔmuc in a NHP vaccine study using EBOV virus-like particles (VLP) vaccine expressing GP, VP40 and the nucleoprotein. Additionally, these ELISAs were used to successfully detect antibody responses to VP40, GPΔTM and GPΔmuc in human sera from EBOV infected individuals. Copyright © 2015 Elsevier B.V. All rights reserved.

N-linked glycosylation of the immunoglobulin variable region

NARCIS (Netherlands)

van de Bovenkamp, Fleur S.; Derksen, Ninotska I. L.; Ooijevaar-de Heer, Pleuni; van Schie, Karin A.; Kruithof, Simone; Berkowska, Magdalena A.; van der Schoot, C. Ellen; Ijspeert, Hanna; van der Burg, Mirjam; Gils, Ann; Hafkenscheid, Lise; Toes, René E. M.; Rombouts, Yoann; Plomp, Rosina; Wuhrer, Manfred; van Ham, S. Marieke; Vidarsson, Gestur; Rispens, Theo

2018-01-01

N-glycosylation sites are introduced at positions in which glycans can affect antigen binding as a result of a specific clustering of progenitor glycosylation sites in the germline sequences of variable domain genes. By analyzing multiple human monoclonal and polyclonal (auto)antibody responses, we

Antibody responses in pregnancy-induced transmammary transmission of Ancylostoma caninum hookworm larvae.

Science.gov (United States)

Arasu, P; Heller, A

1999-09-20

Third stage larvae of the Ancylostoma caninum hookworm nematode have the capacity to infect a dog, abort the normal maturation pathway to become blood-feeding intestinal worms, and instead distribute throughout the body in a developmentally arrested state that is relatively resilient to most chemotherapeutic agents. During pregnancy, a percentage of the arrested larvae reactivate and transmit via the mammary glands to infect the nursing puppies with resulting iron-deficiency anemia and potential mortality. To determine if the suppression of parasite-specific antibody responses during pregnancy facilitates the reactivation and transmammary transfer of hookworm larvae, a murine model of A. caninum infection was used to compare the infected versus uninfected animals that were either bred or not bred. Initial comparisons of genetically divergent BALB/c versus C57BL/6 mice showed that both the strains mounted strong Th2 biased IgG1 and IgE antibody responses to A. caninum infection. Using the BALB/c strain for the breeding analyses, it was confirmed that larval transfer to the mouse pups only occurred during the post-partum lactational period. In the dams, levels of total and antigen-specific IgG1 and total IgE were highly correlated with parasite burden. During most phases of pregnancy and lactation, infected dams had lower total IgG1, IgG2a and IgE levels as compared to unbred mice at comparable times post-infection; this downward modulation of antibody responses supports the established dogma of a generalized immunosuppression associated with pregnancy. However, at parturition and post-partum lactation, antigen-specific IgG1 levels measured at 1:5000 serum dilutions were comparable between bred and unbred mice, and antigen-specific IgG2a levels at 1:100 serum dilutions were also not significantly different except for a marginal reduction in the bred mice at the lactational timepoint. The comparable anti-A. caninum IgG1 levels between bred and unbred mice, and low

Antibody Responses of Cervids (Cervus elaphus) following Experimental Mycobacterium bovis Infection and the Implications for Immunodiagnosis ▿

Science.gov (United States)

Harrington, Noel P.; Surujballi, Om P.; Prescott, John F.; Duncan, J. Robert; Waters, W. Ray; Lyashchenko, Konstantin; Greenwald, Rena

2008-01-01

Captive and free-ranging wildlife animals are implicated in the maintenance and transmission of bovine tuberculosis and therefore pose a significant obstacle to eradication of the disease from domestic livestock. The current antemortem diagnostic method, the intradermal tuberculin skin test, is impractical for routine use with many wild animals. Antibody-based assays are particularly attractive because the animals are handled only once and immediate processing of the sample is not required. This report characterizes the antibody responses of red deer-elk hybrids (Cervus elaphus) against Mycobacterium bovis and subsequently evaluates the diagnostic performance of select antigens in a rapid-test format. Sequential serum samples were collected from 10 animals experimentally infected with M. bovis and 5 noninfected animals over a 7-month period postinfection (p.i.). Samples were evaluated by enzyme-linked immunosorbent assays, immunoblot analyses, and multiantigen print immunoassays for seroreactivity to mycobacterial antigens. Although all infected animals produced antibodies to M. bovis protein antigens, there was significant animal-to-animal variation in the kinetics and magnitudes of responses and the antigens recognized. The most frequently recognized antigens included MPB83, ESAT-6, CFP10, and MPB70. Responses to some antigens, such as MPB83, were consistently detected as early as 4 weeks after inoculation, whereas other antigens were detected only much later (>140 days p.i.). Antibody responses were boosted by injection of tuberculin for intradermal tuberculin skin testing. Comparison of single-antigen (fluorescence polarization assay) with multiantigen (CervidTB STAT-PAK) rapid tests demonstrated that a highly sensitive and specific serodiagnostic test for tuberculosis in cervids will require multiple and carefully selected seroreactive antigens covering a broad spectrum of antibody specificities. PMID:18815233

Adoptive transfer of natural antibodies to non-immunized chickens affects subsequent antigen-specific humoral and cellular immune responses

NARCIS (Netherlands)

Lammers, A.; Klomp, M.E.V.; Nieuwland, M.G.B.; Savelkoul, H.F.J.; Parmentier, H.K.

2004-01-01

To determine a regulatory function of natural antibodies in the immune response of chickens, pooled plasma obtained from non-immunized (naive) 15 months old hens was subjected to keyhole limpet hemocyanin (KLH) antigen-affinity chromatography. Purified KLH-binding antibodies were adoptively

Cloning and molecular characterization of the cDNAs encoding the variable regions of an anti-CD20 monoclonal antibody.

Science.gov (United States)

Shanehbandi, Dariush; Majidi, Jafar; Kazemi, Tohid; Baradaran, Behzad; Aghebati-Maleki, Leili

2017-01-01

CD20-based targeting of B-cells in hematologic malignancies and autoimmune disorders is associated with outstanding clinical outcomes. Isolation and characterization of VH and VL cDNAs encoding the variable regions of the heavy and light chains of monoclonal antibodies (MAb) is necessary to produce next generation MAbs and their derivatives such as bispecific antibodies (bsAb) and single-chain variable fragments (scFv). This study was aimed at cloning and characterization of the VH and VL cDNAs from a hybridoma cell line producing an anti-CD20 MAb. VH and VL fragments were amplified, cloned and characterized. Furthermore, amino acid sequences of VH, VL and corresponding complementarity-determining regions (CDR) were determined and compared with those of four approved MAbs including Rituximab (RTX), Ibritumomab tiuxetan, Ofatumumab and GA101. The cloned VH and VL cDNAs were found to be functional and follow a consensus pattern. Amino acid sequences corresponding to the VH and VL fragments also indicated noticeable homologies to those of RTX and Ibritumomab. Furthermore, amino acid sequences of the relating CDRs had remarkable similarities to their counterparts in RTX and Ibritumomab. Successful recovery of VH and VL fragments encourages the development of novel CD20 targeting bsAbs, scFvs, antibody conjugates and T-cells armed with chimeric antigen receptors.

Differential Antibody Responses to Conserved HIV-1 Neutralizing Epitopes in the Context of Multivalent Scaffolds and Native-Like gp140 Trimers.

Science.gov (United States)

Morris, Charles D; Azadnia, Parisa; de Val, Natalia; Vora, Nemil; Honda, Andrew; Giang, Erick; Saye-Francisco, Karen; Cheng, Yushao; Lin, Xiaohe; Mann, Colin J; Tang, Jeffrey; Sok, Devin; Burton, Dennis R; Law, Mansun; Ward, Andrew B; He, Linling; Zhu, Jiang

2017-02-28

Broadly neutralizing antibodies (bNAbs) have provided valuable insights into the humoral immune response to HIV-1. While rationally designed epitope scaffolds and well-folded gp140 trimers have been proposed as vaccine antigens, a comparative understanding of their antibody responses has not yet been established. In this study, we probed antibody responses to the N332 supersite and the membrane-proximal external region (MPER) in the context of heterologous protein scaffolds and native-like gp140 trimers. Ferritin nanoparticles and fragment crystallizable (Fc) regions were utilized as multivalent carriers to display scaffold antigens with grafted N332 and MPER epitopes, respectively. Trimeric scaffolds were also identified to stabilize the MPER-containing BG505 gp140.681 trimer in a native-like conformation. Following structural and antigenic evaluation, a subset of scaffold and trimer antigens was selected for immunization in BALB/c mice. Serum binding revealed distinct patterns of antibody responses to these two bNAb targets presented in different structural contexts. For example, the N332 nanoparticles elicited glycan epitope-specific antibody responses that could also recognize the native trimer, while a scaffolded BG505 gp140.681 trimer generated a stronger and more rapid antibody response to the trimer apex than its parent gp140.664 trimer. Furthermore, next-generation sequencing (NGS) of mouse splenic B cells revealed expansion of antibody lineages with long heavy-chain complementarity-determining region 3 (HCDR3) loops upon activation by MPER scaffolds, in contrast to the steady repertoires primed by N332 nanoparticles and a soluble gp140.664 trimer. These findings will facilitate the future development of a coherent vaccination strategy that combines both epitope-focused and trimer-based approaches. IMPORTANCE Both epitope-focused and trimer-based strategies are currently being explored in HIV-1 vaccine development, which aims to elicit broadly neutralizing

B7h-expressing dendritic cells and plasma B cells mediate distinct outcomes of ICOS costimulation in T cell-dependent antibody responses

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Larimore Kevin

2012-06-01

Full Text Available Abstract Background The ICOS-B7h costimulatory receptor-ligand pair is required for germinal center formation, the production of isotype-switched antibodies, and antibody affinity maturation in response to T cell-dependent antigens. However, the potentially distinct roles of regulated B7h expression on B cells and dendritic cells in T cell-dependent antibody responses have not been defined. Results We generated transgenic mice with lineage-restricted B7h expression to assess the cell-type specific roles of B7h expression on B cells and dendritic cells in regulating T cell-dependent antibody responses. Our results show that endogenous B7h expression is reduced on B cells after activation in vitro and is also reduced in vivo on antibody-secreting plasma B cells in comparison to both naïve and germinal center B cells from which they are derived. Increasing the level of B7h expression on activated and plasma B cells in B-B7hTg mice led to an increase in the number of antibody-secreting plasma cells generated after immunization and a corresponding increase in the concentration of antigen-specific high affinity serum IgG antibodies of all isotypes, without affecting the number of responding germinal center B cells. In contrast, ICOS costimulation mediated by dendritic cells in DC-B7hTg mice contributed to germinal center formation and selectively increased IgG2a production without affecting the overall magnitude of antibody responses. Conclusions Using transgenic mice with lineage-restricted B7h expression, we have revealed distinct roles of ICOS costimulation mediated by dendritic cells and B cells in the regulation of T cell-dependent antibody responses.

Differential Antibody Responses to Conserved HIV-1 Neutralizing Epitopes in the Context of Multivalent Scaffolds and Native-Like gp140 Trimers

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Charles D. Morris

2017-02-01

Full Text Available Broadly neutralizing antibodies (bNAbs have provided valuable insights into the humoral immune response to HIV-1. While rationally designed epitope scaffolds and well-folded gp140 trimers have been proposed as vaccine antigens, a comparative understanding of their antibody responses has not yet been established. In this study, we probed antibody responses to the N332 supersite and the membrane-proximal external region (MPER in the context of heterologous protein scaffolds and native-like gp140 trimers. Ferritin nanoparticles and fragment crystallizable (Fc regions were utilized as multivalent carriers to display scaffold antigens with grafted N332 and MPER epitopes, respectively. Trimeric scaffolds were also identified to stabilize the MPER-containing BG505 gp140.681 trimer in a native-like conformation. Following structural and antigenic evaluation, a subset of scaffold and trimer antigens was selected for immunization in BALB/c mice. Serum binding revealed distinct patterns of antibody responses to these two bNAb targets presented in different structural contexts. For example, the N332 nanoparticles elicited glycan epitope-specific antibody responses that could also recognize the native trimer, while a scaffolded BG505 gp140.681 trimer generated a stronger and more rapid antibody response to the trimer apex than its parent gp140.664 trimer. Furthermore, next-generation sequencing (NGS of mouse splenic B cells revealed expansion of antibody lineages with long heavy-chain complementarity-determining region 3 (HCDR3 loops upon activation by MPER scaffolds, in contrast to the steady repertoires primed by N332 nanoparticles and a soluble gp140.664 trimer. These findings will facilitate the future development of a coherent vaccination strategy that combines both epitope-focused and trimer-based approaches.

Acquired Antibody Responses against Plasmodium vivax Infection Vary with Host Genotype for Duffy Antigen Receptor for Chemokines (DARC)

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Maestre, Amanda; Muskus, Carlos; Duque, Victoria; Agudelo, Olga; Liu, Pu; Takagi, Akihide; Ntumngia, Francis B.; Adams, John H.; Sim, Kim Lee; Hoffman, Stephen L.; Corradin, Giampietro; Velez, Ivan D.; Wang, Ruobing

2010-01-01

Background Polymorphism of the Duffy Antigen Receptor for Chemokines (DARC) is associated with susceptibility to and the severity of Plasmodium vivax malaria in humans. P. vivax uses DARC to invade erythrocytes. Individuals lacking DARC are ‘resistant’ to P. vivax erythrocytic infection. However, susceptibility to P. vivax in DARC+ individuals is reported to vary between specific DARC genotypes. We hypothesized that the natural acquisition of antibodies to P. vivax blood stages may vary with the host genotype and the level of DARC expression. Furthermore, high parasitemia has been reported to effect the acquisition of immunity against pre-erythrocytic parasites. We investigated the correlation between host DARC genotypes and the frequency and magnitude of antibodies against P. vivax erythrocytic stage antigens. Methodology/Findings We assessed the frequencies and magnitudes of antibody responses against P. vivax and P. falciparum sporozoite and erythrocytic antigens in Colombian donors from malaria-endemic regions. The frequency and level of naturally-acquired antibodies against the P. vivax erythrocytic antigens merozoite surface protein 1 (PvMSP1) and Duffy binding protein (PvDBP) varied with the host DARC genotypes. Donors with one negative allele (FY*B/FY*Bnull and FY*A/FY*Bnull) were more likely to have anti-PvMSP1 and anti-PvDBP antibodies than those with two positive alleles (FY*B/FY*B and FY*A/FY*B). The lower IgG3 and IgG1 components of the total IgG response may account for the decreased responses to P. vivax erythrocytic antigens with FY*A/FY*B and FY*B/FY*B genotypes. No such association was detected with P. falciparum erythrocytic antigens, which does not use DARC for erythrocyte invasion. Conclusion/Significance Individuals with higher DARC expression, which is associated with higher susceptibility to P. vivax infection, exhibited low frequencies and magnitudes of P. vivax blood-stage specific antibody responses. This may indicate that one of the

Acquired antibody responses against Plasmodium vivax infection vary with host genotype for duffy antigen receptor for chemokines (DARC.

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Amanda Maestre

2010-07-01

Full Text Available Polymorphism of the Duffy Antigen Receptor for Chemokines (DARC is associated with susceptibility to and the severity of Plasmodium vivax malaria in humans. P. vivax uses DARC to invade erythrocytes. Individuals lacking DARC are 'resistant' to P. vivax erythrocytic infection. However, susceptibility to P. vivax in DARC+ individuals is reported to vary between specific DARC genotypes. We hypothesized that the natural acquisition of antibodies to P. vivax blood stages may vary with the host genotype and the level of DARC expression. Furthermore, high parasitemia has been reported to effect the acquisition of immunity against pre-erythrocytic parasites. We investigated the correlation between host DARC genotypes and the frequency and magnitude of antibodies against P. vivax erythrocytic stage antigens.We assessed the frequencies and magnitudes of antibody responses against P. vivax and P. falciparum sporozoite and erythrocytic antigens in Colombian donors from malaria-endemic regions. The frequency and level of naturally-acquired antibodies against the P. vivax erythrocytic antigens merozoite surface protein 1 (PvMSP1 and Duffy binding protein (PvDBP varied with the host DARC genotypes. Donors with one negative allele (FY*B/FY*Bnull and FY*A/FY*Bnull were more likely to have anti-PvMSP1 and anti-PvDBP antibodies than those with two positive alleles (FY*B/FY*B and FY*A/FY*B. The lower IgG3 and IgG1 components of the total IgG response may account for the decreased responses to P. vivax erythrocytic antigens with FY*A/FY*B and FY*B/FY*B genotypes. No such association was detected with P. falciparum erythrocytic antigens, which does not use DARC for erythrocyte invasion.Individuals with higher DARC expression, which is associated with higher susceptibility to P. vivax infection, exhibited low frequencies and magnitudes of P. vivax blood-stage specific antibody responses. This may indicate that one of the primary mechanisms by which P. vivax evades

Identification of antigen-specific human monoclonal antibodies using high-throughput sequencing of the antibody repertoire.

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Liu, Ju; Li, Ruihua; Liu, Kun; Li, Liangliang; Zai, Xiaodong; Chi, Xiangyang; Fu, Ling; Xu, Junjie; Chen, Wei

2016-04-22

High-throughput sequencing of the antibody repertoire provides a large number of antibody variable region sequences that can be used to generate human monoclonal antibodies. However, current screening methods for identifying antigen-specific antibodies are inefficient. In the present study, we developed an antibody clone screening strategy based on clone dynamics and relative frequency, and used it to identify antigen-specific human monoclonal antibodies. Enzyme-linked immunosorbent assay showed that at least 52% of putative positive immunoglobulin heavy chains composed antigen-specific antibodies. Combining information on dynamics and relative frequency improved identification of positive clones and elimination of negative clones. and increase the credibility of putative positive clones. Therefore the screening strategy could simplify the subsequent experimental screening and may facilitate the generation of antigen-specific antibodies. Copyright © 2016 Elsevier Inc. All rights reserved.

A life-style physical activity intervention and the antibody response to pneumococcal vaccination in women.

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Long, Joanna E; Ring, Chris; Bosch, Jos A; Eves, Francis; Drayson, Mark T; Calver, Rebecca; Say, Vanessa; Allen, Daniel; Burns, Victoria E

2013-10-01

To assess whether a life-style physical activity intervention improved antibody response to a pneumococcal vaccination in sedentary middle-aged women. Eighty-nine sedentary women completed a 16-week exercise (physical activity consultation, pedometer, telephone/e-mail prompts; n = 44) or control (advisory leaflet; n = 45) intervention. Pneumococcal vaccination was administered at 12 weeks, and antibody titers (11 of the 23 contained in the pneumococcal vaccine) were determined before vaccination and 4 weeks and 6 months later. Physical activity, aerobic fitness, body composition, and psychological factors were measured before and after the intervention. The intervention group displayed a greater increase in walking behavior (from mean [standard deviation] = 82.16 [90.90] to 251.87 [202.13]) compared with the control condition (111.67 [94.64] to 165.16 [117.22]; time by group interaction: F(1,68) = 11.25, p = .001, η(2) = 0.14). Quality of life also improved in the intervention group (from 19.37 [3.22] to 16.70 [4.29]) compared with the control condition (19.97 [4.22] to 19.48 [5.37]; time by group interaction: F(1,66) = 4.44, p = .039, η(2) = 0.06). However, no significant effects of the intervention on antibody response were found (time by group η(2) for each of the 11 pneumococcal strains ranged from 0.001 to 0.018; p values all >.264). Participation in a life-style physical activity intervention increased subjective and objective physical activity levels and quality of life but did not affect antibody response to pneumococcal vaccination.

Antibody responses to allergen Lol pIV are suppressed following adoptive transfer of B lymphocytes from the internal image anti-idiotypic antibody-treated mice.

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Zhou, E M; Kisil, F T

1995-10-01

An internal image anti-idiotypic antibody, designated B1/1, was generated against an idiotope (Id91) of the monoclonal antibody (mAb91) specific for Lol pIV. The administration of B1/1 in PBS, at doses ranging from 100 ng to 100 micrograms/mouse, to syngeneic Balb/c mice resulted in the suppression of the formation of anti-Lol pIV antibodies that possessed the Id91. Spleen cells obtained from the mice 2 weeks after the treatment with B1/1 (25 micrograms/mouse) were adoptively transferred intravenously into the syngeneic recipients which were challenged intraperitoneally with Lol pIV in alum 2 hr after the transfer. The recipients were boosted with Lol pIV 14 days later. It was demonstrated that the transfer of splenic B cells (but not of T cells) from B1/1-treated donors induced a significant suppression of not only the level of IgE and IgG antibodies to Lol pIV, but also the level of antibodies possessing the Id91. Treatment of the B cells with mAb91 plus complement abrogated their ability to transfer the suppression. This study indicates that the treatment with the anti-Id B1/1 generated B cells that were characterized, serologically, as possessing the anti-Id-like antibodies on their surface and were responsible for transferring the suppression of the formation of antibodies to allergen Lol pIV and the expression of Id91.

Antibody Response against Parvovirus in Patients with Inflammatory Rheumatological Diseases

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SH Raeisi

2011-07-01

Full Text Available Introduction: Some viral infections have been suggested to trigger or cause autoimmune diseases. One of these viruses is parvovirus B19 which can have various rheumatologic manifestations. In this study we investigated the association between parvovirus and rheumatoid arthritis (RA, systemic lupus erythematosis(SLE, systemic sclerosis(SSc and undifferentiated arthritis at the Rheumatological Clinic, Imam Khomeini hospital. Methods: In this sectional case-control study, IgM and IgG antibodies against parvovirus B19 were measured with ELISA in 41 patients with RA, 28 patients with SLE, 13 patients with SSc, 8 patients with undifferentiated arthritis as well as 90 healthy controls. The ELISA kit (DRG, Germany was semi-quantitative and qualititative. Results: Parvovirus B19 IgM was detected in one patient with RA, one with SSc and four in the control group. IgG anti- B19-specific antibody was detected in 58.5% of RA patients, 67.9% of SLE patients, 69. 2% of SSc patients, 87.5% of undifferentiated arthritis patients as compared to 53.3% of controls. The results were compared between the patient and control groups(p>0.05. Conclusion: According to the results, there was no significant correlation for the antibody titer against parvovirus B19 in the patient and control group. The highly positive response of IgG against parvovirus in undifferentiated arthritis implies the need for more research.

Previous 60-Co radiation from Paratrygon aiereba mucus induces the production of highly responsive antibodies and a better immune response in mice

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Thomazi, Gabriela Ortega Coelho; Alves, Glaucie Jussilane; Turíbio, Thompson de Oliveira; Rocha, André Moreira; Aires, Raquel da Silva; Jácome, Larissa Barros Silvestre; Spencer, Patrick Jack, E-mail: gabiortegacoelho@usp.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil). Centro de Biotecnologia; Costa, Andrea da; Rodrigues, Jaqueline Pollizeli; Galisteo Júnior, Andrés Jimenez; Andrade Júnior, Heitor Franco de, E-mail: hfandrad@usp.br, E-mail: raquelaires@itpacporto.com.br [Universidade de São Paulo (USP), São Paulo, SP (Brazil). Laboratório de Protozoologia; Seibert, Carla Simone, E-mail: seibertcs@uft.edu.br [Universidade Federal do Tocantins (UFT), Porto Nacional, TO (Brazil)

2017-07-01

Wounds from stinging freshwater stingrays are painful, difficult to heal and cause extensive necrosis and systemic phenomena. The treatment is symptomatic, of low efficiency and there is no therapy, which causes more suffering to the injured. This study aimed to evaluate the immune response induced by the native or irradiated by 60-Co gamma from Paratrygon aiereba mucus. IPEN’s Committee on Ethics in the Use of Animals (n.º126/2013) and lanes captured under license from the Chico Mendes Institute for Biodiversity Conservation (n.º6781-1/2014) approved this research. For the assays, sera from Swiss mice previously immunized against native or irradiated mucus were used. The proliferation of splenic B cells in response to mucus was evaluated by the In Vitro Induced Antibody Production method and serum and splenic cytokines were also quantified. Our data demonstrate that the irradiated mucus of P. aiereba induces greater production of antibodies and more immunological memory in the mice. Spleen cells from animals immunized against irradiated mucus produced IFN-γ, TNF-α and IL-10, and serum TNF-α (immunized group against irradiated mucus) and IL-6 and IL-17 (immunized group against native mucus). The results corroborate the use of ionizing radiation, with production of highly responsive antibodies and better immune response, besides proving that Paratrygon aiereba mucus is capable of stimulating cellular and humoral adaptive immune response, contributing to the continuity of associated investigations. (author)

Previous 60-Co radiation from Paratrygon aiereba mucus induces the production of highly responsive antibodies and a better immune response in mice

International Nuclear Information System (INIS)

Thomazi, Gabriela Ortega Coelho; Alves, Glaucie Jussilane; Turíbio, Thompson de Oliveira; Rocha, André Moreira; Aires, Raquel da Silva; Jácome, Larissa Barros Silvestre; Spencer, Patrick Jack

2017-01-01

Wounds from stinging freshwater stingrays are painful, difficult to heal and cause extensive necrosis and systemic phenomena. The treatment is symptomatic, of low efficiency and there is no therapy, which causes more suffering to the injured. This study aimed to evaluate the immune response induced by the native or irradiated by 60-Co gamma from Paratrygon aiereba mucus. IPEN’s Committee on Ethics in the Use of Animals (n.º126/2013) and lanes captured under license from the Chico Mendes Institute for Biodiversity Conservation (n.º6781-1/2014) approved this research. For the assays, sera from Swiss mice previously immunized against native or irradiated mucus were used. The proliferation of splenic B cells in response to mucus was evaluated by the In Vitro Induced Antibody Production method and serum and splenic cytokines were also quantified. Our data demonstrate that the irradiated mucus of P. aiereba induces greater production of antibodies and more immunological memory in the mice. Spleen cells from animals immunized against irradiated mucus produced IFN-γ, TNF-α and IL-10, and serum TNF-α (immunized group against irradiated mucus) and IL-6 and IL-17 (immunized group against native mucus). The results corroborate the use of ionizing radiation, with production of highly responsive antibodies and better immune response, besides proving that Paratrygon aiereba mucus is capable of stimulating cellular and humoral adaptive immune response, contributing to the continuity of associated investigations. (author)

Respons Antibodi Sekunder Terhadap Penyakit Tetelo pada Ayam Petelur Pascavaksinasi Ulangan dengan Vaksin Tetelo Aktif (NEWCASTLE DISEASESECONDARY ANTIBODY RESPONSE AFTER REVACCINATION IN LAYER WITH THE ACTIVE ND VACCINE

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Andika Budi Kurnianto

2016-11-01

Full Text Available Revaccination is required in order to preventNewcastle Disease (ND reccurence inlayers chickens. Oneof vaccine for ND revaccination is freeze-died ND active vaccine containing e” 106,5EID50. Revaccinationisdone to trigger a faster secondary antibody responses in layers and can achieve protective antibody titersagainst ND that can be monitored by a hemagglutinationinhibition (HI. The aim of this study was todetermine the ND secondary antibody responses in layers after revaccination with ND active vaccine.Antibody titer of 20 layers chickens of 20 week old were determined before revaccinations (week 0 andafter revaccinations (week 1 until week 9. The first vaccination was conducted using ND-IB (NewcastleDisease-Infectious Bronchitis at the age of 2 days through eye drops and subcutaneous injection at the ageof 5 days using a dose of 1 ampoule.Vaccination is repeated at the age of 20 weeks at a dose of 1 ½ ampoule through drinking water. Blood samples were collected on the wing vein (venous cutane ulnar and left for 5-10 minutes at room temperature.Sera were then collected and stored at -20oC until use. HI antibody titerwas determined by micro titeration system. The HI mean titers were analyzed by Duncan test. The studyresults showed that antibody titer before revaccination was3,47 HI log 2 and the HI titers after revaccinationwere 4,02; 5,22; 6,52; 7,85; 8,4; 8,6; 7,7; 5,92; dan 3,87 HI log 2 respectivelly at weeks 1, 2, 3, 4, 5, 6, 7, 8, and9.The NDV revaccination with ND active vaccine significantly (P <0.01 increased in antibody titer inlayers starting from week 1 to week 6, but decreased following week 7 to week-9. It can be concluded thatrevaccinantion with ND active vaccine increases the antibody titers in layer chickens.

Vibrio cholerae O1 secretes an extracellular matrix in response to antibody-mediated agglutination.

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Danielle E Baranova

Full Text Available Vibrio cholerae O1 is one of two serogroups responsible for epidemic cholera, a severe watery diarrhea that occurs after the bacterium colonizes the human small intestine and secretes a potent ADP-ribosylating toxin. Immunity to cholera is associated with intestinal anti-lipopolysaccharide (LPS antibodies, which are known to inhibit V. cholerae motility and promote bacterial cell-cell crosslinking and aggregation. Here we report that V. cholerae O1 classical and El Tor biotypes produce an extracellular matrix (ECM when forcibly immobilized and agglutinated by ZAC-3 IgG, an intestinally-derived monoclonal antibody (MAb against the core/lipid A region of LPS. ECM secretion, as demonstrated by crystal violet staining and scanning electron microscopy, occurred within 30 minutes of antibody exposure and peaked by 3 hours. Non-motile mutants of V. cholerae did not secrete ECM following ZAC-3 IgG exposure, even though they were susceptible to agglutination. The ECM was enriched in O-specific polysaccharide (OSP but not Vibrio polysaccharide (VPS. Finally, we demonstrate that ECM production by V. cholerae in response to ZAC-3 IgG was associated with bacterial resistant to a secondary complement-mediated attack. In summary, we propose that V. cholerae O1, upon encountering anti-LPS antibodies in the intestinal lumen, secretes an ECM (or O-antigen capsule possibly as a strategy to shield itself from additional host immune factors and to exit an otherwise inhospitable host environment.

Steroid-Responsive Chronic Schizophreniform Syndrome in the Context of Mildly Increased Antithyroid Peroxidase Antibodies

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Ludger Tebartz van Elst

2017-04-01

Full Text Available BackgroundSchizophreniform syndromes can be divided into primary forms from polygenic causes or secondary forms due to immunological, epileptiform, monogenic, or degenerative causes. Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT is a secondary immunological form associated with increased thyroid antibodies, such as antithyroid peroxidase antibodies and shows a good response to corticosteroids.Case presentationWe present the case of a 41-year-old woman suffering from a schizophreniform syndrome. Starting at the age of 35, she developed psychotic exacerbations with formal thought disorder, acoustic hallucinations, cenesthopathic experiences, and loss of ego boundaries. At the same time, she began to suffer from chronic sexual delusions and olfactory hallucinations, which did not respond to neuroleptic medication. Her levels of antithyroid peroxidase antibodies were slightly increased, and the blood–brain barrier was disturbed. An electroencephalogram (EEG showed intermittent generalized slowing, and cerebral magnetic resonance imaging (cMRI depicted mild temporolateral atrophy. High-dose corticosteroid treatment led to convincing improvement of attentional performance and the disappearance of delusions and olfactory hallucinations.ConclusionSREAT can mimic typical symptoms of schizophreniform syndromes. The increased titer of antithyroid peroxidase antibodies in combination with the EEG slowing, blood–brain barrier dysfunction, and the cMRI alterations were the basis for suspecting an immunological cause in our patient. Chronic delusions, olfactory hallucinations, and cognitive deficits were successfully treated with corticosteroids. The occurrence of secondary immunological forms of schizophreniform syndromes demonstrates the need for innovative immunosuppressive treatment options.

Antibody Engineering and Therapeutics

Science.gov (United States)

Almagro, Juan Carlos; Gilliland, Gary L; Breden, Felix; Scott, Jamie K; Sok, Devin; Pauthner, Matthias; Reichert, Janice M; Helguera, Gustavo; Andrabi, Raiees; Mabry, Robert; Bléry, Mathieu; Voss, James E; Laurén, Juha; Abuqayyas, Lubna; Barghorn, Stefan; Ben-Jacob, Eshel; Crowe, James E; Huston, James S; Johnston, Stephen Albert; Krauland, Eric; Lund-Johansen, Fridtjof; Marasco, Wayne A; Parren, Paul WHI; Xu, Kai Y

2014-01-01

The 24th Antibody Engineering & Therapeutics meeting brought together a broad range of participants who were updated on the latest advances in antibody research and development. Organized by IBC Life Sciences, the gathering is the annual meeting of The Antibody Society, which serves as the scientific sponsor. Preconference workshops on 3D modeling and delineation of clonal lineages were featured, and the conference included sessions on a wide variety of topics relevant to researchers, including systems biology; antibody deep sequencing and repertoires; the effects of antibody gene variation and usage on antibody response; directed evolution; knowledge-based design; antibodies in a complex environment; polyreactive antibodies and polyspecificity; the interface between antibody therapy and cellular immunity in cancer; antibodies in cardiometabolic medicine; antibody pharmacokinetics, distribution and off-target toxicity; optimizing antibody formats for immunotherapy; polyclonals, oligoclonals and bispecifics; antibody discovery platforms; and antibody-drug conjugates. PMID:24589717

Comparison of antibody and cytokine responses to primary Giardia muris infection in H-2 congenic strains of mice.

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Venkatesan, P; Finch, R G; Wakelin, D

1996-11-01

The course of primary infections with Giardia muris differs between BALB and B10 H-2 congenic strains of mice. In the first 3 weeks of infection, there is a more rapid decline in intestinal trophozoite and fecal cyst counts in B10 strains than in BALB strains. To determine whether this difference could be explained by variation in specific antibody responses, both secretory immunoglobulin A (IgA) and serum antibody responses were compared between these strains. No significant differences in the timing, titer, or specificity of secretory or serum antibodies were found. However, on comparing specific anti-G. muris serum IgG subclass responses, we found that B10 strains produced IgG2a while BALB strains produced IgG1, suggesting differential involvement of T helper 1 and 2 subsets of lymphocytes. When cells harvested from mesenteric lymph nodes were stimulated with concanavalin A in vitro, both gamma interferon and interleukin-5 were secreted by cells from B10 mice, but only interleukin-5 was secreted by cells from BALB/c mice. Specific blockade of gamma interferon by monoclonal antibody administered to B10 mice resulted in an enhanced intensity of infection.

Treatment of VGKC complex antibody-associated limbic encephalitis: a systematic review.

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Radja, Guirindhra Koumar; Cavanna, Andrea Eugenio

2013-01-01

Limbic encephalitis is an autoimmune neuropsychiatric condition characterized by subacute cognitive symptoms, seizures, and affective changes. Although limbic encephalitis is usually caused by an immune reaction secondary to neoplasms, different types of potentially treatable non-paraneoplastic limbic encephalitis (nPLE) have recently been described. In particular, published studies have reported variable responses to immunosuppressive therapy in Voltage-Gated Potassium Channel (VGKC) complex antibody-associated nPLE. This systematic literature review found that the most significant improvements were reported by patients presenting with affective symptoms and consistent neuroradiological changes. In these patients, improved clinical outcomes correlated with the largest decreases in antibody titers.

H. pylori-infection and antibody immune response in a rural Tanzanian population

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Biggar Robert J

2006-09-01

Full Text Available Abstract Background Helicobacter pylori (H. pylori infection is ubiquitous in sub-Saharan Africa, but paradoxically gastric cancer is rare. Methods Sera collected during a household-based survey in rural Tanzania in 1985 were tested for anti-H. pylori IgG and IgG subclass antibodies by enzyme immunoassay. Odds ratios (OR and confidence intervals (CI of association of seropositivity with demographic variables were computed by logistic regression models. Results Of 788 participants, 513 were aged ≤17 years. H. pylori seropositivity increased from 76% at 0–4 years to 99% by ≥18 years of age. Seropositivity was associated with age (OR 11.5, 95% CI 4.2–31.4 for 10–17 vs. 0–4 years, higher birth-order (11.1; 3.6–34.1 for ≥3rd vs. 1st born, and having a seropositive next-older sibling (2.7; 0.9–8.3. Median values of IgG subclass were 7.2 for IgG1 and 2.0 for IgG2. The median IgG1/IgG2 ratio was 3.1 (IQR: 1.7–5.6, consistent with a Th2-dominant immune profile. Th2-dominant response was more frequent in children than adults (OR 2.4, 95% CI 1.3–4.4. Conclusion H. pylori seropositivity was highly prevalent in Tanzania and the immunological response was Th2-dominant. Th2-dominant immune response, possibly caused by concurrent bacterial or parasitic infections, could explain, in part, the lower risk of H. pylori-associated gastric cancer in Africa.

Short-term and long-term antibody response by mice after immunization against Neisseria meningitidis B or diphtheria toxoid

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G.P. Silva

2013-02-01

Full Text Available Serogroup B Neisseria meningitidis (MenB is a major cause of invasive disease in early childhood worldwide. The only MenB vaccine available in Brazil was produced in Cuba and has shown unsatisfactory efficacy when used to immunize millions of children in Brazil. In the present study, we compared the specific functional antibody responses evoked by the Cuban MenB vaccine with a standard vaccine against diphtheria (DTP: diphtheria, tetanus, pertussis after primary immunization and boosting of mice. The peak of bactericidal and opsonic antibody titers to MenB and of neutralizing antibodies to diphtheria toxoid (DT was reached after triple immunization with the MenB vaccine or DTP vaccine, respectively. However, 4 months after immunization, protective DT antibody levels were present in all DTP-vaccinated mice but in only 20% of the mice immunized against MenB. After 6 months of primary immunization, about 70% of animals still had protective neutralizing DT antibodies, but none had significant bactericidal antibodies to MenB. The booster doses of DTP or MenB vaccines produced a significant antibody recall response, suggesting that both vaccines were able to generate and maintain memory B cells during the period studied (6 months post-triple immunization. Therefore, due to the short duration of serological memory induced by the MenB vaccine (VA-MENGOC-BC® vaccine, its use should be restricted to outbreaks of meningococcal disease.

A VAR2CSA:CSP conjugate capable of inducing dual specificity antibody responses

DEFF Research Database (Denmark)

Matondo, Sungwa; Thrane, Susan; Janitzek, Christoph Mikkel

2017-01-01

Catcher peptide. The covalent interaction between SpyTag/SpyCatcher enables the formation of DBL1x-DBL2x-ID2a:CSP conjugate vaccine. Immunogenicity and quality of antibody responses induced by the conjugate vaccine, as well as a control CSP-SpyCatcher vaccine, was tested in BALB/c mice.  Results: Serum samples...... obtained from mice immunized with the conjugate vaccine were able to recognize both untagged DBL1x-DBL2x-ID2a as well as CSP antigen. Moreover, the geometric mean anti-CSP antibody titer was 1.9-fold higher in serum (at day 35 and 55 post-first immunization) from mice immunized with the conjugate vaccine......, as compared to mice receiving the control vaccine.  Conclusion: The data obtained in this study serves as proof-of-concept for the simultaneous induction of antibodies directed against individual antigen components in a dual stage anti-malaria vaccine....

Response-rate differences in variable-interval and variable-ratio schedules: An old problem revisited

OpenAIRE

Cole, Mark R.

1994-01-01

In Experiment 1, a variable-ratio 10 schedule became, successively, a variable-interval schedule with only the minimum interreinforcement intervals yoked to the variable ratio, or a variable-interval schedule with both interreinforcement intervals and reinforced interresponse times yoked to the variable ratio. Response rates in the variable-interval schedule with both interreinforcement interval and reinforced interresponse time yoking fell between the higher rates maintained by the variable-...

Affinity maturation in an HIV broadly neutralizing B-cell lineage through reorientation of variable domains.

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Fera, Daniela; Schmidt, Aaron G; Haynes, Barton F; Gao, Feng; Liao, Hua-Xin; Kepler, Thomas B; Harrison, Stephen C

2014-07-15

Rapidly evolving pathogens, such as human immunodeficiency and influenza viruses, escape immune defenses provided by most vaccine-induced antibodies. Proposed strategies to elicit broadly neutralizing antibodies require a deeper understanding of antibody affinity maturation and evolution of the immune response to vaccination or infection. In HIV-infected individuals, viruses and B cells evolve together, creating a virus-antibody "arms race." Analysis of samples from an individual designated CH505 has illustrated the interplay between an antibody lineage, CH103, and autologous viruses at various time points. The CH103 antibodies, relatively broad in their neutralization spectrum, interact with the CD4 binding site of gp120, with a contact dominated by CDRH3. We show by analyzing structures of progenitor and intermediate antibodies and by correlating them with measurements of binding to various gp120s that there was a shift in the relative orientation of the light- and heavy-chain variable domains during evolution of the CH103 lineage. We further show that mutations leading to this conformational shift probably occurred in response to insertions in variable loop 5 (V5) of the HIV envelope. The shift displaced the tips of the light chain away from contact with V5, making room for the inserted residues, which had allowed escape from neutralization by the progenitor antibody. These results, which document the selective mechanism underlying this example of a virus-antibody arms race, illustrate the functional significance of affinity maturation by mutation outside the complementarity determining region surface of the antibody molecule.

Improvement in latent variable indirect response modeling of multiple categorical clinical endpoints: application to modeling of guselkumab treatment effects in psoriatic patients.

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Hu, Chuanpu; Randazzo, Bruce; Sharma, Amarnath; Zhou, Honghui

2017-10-01

Exposure-response modeling plays an important role in optimizing dose and dosing regimens during clinical drug development. The modeling of multiple endpoints is made possible in part by recent progress in latent variable indirect response (IDR) modeling for ordered categorical endpoints. This manuscript aims to investigate the level of improvement achievable by jointly modeling two such endpoints in the latent variable IDR modeling framework through the sharing of model parameters. This is illustrated with an application to the exposure-response of guselkumab, a human IgG1 monoclonal antibody in clinical development that blocks IL-23. A Phase 2b study was conducted in 238 patients with psoriasis for which disease severity was assessed using Psoriasis Area and Severity Index (PASI) and Physician's Global Assessment (PGA) scores. A latent variable Type I IDR model was developed to evaluate the therapeutic effect of guselkumab dosing on 75, 90 and 100% improvement of PASI scores from baseline and PGA scores, with placebo effect empirically modeled. The results showed that the joint model is able to describe the observed data better with fewer parameters compared with the common approach of separately modeling the endpoints.

Error response test system and method using test mask variable

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Gender, Thomas K. (Inventor)

2006-01-01

An error response test system and method with increased functionality and improved performance is provided. The error response test system provides the ability to inject errors into the application under test to test the error response of the application under test in an automated and efficient manner. The error response system injects errors into the application through a test mask variable. The test mask variable is added to the application under test. During normal operation, the test mask variable is set to allow the application under test to operate normally. During testing, the error response test system can change the test mask variable to introduce an error into the application under test. The error response system can then monitor the application under test to determine whether the application has the correct response to the error.

A novel variable antibody fragment dimerized by leucine zippers with enhanced neutralizing potency against rabies virus G protein compared to its corresponding single-chain variable antibody fragment.

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Li, Zhuang; Cheng, Yue; Xi, Hualong; Gu, Tiejun; Yuan, Ruosen; Chen, Xiaoxu; Jiang, Chunlai; Kong, Wei; Wu, Yongge

2015-12-01

Fatal rabies can be prevented effectively by post-exposure prophylactic (PEP) with rabies immunoglobulin (RIG). Single-chain variable fragments (scFv), which are composed of a variable heavy chain (VH) and a variable light chain (VL) connected by a peptide linker, can potentially be used to replace RIG. However, in our previous study, a scFv (scFV57S) specific for the rabies virus (RV) G protein showed a lower neutralizing potency than that of its parent IgG due to lower stability and altered peptide assembly pattern. In monoclonal antibodies, the VH and VL interact non-covalently, while in scFvs the VH is connected covalently with the VL by the artificial linker. In this study, we constructed and expressed two peptides 57VL-JUN-HIS and 57VH-FOS-HA in Escherichia coli. The well-known Fos and Jun leucine zippers were utilized to dimerize VH and VL similarly to the IgG counterpart. The two peptides assembled to form zipFv57S in vitro. Due to the greater similarity in structure with IgG, the zipFv57S protein showed a higher binding ability and affinity resulting in notable improvement of in vitro neutralizing activity over its corresponding scFv. The zipFv57S protein was also found to be more stable and showed similar protective rate as RIG in mice challenged with a lethal dose of RV. Our results not only indicated zipFv57S as an ideal alternative for RIG in PEP but also offered a novel and efficient hetero-dimerization pattern of VH and VL leading to enhanced neutralizing potency. Copyright © 2015. Published by Elsevier Ltd.

Immunogenicity of anti-tumor necrosis factor antibodies-toward improved methods of anti-antibody measurement.

Science.gov (United States)

Aarden, Lucien; Ruuls, Sigrid R; Wolbink, Gertjan

2008-08-01

To date, millions of people have been treated with therapeutic monoclonal antibodies (TmAbs) for various indications. It is becoming increasingly clear that TmAbs can be immunogenic, which may reduce efficacy or induce adverse effects. Over the years, the importance of antibody formation has been questioned and sometimes minimized, as few antibody responses to TmAbs (HACA or HAHA) were reported. However, the methods to detect and quantify such antibodies used in the past have been problematic. Only recently, methods have been developed that have adequate sensitivity and are not seriously disturbed by false-positive reactions caused by rheumatoid factors, natural antibodies to Fab or F(ab')2 fragments, or Fc interactions of IgG4. The large number of treated patients, in combination with these new assays, presents a unique opportunity to study the anti-antibody immune response in man, possibly allowing us to manipulate immunogenicity in the future.

Effect of increased CRM₁₉₇ carrier protein dose on meningococcal C bactericidal antibody response.

Science.gov (United States)

Lee, Lucia H; Blake, Milan S

2012-04-01

New multivalent CRM(197)-based conjugate vaccines are available for childhood immunization. Clinical studies were reviewed to assess meningococcal group C (MenC) antibody responses following MenC-CRM(197) coadministration with CRM(197)-based pneumococcal or Haemophilus influenzae type b conjugate vaccines. Infants receiving a total CRM(197) carrier protein dose of ∼50 μg and concomitant diphtheria-tetanus-acellular pertussis (DTaP)-containing vaccine tended to have lower MenC geometric mean antibody titers and continued to have low titers after the toddler dose. Nevertheless, at least 95% of children in the reported studies achieved a MenC serum bactericidal antibody (SBA) titer of ≥ 1:8 after the last infant or toddler dose. SBA was measured using an assay with a baby rabbit or human complement source. Additional studies are needed to assess long-term antibody persistence and MenC CRM(197) conjugate vaccine immunogenicity using alternative dosing schedules.

Does infection with Human Immunodeficiency Virus affect the antibody responses to Plasmodium falciparum antigenic determinants in asymptomatic pregnant women?

NARCIS (Netherlands)

Ayisi, J. G.; Branch, OraLee H.; Rafi-Janajreh, A.; van Eijk, A. M.; ter Kuile, F. O.; Rosen, D. H.; Kager, P. A.; Lanar, D. E.; Barbosa, A.; Kaslow, D.; Nahlen, B. L.; Lal, A. A.

2003-01-01

OBJECTIVES: HIV-seropositive pregnant women are more susceptible to malaria than HIV-seronegative women. We assessed whether HIV infection alters maternal and cord plasma malarial antibody responses and the mother-to-infant transfer of malaria antibodies. METHODS: We determined plasma levels of

Cytokine, antibody and proliferative cellular responses elicited by Taenia solium calreticulin upon experimental infection in hamsters.

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Fela Mendlovic

Full Text Available Taenia solium causes two diseases in humans, cysticercosis and taeniosis. Tapeworm carriers are the main risk factor for neurocysticercosis. Limited information is available about the immune response elicited by the adult parasite, particularly the induction of Th2 responses, frequently associated to helminth infections. Calreticulin is a ubiquitous, multifunctional protein involved in cellular calcium homeostasis, which has been suggested to play a role in the regulation of immune responses. In this work, we assessed the effect of recombinant T. solium calreticulin (rTsCRT on the cytokine, humoral and cellular responses upon experimental infection in Syrian Golden hamsters (Mesocricetus auratus. Animals were infected with T. solium cysticerci and euthanized at different times after infection. Specific serum antibodies, proliferative responses in mesenteric lymph nodes and spleen cells, as well as cytokines messenger RNA (mRNA were analyzed. The results showed that one third of the infected animals elicited anti-rTsCRT IgG antibodies. Interestingly, mesenteric lymph node (MLN cells from either infected or non-infected animals did not proliferate upon in vitro stimulation with rTsCRT. Additionally, stimulation with a tapeworm crude extract resulted in increased expression of IL-4 and IL-5 mRNA. Upon stimulation, rTsCRT increased the expression levels of IL-10 in spleen and MLN cells from uninfected and infected hamsters. The results showed that rTsCRT favors a Th2-biased immune response characterized by the induction of IL-10 in mucosal and systemic lymphoid organs. Here we provide the first data on the cytokine, antibody and cellular responses to rTsCRT upon in vitro stimulation during taeniasis.

T cell responsiveness correlates differentially with antibody isotype levels in clinical and asymptomatic filariasis

NARCIS (Netherlands)

Yazdanbakhsh, M.; Paxton, W. A.; Kruize, Y. C.; Sartono, E.; Kurniawan, A.; van het Wout, A.; Selkirk, M. E.; Partono, F.; Maizels, R. M.

1993-01-01

To establish the relationships among T and B cell responses, active infection, and clinical manifestations in lymphatic filariasis, filarial-specific lymphocyte proliferation, IgG antibody isotypes, and IgE levels were determined in an exposed population: 31 asymptomatic amicrofilaremics, 43

Vaccine Induced Antibody Response to Foot and Mouth Disease in Infectious Bovine Rhinotracheitis Seropositive Cattle

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Murat Şevik

2014-01-01

Full Text Available Foot and mouth disease (FMD and infectious bovine rhinotracheitis (IBR are two important infectious diseases of cattle. Inactivated FMD vaccines are the most powerful tools to protect animals against FMD. Previous studies showed that recombinant IBR-FMD viruses protected cattle from virulent BHV-1 challenge and induced protective levels of anti-FMDV antibodies. FMD is considered to be endemic in Turkey and inactivated oil adjuvanted vaccines are used for the immunization of cattle. Previous studies showed that seroprevalence of IBR in the Turkey’s dairy herd more than 50%. In this study, antibody response in IBR seropositive cattle following vaccination against FMD was investigated. IBR seropositive (n=208 and IBR seronegative (n=212 cattle were vaccinated with oil-adjuvanted bivalent vaccine (containing O1 Manisa, A22 Iraq FMDV strains. Solid-phase competitive ELISA (SPCE was used to measure antibodies produced in cattle. Protective level of antibody against serotype O was detected in 77.4% and serotypes A in 83.6% of IBR seropositive cattle. Protective level of antibody against serotype O antibody was detected in 49% and serotypes A in 66.9% of IBR seronegative cattle. The differences between the protection rates against both serotype O (P=0.0001 and serotype A (P=0.0001 in IBR seropositive and seronegative animals were statistically important (Fisher’s exact test, P<0.01. Results showed that after FMD vaccination, IBR seropositive animals produced high titres of antibodies than seronegative animals.

Canine antibody response to Phlebotomus perniciosus bites negatively correlates with the risk of Leishmania infantum transmission.

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Michaela Vlkova

2011-10-01

Full Text Available BACKGROUND: Phlebotomine sand flies are blood-sucking insects that can transmit Leishmania parasites. Hosts bitten by sand flies develop an immune response against sand fly salivary antigens. Specific anti-saliva IgG indicate the exposure to the vector and may also help to estimate the risk of Leishmania spp. transmission. In this study, we examined the canine antibody response against the saliva of Phlebotomus perniciosus, the main vector of Leishmania infantum in the Mediterranean Basin, and characterized salivary antigens of this sand fly species. METHODOLOGY/PRINCIPAL FINDINGS: Sera of dogs bitten by P. perniciosus under experimental conditions and dogs naturally exposed to sand flies in a L. infantum focus were tested by ELISA for the presence of anti-P. perniciosus antibodies. Antibody levels positively correlated with the number of blood-fed P. perniciosus females. In naturally exposed dogs the increase of specific IgG, IgG1 and IgG2 was observed during sand fly season. Importantly, Leishmania-positive dogs revealed significantly lower anti-P. perniciosus IgG2 compared to Leishmania-negative ones. Major P. perniciosus antigens were identified by western blot and mass spectrometry as yellow proteins, apyrases and antigen 5-related proteins. CONCLUSIONS: Results suggest that monitoring canine antibody response to sand fly saliva in endemic foci could estimate the risk of L. infantum transmission. It may also help to control canine leishmaniasis by evaluating the effectiveness of anti-vector campaigns. Data from the field study where dogs from the Italian focus of L. infantum were naturally exposed to P. perniciosus bites indicates that the levels of anti-P. perniciosus saliva IgG2 negatively correlate with the risk of Leishmania transmission. Thus, specific IgG2 response is suggested as a risk marker of L. infantum transmission for dogs.

Stereophysicochemical variability plots highlight conserved antigenic areas in Flaviviruses

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Zhou Bin

2005-04-01

Full Text Available Abstract Background Flaviviruses, which include Dengue (DV and West Nile (WN, mutate in response to immune system pressure. Identifying escape mutants, variant progeny that replicate in the presence of neutralizing antibodies, is a common way to identify functionally important residues of viral proteins. However, the mutations typically occur at variable positions on the viral surface that are not essential for viral replication. Methods are needed to determine the true targets of the neutralizing antibodies. Results Stereophysicochemical variability plots (SVPs, 3-D images of protein structures colored according to variability, as determined by our PCPMer program, were used to visualize residues conserved in their physical chemical properties (PCPs near escape mutant positions. The analysis showed 1 that escape mutations in the flavivirus envelope protein are variable residues by our criteria and 2 two escape mutants found at the same position in many flaviviruses sit above clusters of conserved residues from different regions of the linear sequence. Conservation patterns in T-cell epitopes in the NS3- protease suggest a similar mechanism of immune system evasion. Conclusion The SVPs add another dimension to structurally defining the binding sites of neutralizing antibodies. They provide a useful aid for determining antigenically important regions and designing vaccines.

Antibody response to an anti-rabies vaccine in a dog population under field conditions in Bolivia.

Science.gov (United States)

Suzuki, K; González, E T; Ascarrunz, G; Loza, A; Pérez, M; Ruiz, G; Rojas, L; Mancilla, K; Pereira, J A C; Guzman, J A; Pecoraro, M R

2008-10-01

Rabies remains an important public health issue in Bolivia, South America. Public concern and fears are most focussed on dogs as the source of rabies. The objective of the present study was to assess immunity of an inactivated suckling mouse brain vaccine against canine rabies used for the official vaccination campaigns under field conditions in an endemic area of rabies in Bolivia. A total of 236 vaccinated and 44 unvaccinated dogs in Santa Cruz de la Sierra, selected using stratified random sampling, were investigated in order to obtain owned dog characteristics and antibody titres against rabies in April 2007. The proportion of vaccinated dogs with an antibody titre exceeded the protection threshold value of 0.5 EU/ml was 58% [95% confidence intervals (CI): 52-65], indicating that vaccination is likely to elicit an antibody response (odds ratio 6.3, 95% CI: 1.2-11.5). The range of geometric mean of antibody titre for vaccinated dogs (0.89 EU/ml; 95% CI: 0.75-1.04) was considered to meet the minimal acceptable level indicating an adequate immune response to the vaccine. However, the titre level was not satisfactory in comparison with the results from other field investigations with inactivated tissue culture vaccines. It is recommended for public health authorities to (1) consider modernizing their vaccine manufacturing method because the level of immunity induced by the current vaccine is comparably low, (2) conduct frequent vaccination campaigns to maintain high levels of vaccination coverage, and (3) actively manage the domestic dog population in the study area, which is largely responsible for rabies maintenance.

Antibody responses to vaccination and immune function in patients with haematological malignancies - studies in patients with chronic lymphocytic leukaemia autologous stem cell recipients

NARCIS (Netherlands)

Velden, A.M.T. van der

2007-01-01

This thesis concerns the antibody responses to vaccination and immune function of patients with several forms of haematological diseases. Antibody responses in patients with chronic lymphocytic leukaemia (CLL) and in autologous stem cell transplant recipients were studied. In the autologous stem

Barn Owl Productivity Response to Variability of Vole Populations.

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Petr Pavluvčík

Full Text Available We studied the response of the barn owl annual productivity to the common vole population numbers and variability to test the effects of environmental stochasticity on their life histories. Current theory predicts that temporal environmental variability can affect long-term nonlinear responses (e.g., production of young both positively and negatively, depending on the shape of the relationship between the response and environmental variables. At the level of the Czech Republic, we examined the shape of the relationship between the annual sum of fledglings (annual productivity and vole numbers in both non-detrended and detrended data. At the districts' level, we explored whether the degree of synchrony (measured by the correlation coefficient and the strength of the productivity response increase (measured by the regression coefficient in areas with higher vole population variability measured by the s-index. We found that the owls' annual productivity increased linearly with vole numbers in the Czech Republic. Furthermore, based on district data, we also found that synchrony between dynamics in owls' reproductive output and vole numbers increased with vole population variability. However, the strength of the response was not affected by the vole population variability. Additionally, we have shown that detrending remarkably increases the Taylor's exponent b relating variance to mean in vole time series, thereby reversing the relationship between the coefficient of variation and the mean. This shift was not responsible for the increased synchrony with vole population variability. Instead, we suggest that higher synchrony could result from high food specialization of owls on the common vole in areas with highly fluctuating vole populations.

Complexity of Human Antibody Response to Dengue Virus: Implication for Vaccine Development.

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Tsai, Wen-Yang; Lin, Hong-En; Wang, Wei-Kung

2017-01-01

The four serotypes of dengue virus (DENV) are the leading cause of arboviral diseases in humans. Decades of efforts have made remarkable progress in dengue vaccine development. Despite the first dengue vaccine (dengvaxia from Sanofi Pasteur), a live-attenuated tetravalent chimeric yellow fever-dengue vaccine, has been licensed by several countries since 2016, its overall moderate efficacy (56.5-60.8%) in the presence of neutralizing antibodies during the Phase 2b and 3 trials, lower efficacy among dengue naïve compared with dengue experienced individuals, and increased risk of hospitalization among young children during the follow-up highlight the need for a better understanding of humoral responses after natural DENV infection. Recent studies of more than 300 human monoclonal antibodies (mAbs) against DENV have led to the discovery of several novel epitopes on the envelope protein recognized by potent neutralizing mAbs. This information together with in-depth studies on polyclonal sera and B-cells following natural DENV infection has tremendous implications for better immunogen design for a safe and effective dengue vaccine. This review outlines the progress in our understanding of mouse mAbs, human mAbs, and polyclonal sera against DENV envelope and precursor membrane proteins, two surface proteins involved in vaccine development, following natural infection; analyses of these discoveries have provided valuable insight into new strategies involving molecular technology to induce more potent neutralizing antibodies and less enhancing antibodies for next-generation dengue vaccine development.

Complexity of Human Antibody Response to Dengue Virus: Implication for Vaccine Development

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Wen-Yang Tsai

2017-07-01

Full Text Available The four serotypes of dengue virus (DENV are the leading cause of arboviral diseases in humans. Decades of efforts have made remarkable progress in dengue vaccine development. Despite the first dengue vaccine (dengvaxia from Sanofi Pasteur, a live-attenuated tetravalent chimeric yellow fever-dengue vaccine, has been licensed by several countries since 2016, its overall moderate efficacy (56.5–60.8% in the presence of neutralizing antibodies during the Phase 2b and 3 trials, lower efficacy among dengue naïve compared with dengue experienced individuals, and increased risk of hospitalization among young children during the follow-up highlight the need for a better understanding of humoral responses after natural DENV infection. Recent studies of more than 300 human monoclonal antibodies (mAbs against DENV have led to the discovery of several novel epitopes on the envelope protein recognized by potent neutralizing mAbs. This information together with in-depth studies on polyclonal sera and B-cells following natural DENV infection has tremendous implications for better immunogen design for a safe and effective dengue vaccine. This review outlines the progress in our understanding of mouse mAbs, human mAbs, and polyclonal sera against DENV envelope and precursor membrane proteins, two surface proteins involved in vaccine development, following natural infection; analyses of these discoveries have provided valuable insight into new strategies involving molecular technology to induce more potent neutralizing antibodies and less enhancing antibodies for next-generation dengue vaccine development.

Anti-DNA antibodies: Sequencing, cloning, and expression

Energy Technology Data Exchange (ETDEWEB)

Barry, M.M.

1992-01-01

To gain some insight into the mechanism of systemic lupus erythematosus, and the interactions involved in proteins binding to DNA four anti-DNA antibodies have been investigated. Two of the antibodies, Hed 10 and Jel 242, have previously been prepared from female NZB/NZW mice which develop an autoimmune disease resembling human SLE. The remaining two antibodies, Jel 72 and Jel 318, have previously been produced via immunization of C57BL/6 mice. The isotypes of the four antibodies investigated in this thesis were determined by an enzyme-linked-immunosorbent assay. All four antibodies contained [kappa] light chains and [gamma]2a heavy chains except Jel 318 which contains a [gamma]2b heavy chain. The complete variable regions of the heavy and light chains of these four antibodies were sequenced from their respective mRNAs. The gene segments and variable gene families expressed in each antibody were identified. Analysis of the genes used in the autoimmune anti-DNA antibodies and those produced by immunization indicated no obvious differences to account for their different origins. Examination of the amino acid residues present in the complementary-determining regions of these four antibodies indicates a preference for aromatic amino acids. Jel 72 and Jel 242 contain three arginine residues in the third complementary-determining region. A single-chain Fv and the variable region of the heavy chain of Hed 10 were expressed in Escherichia coli. Expression resulted in the production of a 26,000 M[sub r] protein and a 15,000 M[sub r] protein. An immunoblot indicated that the 26,000 M[sub r] protein was the Fv for Hed 10, while the 15,000 M[sub r] protein was shown to bind poly (dT). The contribution of the heavy chain to DNA binding was assessed.

Association of microRNAs with antibody response to mycoplasma bovis in beef cattle

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The objective of this study was to identify microRNAs associated with a serum antibody response to Mycoplasma bovis in beef cattle. Serum from sixteen beef calves was collected at three points: in summer after calves were born, in fall at weaning, and in the following spring. All sera collected in t...

Three monoclonal antibodies to the VHS virus glycoprotein: comparison of reactivity in relation to differences in immunoglobulin variable domain gene sequences

DEFF Research Database (Denmark)

Lorenzen, Niels; Cupit, P.M.; Secombes, C.J.

2000-01-01

and their neutralising activity was evident. Binding kinetic analyses by plasmon resonance identified differences in the dissociation rate constant (kd) as a possible explanation for the different reactivity levels of the MAbs. The Ig variable heavy (VH) and light (V kappa) domain gene sequences of the three hybridomas...... were compared. The inferred amino acid sequence of the two neutralising antibody VH domains differed by three amino acid residues (97% identity) and only one residue difference was evident in the Vk. domains. In contrast, IP1H3 shared only 38 and 39% identity with the 3F1A2 and 3F1H10 VH domains...... respectively and 49 and 50% identity with the 3F1A2 and 3F1H10 VK domains respectively. The neutralising antibodies were produced by hybridomas originating from the same fusion and the high nucleotide sequence homology of the variable Ig gene regions indicated that the plasma cell partners of the hybridomas...

IL-15 enhances cross-reactive antibody recall responses to seasonal H3 influenza viruses in vitro [version 1; referees: 2 approved

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Junqiong Huang

2017-11-01

Full Text Available Background: Recently, several human monoclonal antibodies that target conserved epitopes on the stalk region of influenza hemagglutinin (HA have shown broad reactivity to influenza A subtypes. Also, vaccination with recombinant chimeric HA or stem fragments from H3 influenza viruses induce broad immune protection in mice and humans. However, it is unclear whether stalk-binding antibodies can be induced in human memory B cells by seasonal H3N2 viruses. Methods: In this study, we recruited 13 donors previously exposed to H3 viruses, the majority (12 of 13 of which had been immunized with seasonal influenza vaccines. We evaluated plasma baseline strain-specific and stalk-reactive anti-HA antibodies and B cell recall responses to inactivated H3N2 A/Victoria/361/2011 virus in vitro using a high throughput multiplex (mPlex-Flu assay. Results: Stalk-reactive IgG was detected in the plasma of 7 of the subjects. Inactivated H3 viral particles rapidly induced clade cross-reactive antibodies in B cell cultures derived from all 13 donors. In addition, H3 stalk-reactive antibodies were detected in culture supernatants from 7 of the 13 donors (53.8%.  H3 stalk-reactive antibodies were also induced by H1 and H7 subtypes. Interestingly, broadly cross-reactive antibody recall responses to H3 strains were also enhanced by stimulating B cells in vitro with CpG2006 ODN in the presence of IL-15. H3 stalk-reactive antibodies were detected in  CpG2006 ODN + IL-15 stimulated B cell cultures derived from 12 of the 13 donors (92.3%, with high levels detected in cultures from 7 of the 13 donors. Conclusions: Our results demonstrate that stalk-reactive antibody recall responses induced by seasonal H3 viruses and CpG2006 ODN can be enhanced by IL-15.

Porous silicon biosensor for detection of variable domain of heavy-chain of HCAb antibody

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Zhang, Hong-yan; Lü, Xiao-yi; Jia, Zhen-hong; Li, Jiang-wei; Zhang, Fu-chun

2012-03-01

In this paper, we produce porous silicon (PSi) by electrochemical etching, and it is the first time to evaluate the performance of label-free porous silicon biosensor for detection of variable domain of heavy chain of heavy-chain antibody (VHH). The binding of hen egg white lysozyme (HEWL) and VHH causes a red shift in the reflection spectrum of the biosensor. The red shift is proportional to the VHH concentration in the range from 14 g·ml-1 to 30 g·ml-1 with a detection limit of 0.648 ng·ml-1. The research is useful for the development of label-free biosensor applied in the rapid and sensitive determination of small molecules.

Single chain variable fragment antibodies block aggregation and toxicity induced by familial ALS-linked mutant forms of SOD1.

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Ghadge, Ghanashyam D; Pavlovic, John D; Koduvayur, Sujatha P; Kay, Brian K; Roos, Raymond P

2013-08-01

Approximately 10% of amyotrophic lateral sclerosis (ALS) cases are familial (known as FALS) with an autosomal dominant inheritance pattern, and ~25% of FALS cases are caused by mutations in Cu/Zn superoxide dismutase (SOD1). There is convincing evidence that mutant SOD1 (mtSOD1) kills motor neurons (MNs) because of a gain-of-function toxicity, most likely related to aggregation of mtSOD1. A number of recent reports have suggested that antibodies can be used to treat mtSOD1-induced FALS. To follow up on the use of antibodies as potential therapeutics, we generated single chain fragments of variable region antibodies (scFvs) against SOD1, and then expressed them as 'intrabodies' within a motor neuron cell line. In the present study, we describe isolation of human scFvs that interfere with mtSOD1 in vitro aggregation and toxicity. These scFvs may have therapeutic potential in sporadic ALS, as well as FALS, given that sporadic ALS may also involve abnormalities in the SOD1 protein or activity. Copyright © 2013 Elsevier Inc. All rights reserved.

Structural Characterization of Peptide Antibodies

DEFF Research Database (Denmark)

Chailyan, Anna; Marcatili, Paolo

2015-01-01

The role of proteins as very effective immunogens for the generation of antibodies is indisputable. Nevertheless, cases in which protein usage for antibody production is not feasible or convenient compelled the creation of a powerful alternative consisting of synthetic peptides. Synthetic peptides...... can be modified to obtain desired properties or conformation, tagged for purification, isotopically labeled for protein quantitation or conjugated to immunogens for antibody production. The antibodies that bind to these peptides represent an invaluable tool for biological research and discovery....... To better understand the underlying mechanisms of antibody-antigen interaction here we present a pipeline developed by us to structurally classify immunoglobulin antigen binding sites and to infer key sequence residues and other variables that have a prominent role in each structural class....

Design of a Heterotetravalent Synthetic Allergen That Reflects Epitope Heterogeneity and IgE Antibody Variability to Study Mast Cell Degranulation

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Handlogten, Michael W.; Kiziltepe, Tanyel; Bilgicer, Basar

2013-01-01

SYNOPSIS This study describes the design of a heterotetravalent allergen (HtTA) as a multi-component experimental system that enables an integrative approach to study mast cell degranulation. The HtTA design allows presentation of two distinct haptens, each with a valency of two, thereby better reflecting the complexity of natural allergens by displaying epitope heterogeneity and IgE antibody variability. Using the HtTA design, synthetic allergens HtTA-1 and HtTA-2 were synthesized to model a combination of epitope/IgE affinities. HtTA-1 presented DNP and dansyl haptens (Kd = 22 and 54 nM for IgEDNP and IgEdansyl respectively), and HtTA-2 presented dansyl and the weak affinity DNP-Pro haptens (Kd = 550 nM for IgEDNP). Both HtTAs effectively induced degranulation when mast cells were primed with both IgEDNP and IgEdansyl antibodies. Interestingly, tetravalent DNP-Pro or bivalent dansyl were insufficient in stimulating a degranulation response, illustrating the significance of valency, affinity, and synergy in allergen-IgE interactions. Importantly, maximum degranulation with both HtTA-1 and HtTA-2 was observed when only 50% of the mast cell-bound IgEs were hapten specific (25% IgEdansyl + 25% IgEDNP). Taken together, this study establishes the HtTA system as a physiologically relevant experimental model and demonstrates its utility in elucidating critical mechanisms of mast cell degranulation. PMID:23050868

Dengue-Immune Humans Have Higher Levels of Complement-Independent Enhancing Antibody than Complement-Dependent Neutralizing Antibody.

Science.gov (United States)

Yamanaka, Atsushi; Konishi, Eiji

2017-09-25

Dengue is the most important arboviral disease worldwide. We previously reported that most inhabitants of dengue-endemic countries who are naturally immune to the disease have infection-enhancing antibodies whose in vitro activity does not decrease in the presence of complement (complement-independent enhancing antibodies, or CiEAb). Here, we compared levels of CiEAb and complement-dependent neutralizing antibodies (CdNAb) in dengue-immune humans. A typical antibody dose-response pattern obtained in our assay system to measure the balance between neutralizing and enhancing antibodies showed both neutralizing and enhancing activities depending on serum dilution factor. The addition of complement to the assay system increased the activity of neutralizing antibodies at lower dilutions, indicating the presence of CdNAb. In contrast, similar dose-response curves were obtained with and without complement at higher dilutions, indicating higher levels of CiEAb than CdNAb. For experimental support for the higher CiEAb levels, a cocktail of mouse monoclonal antibodies against dengue virus type 1 was prepared. The antibody dose-response curves obtained in this assay, with or without complement, were similar to those obtained with human serum samples when a high proportion of D1-V-3H12 (an antibody exhibiting only enhancing activity and thus a model for CiEAb) was used in the cocktail. This study revealed higher-level induction of CiEAb than CdNAb in humans naturally infected with dengue viruses.

Multi-Wheat-Model Ensemble Responses to Interannual Climate Variability

Science.gov (United States)

Ruane, Alex C.; Hudson, Nicholas I.; Asseng, Senthold; Camarrano, Davide; Ewert, Frank; Martre, Pierre; Boote, Kenneth J.; Thorburn, Peter J.; Aggarwal, Pramod K.; Angulo, Carlos

2016-01-01

We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981e2010 grain yield, and we evaluate results against the interannual variability of growing season temperature, precipitation, and solar radiation. The amount of information used for calibration has only a minor effect on most models' climate response, and even small multi-model ensembles prove beneficial. Wheat model clusters reveal common characteristics of yield response to climate; however models rarely share the same cluster at all four sites indicating substantial independence. Only a weak relationship (R2 0.24) was found between the models' sensitivities to interannual temperature variability and their response to long-termwarming, suggesting that additional processes differentiate climate change impacts from observed climate variability analogs and motivating continuing analysis and model development efforts.

Monoclonal Antibodies Directed toward the Hepatitis C Virus Glycoprotein E2 Detect Antigenic Differences Modulated by the N-Terminal Hypervariable Region 1 (HVR1), HVR2, and Intergenotypic Variable Region.

Science.gov (United States)

Alhammad, Yousef; Gu, Jun; Boo, Irene; Harrison, David; McCaffrey, Kathleen; Vietheer, Patricia T; Edwards, Stirling; Quinn, Charles; Coulibaly, Fásseli; Poumbourios, Pantelis; Drummer, Heidi E

2015-12-01

Hepatitis C virus (HCV) envelope glycoproteins E1 and E2 form a heterodimer and mediate receptor interactions and viral fusion. Both E1 and E2 are targets of the neutralizing antibody (NAb) response and are candidates for the production of vaccines that generate humoral immunity. Previous studies demonstrated that N-terminal hypervariable region 1 (HVR1) can modulate the neutralization potential of monoclonal antibodies (MAbs), but no information is available on the influence of HVR2 or the intergenotypic variable region (igVR) on antigenicity. In this study, we examined how the variable regions influence the antigenicity of the receptor binding domain of E2 spanning HCV polyprotein residues 384 to 661 (E2661) using a panel of MAbs raised against E2661 and E2661 lacking HVR1, HVR2, and the igVR (Δ123) and well-characterized MAbs isolated from infected humans. We show for a subset of both neutralizing and nonneutralizing MAbs that all three variable regions decrease the ability of MAbs to bind E2661 and reduce the ability of MAbs to inhibit E2-CD81 interactions. In addition, we describe a new MAb directed toward the region spanning residues 411 to 428 of E2 (MAb24) that demonstrates broad neutralization against all 7 genotypes of HCV. The ability of MAb24 to inhibit E2-CD81 interactions is strongly influenced by the three variable regions. Our data suggest that HVR1, HVR2, and the igVR modulate exposure of epitopes on the core domain of E2 and their ability to prevent E2-CD81 interactions. These studies suggest that the function of HVR2 and the igVR is to modulate antibody recognition of glycoprotein E2 and may contribute to immune evasion. This study reveals conformational and antigenic differences between the Δ123 and intact E2661 glycoproteins and provides new structural and functional data about the three variable regions and their role in occluding neutralizing and nonneutralizing epitopes on the E2 core domain. The variable regions may therefore function to

Isolation and characterization of anti c-met single chain fragment variable (scFv) antibodies.

Science.gov (United States)

Qamsari, Elmira Safaie; Sharifzadeh, Zahra; Bagheri, Salman; Riazi-Rad, Farhad; Younesi, Vahid; Abolhassani, Mohsen; Ghaderi, Sepideh Safaei; Baradaran, Behzad; Somi, Mohammad Hossein; Yousefi, Mehdi

2017-12-01

The receptor tyrosine kinase (RTK) Met is the cell surface receptor for hepatocyte growth factor (HGF) involved in invasive growth programs during embryogenesis and tumorgenesis. There is compelling evidence suggesting important roles for c-Met in colorectal cancer proliferation, migration, invasion, angiogenesis, and survival. Hence, a molecular inhibitor of an extracellular domain of c-Met receptor that blocks c-Met-cell surface interactions could be of great thera-peutic importance. In an attempt to develop molecular inhibitors of c-Met, single chain variable fragment (scFv) phage display libraries Tomlinson I + J against a specific synthetic oligopeptide from the extracellular domain of c-Met receptor were screened; selected scFv were then characterized using various immune techniques. Three c-Met specific scFv (ES1, ES2, and ES3) were selected following five rounds of panning procedures. The scFv showed specific binding to c-Met receptor, and significantly inhibited proliferation responses of a human colorectal carcinoma cell line (HCT-116). Moreover, anti- apoptotic effects of selected scFv antibodies on the HCT-116 cell line were also evaluated using Annexin V/PI assays. The results demonstrated rates of apoptotic cell death of 46.0, 25.5, and 37.8% among these cells were induced by use of ES1, ES2, and ES3, respectively. The results demonstrated ability to successfully isolate/char-acterize specific c-Met scFv that could ultimately have a great therapeutic potential in immuno-therapies against (colorectal) cancers.

Comparison of the cross-antibody response induced in sheep by inactivated bovine viral diarrhoea virus 1 and Hobi-like pestivirus.

Science.gov (United States)

Decaro, Nicola; Mari, Viviana; Sciarretta, Rossana; Lucente, Maria Stella; Camero, Michele; Losurdo, Michele; Larocca, Vittorio; Colao, Valeriana; Cavaliere, Nicola; Lovero, Angela; Lorusso, Eleonora; Buonavoglia, Canio

2013-06-01

Hobi-like pestivirus, a new tentative species within genus Pestivirus, was firstly detected in foetal bovine serum batches and later associated to respiratory distress and reproductive failures in cattle. In the present study, the cross-antibody response between bovine viral diarrhoea virus 1 (BVDV-1) and the emerging pestivirus was evaluated in the sheep model. Ten sheep were immunised against BVDV-1 or Hobi-like pestivirus using inactivated preparations and the induced antibody responses were evaluated against the homologous and heterologous viruses. The results showed that heterologous antibody titres were significantly lower than the homologous ones, thus suggesting the need to develop specific vaccines against the emerging pestiviral species. Copyright © 2012 Elsevier Ltd. All rights reserved.

Antibody responses to a Cryptosporidium parvum rCP15/60 vaccine

OpenAIRE

Alexandra J. Burton; Daryl V. Nydam; Gary Jones; Jennifer Zambriski; Thomas C. Linden; Graham Cox; Randy Davis; Alicia Brown; Dwight D. Bowman

2009-01-01

Cryptosporidium parvum is a zoonotic apicomplexa-protozoan pathogen that causes gastroenteritis and diarrhoea in mammals worldwide. The organism is transmitted by ingestion of oocysts, which are shed in faeces, and completes its lifecycle in a single host.^1^ C. parvum is ubiquitous on dairy operations worldwide and is one of the leading causes of diarrhoea in calves on these farms.^2,3^ Here, for the first time, we describe the antibody response in a large group of cows to a recombinant C. p...

Association of Circulating Transfer RNA fragments with antibody response to Mycoplasma bovis in beef cattle.

Science.gov (United States)

Casas, Eduardo; Cai, Guohong; Kuehn, Larry A; Register, Karen B; McDaneld, Tara G; Neill, John D

2018-03-13

High throughput sequencing allows identification of small non-coding RNAs. Transfer RNA Fragments are a class of small non-coding RNAs, and have been identified as being involved in inhibition of gene expression. Given their role, it is possible they may be involved in mediating the infection-induced defense response in the host. Therefore, the objective of this study was to identify 5' transfer RNA fragments (tRF5s) associated with a serum antibody response to M. bovis in beef cattle. The tRF5s encoding alanine, glutamic acid, glycine, lysine, proline, selenocysteine, threonine, and valine were associated (P < 0.05) with antibody response against M. bovis. tRF5s encoding alanine, glutamine, glutamic acid, glycine, histidine, lysine, proline, selenocysteine, threonine, and valine were associated (P < 0.05) with season, which could be attributed to calf growth. There were interactions (P < 0.05) between antibody response to M. bovis and season for tRF5 encoding selenocysteine (anticodon UGA), proline (anticodon CGG), and glutamine (anticodon TTG). Selenocysteine is a rarely used amino acid that is incorporated into proteins by the opal stop codon (UGA), and its function is not well understood. Differential expression of tRF5s was identified between ELISA-positive and negative animals. Production of tRF5s may be associated with a host defense mechanism triggered by bacterial infection, or it may provide some advantage to a pathogen during infection of a host. Further studies are needed to establish if tRF5s could be used as a diagnostic marker of chronic exposure.

Antibody Responses to Pneumococcal Polysaccharide Vaccine in Taiwanese Patients with Chronic Obstructive Pulmonary Disease

Directory of Open Access Journals (Sweden)

Chih-Cheng Lai

2007-01-01

Conclusion: Taiwanese elderly adults with COPD, even in advanced age, can mount a significant antibody response to pneumococcal polysaccharide vaccine. This study may support the existing recommendation that pneumococcal vaccine be offered to persons ≥ 65 years old with COPD. [J Formos Med Assoc 2007;106(3: 196-203

Monoclonal antibodies for treating cancer

International Nuclear Information System (INIS)

Dillman, R.O.

1989-01-01

The purpose of this study is to assess the current status of in-vivo use of monoclonal antibodies for treating cancer. Publications appearing between 1980 and 1988 were identified by computer searches using MEDLINE and CANCERLIT, by reviewing the table of contents of recently published journals, and by searching bibliographies of identified books and articles. More than 700 articles, including peer-reviewed articles and book chapters, were identified and selected for analysis. The literature was reviewed and 235 articles were selected as relevant and representative of the current issues and future applications for in-vivo monoclonal antibodies for cancer therapy and of the toxicity and efficacy which has been associated with clinical trials. Approaches include using antibody alone (interacting with complement or effector cells or binding directly with certain cell receptors) and immunoconjugates (antibody coupled to radioisotopes, drugs, toxins, or other biologicals). Most experience has been with murine antibodies. Trials of antibody alone and radiolabeled antibodies have confirmed the feasibility of this approach and the in-vivo trafficking of antibodies to tumor cells. However, tumor cell heterogeneity, lack of cytotoxicity, and the development of human antimouse antibodies have limited clinical efficacy. Although the immunoconjugates are very promising, heterogeneity and the antimouse immune response have hampered this approach as has the additional challenge of chemically or genetically coupling antibody to cytotoxic agents. As a therapeutic modality, monoclonal antibodies are still promising but their general use will be delayed for several years. New approaches using human antibodies and reducing the human antiglobulin response should facilitate treatment. 235 references

Surface plasmon resonance analysis shows an IgG-isotype-specific defect in ABO blood group antibody formation in patients with common variable immunodeficiency

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Michael Bernhard Fischer

2015-05-01

Full Text Available Background: Common variable immunodeficiency (CVID is the most common clinically severe primary immunodeficiency and comprises a heterogeneous group of patients with recurrent severe bacterial infections due to the failure to produce IgG antibodies after exposure to infectious agents and immunization. Diagnostic recommendations for antibody failure include assessment of isoagglutinins. We have readdressed this four decades old but still accepted recommendation with up to date methodology.Methods: Anti-A/B IgM- and IgG-antibodies were measured by Diamed-ID Micro Typing, surface plasmon resonance (SPR using the Biacore® device and flow cytometry.Results: When Diamed-ID Micro Typing was used, CVID patients (n=34 showed IgG- and IgM-isoagglutinins that were comparable to healthy volunteers (n=28, while all XLA patients (n=8 had none. Anti-A/B IgM-antibodies were present in more than 2/3 of the CVID patients and showed binding kinetics comparable to anti-A/B IgM-antibodies from healthy individuals. A correlation could be found in CVID patients between levels of anti-A/B IgM-antibodies and levels of serum IgM and PnP-IgM-antibodies. In contrast in CVID patients as a group ABO antibodies were significantly decreased when assessed by SPR, which correlated with levels of switched memory, non-switched memory and naïve B cells, but all CVID patients had low/undetectable anti-A/B IgG-antibodies.Conclusion: These results indicate that conventional isoagglutinin assessment and assessment of anti-A/B IgM antibodies are not suited for the diagnosis of impaired antibody production in CVID. Examination of anti-A/B IgG antibodies by SPR provides a useful method for the diagnosis of IgG antibody failure in all CVID patients studied, thus indicating an important additional rationale to start immunoglobulin replacement therapy early in these patients, before post-infectious sequelae develop.

Enhancement of anamnestic immunospecific antibody response in orally immunized chickens

DEFF Research Database (Denmark)

Mayo, Susan; Carlsson, Hans-Erik; Zagon, Andrea

2008-01-01

Production of immunospecific egg yolk antibodies (IgY antibodies) in egg laying hens through oral immunization is an attractive alternative to conventional antibody production in mammals for economic reasons as well as for animal welfare reasons. Oral immunization results in a systemic humoral...... of the immunization in week 18, demonstrating the presence of memory cells following the two initial oral immunizations. Considering that oral immunization results in approximately ten times lower concentrations of immunospecific antibodies in the egg yolk, compared to traditional subcutaneous immunization schemes...

A life-style physical activity intervention and the antibody response to pneumococcal vaccination in women

NARCIS (Netherlands)

Long, J.E.; Ring, C.; Bosch, J.A.; Eves, F.; Drayson, M.T.; Calver, R.; Say, V.; Allen, D.; Burns, V.E.

2013-01-01

Objective: To assess whether a life-style physical activity intervention improved antibody response to a pneumococcal vaccination in sedentary middle-aged women. Methods: Eighty-nine sedentary women completed a 16-week exercise (physical activity consultation, pedometer, telephone/e-mail prompts; n

Nanobodies - the new concept in antibody engineering

African Journals Online (AJOL)

STORAGESEVER

2009-06-17

Jun 17, 2009 ... These heavy-chain antibodies contain a single variable domain (VHH) and two ... clonal antibody products were on the market and more than 100 in ..... genous showing no sign of spontaneous dimerisation in contrast to scFv ...

Generation of human antibody fragments against Streptococcus mutans using a phage display chain shuffling approach

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Barth Stefan

2005-01-01

Full Text Available Abstract Background Common oral diseases and dental caries can be prevented effectively by passive immunization. In humans, passive immunotherapy may require the use of humanized or human antibodies to prevent adverse immune responses against murine epitopes. Therefore we generated human single chain and diabody antibody derivatives based on the binding characteristics of the murine monoclonal antibody Guy's 13. The murine form of this antibody has been used successfully to prevent Streptococcus mutans colonization and the development of dental caries in non-human primates, and to prevent bacterial colonization in human clinical trials. Results The antibody derivatives were generated using a chain-shuffling approach based on human antibody variable gene phage-display libraries. Like the parent antibody, these derivatives bound specifically to SAI/II, the surface adhesin of the oral pathogen S. mutans. Conclusions Humanization of murine antibodies can be easily achieved using phage display libraries. The human antibody fragments bind the antigen as well as the causative agent of dental caries. In addition the human diabody derivative is capable of aggregating S. mutans in vitro, making it a useful candidate passive immunotherapeutic agent for oral diseases.

The effect of prophylactic antipyretic administration on post-vaccination adverse reactions and antibody response in children: a systematic review.

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Rashmi Ranjan Das

Full Text Available Prophylactic antipyretic administration decreases the post-vaccination adverse reactions. Recent study finds that they may also decrease the antibody responses to several vaccine antigens. This systematic review aimed to assess the evidence for a relationship between prophylactic antipyretic administration, post-vaccination adverse events, and antibody response in children.A systematic search of major databases including MEDLINE and EMBASE was carried out till March 2014. Randomized controlled trials (RCTs comparing prophylactic antipyretic treatment versus placebo post-vaccination in children ≤ 6 years of age were included. Two reviewers independently applied eligibility criteria, assessed the studies for methodological quality, and extracted data [PROSPERO registration: CRD42014009717].Of 2579 citations retrieved, a total of 13 RCTs including 5077 children were included in the review. Prophylactic antipyretic administration significantly reduced the febrile reactions (≥ 38.0 °C after primary and booster vaccinations. Though there were statistically significant differences in the antibody responses between the two groups, the prophylactic PCM group had what would be considered protective levels of antibodies to all of the antigens given after the primary and booster vaccinations. No significant difference in the nasopharyngeal carriage rates (short-term and long-term of H. influenzae or S. pneumoniae serotypes was found between the prophylactic and no prophylactic PCM group. There was a significant reduction in the local and systemic symptoms after primary, but not booster vaccinations.Though prophylactic antipyretic administration leads to relief of the local and systemic symptoms after primary vaccinations, there is a reduction in antibody responses to some vaccine antigens without any effect on the nasopharyngeal carriage rates of S. pneumoniae & H. influenza serotypes. Future trials and surveillance programs should also aim at

Vaxfectin enhances antigen specific antibody titers and maintains Th1 type immune responses to plasmid DNA immunization.

Science.gov (United States)

Reyes, L; Hartikka, J; Bozoukova, V; Sukhu, L; Nishioka, W; Singh, G; Ferrari, M; Enas, J; Wheeler, C J; Manthorpe, M; Wloch, M K

2001-06-14

Antigen specific immune responses were characterized after intramuscular immunization of BALB/c mice with 5 antigen encoding plasmid DNAs (pDNAs) complexed with Vaxfectin, a cationic lipid formulation. Vaxfectin increased IgG titers for all of the antigens with no effect on the CTL responses to the 2 antigens for which CTL assays were performed. Both antigen specific IgG1 and IgG2a were increased, although IgG2a remained greater than IgG1. Furthermore, Vaxfectin had no effect on IFN-gamma or IL-4 production by splenocytes re-stimulated with antigen, suggesting that the Th1 type responses typical of intramuscular pDNA immunization were not altered. Studies with IL-6 -/- mice suggest that the antibody enhancement is IL-6 dependent and results in a correlative increase in antigen specific antibody secreting cells.

Directional Selection for Specific Sheep Cell Antibody Responses Affects Natural Rabbit Agglutinins of Chickens

NARCIS (Netherlands)

Cotter, P.F.; Ayoub, J.; Parmentier, H.K.

2005-01-01

Agglutination data from generations 8 through 19 indicate that bidirectional selection for specific SRBC antibody responses was successful in a line cross of ISA × Warren medium heavy layers. After 11 generations titers of the high SRBC selected line (H line) were nearly 1:32,000; those of the low

Antibody response to Giardia muris trophozoites in mouse intestine.

Science.gov (United States)

Heyworth, M F

1986-05-01

The protozoan parasite Giardia muris colonizes the mouse small intestinal lumen. This parasite is cleared immunologically from the intestine of normal mice. In contrast, T-lymphocyte-deficient (nude) mice have an impaired immunological response to G. muris and become chronically infected. In the present study, trophozoites were harvested from the intestinal lumen of immunocompetent BALB/c mice and nude mice and examined for surface-bound mouse immunoglobulins by immunofluorescence microscopy. Immunoglobulin A (IgA) and IgG, but not IgM, were detected on trophozoites obtained from BALB/c mice, from day 10 of the infection onwards. Trophozoites from nude mice showed very little evidence of surface-bound mouse immunoglobulin at any time during the 5-week period immediately following infection of these animals with G. muris cysts. Intestinal G. muris infection was cleared by the BALB/c mice but not by the nude animals. The data suggest that parasite-specific IgA and IgG bind to G. muris trophozoites in the intestinal lumen of immunocompetent BALB/c mice. Intestinal antibodies that bind to trophozoite surfaces are likely to play an important part in the clearance of G. muris infection by immunocompetent mice. The inability of nude mice to clear this infection at a normal rate is likely to be due to impairment of Giardia-specific intestinal antibody production.

Novel adenoviral vector induces T-cell responses despite anti-adenoviral neutralizing antibodies in colorectal cancer patients.

Science.gov (United States)

Morse, Michael A; Chaudhry, Arvind; Gabitzsch, Elizabeth S; Hobeika, Amy C; Osada, Takuya; Clay, Timothy M; Amalfitano, Andrea; Burnett, Bruce K; Devi, Gayathri R; Hsu, David S; Xu, Younong; Balcaitis, Stephanie; Dua, Rajesh; Nguyen, Susan; Balint, Joseph P; Jones, Frank R; Lyerly, H Kim

2013-08-01

First-generation, E1-deleted adenovirus subtype 5 (Ad5)-based vectors, although promising platforms for use as cancer vaccines, are impeded in activity by naturally occurring or induced Ad-specific neutralizing antibodies. Ad5-based vectors with deletions of the E1 and the E2b regions (Ad5 [E1-, E2b-]), the latter encoding the DNA polymerase and the pre-terminal protein, by virtue of diminished late phase viral protein expression, were hypothesized to avoid immunological clearance and induce more potent immune responses against the encoded tumor antigen transgene in Ad-immune hosts. Indeed, multiple homologous immunizations with Ad5 [E1-, E2b-]-CEA(6D), encoding the tumor antigen carcinoembryonic antigen (CEA), induced CEA-specific cell-mediated immune (CMI) responses with antitumor activity in mice despite the presence of preexisting or induced Ad5-neutralizing antibody. In the present phase I/II study, cohorts of patients with advanced colorectal cancer were immunized with escalating doses of Ad5 [E1-, E2b-]-CEA(6D). CEA-specific CMI responses were observed despite the presence of preexisting Ad5 immunity in a majority (61.3 %) of patients. Importantly, there was minimal toxicity, and overall patient survival (48 % at 12 months) was similar regardless of preexisting Ad5 neutralizing antibody titers. The results demonstrate that, in cancer patients, the novel Ad5 [E1-, E2b-] gene delivery platform generates significant CMI responses to the tumor antigen CEA in the setting of both naturally acquired and immunization-induced Ad5-specific immunity.

Development of a mouse-feline chimeric antibody against feline tumor necrosis factor-alpha

Science.gov (United States)

DOKI, Tomoyoshi; TAKANO, Tomomi; HOHDATSU, Tsutomu

2016-01-01

Feline infectious peritonitis (FIP) is a fatal inflammatory disease caused by FIP virus infection. Feline tumor necrosis factor (fTNF)-alpha is closely involved in the aggravation of FIP pathology. We previously described the preparation of neutralizing mouse anti-fTNF-alpha monoclonal antibody (mAb 2–4) and clarified its role in the clinical condition of cats with FIP using in vitro systems. However, administration of mouse mAb 2–4 to cat may lead to a production of feline anti-mouse antibodies. In the present study, we prepared a mouse-feline chimeric mAb (chimeric mAb 2–4) by fusing the variable region of mouse mAb 2–4 to the constant region of feline antibody. The chimeric mAb 2–4 was confirmed to have fTNF-alpha neutralization activity. Purified mouse mAb 2–4 and chimeric mAb 2–4 were repeatedly administered to cats, and the changes in the ability to induce feline anti-mouse antibody response were investigated. In the serum of cats treated with mouse mAb 2–4, feline anti-mouse antibody production was induced, and the fTNF-alpha neutralization effect of mouse mAb 2–4 was reduced. In contrast, in cats treated with chimeric mAb 2–4, the feline anti-mouse antibody response was decreased compared to that of mouse mAb 2–4-treated cats. PMID:27264736

Serum antibody responses in pigs trickle-infected with Ascaris and Trichuris: Heritabilities and associations with parasitological findings.

Science.gov (United States)

Kringel, Helene; Thamsborg, Stig Milan; Petersen, Heidi Huus; Göring, Harald Heinz Herbert; Skallerup, Per; Nejsum, Peter

2015-07-30

A humoral immune response following helminth infection in pigs is well documented. However, it has been difficult to confirm the existence of antibody mediated resistance against the large roundworm, Ascaris suum, and whipworm, Trichuris suis, in experimental settings by correlating worm burdens or egg excretion with specific antibody levels. We set out to investigate the association between worm load and T. suis and A. suum specific serum antibody levels (IgG1, IgG2 and IgA) against excretory-secretory products of adults and third stage larvae, respectively, measured at 0, 7 and 14 weeks p.i. in a trickle-infected F1-resource-population of crossbred pigs (n=195). Furthermore, we wanted to determine the heritability of these antibody isotypes during the course of infection. Most pigs remained infected with A. suum throughout the experiment while they expelled T. suis between 7 and 14 weeks post infection (p.i.). Parasite specific IgG1 and IgA were significantly (P<0.001) elevated after 7 and 14 weeks of infection, whereas parasite specific IgG2 levels only changed slightly at 14 weeks p.i.. However, the observed association between specific antibody isotype levels and faecal egg counts and macroscopic worm load was weak. The relative heritabilities of the different parasite specific isotypes were assessed and resulted in significant heritability estimates for parasite specific IgG1 and IgA. The highest heritabilities were found for A. suum specific IgG1 (h(2)=0.41 and 0.46 at 7 and 14 weeks p.i., respectively). Thus, the present study demonstrates that host genetic factors influence the IgG1 and IgA antibody isotype responses specific to two of the most common gastrointestinal nematodes of swine whereas specific antibody levels were poorly associated with egg excretion and the presence of macroscopic worms. Copyright © 2015. Published by Elsevier B.V.

Antibodies from plants for bionanomaterials

OpenAIRE

Edgue, G.; Twyman, R.M.; Beiss, V.; Fischer, R.; Sack, M.

2017-01-01

Antibodies are produced as part of the vertebrate adaptive immune response and are not naturally made by plants. However, antibody DNA sequences can be introduced into plants, and together with laboratory technologies that allow the design of antibodies recognizing any conceivable molecular structure, plants can be used as green factories' to produce any antibody at all. The advent of plant-based transient expression systems in particular allows the rapid, convenient, and safe production of a...

Identification of antibody glycosylation structures that predict monoclonal antibody Fc-effector function.

Science.gov (United States)

Chung, Amy W; Crispin, Max; Pritchard, Laura; Robinson, Hannah; Gorny, Miroslaw K; Yu, Xiaojie; Bailey-Kellogg, Chris; Ackerman, Margaret E; Scanlan, Chris; Zolla-Pazner, Susan; Alter, Galit

2014-11-13

To determine monoclonal antibody (mAb) features that predict fragment crystalizable (Fc)-mediated effector functions against HIV. Monoclonal antibodies, derived from Chinese hamster ovary cells or Epstein-Barr virus-immortalized mouse heteromyelomas, with specificity to key regions of the HIV envelope including gp120-V2, gp120-V3 loop, gp120-CD4(+) binding site, and gp41-specific antibodies, were functionally profiled to determine the relative contribution of the variable and constant domain features of the antibodies in driving robust Fc-effector functions. Each mAb was assayed for antibody-binding affinity to gp140(SR162), antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP) and for the ability to bind to FcγRIIa, FcγRIIb and FcγRIIIa receptors. Antibody glycan profiles were determined by HPLC. Neither the specificity nor the affinity of the mAbs determined the potency of Fc-effector function. FcγRIIIa binding strongly predicted ADCC and decreased galactose content inversely correlated with ADCP, whereas N-glycolylneuraminic acid-containing structures exhibited enhanced ADCP. Additionally, the bi-antenary glycan arm onto which galactose was added predicted enhanced binding to FcγRIIIa and ADCC activity, independent of the specificity of the mAb. Our studies point to the specific Fc-glycan structures that can selectively promote Fc-effector functions independently of the antibody specificity. Furthermore, we demonstrated antibody glycan structures associated with enhanced ADCP activity, an emerging Fc-effector function that may aid in the control and clearance of HIV infection.

Minor displacements in the insertion site provoke major differences in the induction of antibody responses by chimeric parvovirus-like particles

DEFF Research Database (Denmark)

Rueda, P.; Hurtado, A.; del Barrio, M.

1999-01-01

inserted into these positions was well recognized by the specific monoclonal antibody C3 by immunoelectron microscopy. BALB/c mice immunized with these chimeric C3:B CPV:VLPs were able to elicit an strong neutralizing antibody response (>3 log(10) units) against poliovirus type 1 (Mahoney strain...

Immunoglobulin G1 Allotype Influences Antibody Subclass Distribution in Response to HIV gp140 Vaccination

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Sven Kratochvil

2017-12-01

Full Text Available Antibody subclasses exhibit extensive polymorphisms (allotypes that could potentially impact the quality of HIV-vaccine induced B cell responses. Allotypes of immunoglobulin (Ig G1, the most abundant serum antibody, have been shown to display altered functional properties in regard to serum half-life, Fc-receptor binding and FcRn-mediated mucosal transcytosis. To investigate the potential link between allotypic IgG1-variants and vaccine-generated humoral responses in a cohort of 14 HIV vaccine recipients, we developed a novel protocol for rapid IgG1-allotyping. We combined PCR and ELISA assays in a dual approach to determine the IgG1 allotype identity (G1m3 and/or G1m1 of trial participants, using human plasma and RNA isolated from PBMC. The IgG1-allotype distribution of our participants mirrored previously reported results for caucasoid populations. We observed elevated levels of HIV gp140-specific IgG1 and decreased IgG2 levels associated with the G1m1-allele, in contrast to G1m3 carriers. These data suggest that vaccinees homozygous for G1m1 are predisposed to develop elevated Ag-specific IgG1:IgG2 ratios compared to G1m3-carriers. This elevated IgG1:IgG2 ratio was further associated with higher FcγR-dimer engagement, a surrogate for potential antibody-dependent cellular cytotoxicity (ADCC and antibody-dependent cellular phagocytosis (ADCP function. Although preliminary, these results suggest that IgG1 allotype may have a significant impact on IgG subclass distribution in response to vaccination and associated Fc-mediated effector functions. These results have important implications for ongoing HIV vaccine efficacy studies predicated on engagement of FcγR-mediated cellular functions including ADCC and ADCP, and warrant further investigation. Our novel allotyping protocol provides new tools to determine the potential impact of IgG1 allotypes on vaccine efficacy.

Targeting Malignant Brain Tumors with Antibodies

Directory of Open Access Journals (Sweden)

Rok Razpotnik

2017-09-01

Full Text Available Antibodies have been shown to be a potent therapeutic tool. However, their use for targeting brain diseases, including neurodegenerative diseases and brain cancers, has been limited, particularly because the blood–brain barrier (BBB makes brain tissue hard to access by conventional antibody-targeting strategies. In this review, we summarize new antibody therapeutic approaches to target brain tumors, especially malignant gliomas, as well as their potential drawbacks. Many different brain delivery platforms for antibodies have been studied such as liposomes, nanoparticle-based systems, cell-penetrating peptides (CPPs, and cell-based approaches. We have already shown the successful delivery of single-chain fragment variable (scFv with CPP as a linker between two variable domains in the brain. Antibodies normally face poor penetration through the BBB, with some variants sufficiently passing the barrier on their own. A “Trojan horse” method allows passage of biomolecules, such as antibodies, through the BBB by receptor-mediated transcytosis (RMT. Such examples of therapeutic antibodies are the bispecific antibodies where one binding specificity recognizes and binds a BBB receptor, enabling RMT and where a second binding specificity recognizes an antigen as a therapeutic target. On the other hand, cell-based systems such as stem cells (SCs are a promising delivery system because of their tumor tropism and ability to cross the BBB. Genetically engineered SCs can be used in gene therapy, where they express anti-tumor drugs, including antibodies. Different types and sources of SCs have been studied for the delivery of therapeutics to the brain; both mesenchymal stem cells (MSCs and neural stem cells (NSCs show great potential. Following the success in treatment of leukemias and lymphomas, the adoptive T-cell therapies, especially the chimeric antigen receptor-T cells (CAR-Ts, are making their way into glioma treatment as another type of cell

Production of bifunctional proteins by Aspergillus awamori: Llama variable heavy chain antibody fragment (VHH) R9 coupled to Arthromyces ramosus peroxidase (ARP)

NARCIS (Netherlands)

Joosten, V.; Roelofs, M.S.; Dries, N. van den; Goosen, T.; Verrips, C.T.; Hondel, C.A.M.J.J. van den; Lokman, B.C.

2005-01-01

The Arthromyces ramosus peroxidase gene (arp) was genetically fused to either the 5′- or 3′-terminal ends of the gene encoding llama variable heavy chain antibody fragment VHH R9, resulting in the fusion expression cassettes ARP-R9 or R9-ARP. Aspergillus awamori transformants were obtained which

Multi-wheat-model ensemble responses to interannual climatic variability

DEFF Research Database (Denmark)

Ruane, A C; Hudson, N I; Asseng, S

2016-01-01

We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981–2010 grain yield, and ......-term warming, suggesting that additional processes differentiate climate change impacts from observed climate variability analogs and motivating continuing analysis and model development efforts.......We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981–2010 grain yield, and we...... evaluate results against the interannual variability of growing season temperature, precipitation, and solar radiation. The amount of information used for calibration has only a minor effect on most models' climate response, and even small multi-model ensembles prove beneficial. Wheat model clusters reveal...

Rotavirus specific maternal antibodies and immune response to RV3-BB neonatal rotavirus vaccine in New Zealand

OpenAIRE

Chen, Mee-Yew; Kirkwood, Carl D.; Bines, Julie; Cowley, Daniel; Pavlic, Daniel; Lee, Katherine J.; Orsini, Francesca; Watts, Emma; Barnes, Graeme; Danchin, Margaret

2017-01-01

Background: Maternal antibodies, acquired passively via placenta and/or breast milk, may contribute to the reduced efficacy of oral rotavirus vaccines observed in children in developing countries. This study aimed to investigate the effect of rotavirus specific maternal antibodies on the serum IgA response or stool excretion of vaccine virus after any dose of an oral rotavirus vaccine, RV3-BB, in parallel to a Phase IIa clinical trial conducted at Dunedin Hospital, New Zealand. At the time o...

Mycobacterium leprae antigens involved in human immune responses. I. Identification of four antigens by monoclonal antibodies

Energy Technology Data Exchange (ETDEWEB)

Britton, W.J.; Hellqvist, L.; Basten, A.; Raison, R.L.

1985-12-01

Four distinct antigens were identified in soluble sonicates of Mycobacterium leprae by using a panel of 11 monoclonal antibodies. Cross-reactivity studies with other mycobacterial species were conducted by using ELISA and immunoblot assays, and demonstrated that determinants on two of the antigens were present in many mycobacteria, whereas the other two were limited in distribution. Competitive inhibition experiments with radiolabeled monoclonal antibodies showed cross-inhibition between antibodies identifying two of the four antigenicbands. These two bands, of M/sub tau/ 4.5 to 6 KD and 30 to 40 KD, were resistant to protease treatment after immunoblotting. In contrast the two other bands of 16 and 70 KD were protease-sensitive. Although all four bands reacted with some human lepromatous leprosy sera in immunoblots, the 4.5 to 6 KD and 30 to 40 KD bands were most prominent. Lepromatous leprosy sera also inhibited the binding of radiolabeled monoclonal antibodies to each of the four antigens, with the mean titer causing 50% inhibition being higher for antibodies reacting with the 4.5 to 6 KD and 30 to 40 KD bands. These findings indicated that all four antigens were involved in the human B cell response to M. leprae.

Mycobacterium leprae antigens involved in human immune responses. I. Identification of four antigens by monoclonal antibodies

International Nuclear Information System (INIS)

Britton, W.J.; Hellqvist, L.; Basten, A.; Raison, R.L.

1985-01-01

Four distinct antigens were identified in soluble sonicates of Mycobacterium leprae by using a panel of 11 monoclonal antibodies. Cross-reactivity studies with other mycobacterial species were conducted by using ELISA and immunoblot assays, and demonstrated that determinants on two of the antigens were present in many mycobacteria, whereas the other two were limited in distribution. Competitive inhibition experiments with radiolabeled monoclonal antibodies showed cross-inhibition between antibodies identifying two of the four antigenicbands. These two bands, of M/sub tau/ 4.5 to 6 KD and 30 to 40 KD, were resistant to protease treatment after immunoblotting. In contrast the two other bands of 16 and 70 KD were protease-sensitive. Although all four bands reacted with some human lepromatous leprosy sera in immunoblots, the 4.5 to 6 KD and 30 to 40 KD bands were most prominent. Lepromatous leprosy sera also inhibited the binding of radiolabeled monoclonal antibodies to each of the four antigens, with the mean titer causing 50% inhibition being higher for antibodies reacting with the 4.5 to 6 KD and 30 to 40 KD bands. These findings indicated that all four antigens were involved in the human B cell response to M. leprae

Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenza A viruses.

Science.gov (United States)

Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Varečková, E

2015-06-01

In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenza A viruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population.

Capturing the dynamics of response variability in the brain in ADHD

Directory of Open Access Journals (Sweden)

Janna van Belle

2015-01-01

Full Text Available ADHD is characterized by increased intra-individual variability in response times during the performance of cognitive tasks. However, little is known about developmental changes in intra-individual variability, and how these changes relate to cognitive performance. Twenty subjects with ADHD aged 7–24 years and 20 age-matched, typically developing controls participated in an fMRI-scan while they performed a go-no-go task. We fit an ex-Gaussian distribution on the response distribution to objectively separate extremely slow responses, related to lapses of attention, from variability on fast responses. We assessed developmental changes in these intra-individual variability measures, and investigated their relation to no-go performance. Results show that the ex-Gaussian measures were better predictors of no-go performance than traditional measures of reaction time. Furthermore, we found between-group differences in the change in ex-Gaussian parameters with age, and their relation to task performance: subjects with ADHD showed age-related decreases in their variability on fast responses (sigma, but not in lapses of attention (tau, whereas control subjects showed a decrease in both measures of variability. For control subjects, but not subjects with ADHD, this age-related reduction in variability was predictive of task performance. This group difference was reflected in neural activation: for typically developing subjects, the age-related decrease in intra-individual variability on fast responses (sigma predicted activity in the dorsal anterior cingulate gyrus (dACG, whereas for subjects with ADHD, activity in this region was related to improved no-go performance with age, but not to intra-individual variability. These data show that using more sophisticated measures of intra-individual variability allows the capturing of the dynamics of task performance and associated neural changes not permitted by more traditional measures.

Double-antibody solid-phase radioimmunoassay: a simplified phase-separation procedure applied to various ligands

International Nuclear Information System (INIS)

Tevaarwerk, G.J.M.; Boyle, D.A.; Hurst, C.J.; Anguish, I.; Uksik, P.

1980-01-01

The purpose was to develop a simplified and reliable method of separating free from antibody-bound ligand using a precipitating antibody linked to a cellulose derivative. Dose-response curves and control sera were set up in parallel for various pituitary and placental polypeptides, steroid hormones, insulin, glucagon, triiodothyronine, thyroxine, angiotensin I, calcitonin, gastrin, cyclic AMP, and digoxin. After first-antibody reactions had reached equilibrium, free and bound ligand were separated using a double-antibody solid-phase system in parallel with conventional methods, including dextran-coated charcoal, double-antibody precipitation, single-antibody solid phase, organic solvents, salt precipitation, and anion-exchange resins. The effect of variations in temperature, incubation time, protein content, pH, and amount of separating material added were studied. The results showed that separation was complete within 1 hr for small ligand molecules and within 2 hr for larger ones. Dose-response curves and control-sera results closely paralleled those obtained with conventional methods. The method was not affected by moderate variations in incubation variables. Nonspecific binding was less than 3% in all assays, while intra-assay and interassay coefficients of variation were similar to those obtained with conventional phase-separation methods. It is concluded that the method is a simple and rapid alternative phase-separation system. It has the advantage of being free from common nonspecific intersample variations, and can be applied to any assay system based on rabbit or guinea pig antibodies without preliminay time- or reagent-consuming titration or adjustments to establish optimum phase-separating conditions

Strong Antibody Responses Induced by Protein Antigens Conjugated onto the Surface of Lecithin-Based Nanoparticles

Science.gov (United States)

Sloat, Brian R.; Sandoval, Michael A.; Hau, Andrew M.; He, Yongqun; Cui, Zhengrong

2009-01-01

An accumulation of research over the years has demonstrated the utility of nanoparticles as antigen carriers with adjuvant activity. Herein we defined the adjuvanticity of a novel lecithin-based nanoparticle engineered from emulsions. The nanoparticles were spheres of around 200 nm. Model protein antigens, bovine serum albumin (BSA) or Bacillus anthracis protective antigen (PA) protein, were covalently conjugated onto the nanoparticles. Mice immunized with the BSA-conjugated nanoparticles developed strong anti-BSA antibody responses comparable to that induced by BSA adjuvanted with incomplete Freund's adjuvant and 6.5-fold stronger than that induced by BSA adsorbed onto aluminum hydroxide. Immunization of mice with the PA-conjugated nanoparticles elicited a quick, strong, and durable anti-PA antibody response that afforded protection of the mice against a lethal dose of anthrax lethal toxin challenge. The potent adjuvanticity of the nanoparticles was likely due to their ability to move the antigens into local draining lymph nodes, to enhance the uptake of the antigens by antigen-presenting cells (APCs), and to activate APCs. This novel nanoparticle system has the potential to serve as a universal protein-based vaccine carrier capable of inducing strong immune responses. PMID:19729045

Neutralizing antibody response during human immunodeficiency virus type 1 infection: type and group specificity and viral escape

DEFF Research Database (Denmark)

Arendrup, M; Sönnerborg, A; Svennerholm, B

1993-01-01

The paradox that group-specific neutralizing antibodies (NA) exist in the majority of human immunodeficiency virus type 1 (HIV-1)-infected patients, whereas the NA response against autologous HIV-1 virus isolates is highly type-specific, motivated us to study the type- and group-specific NA...... demonstrated, suggesting that the majority of the change in neutralization sensitivity is driven by the selective pressure of type-specific NA. Furthermore, no differences were observed in sensitivity to neutralization by anti-carbohydrate neutralizing monoclonal antibodies or the lectin concanavalin A...

Molecular aspects of antibody-antigen interactions : size reduction of a herpes simplex virus neutralizing antibody and its antigen

NARCIS (Netherlands)

Schellekens, Gerardus Antonius

1996-01-01

Antibody molecules, produced as a response against foreign substances, interact with their antigen in a very specific manner. Antibodies with a predetermined specificity (monoclonal antibodies) can be produced and are widely used in medicine and science as indicator molecules. Genetic engineering of

Variable reflectivity signal mirrors and signal response measurements

International Nuclear Information System (INIS)

Vine, Glenn de; Shaddock, Daniel A; McClelland, David E

2002-01-01

Future gravitational wave detectors will include some form of signal mirror in order to alter the signal response of the device. We introduce interferometer configurations which utilize a variable reflectivity signal mirror allowing a tunable peak frequency and variable signal bandwidth. A detector configured with a Fabry-Perot cavity as the signal mirror is compared theoretically with one using a Michelson interferometer for a signal mirror. A system for the measurement of the interferometer signal responses is introduced. This technique is applied to a power-recycled Michelson interferometer with resonant sideband extraction. We present broadband measurements of the benchtop prototype's signal response for a range of signal cavity detunings. This technique is also applicable to most other gravitational wave detector configurations

Variable reflectivity signal mirrors and signal response measurements

CERN Document Server

Vine, G D; McClelland, D E

2002-01-01

Future gravitational wave detectors will include some form of signal mirror in order to alter the signal response of the device. We introduce interferometer configurations which utilize a variable reflectivity signal mirror allowing a tunable peak frequency and variable signal bandwidth. A detector configured with a Fabry-Perot cavity as the signal mirror is compared theoretically with one using a Michelson interferometer for a signal mirror. A system for the measurement of the interferometer signal responses is introduced. This technique is applied to a power-recycled Michelson interferometer with resonant sideband extraction. We present broadband measurements of the benchtop prototype's signal response for a range of signal cavity detunings. This technique is also applicable to most other gravitational wave detector configurations.

Generation of high-affinity, internalizing anti-FGFR2 single-chain variable antibody fragment fused with Fc for targeting gastrointestinal cancers.

Science.gov (United States)

Borek, Aleksandra; Sokolowska-Wedzina, Aleksandra; Chodaczek, Grzegorz; Otlewski, Jacek

2018-01-01

Fibroblast growth factor receptors (FGFRs) are promising targets for antibody-based cancer therapies, as their substantial overexpression has been found in various tumor cells. Aberrant activation of FGF receptor 2 (FGFR2) signaling through overexpression of FGFR2 and/or its ligands, mutations, or receptor amplification has been reported in multiple cancer types, including gastric, colorectal, endometrial, ovarian, breast and lung cancer. In this paper, we describe application of the phage display technology to produce a panel of high affinity single chain variable antibody fragments (scFvs) against the extracellular ligand-binding domain of FGFR2 (ECD_FGFR2). The binders were selected from the human single chain variable fragment scFv phage display libraries Tomlinson I + J and showed high specificity and binding affinity towards human FGFR2 with nanomolar KD values. To improve the affinity of the best binder selected, scFvF7, we reformatted it to a bivalent diabody format, or fused it with the Fc region (scFvF7-Fc). The scFvF7-Fc antibody construct presented the highest affinity for FGFR2, with a KD of 0.76 nM, and was selectively internalized into cancer cells overexpressing FGFR2, Snu-16 and NCI-H716. Finally, we prepared a conjugate of scFvF7-Fc with the cytotoxic drug monomethyl-auristatin E (MMAE) and evaluated its cytotoxicity. The conjugate delivered MMAE selectively to FGFR2-positive tumor cells. These results indicate that scFvF7-Fc-vcMMAE is a highly potent molecule for the treatment of cancers with FGFR2 overexpression.

Serum Antibody Response to Five Streptococcus pneumoniae Proteins during Acute Otitis Media in Otitis Prone and Non-Otitis Prone Children

Science.gov (United States)

Kaur, Ravinder; Casey, Janet R.; Pichichero, Michael E.

2011-01-01

Background Streptococcus pneumoniae (Spn) is one of the common bacteria responsible for episodic acute otitis media (AOM; non-otitis prone), recurrent AOM (otitis-prone) and AOM treatment failure (AOMTF) in children. Objective From a population of 268 children we sought to compare the serum IgG antibody titers to five different Spn proteins (PhtD, LytB, PcpA, PhtE and Ply) that are vaccine candidates in children with episodic AOM (n=34), who were otitis prone (n=35), and who had AOMTF (n=25) caused by Spn. Methods Antibody was quantitated by ELISA. Results At their acute AOM visit, anti-PhtD, -LytB, -PhtE and −Ply IgG antibody titers in otitis-prone children were significantly lower compared to non-otitis prone children (p otitis-prone, AOMTF and non-otitis prone children had no significant change in geometric mean IgG antibody titers against the five proteins (except for PhtE in children with AOMTF), but detailed analysis showed that about one-third of the children in each cohort had a 2-fold rise in antibody to the studied antigens. While non-otitis prone children had significant increases (p otitis-prone children either failed to show rises or the rises were significantly less than the non-otitis prone children. Conclusion Otitis-prone and AOMTF children mount less of an IgG serum antibody response than non-otitis prone children to Spn proteins following AOM and nasopharyngeal colonization. PMID:21487325

Quantification of the antibody response to Propionibacterium acnes in a patient with prosthetic valve endocarditis: - a case report.

Science.gov (United States)

Herren, T; Middendorp, M A; Zbinden, R

2016-04-29

The isolation of Propionibacterium acnes in blood cultures is often considered a contaminant. On rare occasions, P. acnes can cause severe infections, including endocarditis and intravascular prosthesis-associated infections. To evaluate the discrimination between a contaminant and a clinically relevant infection we used an Ouchterlony test system to quantify the antibody response to P. acnes in a patient with a proven P. acnes endocarditis. We report on a 64-year-old Caucasian man who developed P. acnes endocarditis four years following a composite valve-graft conduit replacement of the aortic root. Bacterial growth in blood cultures was detected after an incubation period of 6 days. However, the antibody titer to P. acnes was 1:8 at the time of diagnosis and declined slowly thereafter over 2½ years. The patient's response to the antibiotic treatment was excellent, and no surgical re-intervention was necessary. The working hypothesis of infective endocarditis can be substantiated by serologic testing, which, if positive, provides one additional minor criterion. Moreover, quantification of the antibody response to P. acnes, though not specific, may assist in the differentiation between contaminants and an infection. This quantification may have implications for the patient management, e.g. indication for and choice of the antibiotic therapy.

A microculture system for generating haemolytic antibody responses from human tonsillar lymphocytes.

Science.gov (United States)

Booth, R J

1979-01-01

Small numbers of Ficoll-Hypaque purified human tonsillar lymphocytes were stimulated with PWM to produce SRBC-specific PFC in a microculture system. The magnitude of the response varied among different tonsils but was typically between 200 and 1000 PFC/10(6) cells cultured. Little or no response was observed in the absence of PWM. SRBC failed to stimulate a SRBC-specific response and the presence of this antigen in PWM-stimulated cultures depressed the response. The time of the maximum response was inversely related to the number of cells cultured. In addition, the duration of the response was limited by rapid depletion of critical medium requirements and/or build up of inhibitory factors especially when the cell concentration exceeded 5 x 10(5) cells/culture. This effect could be partially overcome by daily feeding of cultures with fresh medium. Fractionation studies indicated a requirement for both T and B cell populations. Constant efficiency of PFC production with respect to cell number could be achieved by the addition of inactivated autologous 'filler' cells. The significance of these results and applicability of the microculture system to a detailed analysis of human antibody responses will be discussed.

Monoclonal antibodies and cancer

International Nuclear Information System (INIS)

Haisma, H.J.

1987-01-01

The usefulness of radiolabeled monoclonal antibodies for imaging and treatment of human (ovarian) cancer was investigated. A review of tumor imaging with monoclonal antibodies is presented. Special attention is given to factors that influence the localization of the antibodies in tumors, isotope choice and methods of radiolabeling of the monoclonal antibodies. Two monoclonal antibodies, OC125 and OV-TL3, with high specificity for human epithelial ovarian cancer are characterized. A simple radio-iodination technique was developed for clinical application of the monoclonal antibodies. The behavior of monoclonal antibodies in human tumor xenograft systems and in man are described. Imaging of tumors is complicated because of high background levels of radioactivity in other sites than the tumor, especially in the bloodpool. A technique was developed to improve imaging of human tumor xenographs in nude mice, using subtraction of a specific and a non-specific antibody, radiolabeled with 111 In, 67 Ga and 131 I. To investigate the capability of the two monoclonal antibodies, to specifically localize in human ovarian carcinomas, distribution studies in mice bearing human ovarian carcinoma xenografts were performed. One of the antibodies, OC125, was used for distribution studies in ovarian cancer patients. OC125 was used because of availability and approval to use this antibody in patients. The same antibody was used to investigate the usefulness of radioimmunoimaging in ovarian cancer patients. The interaction of injected radiolabeled antibody OC125 with circulating antigen and an assay to measure the antibody response in ovarian cancer patients after injection of the antibody is described. 265 refs.; 30 figs.; 19 tabs

Naturally acquired antibody responses to recombinant Pfs230 and Pfs48/45 transmission blocking vaccine candidates

NARCIS (Netherlands)

Jones, S; Grignard, L.; Nebie, I.; Chilongola, J.; Dodoo, D.; Sauerwein, R.W.; Theisen, M.; Roeffen, W.F.; Singh, S.K; Singh, R.K.; Kyei-Baafour, E.; Tetteh, K.; Drakeley, C.; Bousema, T.

2015-01-01

OBJECTIVES: Pfs48/45 and Pfs230 are Plasmodium falciparum sexual stage proteins and promising malaria transmission-blocking vaccine candidates. Antibody responses against these proteins may be naturally acquired and target antigens may be under selective pressure. This has consequences for the

Suppression of Aggrus/podoplanin-induced platelet aggregation and pulmonary metastasis by a single-chain antibody variable region fragment

International Nuclear Information System (INIS)

Miyata, Kenichi; Takagi, Satoshi; Sato, Shigeo; Morioka, Hiroshi; Shiba, Kiyotaka; Minamisawa, Tamiko; Takami, Miho; Fujita, Naoya

2014-01-01

Almost all highly metastatic tumor cells possess high platelet aggregating abilities, thereby form large tumor cell-platelet aggregates in the microvasculature. Embolization of tumor cells in the microvasculature is considered to be the first step in metastasis to distant organs. We previously identified the platelet aggregation-inducing factor expressed on the surfaces of highly metastatic tumor cells and named as Aggrus. Aggrus was observed to be identical to the marker protein podoplanin (alternative names, T1α, OTS-8, and others). Aggrus is frequently overexpressed in several types of tumors and enhances platelet aggregation by interacting with the platelet receptor C-type lectin-like receptor 2 (CLEC-2). Here, we generated a novel single-chain antibody variable region fragment (scFv) by linking the variable regions of heavy and light chains of the neutralizing anti-human Aggrus monoclonal antibody MS-1 with a flexible peptide linker. Unfortunately, the generated KM10 scFv failed to suppress Aggrus-induced platelet aggregation in vitro. Therefore, we performed phage display screening and finally obtained a high-affinity scFv, K-11. K-11 scFv was able to suppress Aggrus-induced platelet aggregation in vitro. Moreover, K-11 scFv prevented the formation of pulmonary metastasis in vivo. These results suggest that K-11 scFv may be useful as metastasis inhibitory scFv and is expected to aid in the development of preclinical and clinical examinations of Aggrus-targeted cancer therapies

c-Myb Regulates the T-Bet-Dependent Differentiation Program in B Cells to Coordinate Antibody Responses

Directory of Open Access Journals (Sweden)

Dana Piovesan

2017-04-01

Full Text Available Summary: Humoral immune responses are tailored to the invading pathogen through regulation of key transcription factors and their networks. This is critical to establishing effective antibody-mediated responses, yet it is unknown how B cells integrate pathogen-induced signals to drive or suppress transcriptional programs specialized for each class of pathogen. Here, we detail the key role of the transcription factor c-Myb in regulating the T-bet-mediated anti-viral program. Deletion of c-Myb in mature B cells significantly increased serum IgG2c and CXCR3 expression by upregulating T-bet, normally suppressed during Th2-cell-mediated responses. Enhanced expression of T-bet resulted in aberrant plasma cell differentiation within the germinal center, mediated by CXCR3 expression. These findings identify a dual role for c-Myb in limiting inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Identifying such intrinsic regulators of specialized antibody responses can assist in vaccine design and therapeutic intervention in B-cell-mediated immune disorders. : Piovesan et al. examine how B cells establish transcriptional programs that result in tailored responses to invading pathogens. The authors find that the transcription factor c-Myb represses the T-bet-mediated anti-viral program in B cells. c-Myb limits inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Keywords: B cells, c-Myb, T-bet, immunoglobulin, CXCR3, plasma cell, germinal center

Schistosoma mansoni Infection Can Jeopardize the Duration of Protective Levels of Antibody Responses to Immunizations against Hepatitis B and Tetanus Toxoid.

Science.gov (United States)

Riner, Diana K; Ndombi, Eric M; Carter, Jennifer M; Omondi, Amos; Kittur, Nupur; Kavere, Emmy; Korir, Harrison K; Flaherty, Briana; Karanja, Diana; Colley, Daniel G

2016-12-01

Schistosomiasis is a disease of major public health importance in sub-Saharan Africa. Immunoregulation begins early in schistosome infection and is characterized by hyporesponsiveness to parasite and bystander antigens, suggesting that a schistosome infection at the time of immunization could negatively impact the induction of protective vaccine responses. This study examined whether having a Schistosoma mansoni infection at the time of immunization with hepatitis B and tetanus toxoid (TT) vaccines impacts an individual's ability to achieve and maintain protective antibody levels against hepatitis B surface antigen or TT. Adults were recruited from Kisumu Polytechnic College in Western Kenya. At enrollment, participants were screened for schistosomiasis and soil transmitted helminths (STHs) and assigned to groups based on helminth status. The vaccines were then administered and helminth infections treated a week after the first hepatitis B boost. Over an 8 month period, 3 blood specimens were obtained for the evaluation of humoral and cytokine responses to the vaccine antigens and for immunophenotyping. 146 individuals were available for final analysis and 26% were S. mansoni positive (Sm+). Schistosomiasis did not impede the generation of initial minimum protective antibody levels to either hepatitis B or TT vaccines. However, median hepatitis B surface antibody levels were significantly lower in the Sm+ group after the first boost and remained lower, but not significantly lower, following praziquantel (PZQ) treatment and final boost. In addition, 8 months following TT boost and 7 months following PZQ treatment, Sm+ individuals were more likely to have anti-TT antibody levels fall below levels considered optimal for long term protection. IL-5 levels in response to in vitro TT stimulation of whole blood were significantly higher in the Sm+ group at the 8 month time period as well. Individuals with schistosomiasis at the start the immunizations were capable of

Tabhu: tools for antibody humanization

DEFF Research Database (Denmark)

Olimpieri, Pier Paolo; Marcatili, Paolo; Tramontano, Anna

2015-01-01

Antibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can...... elicit unwanted and dangerous immunogenic responses. Antibody humanization methods are designed to produce molecules with a better safety profile still maintaining their ability to bind the antigen. This can be accomplished by grafting the non-human regions determining the antigen specificity...... and time-consuming experiments. Here we present tools for antibody humanization (Tabhu) a web server for antibody humanization. Tabhu includes tools for human template selection, grafting, back-mutation evaluation, antibody modelling and structural analysis, helping the user in all the critical steps...

Modulation of immune response to Lol p I by pretreatment with anti-idiotypic antibody is not restricted to the idiotypic expression.

Science.gov (United States)

Boutin, Y; Hébert, J

1994-05-01

To study the role of anti-idiotypic antibodies in the regulation of the immune response to Lol p I (the major allergenic component of rye grass pollen), we have recently generated a panel of three MoAbs directed against distinct epitopes of Lolp I and an anti-idiotypic MoAb directed against the idiotype borne by one of the anti-Lol p I MoAbs (290A-167). The effects of pretreatment with this anti-idiotypic MoAb in BALB/c mice before immunization with the antigen have been examined. The anti-idiotypic MoAb or unrelated MoAb were given weekly for 8 weeks intraperitoneally. Mice then received the antigen (2 micrograms) adsorbed with alum (2 mg) at weeks 9, 11 and 13. Serum anti-Lol p I antibodies (IgG or IgE) and specific idiotypic responses were measured. Anti-Lol p I IgG antibodies could be detected before immunization with Lol p I only in mice pretreated with anti-idiotypic MoAb. Immunization with Lol p I induced an anti-Lol p I IgG response in both groups, but this response was higher in mice that received anti-idiotypic MoAb. Similar profiles were seen for specific IgE antibodies and idiotypic responses. Surprisingly, idiotypes borne by other anti-Lol p I MoAbs (539A-6 and 348A-6) had also been enhanced after pretreatment with the anti-290A-167 MoAb. These observations suggested that the pretreatment with this anti-idiotypic MoAb modulates not only the expression of the respective idiotype, but also affects other idiotype responses.

Production of bifunctional proteins by Aspergillus awamori: Llama variable heavy chain antibody fragment (V-HH) R9 coupled to Arthromyces ramosus peroxidase (ARP)

NARCIS (Netherlands)

Joosten, V.; Roelofs, M.S.; Dries, van den N.; Goosen, T.; Verrips, C.T.; Hondel, van den C.A.M.J.J.; Lokman, B.C.

2005-01-01

The Arthromyces ramosus peroxidase gene (arp) was genetically fused to either the 5'- or 3'-terminal ends of the gene encoding llama variable heavy chain antibody fragment V-HH R9, resulting in the fusion expression cassettes ARP-R9 or R9-ARP. Aspergillus awamori transformants were obtained which

Neutralisation and binding of VHS virus by monovalent antibody fragments

DEFF Research Database (Denmark)

Cupit, P.M.; Lorenzen, Niels; Strachan, G.

2001-01-01

We have previously reported the cloning and characterisation of the heavy and light chain variable domain genes encoding three monoclonal antibodies (Mabs) that bind viral haemorrhagic septicaemia virus (VHSV). Two of these antibodies, 3F1H10 and 3F1A2 both neutralised the virus though 3F1A2...... appeared to recognise a broader range of virus isolates. The variable domains of these two antibodies differ by only four residues (Lorenzen et al., 2000a. Fish Shellfish Immunol. 10, 129-142). To further study the mechanism of neutralisation, Fab fragments as well as a series of recombinant bacterial...... single chain antibody (scAb) fragments were generated from the three anti-VHSV Mabs and their variable domain genes, respectively. Fabs and scAbs derived from the neutralising Mabs were both able to neutralise the VHSV type 1 isolate DK-F1. In addition, a series of scAb fragments were produced using...

A multi-subunit Chlamydia vaccine inducing neutralizing antibodies and strong IFN-γ(+) CMI responses protects against a genital infection in minipigs

DEFF Research Database (Denmark)

Bøje, Sarah; Olsen, Anja Weinreich; Erneholm, Karin

2016-01-01

Chlamydia is the most widespread sexually transmitted bacterial disease and a prophylactic vaccine is highly needed. Ideally, this vaccine is required to induce a combined response of Th1 cell-mediated immune (CMI) response in concert with neutralizing antibodies. Using a novel Göttingen minipig...... trachomatis SvD bacteria (UV-SvD/CAF01) or CAF01. The Hirep1+CTH93/CAF01 vaccine induced a strong CMI response against the vaccine antigens and high titers of antibodies, particularly against the VD4 region of MOMP. Sera from Hirep1+CTH93/CAF01 immunized pigs neutralized C. trachomatis SvD and SvF infectivity...

Interplay of foot-and-mouth disease virus, antibodies and plasmacytoid dendritic cells: virus opsonization under non-neutralizing conditions results in enhanced interferon-alpha responses

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Lannes Nils

2012-08-01

Full Text Available Abstract Foot-and-mouth disease virus (FMDV is a highly infectious member of the Picornaviridae inducing an acute disease of cloven-hoofed species. Vaccine-induced immune protection correlates with the presence of high levels of neutralizing antibodies but also opsonising antibodies have been proposed as an important mechanism of the immune response contributing to virus clearance by macrophages and leading to the production of type-I interferon (IFN by plasmacytoid dendritic cells (pDC. The present study demonstrates that the opsonising antibody titres mediating enhanced IFN-α responses in pDC were similar to neutralizing titres, when antigenically related viruses from the same serotype were employed. However, sera cross-reacted also with non-neutralized isolates of multiple serotypes, when tested in this assay. Both uncomplexed virus and immune complexed virus stimulated pDC via Toll-like receptor 7. An additional finding of potential importance for strain-specific differences in virulence and/or immunogenicity was that pDC activation by FMDV strongly differed between viral isolates. Altogether, our results indicate that opsonising antibodies can have a broader reactivity than neutralizing antibodies and may contribute to antiviral responses induced against antigenically distant viruses.

Multiple Sclerosis Patients with Markedly Low Intrathecal Antibody Response in Sri Lanka

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S. M. K. Gamage

2018-01-01

Full Text Available Multiple sclerosis (MS is a heterogeneous disease which is poorly studied in Asia, where the disease is known to be rare with significant differences in clinical and radiological presentations and intrathecal antibody response. Therefore the objective of this study was to determine clinical presentation, radiological and neurophysiological characteristics, and oligoclonal band status in Sri Lankan MS patients, following careful exclusion of patients with neuromyelitis optica spectrum disorders and other conditions mimicking multiple sclerosis. Sixty-nine MS patients were recruited to the study adhering to McDonald 2010 criteria. Their clinical presentation, characteristics of central nervous system lesions in magnetic resonance imaging, visual evoked potential (VEP results, oligoclonal bands (OCB, and AQP4 antibody status were studied. Of 69 MS patients, 54%, 6%, and 1% were relapsing remitting, secondary progressive, and primary progressive, respectively, and 39% were patients with clinically isolated syndrome. The commonest clinical presentations were cerebral motor followed by cerebral sensory and optic neuritis. Majority had typical periventricular and infratentorial lesions in MRI. Though not clinically apparent, bilateral delay of P100 wave latency was present in 52%. OCB positivity was 42% and AQP4 antibody was positive in only one patient. In conclusion, this group of Sri Lankan MS patients shares most of the clinical and radiological features of Caucasian MS patients. However, the OCB positivity is lower in this group, when compared to the Caucasian MS populations.

Macrophages are critical effectors of antibody therapies for cancer.

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Weiskopf, Kipp; Weissman, Irving L

2015-01-01

Macrophages are innate immune cells that derive from circulating monocytes, reside in all tissues, and participate in many states of pathology. Macrophages play a dichotomous role in cancer, where they promote tumor growth but also serve as critical immune effectors of therapeutic antibodies. Macrophages express all classes of Fcγ receptors, and they have immense potential to destroy tumors via the process of antibody-dependent phagocytosis. A number of studies have demonstrated that macrophage phagocytosis is a major mechanism of action of many antibodies approved to treat cancer. Consequently, a number of approaches to augment macrophage responses to therapeutic antibodies are under investigation, including the exploration of new targets and development of antibodies with enhanced functions. For example, the interaction of CD47 with signal-regulatory protein α (SIRPα) serves as a myeloid-specific immune checkpoint that limits the response of macrophages to antibody therapies, and CD47-blocking agents overcome this barrier to augment phagocytosis. The response of macrophages to antibody therapies can also be enhanced with engineered Fc variants, bispecific antibodies, or antibody-drug conjugates. Macrophages have demonstrated success as effectors of cancer immunotherapy, and further investigation will unlock their full potential for the benefit of patients.

Seroprevalence and placental transmission of maternal antibodies specific for Neisseria meningitidis Serogroups A, C, Y and W135 and influence of maternal antibodies on the immune response to a primary course of MenACWY-CRM vaccine in the United Kingdom.

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Blanchard-Rohner, Geraldine; Snape, Matthew D; Kelly, Dominic F; O'Connor, Daniel; John, Tessa; Kibwana, Elizabeth; Parks, Hannah; Ford, Karen; Dull, Peter M; Pollard, Andrew J

2013-07-01

Maternal antibodies give neonates some protection against bacterial infection. We measured antibodies against Neisseria meningitidis serogroups A, C, Y and W135 in mothers and their 2-month-old infants at study enrollment. We also assessed the impact of maternal antibody present at 2 months of age on the immune response to a primary course of quadrivalent meningococcal conjugate vaccine (MenACWY-CRM197) given at 2 and 4 months of age. This was a single-center, open-label, randomized study undertaken in Oxford, United Kingdom. Two hundred sixteen healthy infants were enrolled in the study and vaccinated with MenACWY-CRM197 at 2 and 4 months of age. Blood was obtained from all mothers, in a subset of infants at 2 months and all infants at 5 months. Antibody and memory B-cell responses at 5 months were correlated with maternal antibodies. Mothers had low IgG antibodies against serogroups C, W135 and Y polysaccharides, but high serogroup A antibody, whereas 61-78% had protective human complement serum bactericidal activity (hSBA) (≥1:4) for serogroups C, W135 and Y but only 31% for serogroup A. Only 9%, 32%, 45% and 19% of 2-month-old infants had hSBA ≥1:4 for serogroups A, C, W135 and Y, respectively. Maternal antibody had little association on responses to MenACWY-CRM197, except a moderate negative association between MenC-specific bactericidal antibody at 2 and 5 months (r = -0.5, P = 0.006, n = 28) and between carrier-specific IgG antibody at 2 months and MenC-specific hSBA/IgG antibody at 5 months (r = -0.4, P = 0.02 and 0.04, n = 32 and 23). Nonetheless, 90% of infants achieved protective MenC-hSBA titers after vaccination at 2 and 4 months of age. The levels of serogroup-specific meningococcal antibodies were low in mothers and 2-month-old infants. Immunizing mothers before or during pregnancy with meningococcal conjugate vaccines might increase antibody levels in early infancy and provide protection against infection due to N. meningitidis.

Simplifying complex sequence information: a PCP-consensus protein binds antibodies against all four Dengue serotypes.

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Bowen, David M; Lewis, Jessica A; Lu, Wenzhe; Schein, Catherine H

2012-09-14

Designing proteins that reflect the natural variability of a pathogen is essential for developing novel vaccines and drugs. Flaviviruses, including Dengue (DENV) and West Nile (WNV), evolve rapidly and can "escape" neutralizing monoclonal antibodies by mutation. Designing antigens that represent many distinct strains is important for DENV, where infection with a strain from one of the four serotypes may lead to severe hemorrhagic disease on subsequent infection with a strain from another serotype. Here, a DENV physicochemical property (PCP)-consensus sequence was derived from 671 unique sequences from the Flavitrack database. PCP-consensus proteins for domain 3 of the envelope protein (EdomIII) were expressed from synthetic genes in Escherichia coli. The ability of the purified consensus proteins to bind polyclonal antibodies generated in response to infection with strains from each of the four DENV serotypes was determined. The initial consensus protein bound antibodies from DENV-1-3 in ELISA and Western blot assays. This sequence was altered in 3 steps to incorporate regions of maximum variability, identified as significant changes in the PCPs, characteristic of DENV-4 strains. The final protein was recognized by antibodies against all four serotypes. Two amino acids essential for efficient binding to all DENV antibodies are part of a discontinuous epitope previously defined for a neutralizing monoclonal antibody. The PCP-consensus method can significantly reduce the number of experiments required to define a multivalent antigen, which is particularly important when dealing with pathogens that must be tested at higher biosafety levels. Copyright © 2012 Elsevier Ltd. All rights reserved.

Application of cyclodextrins in antibody microparticles: potentials for antibody protection in spray drying.

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Ramezani, Vahid; Vatanara, Alireza; Seyedabadi, Mohammad; Nabi Meibodi, Mohsen; Fanaei, Hamed

2017-07-01

Dry powder formulations are extensively used to improve the stability of antibodies. Spray drying is one of important methods for protein drying. This study investigated the effects of trehalose, hydroxypropyl beta cyclodextrin (HPBCD) and beta cyclodextrin (BCD) on the stability and particle properties of spray-dried IgG. D-optimal design was employed for both experimental design and analysis and optimization of the variables. The size and aerodynamic behavior of particles were determined using laser light scattering and glass twin impinger, respectively. In addition, stability, ratio of beta sheets and morphology of antibody were analyzed using size exclusion chromatography, IR spectroscopy and electron microscopy, respectively. Particle properties and antibody stability were significantly improved in the presence of HPBCD. In addition, particle aerodynamic behavior, in terms of fine-particle fraction (FPF), enhanced up to 52.23%. Furthermore, antibody was better preserved not only during spray drying, but also during long-term storage. In contrast, application of BCD resulted in the formation of larger particles. Although trehalose caused inappropriate aerodynamic property, it efficiently decreased antibody aggregation. HPBCD is an efficient excipient for the development of inhalable protein formulations. In this regard, optimal particle property and antibody stability was obtained with proper combination of cyclodextrins and simple sugars, such as trehalose.

Differential lymphocyte and antibody responses in deer mice infected with Sin Nombre hantavirus or Andes hantavirus.

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Schountz, Tony; Quackenbush, Sandra; Rovnak, Joel; Haddock, Elaine; Black, William C; Feldmann, Heinz; Prescott, Joseph

2014-08-01

Hantavirus cardiopulmonary syndrome (HCPS) is a rodent-borne disease with a high case-fatality rate that is caused by several New World hantaviruses. Each pathogenic hantavirus is naturally hosted by a principal rodent species without conspicuous disease and infection is persistent, perhaps for life. Deer mice (Peromyscus maniculatus) are the natural reservoirs of Sin Nombre virus (SNV), the etiologic agent of most HCPS cases in North America. Deer mice remain infected despite a helper T cell response that leads to high-titer neutralizing antibodies. Deer mice are also susceptible to Andes hantavirus (ANDV), which causes most HCPS cases in South America; however, deer mice clear ANDV. We infected deer mice with SNV or ANDV to identify differences in host responses that might account for this differential outcome. SNV RNA levels were higher in the lungs but not different in the heart, spleen, or kidneys. Most ANDV-infected deer mice had seroconverted 14 days after inoculation, but none of the SNV-infected deer mice had. Examination of lymph node cell antigen recall responses identified elevated immune gene expression in deer mice infected with ANDV and suggested maturation toward a Th2 or T follicular helper phenotype in some ANDV-infected deer mice, including activation of the interleukin 4 (IL-4) pathway in T cells and B cells. These data suggest that the rate of maturation of the immune response is substantially higher and of greater magnitude during ANDV infection, and these differences may account for clearance of ANDV and persistence of SNV. Hantaviruses persistently infect their reservoir rodent hosts without pathology. It is unknown how these viruses evade sterilizing immune responses in the reservoirs. We have determined that infection of the deer mouse with its homologous hantavirus, Sin Nombre virus, results in low levels of immune gene expression in antigen-stimulated lymph node cells and a poor antibody response. However, infection of deer mice with a

A plant's perspective of extremes: terrestrial plant responses to changing climatic variability.

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Reyer, Christopher P O; Leuzinger, Sebastian; Rammig, Anja; Wolf, Annett; Bartholomeus, Ruud P; Bonfante, Antonello; de Lorenzi, Francesca; Dury, Marie; Gloning, Philipp; Abou Jaoudé, Renée; Klein, Tamir; Kuster, Thomas M; Martins, Monica; Niedrist, Georg; Riccardi, Maria; Wohlfahrt, Georg; de Angelis, Paolo; de Dato, Giovanbattista; François, Louis; Menzel, Annette; Pereira, Marízia

2013-01-01

We review observational, experimental, and model results on how plants respond to extreme climatic conditions induced by changing climatic variability. Distinguishing between impacts of changing mean climatic conditions and changing climatic variability on terrestrial ecosystems is generally underrated in current studies. The goals of our review are thus (1) to identify plant processes that are vulnerable to changes in the variability of climatic variables rather than to changes in their mean, and (2) to depict/evaluate available study designs to quantify responses of plants to changing climatic variability. We find that phenology is largely affected by changing mean climate but also that impacts of climatic variability are much less studied, although potentially damaging. We note that plant water relations seem to be very vulnerable to extremes driven by changes in temperature and precipitation and that heat-waves and flooding have stronger impacts on physiological processes than changing mean climate. Moreover, interacting phenological and physiological processes are likely to further complicate plant responses to changing climatic variability. Phenological and physiological processes and their interactions culminate in even more sophisticated responses to changing mean climate and climatic variability at the species and community level. Generally, observational studies are well suited to study plant responses to changing mean climate, but less suitable to gain a mechanistic understanding of plant responses to climatic variability. Experiments seem best suited to simulate extreme events. In models, temporal resolution and model structure are crucial to capture plant responses to changing climatic variability. We highlight that a combination of experimental, observational, and/or modeling studies have the potential to overcome important caveats of the respective individual approaches. © 2012 Blackwell Publishing Ltd.

Antibody and T cell responses to Fusobacterium nucleatum and Treponema denticola in health and chronic periodontitis.

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Jieun Shin

Full Text Available The characteristics of the T cell response to the members of oral flora are poorly understood. We characterized the antibody and T cell responses to FadA and Td92, adhesins from Fusobacterium nucleatum, an oral commensal, and Treponema denticola, a periodontal pathogen, respectively. Peripheral blood and saliva were obtained from healthy individuals and patients with untreated chronic periodontitis (CP, n = 11 paris and after successful treatment of the disease (n = 9. The levels of antigen-specific antibody were measured by ELISA. In plasma, IgG1 was the most abundant isotype of Ab for both Ags, followed by IgA and then IgG4. The levels of FadA-specific salivary IgA (sIgA were higher than Td92-specific sIgA and the FadA-specific IgA levels observed in plasma. However, the periodontal health status of the individuals did not affect the levels of FadA- or Td92-specific antibody. Even healthy individuals contained FadA- and Td92-specific CD4(+ T cells, as determined by the detection of intracytoplasmic CD154 after short-term in vitro stimulation of peripheral blood mononuclear cells (PBMCs with the antigens. Patients with CP tended to possess increased numbers of FadA- and Td92-specific CD4(+ T cells but reduced numbers of Td92-specific Foxp3(+CD4(+ Tregs than the healthy subjects. Both FadA and Td92 induced the production of IFNγ and IL-10 but inhibited the secretion of IL-4 by PBMCs. In conclusion, F. nucleatum induced Th3 (sIgA- and Th1 (IFNγ and IgG1-dominant immune responses, whereas T. denticola induced a Th1 (IFNγ and IgG1-dominant response. This IFNγ-dominant cytokine response was impaired in CP patients, and the Td92-induced IFNγ levels were negatively associated with periodontal destruction in patients. These findings may provide new insights into the homeostatic interaction between the immune system and oral bacteria and the pathogenesis of periodontitis.

A multi-subunit Chlamydia vaccine inducing neutralizing antibodies and strong IFN-γ(+) CMI responses protects against a genital infection in minipigs

DEFF Research Database (Denmark)

Bøje, Sarah; Olsen, Anja Weinreich; Erneholm, Karin

2016-01-01

Chlamydia is the most widespread sexually transmitted bacterial disease and a prophylactic vaccine is highly needed. Ideally, this vaccine is required to induce a combined response of Th1 cell-mediated immune (CMI) response in concert with neutralizing antibodies. Using a novel Göttingen minipig...... animal model, we evaluated the immunogenicity and efficacy of a multi-subunit vaccine formulated in the strong Th1-inducing adjuvant CAF01. We evaluated a mixture of two fusion proteins (Hirep1 and CTH93) designed to promote either neutralizing antibodies or cell-mediated immunity, respectively. Hirep1...

Antibody response to Haemophilus influenzae type b capsular polysaccharide conjugated to tetanus toxoid in preterm infants

DEFF Research Database (Denmark)

Kristensen, Kim; Gyhrs, A; Lausen, B

1996-01-01

OBJECTIVE: To evaluate the antibody response to a Haemophilus influenzae type b capsular polysaccharide (HibCP) tetanus toxoid (TT) conjugate vaccine (HibCP-TT) in preterm infants. SUBJECTS: Thirty-five healthy preterm infants with gestational ages (GA) from 27 to 36 weeks and birth weights from...

Intracellular Targeting of CEA Results in Th1-Type Antibody Responses Following Intradermal Genetic Vaccination by a Needle-Free Jet Injection Device

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Susanne Johansson

2007-01-01

Full Text Available The route and method of immunization, as well as the cellular localization of the antigen, can influence the generation of an immune response. In general, intramuscular immunization results in Th1 responses, whereas intradermal delivery of DNA by gene gun immunization often results in more Th2 responses. Here we investigate how altering the cellular localization of the tumor antigen CEA (carcinoembryonic antigen affects the quality and amplitude of DNA vaccine-induced antibody responses in mice following intradermal delivery of DNA by a needle-free jet injection device (Biojector. CEA was expressed either in a membrane-bound form (wild-type CEA or in two truncated forms (CEA6 and CEA66 with cytoplasmic localization, where CEA66 was fused to a promiscuous T-helper epitope from tetanus toxin. Repeated intradermal immunization of BALB/c mice with DNA encoding wild-type CEA produced high antibody titers of a mixed IgG1/IgG2a ratio. In contrast, utilizing the DNA construct that resulted in intracellular targeting of CEA led to a reduced capacity to induce CEA-specific antibodies, but instead induced a Th1-biased immune response.

Relationship between the IgA antibody response against Streptococcus mutans GbpB and severity of dental caries in childhood.

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Colombo, Natália Helena; Pereira, Jesse Augusto; da Silva, Márjully Eduardo Rodrigues; Ribas, Laís Fernanda Fonseca; Parisotto, Thaís Manzano; Mattos-Graner, Renata de Oliveira; Smith, Daniel J; Duque, Cristiane

2016-07-01

Explore the associations between the severity of dental caries in childhood, mutans streptococci (MS) levels and IgA antibody response against Streptococcus mutans GbpB. Moreover, other caries-related etiological factors were also investigated. 36-60 month-old children were grouped into Caries-Free (CF, n=19), Early Childhood Caries (ECC, n=17) and Severe Early Childhood Caries (S-ECC, n=21). Data from socio-economic-cultural status, oral hygiene habits and dietary patterns were obtained from a questionnaire and a food-frequency diary filled out by parents. Saliva was collected from children for microbiological analysis and detection of salivary IgA antibody reactive with S. mutans GbpB in western blot. S-ECC children had reduced family income compared to those with ECC and CF. There was difference between CF and caries groups (ECC and S-ECC) in MS counts. Positive correlations between salivary IgA antibody response against GbpB and MS counts were found when the entire population was evaluated. When children with high MS counts were compared, S-ECC group showed significantly lower IgA antibody levels to GbpB compared to CF group. This finding was not observed for the ECC group. This study suggests that children with S-ECC have reduced salivary IgA immune responses to S. mutans GbpB, potentially compromising their ability to modify MS infection and its cariogenic potential. Furthermore, a reduced family income and high levels of MS were also associated with S-ECC. Copyright © 2016 Elsevier Ltd. All rights reserved.

The cellular bases of antibody responses during dengue virus infection

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Juan Carlos Yam-Puc

2016-06-01

Full Text Available Dengue virus (DENV is one of the most significant human viral pathogens transmitted by mosquitoes and can cause from an asymptomatic disease to mild undifferentiated fever, classical dengue, and severe dengue. Neutralizing memory antibody (Ab responses are one of the most important mechanisms that counteract reinfections and are therefore the main aim of vaccination. However, it has also been proposed that in dengue, some of these class-switched (IgG memory Abs might worsen the disease. Although these memory Abs derive from B cells by T-cell dependent processes, we know rather little about the (acute, chronic or memory B cell responses and the complex cellular mechanisms generating these Abs during DENV infections.This review aims to provide an updated and comprehensive perspective of the B cell responses during DENV infection, starting since the very early events like the cutaneous DENV entrance and the arrival into draining lymph nodes, to the putative B cell activation, proliferation and germinal centers (GCs formation (the source of affinity-matured class-switched memory Abs, till the outcome of GC reactions such as the generation of plasmablasts, Ab-secreting plasma cells and memory B cells. We discuss topics very poorly explored such as the possibility of B cell infection by DENV or even activation-induced B cell death. The current information about the nature of the Ab responses to DENV is also illustrated.

Multi-epitope Models Explain How Pre-existing Antibodies Affect the Generation of Broadly Protective Responses to Influenza.

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Veronika I Zarnitsyna

2016-06-01

Full Text Available The development of next-generation influenza vaccines that elicit strain-transcendent immunity against both seasonal and pandemic viruses is a key public health goal. Targeting the evolutionarily conserved epitopes on the stem of influenza's major surface molecule, hemagglutinin, is an appealing prospect, and novel vaccine formulations show promising results in animal model systems. However, studies in humans indicate that natural infection and vaccination result in limited boosting of antibodies to the stem of HA, and the level of stem-specific antibody elicited is insufficient to provide broad strain-transcendent immunity. Here, we use mathematical models of the humoral immune response to explore how pre-existing immunity affects the ability of vaccines to boost antibodies to the head and stem of HA in humans, and, in particular, how it leads to the apparent lack of boosting of broadly cross-reactive antibodies to the stem epitopes. We consider hypotheses where binding of antibody to an epitope: (i results in more rapid clearance of the antigen; (ii leads to the formation of antigen-antibody complexes which inhibit B cell activation through Fcγ receptor-mediated mechanism; and (iii masks the epitope and prevents the stimulation and proliferation of specific B cells. We find that only epitope masking but not the former two mechanisms to be key in recapitulating patterns in data. We discuss the ramifications of our findings for the development of vaccines against both seasonal and pandemic influenza.

Anti-citrullinated heat shock protein 90 antibodies identified in bronchoalveolar lavage fluid are a marker of lung-specific immune responses.

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Harlow, Lisa; Gochuico, Bernadette R; Rosas, Ivan O; Doyle, Tracy J; Osorio, Juan C; Travers, Timothy S; Camacho, Carlos C; Oddis, Chester V; Ascherman, Dana P

2014-11-01

Previous work has demonstrated a correlation between serum anti-citrullinated HSP90 antibodies and rheumatoid arthritis-associated interstitial lung disease (RA-ILD). To further investigate this potential pathogenic relationship, we used ELISA-based techniques to assess anti-citrullinated HSP90 antibody profiles in bronchoalveolar lavage fluid (BALF) of patients with different stages of RA-ILD. 9/21 RA-derived BALF specimens demonstrated IgG and/or IgA antibodies targeting citrullinated HSP90 proteins/peptides, highlighting disease specific responses (with a predilection for RA-ILD) that did not occur in IPF patients (0/5) or healthy control subjects (0/5). Comparison of antibody profiles between BALF and matching serum specimens revealed various recognition patterns favoring predominant production of anti-citrullinated HSP90 antibodies within the lung microenvironment-further supporting the connection between this antibody specificity and parenchymal lung disease. Equally important, qualitative as well as quantitative differences in anti-citrullinated HSP90 profiles between BALF and serum indicate that the lung plays a direct role in shaping the immune repertoire of RA/RA-ILD. Published by Elsevier Inc.

A Decline in Response Variability Improves Neural Signal Detection during Auditory Task Performance.

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von Trapp, Gardiner; Buran, Bradley N; Sen, Kamal; Semple, Malcolm N; Sanes, Dan H

2016-10-26

The detection of a sensory stimulus arises from a significant change in neural activity, but a sensory neuron's response is rarely identical to successive presentations of the same stimulus. Large trial-to-trial variability would limit the central nervous system's ability to reliably detect a stimulus, presumably affecting perceptual performance. However, if response variability were to decrease while firing rate remained constant, then neural sensitivity could improve. Here, we asked whether engagement in an auditory detection task can modulate response variability, thereby increasing neural sensitivity. We recorded telemetrically from the core auditory cortex of gerbils, both while they engaged in an amplitude-modulation detection task and while they sat quietly listening to the identical stimuli. Using a signal detection theory framework, we found that neural sensitivity was improved during task performance, and this improvement was closely associated with a decrease in response variability. Moreover, units with the greatest change in response variability had absolute neural thresholds most closely aligned with simultaneously measured perceptual thresholds. Our findings suggest that the limitations imposed by response variability diminish during task performance, thereby improving the sensitivity of neural encoding and potentially leading to better perceptual sensitivity. The detection of a sensory stimulus arises from a significant change in neural activity. However, trial-to-trial variability of the neural response may limit perceptual performance. If the neural response to a stimulus is quite variable, then the response on a given trial could be confused with the pattern of neural activity generated when the stimulus is absent. Therefore, a neural mechanism that served to reduce response variability would allow for better stimulus detection. By recording from the cortex of freely moving animals engaged in an auditory detection task, we found that variability

Fully human monoclonal antibodies from antibody secreting cells after vaccination with Pneumovax®23 are serotype specific and facilitate opsonophagocytosis.

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Smith, Kenneth; Muther, Jennifer J; Duke, Angie L; McKee, Emily; Zheng, Nai-Ying; Wilson, Patrick C; James, Judith A

2013-05-01

B lymphocyte memory generates antibody-secreting cells (ASCs) that represent a source of protective antibodies that may be exploited for therapeutics. Here we vaccinated four donors with Pneumovax®23 and produced human monoclonal antibodies (hmAbs) from ASCs. We have cloned 137 hmAbs and the specificities of these antibodies encompass 19 of the 23 serotypes in the vaccine, as well as cell wall polysaccharide (CWPS). Although the majority of the antibodies are serotype specific, 12% cross-react with two serotypes. The Pneumovax®23 ASC antibody sequences are highly mutated and clonal, indicating an anamnestic response, even though this was a primary vaccination. Hmabs from 64% of the clonal families facilitate opsonophagocytosis. Although 9% of the total antibodies bind to CWPS impurity in the vaccine, none of these clonal families showed opsonophagocytic activity. Overall, these studies have allowed us to address unanswered questions in the field of human immune responses to polysaccharide vaccines, including the cross-reactivity of individual antibodies between serotypes and the percentage of antibodies that are protective after vaccination with Pneumovax®23. Copyright © 2012 Elsevier GmbH. All rights reserved.

Assessment of gold nanoparticles as a size-dependent vaccine carrier for enhancing the antibody response against synthetic foot-and-mouth disease virus peptide

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Chen, Yu-Shiun [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, EE137, Hsinchu 300, Taiwan (China); Hung, Yao-Ching [Department of Obstetrics and Gynecology, School of Medicine, China Medical University and Hospital, 91 Hsueh-Shih Road, Taichung 40402, Taiwan (China); Lin, Wei-Hsu [Institute of Nanotechnology, National Chiao Tung University, 1001 University Road, Hsinchu 300, Taiwan (China); Huang, Guewha Steven, E-mail: gstevehuang@mail.nctu.edu.tw [Department of Materials Science and Engineering, Institute of Nanotechnology, National Chiao Tung University, 1001 University Road, Hsinchu 300, Taiwan, Republic of China (China)

2010-05-14

To assess the ability of gold nanoparticles (GNPs) to act as a size-dependent carrier, a synthetic peptide resembling foot-and-mouth disease virus (FMDV) protein was conjugated to GNPs ranging from 2 to 50 nm in diameter (2, 5, 8, 12, 17, 37, and 50 nm). An extra cysteine was added to the C-terminus of the FMDV peptide (pFMDV) to ensure maximal conjugation to the GNPs, which have a high affinity for sulfhydryl groups. The resultant pFMDV-GNP conjugates were then injected into BALB/c mice. Immunization with pFMDV-keyhole limpet hemocyanin (pFMDV-KLH) conjugate was also performed as a control. Blood was obtained from the mice after 4, 6, 8, and 10 weeks and antibody titers against both pFMDV and the carriers were measured. For the pFMDV-GNP immunization, specific antibodies against the synthetic peptide were detected in the sera of mice injected with 2, 5, 8, 12, and 17 nm pFMDV-GNP conjugates. Maximal antibody binding was noted for GNPs of diameter 8-17 nm. The pFMDV-GNPs induced a three-fold increase in the antibody response compared to the response to pFMDV-KLH. However, sera from either immunized mouse group did not exhibit an antibody response to GNPs, while the sera from pFMDV-KLH-immunized mice presented high levels of binding activity against KLH. Additionally, the uptake of pFMDV-GNP in the spleen was examined by inductively coupled plasma mass spectroscopy (ICP-MS) and transmission electron microscopy (TEM). The quantity of GNPs that accumulated in the spleen correlated to the magnitude of the immune response induced by pFMDV-GNP. In conclusion, we demonstrated the size-dependent immunogenic properties of pFMDV-GNP conjugates. Furthermore, we established that GNPs ranging from 8 to 17 nm in diameter may be ideal for eliciting a focused antibody response against a synthetic pFMDV peptide.

Assessment of gold nanoparticles as a size-dependent vaccine carrier for enhancing the antibody response against synthetic foot-and-mouth disease virus peptide

Science.gov (United States)

Chen, Yu-Shiun; Hung, Yao-Ching; Lin, Wei-Hsu; Huang, Guewha Steven

2010-05-01

To assess the ability of gold nanoparticles (GNPs) to act as a size-dependent carrier, a synthetic peptide resembling foot-and-mouth disease virus (FMDV) protein was conjugated to GNPs ranging from 2 to 50 nm in diameter (2, 5, 8, 12, 17, 37, and 50 nm). An extra cysteine was added to the C-terminus of the FMDV peptide (pFMDV) to ensure maximal conjugation to the GNPs, which have a high affinity for sulfhydryl groups. The resultant pFMDV-GNP conjugates were then injected into BALB/c mice. Immunization with pFMDV-keyhole limpet hemocyanin (pFMDV-KLH) conjugate was also performed as a control. Blood was obtained from the mice after 4, 6, 8, and 10 weeks and antibody titers against both pFMDV and the carriers were measured. For the pFMDV-GNP immunization, specific antibodies against the synthetic peptide were detected in the sera of mice injected with 2, 5, 8, 12, and 17 nm pFMDV-GNP conjugates. Maximal antibody binding was noted for GNPs of diameter 8-17 nm. The pFMDV-GNPs induced a three-fold increase in the antibody response compared to the response to pFMDV-KLH. However, sera from either immunized mouse group did not exhibit an antibody response to GNPs, while the sera from pFMDV-KLH-immunized mice presented high levels of binding activity against KLH. Additionally, the uptake of pFMDV-GNP in the spleen was examined by inductively coupled plasma mass spectroscopy (ICP-MS) and transmission electron microscopy (TEM). The quantity of GNPs that accumulated in the spleen correlated to the magnitude of the immune response induced by pFMDV-GNP. In conclusion, we demonstrated the size-dependent immunogenic properties of pFMDV-GNP conjugates. Furthermore, we established that GNPs ranging from 8 to 17 nm in diameter may be ideal for eliciting a focused antibody response against a synthetic pFMDV peptide.

Assessment of gold nanoparticles as a size-dependent vaccine carrier for enhancing the antibody response against synthetic foot-and-mouth disease virus peptide

International Nuclear Information System (INIS)

Chen, Yu-Shiun; Hung, Yao-Ching; Lin, Wei-Hsu; Huang, Guewha Steven

2010-01-01

To assess the ability of gold nanoparticles (GNPs) to act as a size-dependent carrier, a synthetic peptide resembling foot-and-mouth disease virus (FMDV) protein was conjugated to GNPs ranging from 2 to 50 nm in diameter (2, 5, 8, 12, 17, 37, and 50 nm). An extra cysteine was added to the C-terminus of the FMDV peptide (pFMDV) to ensure maximal conjugation to the GNPs, which have a high affinity for sulfhydryl groups. The resultant pFMDV-GNP conjugates were then injected into BALB/c mice. Immunization with pFMDV-keyhole limpet hemocyanin (pFMDV-KLH) conjugate was also performed as a control. Blood was obtained from the mice after 4, 6, 8, and 10 weeks and antibody titers against both pFMDV and the carriers were measured. For the pFMDV-GNP immunization, specific antibodies against the synthetic peptide were detected in the sera of mice injected with 2, 5, 8, 12, and 17 nm pFMDV-GNP conjugates. Maximal antibody binding was noted for GNPs of diameter 8-17 nm. The pFMDV-GNPs induced a three-fold increase in the antibody response compared to the response to pFMDV-KLH. However, sera from either immunized mouse group did not exhibit an antibody response to GNPs, while the sera from pFMDV-KLH-immunized mice presented high levels of binding activity against KLH. Additionally, the uptake of pFMDV-GNP in the spleen was examined by inductively coupled plasma mass spectroscopy (ICP-MS) and transmission electron microscopy (TEM). The quantity of GNPs that accumulated in the spleen correlated to the magnitude of the immune response induced by pFMDV-GNP. In conclusion, we demonstrated the size-dependent immunogenic properties of pFMDV-GNP conjugates. Furthermore, we established that GNPs ranging from 8 to 17 nm in diameter may be ideal for eliciting a focused antibody response against a synthetic pFMDV peptide.

Amplitude variability over trials in hemodynamic responses in adolescents with ADHD

DEFF Research Database (Denmark)

Sørensen, L; Eichele, T; van Wageningen, H

2016-01-01

variable response times. In this study, we asked whether ADHD IIV in reaction time on a commonly-used test of attention might be related to variation in hemodynamic responses (HRs) observed trial-to-trial. Based on previous studies linking IIV to regions within the "default mode" network (DMN), we...... predicted that adolescents with ADHD would have higher HR variability in the DMN compared with controls, and this in turn would be related to behavioral IIV. We also explored the influence of social anxiety on HR variability in ADHD as means to test whether higher arousal associated with high trait anxiety...... would affect the neural abnormalities. We assessed single-trial variability of HRs, estimated from fMRI event-related responses elicited during an auditory oddball paradigm in adolescents with ADHD and healthy controls (11-18 years old; N = 46). Adolescents with ADHD had higher HR variability compared...

Comparison of the adjuvant activity of aluminum hydroxide and calcium phosphate on the antibody response towards Bothrops asper snake venom.

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Olmedo, Hidekel; Herrera, María; Rojas, Leonardo; Villalta, Mauren; Vargas, Mariángela; Leiguez, Elbio; Teixeira, Catarina; Estrada, Ricardo; Gutiérrez, José María; León, Guillermo; Montero, Mavis L

2014-01-01

The adjuvanticity of aluminum hydroxide and calcium phosphate on the antibody response in mice towards the venom of the snake Bothrops asper was studied. It was found that, in vitro, most of the venom proteins are similarly adsorbed by both mineral salts, with the exception of some basic phospholipases A2, which are better adsorbed by calcium phosphate. After injection, the adjuvants promoted a slow release of the venom, as judged by the lack of acute toxicity when lethal doses of venom were administered to mice. Leukocyte recruitment induced by the venom was enhanced when it was adsorbed on both mineral salts; however, venom adsorbed on calcium phosphate induced a higher antibody response towards all tested HPLC fractions of the venom. On the other hand, co-precipitation of venom with calcium phosphate was the best strategy for increasing: (1) the capacity of the salt to couple venom proteins in vitro; (2) the venom ability to induce leukocyte recruitment; (3) phagocytosis by macrophages; and (4) a host antibody response. These findings suggest that the chemical nature is not the only one determining factor of the adjuvant activity of mineral salts.

Immunosignature: Serum Antibody Profiling for Cancer Diagnostics.

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Chapoval, Andrei I; Legutki, J Bart; Stafford, Philip; Trebukhov, Andrey V; Johnston, Stephen A; Shoikhet, Yakov N; Lazarev, Alexander F

2015-01-01

Biomarkers for preclinical diagnosis of cancer are valuable tools for detection of malignant tumors at early stages in groups at risk and screening healthy people, as well as monitoring disease recurrence after treatment of cancer. However the complexity of the body's response to the pathological processes makes it virtually impossible to evaluate this response to the development of the disease using a single biomarker that is present in the serum at low concentrations. An alternative approach to standard biomarker analysis is called immunosignature. Instead of going after biomarkers themselves this approach rely on the analysis of the humoral immune response to molecular changes associated with the development of pathological processes. It is known that antibodies are produced in response to proteins expressed during cancer development. Accordingly, the changes in antibody repertoire associated with tumor growth can serve as biomarkers of cancer. Immunosignature is a highly sensitive method for antibody repertoire analysis utilizing high density peptide microarrays. In the present review we discuss modern methods for antibody detection, as well as describe the principles and applications of immunosignature in research and clinical practice.

Immunoproteomics analysis of the murine antibody response to vaccination with an improved Francisella tularensis live vaccine strain (LVS.

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Susan M Twine

2010-04-01

Full Text Available Francisella tularensis subspecies tularensis is the causative agent of a spectrum of diseases collectively known as tularemia. An attenuated live vaccine strain (LVS has been shown to be efficacious in humans, but safety concerns have prevented its licensure by the FDA. Recently, F. tularensis LVS has been produced under Current Good Manufacturing Practice (CGMP guidelines. Little is known about the immunogenicity of this new vaccine preparation in comparison with extensive studies conducted with laboratory passaged strains of LVS. Thus, the aim of the current work was to evaluate the repertoire of antibodies produced in mouse strains vaccinated with the new LVS vaccine preparation.In the current study, we used an immunoproteomics approach to examine the repertoire of antibodies induced following successful immunization of BALB/c versus unsuccessful vaccination of C57BL/6 mice with the new preparation of F. tularensis LVS. Successful vaccination of BALB/c mice elicited antibodies to nine identified proteins that were not recognized by antisera from vaccinated but unprotected C57BL/6 mice. In addition, the CGMP formulation of LVS stimulated a greater repertoire of antibodies following vaccination compared to vaccination with laboratory passaged ATCC LVS strain. A total of 15 immunoreactive proteins were identified in both studies, however, 16 immunoreactive proteins were uniquely reactive with sera from the new formulation of LVS.This is the first report characterising the antibody based immune response of the new formulation of LVS in the widely used murine model of tularemia. Using two mouse strains, we show that successfully vaccinated mice can be distinguished from unsuccessfully vaccinated mice based upon the repertoire of antibodies generated. This opens the door towards downselection of antigens for incorporation into tularemia subunit vaccines. In addition, this work also highlights differences in the humoral immune response to

Groundwater level responses to precipitation variability in Mediterranean insular aquifers

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Lorenzo-Lacruz, Jorge; Garcia, Celso; Morán-Tejeda, Enrique

2017-09-01

Groundwater is one of the largest and most important sources of fresh water on many regions under Mediterranean climate conditions, which are exposed to large precipitation variability that includes frequent meteorological drought episodes, and present high evapotranspiration rates and water demand during the dry season. The dependence on groundwater increases in those areas with predominant permeable lithologies, contributing to aquifer recharge and the abundance of ephemeral streams. The increasing pressure of tourism on water resources in many Mediterranean coastal areas, and uncertainty related to future precipitation and water availability, make it urgent to understand the spatio-temporal response of groundwater bodies to precipitation variability, if sustainable use of the resource is to be achieved. We present an assessment of the response of aquifers to precipitation variability based on correlations between the Standardized Precipitation Index (SPI) at various time scales and the Standardized Groundwater Index (SGI) across a Mediterranean island. We detected three main responses of aquifers to accumulated precipitation anomalies: (i) at short time scales of the SPI (24 months). The differing responses were mainly explained by differences in lithology and the percentage of highly permeable rock strata in the aquifer recharge areas. We also identified differences in the months and seasons when aquifer storages are more dependent on precipitation; these were related to climate seasonality and the degree of aquifer exploitation or underground water extraction. The recharge of some aquifers, especially in mountainous areas, is related to precipitation variability within a limited spatial extent, whereas for aquifers located in the plains, precipitation variability influence much larger areas; the topography and geological structure of the island explain these differences. Results indicate large spatial variability in the response of aquifers to precipitation in

Long-term persistence of robust antibody and cytotoxic T cell responses in recovered patients infected with SARS coronavirus.

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Taisheng Li

2006-12-01

Full Text Available Most of the individuals infected with SARS coronavirus (SARS-CoV spontaneously recovered without clinical intervention. However, the immunological correlates associated with patients' recovery are currently unknown. In this report, we have sequentially monitored 30 recovered patients over a two-year period to characterize temporal changes in SARS-CoV-specific antibody responses as well as cytotoxic T cell (CTL responses. We have found persistence of robust antibody and CTL responses in all of the study subjects throughout the study period, with a moderate decline one year after the onset of symptoms. We have also identified two potential major CTL epitopes in N proteins based on ELISPOT analysis of pooled peptides. However, despite the potent immune responses and clinical recovery, peripheral lymphocyte counts in the recovered patients have not yet been restored to normal levels. In summary, our study has, for the first time, characterized the temporal and dynamic changes of humoral and CTL responses in the natural history of SARS-recovered individuals, and strongly supports the notion that high and sustainable levels of immune responses correlate strongly with the disease outcome. Our findings have direct implications for future design and development of effective therapeutic agents and vaccines against SARS-CoV infection.

Interpretation of serum antibody response to Anoplocephala perfoliata in relation to parasite burden and faecal egg count

DEFF Research Database (Denmark)

Kjaer, L.N.; Lungholt, M.M.; Nielsen, M.K.

2007-01-01

of development and gross pathological mucosal lesions were recorded and compared with serum antibody responses and faecal egg counts. Faecal egg counts were determined in samples from A. perfoliata infected horses using a semi-quantitative centrifugation/flotation technique. Blood samples collected at slaughter...

Proprietary arabinogalactan extract increases antibody response to the pneumonia vaccine: a randomized, double-blind, placebo-controlled, pilot study in healthy volunteers

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Udani Jay K

2010-08-01

Full Text Available Abstract Background Arabinogalactan from Larch tree (Larix spp. bark has previously demonstrated immunostimulatory activity. The purpose of this study was to test the hypothesis that ingestion of a proprietary arabinogalactan extract, ResistAid™, would selectively enhance the antibody response to the pneumococcal (pneumonia vaccine in healthy adults. Methods This randomized, double-blind, placebo-controlled, parallel group pilot study included 45 healthy adults who had not previously been vaccinated against Streptococcus pneumoniae. The volunteers began taking the study product or placebo (daily dosage 4.5 g at the screening visit (V1-Day 0 and continued over the entire 72 day study period. After 30 days the subjects received the 23-valent pneumococcal vaccine (V2. They were monitored the following day (V3-Day 31, as well as 21 days (V4-Day 51 and 42 days (V5-Day 72 after vaccination. Responses by the adaptive immune system (antigen specific were measured via pneumococcal IgG antibodies (subtypes 4, 6B, 9V, 14, 18C, 19F, and 23F and salivary IgA levels. Responses by the innate immune system (non-specific were measured via white blood cell counts, inflammatory cytokines and the complement system. Results Vaccination significantly increased pneumococcal IgG levels as expected. The arabinogalactan group demonstrated a statistically significant greater IgG antibody response than the placebo group in two antibodies subtypes (18C and 23F at both Day 51 (p = 0.006 and p = 0.002 and at Day 72 (p = 0.008 and p = 0.041. These same subtypes (18C and 23F also demonstrated change scores from baseline which were significant, in favor of the arabinogalactan group, at Day 51 (p = 0.033 and 0.001 and at Day 72 (p = 0.012 and p = 0.003. Change scores from baseline and mean values were greater in the arabinogalactan group than placebo for most time points in antibody subtypes 4, 6B, 9V, and 19F, but these differences did not reach statistical significance. There

Proprietary arabinogalactan extract increases antibody response to the pneumonia vaccine: a randomized, double-blind, placebo-controlled, pilot study in healthy volunteers.

Science.gov (United States)

Udani, Jay K; Singh, Betsy B; Barrett, Marilyn L; Singh, Vijay J

2010-08-26

Arabinogalactan from Larch tree (Larix spp.) bark has previously demonstrated immunostimulatory activity. The purpose of this study was to test the hypothesis that ingestion of a proprietary arabinogalactan extract, ResistAid™, would selectively enhance the antibody response to the pneumococcal (pneumonia) vaccine in healthy adults. This randomized, double-blind, placebo-controlled, parallel group pilot study included 45 healthy adults who had not previously been vaccinated against Streptococcus pneumoniae. The volunteers began taking the study product or placebo (daily dosage 4.5 g) at the screening visit (V1-Day 0) and continued over the entire 72 day study period. After 30 days the subjects received the 23-valent pneumococcal vaccine (V2). They were monitored the following day (V3-Day 31), as well as 21 days (V4-Day 51) and 42 days (V5-Day 72) after vaccination. Responses by the adaptive immune system (antigen specific) were measured via pneumococcal IgG antibodies (subtypes 4, 6B, 9V, 14, 18C, 19F, and 23F) and salivary IgA levels. Responses by the innate immune system (non-specific) were measured via white blood cell counts, inflammatory cytokines and the complement system. Vaccination significantly increased pneumococcal IgG levels as expected. The arabinogalactan group demonstrated a statistically significant greater IgG antibody response than the placebo group in two antibodies subtypes (18C and 23F) at both Day 51 (p = 0.006 and p = 0.002) and at Day 72 (p = 0.008 and p = 0.041). These same subtypes (18C and 23F) also demonstrated change scores from baseline which were significant, in favor of the arabinogalactan group, at Day 51 (p = 0.033 and 0.001) and at Day 72 (p = 0.012 and p = 0.003). Change scores from baseline and mean values were greater in the arabinogalactan group than placebo for most time points in antibody subtypes 4, 6B, 9V, and 19F, but these differences did not reach statistical significance. There was no effect from the vaccine or

[A spectrum of neurological diseases with anti-VGKC antibody].

Science.gov (United States)

Arimura, Kimiyoshi; Watanabe, Osamu; Nagado, Tatsui

2007-11-01

Anti-VGKC antibody causing peripheral nerve hyperexcitability is already an established clinical entity. Recently, many patients with non-herpetic limbic encephalitis (NHLE) with anti-VGKC antibody have been reported. The characteristic clinical features are low serum Na+ concentration and good response to immunotherapy. Anti-VGK antibody positive NHLE is relatively frequent among immune-mediated NHLE. It is important to know that this disease is responsive to immunotherapy. Furthermore, anti-VGKC antibody is also positive in some intractable epilepsies. These findings suggest that anti-VGKC is correlated with hyperexcitability in both the peripheral and central nervous system and that the spectrum of anti-VGKC antibody syndrome is now expanding.

Antibody response to a sterile filtered PPD tuberculin in M. bovis infected and M. bovis sensitized cattle.

Science.gov (United States)

Rennie, Bryan; Filion, Lionel G; Smart, Nonie

2010-11-09

Bovine tuberculosis, caused by Mycobacterium bovis, afflicts approximately 50 million cattle worldwide and is detected by the tuberculin skin test (TST). While it has long been recognized that purified protein derivative (PPD) tuberculin is composed of a mixture of M. bovis derived protein components, little is known about the quality, relative quantity and identity of the proteins that make up PPD tuberculin. We manufactured a sterile filtered PPD tuberculin (SF-PPD) from a nine-week-old M. bovis culture supernatant in order to characterise the culture filtrate proteins (CFP) which make up M. bovis PPD tuberculin and to compare the antibody response of M. bovis infected versus M. bovis sensitized cattle. SF-PPD resolved into approximately 200 discrete spots using two-dimensional polyacrylamide gel electrophoresis (2-DE) while fewer than 65 spots could be discerned from 2-DE gels of tuberculin derived from autoclaved culture supernatant. Two dimensional Western blot analyses indicated that sera from M. bovis sensitized cattle recognized additional SF-PPD antigens as compared to M. bovis infected cattle at seven weeks post infection/sensitization. However, application of a comparative tuberculin skin test resulted in an antibody boosting response to the same set of M. bovis CFPs in both the M. bovis infected and M. bovis sensitized cattle. We concluded that it is the heat sterilization of the M. bovis CFPs that causes severe structural changes to the M. bovis proteins. This work suggests that M. bovis infected cattle and cattle artificially sensitized to M. bovis with an injection of heat killed cells exhibit similar antibody responses to M. bovis antigens.

Interplay between Natural Killer Cells and Anti-HER2 Antibodies: Perspectives for Breast Cancer Immunotherapy

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Aura Muntasell

2017-11-01

Full Text Available Overexpression of the human epidermal growth factor receptor 2 (HER2 defines a subgroup of breast tumors with aggressive behavior. The addition of HER2-targeted antibodies (i.e., trastuzumab, pertuzumab to chemotherapy significantly improves relapse-free and overall survival in patients with early-stage and advanced disease. Nonetheless, considerable proportions of patients develop resistance to treatment, highlighting the need for additional and co-adjuvant therapeutic strategies. HER2-specific antibodies can trigger natural killer (NK cell-mediated antibody-dependent cellular cytotoxicity and indirectly enhance the development of tumor-specific T cell immunity; both mechanisms contributing to their antitumor efficacy in preclinical models. Antibody-dependent NK cell activation results in the release of cytotoxic granules as well as the secretion of pro-inflammatory cytokines (i.e., IFNγ and TNFα and chemokines. Hence, NK cell tumor suppressive functions include direct cytolytic killing of tumor cells as well as the regulation of subsequent antitumor adaptive immunity. Albeit tumors with gene expression signatures associated to the presence of cytotoxic lymphocyte infiltrates benefit from trastuzumab-based treatment, NK cell-related biomarkers of response/resistance to HER2-specific therapeutic antibodies in breast cancer patients remain elusive. Several variables, including (i the configuration of the patient NK cell repertoire; (ii tumor molecular features (i.e., estrogen receptor expression; (iii concomitant therapeutic regimens (i.e., chemotherapeutic agents, tyrosine kinase inhibitors; and (iv evasion mechanisms developed by progressive breast tumors, have been shown to quantitatively and qualitatively influence antibody-triggered NK cell responses. In this review, we discuss possible interventions for restoring/enhancing the therapeutic activity of HER2 therapeutic antibodies by harnessing NK cell antitumor potential through

A cross-reacting material CRM197 conjugate vaccine induces diphtheria toxin neutralizing antibody response in children and adolescents infected or not with HIV.

Science.gov (United States)

Silva, Giselle P; Santos, Rafaela S; Pereira-Manfro, Wânia F; Ferreira, Bianca; Barreto, Daniella M; Frota, Ana Cristina C; Hofer, Cristina B; Milagres, Lucimar G

2017-07-05

Anti-diphtheria antibody levels decrease with aging, and frequent booster vaccinations are required to maintain herd immunity. We analyzed the diphtheria toxin neutralizing antibody (DT-Nab) response induced by a conjugate vaccine (meningococcal C polysaccharide-CRM 197 ) in HIV-vertically infected (HI) children and adolescents and healthy controls (HC) with matched age. We report the association of DT-Nab with the bactericidal antibodies to serogroup C meningococcus (MenC). Before vaccination, 21 HI patients (50%) had no protection against diphtheria (≤0.01IU/ml of antibody) and only 8 (19%) showed complete protection (≥0.1IU/ml). About half of the HC (56%) had complete protection before immunization and 6 subjects (12%) had no protection against diphtheria. After one and two vaccine injections, 96% of HC and 64% of HI vaccinees, respectively, showed full protection against diphtheria. These data indicate that CRM 197 was able to induce primary and/or booster response in both groups of individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comprehensive mapping of common immunodominant epitopes in the West Nile virus nonstructural protein 1 recognized by avian antibody responses.

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Encheng Sun

Full Text Available West Nile virus (WNV is a mosquito-borne flavivirus that primarily infects birds but occasionally infects humans and horses. Certain species of birds, including crows, house sparrows, geese, blue jays and ravens, are considered highly susceptible hosts to WNV. The nonstructural protein 1 (NS1 of WNV can elicit protective immune responses, including NS1-reactive antibodies, during infection of animals. The antigenicity of NS1 suggests that NS1-reactive antibodies could provide a basis for serological diagnostic reagents. To further define serological reagents for diagnostic use, the antigenic sites in NS1 that are targeted by host immune responses need to be identified and the potential diagnostic value of individual antigenic sites also needs to be defined. The present study describes comprehensive mapping of common immunodominant linear B-cell epitopes in the WNV NS1 using avian WNV NS1 antisera. We screened antisera from chickens, ducks and geese immunized with purified NS1 for reactivity against 35 partially overlapping peptides covering the entire WNV NS1. This study identified twelve, nine and six peptide epitopes recognized by chicken, duck and goose antibody responses, respectively. Three epitopes (NS1-3, 14 and 24 were recognized by antibodies elicited by immunization in all three avian species tested. We also found that NS1-3 and 24 were WNV-specific epitopes, whereas the NS1-14 epitope was conserved among the Japanese encephalitis virus (JEV serocomplex viruses based on the reactivity of avian WNV NS1 antisera against polypeptides derived from the NS1 sequences of viruses of the JEV serocomplex. Further analysis showed that the three common polypeptide epitopes were not recognized by antibodies in Avian Influenza Virus (AIV, Newcastle Disease Virus (NDV, Duck Plague Virus (DPV and Goose Parvovirus (GPV antisera. The knowledge and reagents generated in this study have potential applications in differential diagnostic approaches and

Development and evaluation of single domain antibodies for vaccinia and the L1 antigen.

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Scott A Walper

Full Text Available There is ongoing interest to develop high affinity, thermal stable recognition elements to replace conventional antibodies in biothreat detection assays. As part of this effort, single domain antibodies that target vaccinia virus were developed. Two llamas were immunized with killed viral particles followed by boosts with the recombinant membrane protein, L1, to stimulate the immune response for envelope and membrane proteins of the virus. The variable domains of the induced heavy chain antibodies were selected from M13 phage display libraries developed from isolated RNA. Selection via biopanning on the L1 antigen produced single domain antibodies that were specific and had affinities ranging from 4×10(-9 M to 7.0×10(-10 M, as determined by surface plasmon resonance. Several showed good ability to refold after heat denaturation. These L1-binding single domain antibodies, however, failed to recognize the killed vaccinia antigen. Useful vaccinia binding single domain antibodies were isolated by a second selection using the killed virus as the target. The virus binding single domain antibodies were incorporated in sandwich assays as both capture and tracer using the MAGPIX system yielding limits of detection down to 4×10(5 pfu/ml, a four-fold improvement over the limit obtained using conventional antibodies. This work demonstrates the development of anti-vaccinia single domain antibodies and their incorporation into sandwich assays for viral detection. It also highlights the properties of high affinity and thermal stability that are hallmarks of single domain antibodies.

Use of antibodies against the variable regions of the T-cell receptor alpha/beta heterodimer for the study of cutaneous T-cell lymphomas.

Science.gov (United States)

Ralfkiaer, E; Wollf-Sneedorff, A; Vejlsgaard, G L

1991-11-01

Recent studies have suggested that antibodies against the variable (V) regions of the T-cell antigen receptor (TCR) may be used as markers for clonality and malignancy in T-cell infiltrates. We have investigated this by examining biopsy samples from 45 patients with cutaneous T-cell lymphomas (CTCL) for reactivity with seven antibodies against different V-gene families on the TCR alpha/beta heterodimer, i.e. ICI (V beta 5a), W112 (V beta 5b), OT145 (V beta 6a), 16G8 (V beta 8a), S511 (V beta 12a), F1 (V alpha 2a) and LC4 (alpha beta Va). Serial biopsies were available in 13 patients and a total of 62 samples were studied. The neoplastic cells in five cases were positive for either V beta 5 (one case), V beta 6 (one case), V beta 8 (two cases) or V beta 12 (one case). In the remaining 40 cases, no staining was seen of the neoplastic cells. These findings indicate that while antibodies against the TCR V-regions may be used as clonotypic markers for certain T-cell neoplasms, there is as yet not a sufficient number of anti-TCR V-region antibodies available for the routine diagnosis of these conditions.

Generation of anti-idiotype antibodies for application in clinical immunotherapy laboratory analyses.

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Liu, Zhanqi; Panousis, Con; Smyth, Fiona E; Murphy, Roger; Wirth, Veronika; Cartwright, Glenn; Johns, Terrance G; Scott, Andrew M

2003-08-01

The chimeric monoclonal antibody ch806 specifically targets the tumor-associated mutant epidermal growth factor receptor (de 2-7EGFR or EGFRVIII) and is currently under investigation for its potential use in cancer therapy. The humanised monoclonal antibody hu3S193 specifically targets the Lewis Y epithelial antigen and is currently in Phase I clinical trials in patients with advanced breast, colon, and ovarian carcinomas. To assist the clinical evaluation of ch806 and hu3S193, laboratory assays are required to monitor their serum pharmacokinetics and quantitate any immune responses to the antibodies. Mice immunized with ch806 or hu3S193 were used to generate hybridomas producing antibodies with specific binding to ch806 or hu3S193 and competitive for antigen binding. These anti-idiotype antibodies (designated Ludwig Melbourne Hybridomas, LMH) were investigated as reagents suitable for use as positive controls for HAHA or HACA analyses and for measuring hu3S193 or ch806 in human serum. Anti-idiotypes with the ability to concurrently bind two target antibody molecules were identified, which enabled the development of highly reproducible, sensitive, specific ELISA assays for determining serum concentrations of hu3S193 and ch806 with a 3 ng/mL limit of quantitation using LMH-3 and LMH-12, respectively. BIAcore analyses determined high apparent binding affinity for both idiotypes: LMH-3 binding immobilized hu3S193, Ka = 4.76 x 10(8) M(-1); LMH-12 binding immobilised ch806, Ka = 1.74 x 10(9) M(-1). Establishment of HAHA or HACA analysis of sera samples using BIAcore was possible using LMH-3 and LMH-12 as positive controls for quantitation of immune responses to hu3S193 or ch806 in patient sera. These anti-idiotypes could also be used to study the penetrance and binding of ch806 or hu3S193 to tumor cells through immunohistochemical analysis of tumor biopsies. The generation of anti-idiotype antibodies capable of concurrently binding a target antibody on each variable

Serological analysis of human anti-human antibody responses in colon cancer patients treated with repeated doses of humanized monoclonal antibody A33.

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Ritter, G; Cohen, L S; Williams, C; Richards, E C; Old, L J; Welt, S

2001-09-15

Mouse monoclonal antibody A33 (mAb A33) recognizes a M(r) 43,000 cell surface glycoprotein (designated A33) expressed in human colonic epithelium and colon cancer but absent from most other normal tissues. In patients, mAb A33 localizes with high specificity to colon cancer and is retained for up to 6 weeks in the cancer but cleared rapidly from normal colon (5-6 days). As a carrier of (125)I or (131)I, mAb A33 has shown antitumor activity. Induction of strong human anti-mouse antibody (immunoglobulin; HAMA) responses in patients, however, limits the use of the murine mAb A33 to very few injections. A humanized version of this antibody (huAb A33) has been prepared for Phase I and II clinical studies in patients with colon cancer. In those studies, immunogenicity of huAb A33 has been monitored using a novel, highly sensitive BIACORE method, which allows measurement of human anti-human antibodies (HAHAs) without the use of secondary reagents. We found that 63% (26 of 41) of the patients treated with repeated doses of huAb A33 developed HAHAs against a conformational antigenic determinant located in the V(L) and V(H) regions of huAb A33. Detailed serological analysis showed two distinct types of HAHAs. HAHA of type I (49% of patients) was characterized by an early onset with peak HAHA levels after 2 weeks of treatment, which declined with ongoing huAb A33 treatment. HAHA of type II (17% of patients) was characterized by a typically later onset of HAHA than in type I and by progressively increasing HAHA levels with each subsequent huAb A33 administration. Colon cancer patients with type I HAHAs did not develop infusion-related adverse events. In contrast, HAHA of type II was indicative of infusion-related adverse events. By using this new method, we were able to distinguish these two types of HAHAs in patients while on antibody treatment, allowing patients to be removed from study prior to the onset of severe infusion-related adverse events.

Different sources of dietary n-6 polyunsaturated fatty acids and their effects on antibody responses in chickens

NARCIS (Netherlands)

Parmentier, H.K.; Awati, A.; Nieuwland, M.G.B.; Schrama, J.W.; Sijben, J.W.C.

2002-01-01

1. Effects of linoleic and linolenic acid provided via different oil sources on total antibody (Ab) titres, Ab isotypes after primary and secondary immunisation, and cutaneous hypersensitivity (CH) responses to bovine serum albumin (BSA) and maleyl-BSA, respectively, were studied in pullets fed on

Immunization with Clinical HIV-1 Env Proteins Induces Broad Antibody Dependent Cellular Cytotoxicity-Mediating Antibodies in a Rabbit Vaccination Model.

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Karlsson, Ingrid; Borggren, Marie; Jensen, Sanne Skov; Heyndrickx, Leo; Stewart-Jones, Guillaume; Scarlatti, Gabriella; Fomsgaard, Anders

2017-11-17

The induction of both neutralizing antibodies and non-neutralizing antibodies with effector functions, for example, antibody-dependent cellular cytotoxicity (ADCC), is desired in the search for effective vaccines against HIV-1. In the pursuit of novel immunogens capable of inducing an efficient antibody response, rabbits were immunized with selected antigens using different prime-boost strategies. We immunized 35 different groups of rabbits with Env antigens from clinical HIV-1 subtypes A and B, including immunization with DNA alone, protein alone, and DNA prime with protein boost. The rabbit sera were screened for ADCC activity using a GranToxiLux-based assay with human peripheral blood mononuclear cells as effector cells and CEM.NKR CCR5 cells coated with HIV-1 envelope as target cells. The groups with the highest ADCC activity were further characterized for cross-reactivity between HIV-1 subtypes. The immunogen inducing the most potent and broadest ADCC response was a trimeric gp140. The ADCC activity was highest against the HIV-1 subtype corresponding to the immunogen. The ADCC activity did not necessarily reflect neutralizing activity in the pseudovirus-TZMbl assay, but there was an overall correlation between the two antiviral activities. We present a rabbit vaccination model and an assay suitable for screening HIV-1 vaccine candidates for the induction of ADCC-mediating antibodies in addition to neutralizing antibodies. The antigens and/or immunization strategies capable of inducing antibodies with ADCC activity did not necessarily induce neutralizing activity and vice versa. Nevertheless, we identified vaccine candidates that were able to concurrently induce both types of responses and that had ADCC activity that was cross-reactive between different subtypes. When searching for an effective vaccine candidate, it is important to evaluate the antibody response using a model and an assay measuring the desired function.

Individual canine Airway Response Variability to a Deep Inspiration

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Robert H. Brown

2011-01-01

Full Text Available In healthy individuals, a DI can reverse (bronchodilation or prevent (bronchoprotection induced airway constriction. For individuals with asthma or COPD, these effects may be attenuated or absent. Previous work showed that the size and duration of a DI affected the subsequent response of the airways. Also, increased airway tone lead to increased airway size variability. The present study examined how a DI affected the temporal variability in individual airway baseline size and after methacholine challenge in dogs using High-Resolution Computed Tomography. Dogs were anesthetized and ventilated, and on 4 separate days, HRCT scans were acquired before and after a DI at baseline and during a continuous intravenous infusion of methacholine (Mch at 3 dose rates (17, 67, and 200 μg/mm. The Coefficient of Variation was used as an index of temporal variability in airway size. We found that at baseline and the lowest dose of Mch, variability decreased immediately and 5 minutes after the DI ( P < 0.0001. In contrast, with higher doses of Mch, the DI caused a variable response. At a rate of 67 μg/min of Mch, the temporal variability increased after 5 minutes, while at a rate of 200 μg/min of Mch, the temporal variability increased immediately after the DI. Increased airway temporal variability has been shown to be associated with asthma. Although the mechanisms underlying this temporal variability are poorly understood, the beneficial effects of a DI to decrease airway temporal variability was eliminated when airway tone was increased. If this effect is absent in asthmatics, this may suggest a possible mechanism for the loss of bronchoprotective and bronchodilatory effects after a DI in asthma.

Dengue E Protein Domain III-Based DNA Immunisation Induces Strong Antibody Responses to All Four Viral Serotypes.

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Monica Poggianella

Full Text Available Dengue virus (DENV infection is a major emerging disease widely distributed throughout the tropical and subtropical regions of the world affecting several millions of people. Despite constants efforts, no specific treatment or effective vaccine is yet available. Here we show a novel design of a DNA immunisation strategy that resulted in the induction of strong antibody responses with high neutralisation titres in mice against all four viral serotypes. The immunogenic molecule is an engineered version of the domain III (DIII of the virus E protein fused to the dimerising CH3 domain of the IgG immunoglobulin H chain. The DIII sequences were also codon-optimised for expression in mammalian cells. While DIII alone is very poorly secreted, the codon-optimised fusion protein is rightly expressed, folded and secreted at high levels, thus inducing strong antibody responses. Mice were immunised using gene-gun technology, an efficient way of intradermal delivery of the plasmid DNA, and the vaccine was able to induce neutralising titres against all serotypes. Additionally, all sera showed reactivity to a recombinant DIII version and the recombinant E protein produced and secreted from mammalian cells in a mono-biotinylated form when tested in a conformational ELISA. Sera were also highly reactive to infective viral particles in a virus-capture ELISA and specific for each serotype as revealed by the low cross-reactive and cross-neutralising activities. The serotype specific sera did not induce antibody dependent enhancement of infection (ADE in non-homologous virus serotypes. A tetravalent immunisation protocol in mice showed induction of neutralising antibodies against all four dengue serotypes as well.

Cloning, bacterial expression and crystallization of Fv antibody fragments

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E´, Jean-Luc; Boulot, Ginette; Chitarra, V´ronique; Riottot, Marie-Madeleine; Souchon, H´le`ne; Houdusse, Anne; Bentley, Graham A.; Narayana Bhat, T.; Spinelli, Silvia; Poljak, Roberto J.

1992-08-01

The variable Fv fragments of antibodies, cloned in recombinant plasmids, can be expressed in bacteria as functional proteins having immunochemical properties which are very similar or identical with those of the corresponding parts of the parent eukaryotic antibodies. They offer new possibilities for the study of antibody-antigen interactions since the crystals of Fv fragments and of their complexes with antigen reported here diffract X-rays to a higher resolution that those obtained with the cognate Fab fragments. The Fv approach should facilitate the structural study of the combining site of antibodies and the further characterization of antigen-antibody interactions by site-directed mutagenesis experiments.

Analysis of V2 antibody responses induced in vaccinees in the ALVAC/AIDSVAX HIV-1 vaccine efficacy trial.

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Susan Zolla-Pazner

Full Text Available The RV144 clinical trial of a prime/boost immunizing regimen using recombinant canary pox (ALVAC-HIV and two gp120 proteins (AIDSVAX B and E was previously shown to have a 31.2% efficacy rate. Plasma specimens from vaccine and placebo recipients were used in an extensive set of assays to identify correlates of HIV-1 infection risk. Of six primary variables that were studied, only one displayed a significant inverse correlation with risk of infection: the antibody (Ab response to a fusion protein containing the V1 and V2 regions of gp120 (gp70-V1V2. This finding prompted a thorough examination of the results generated with the complete panel of 13 assays measuring various V2 Abs in the stored plasma used in the initial pilot studies and those used in the subsequent case-control study. The studies revealed that the ALVAC-HIV/AIDSVAX vaccine induced V2-specific Abs that cross-react with multiple HIV-1 subgroups and recognize both conformational and linear epitopes. The conformational epitope was present on gp70-V1V2, while the predominant linear V2 epitope mapped to residues 165-178, immediately N-terminal to the putative α4β7 binding motif in the mid-loop region of V2. Odds ratios (ORs were calculated to compare the risk of infection with data from 12 V2 assays, and in 11 of these, the ORs were ≤1, reaching statistical significance for two of the variables: Ab responses to gp70-V1V2 and to overlapping V2 linear peptides. It remains to be determined whether anti-V2 Ab responses were directly responsible for the reduced infection rate in RV144 and whether anti-V2 Abs will prove to be important with other candidate HIV vaccines that show efficacy, however, the results support continued dissection of Ab responses to the V2 region which may illuminate mechanisms of protection from HIV-1 infection and may facilitate the development of an effective HIV-1 vaccine.

Plasmodium vivax VIR Proteins Are Targets of Naturally-Acquired Antibody and T Cell Immune Responses to Malaria in Pregnant Women.

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Requena, Pilar; Rui, Edmilson; Padilla, Norma; Martínez-Espinosa, Flor E; Castellanos, Maria Eugenia; Bôtto-Menezes, Camila; Malheiro, Adriana; Arévalo-Herrera, Myriam; Kochar, Swati; Kochar, Sanjay K; Kochar, Dhanpat K; Umbers, Alexandra J; Ome-Kaius, Maria; Wangnapi, Regina; Hans, Dhiraj; Menegon, Michela; Mateo, Francesca; Sanz, Sergi; Desai, Meghna; Mayor, Alfredo; Chitnis, Chetan C; Bardají, Azucena; Mueller, Ivo; Rogerson, Stephen; Severini, Carlo; Fernández-Becerra, Carmen; Menéndez, Clara; Del Portillo, Hernando; Dobaño, Carlota

2016-10-01

P. vivax infection during pregnancy has been associated with poor outcomes such as anemia, low birth weight and congenital malaria, thus representing an important global health problem. However, no vaccine is currently available for its prevention. Vir genes were the first putative virulent factors associated with P. vivax infections, yet very few studies have examined their potential role as targets of immunity. We investigated the immunogenic properties of five VIR proteins and two long synthetic peptides containing conserved VIR sequences (PvLP1 and PvLP2) in the context of the PregVax cohort study including women from five malaria endemic countries: Brazil, Colombia, Guatemala, India and Papua New Guinea (PNG) at different timepoints during and after pregnancy. Antibody responses against all antigens were detected in all populations, with PNG women presenting the highest levels overall. P. vivax infection at sample collection time was positively associated with antibody levels against PvLP1 (fold-increase: 1.60 at recruitment -first antenatal visit-) and PvLP2 (fold-increase: 1.63 at delivery), and P. falciparum co-infection was found to increase those responses (for PvLP1 at recruitment, fold-increase: 2.25). Levels of IgG against two VIR proteins at delivery were associated with higher birth weight (27 g increase per duplicating antibody levels, ppregnant women had significantly higher antigen-specific IFN-γ TH1 responses (p=0.006) and secreted less pro-inflammatory cytokines TNF and IL-6 after PvLP2 stimulation than P. vivax-infected women (p<0.05). These data demonstrate that VIR antigens induce the natural acquisition of antibody and T cell memory responses that might be important in immunity to P. vivax during pregnancy in very diverse geographical settings.

Comparison of antibody responses to human papillomavirus vaccination as measured by three assays

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Hilary Ann Robbins

2014-01-01

Full Text Available Background: Different assays, including the competitive Luminex immunoassay (cLIA, secreted alkaline phosphatase neutralization assay (SEAP-NA, and virus-like particle-based ELISA, are commonly used to measure antibody responses after human papillomavirus (HPV vaccination. Direct assay comparisons aid interpretation of immunogenicity data evaluated by different assays. Methods: We compared cLIA to SEAP-NA and ELISA among 51 HPV16/18-vaccinated women enrolled in the Costa Rica Vaccine Trial. We tested replicate serum samples collected at months 0, 1, and 12 by HPV16/18 cLIA, SEAP-NA, and ELISA. For a subset (N=10, we further tested month 24 and 36 samples. We calculated seroprevalence estimates and Spearman rank correlation coefficients comparing cLIA to SEAP-NA and ELISA.Results: After one vaccine dose, seroprevalence by SEAP-NA and ELISA was 100% (both HPV16 and HPV18, and by cLIA was 96% (95% CI 87%-100% for HPV16 and 71% (95% CI 56%-83% for HPV18. Seroprevalence was 100% by all assays after 3 doses. Correlation between assays was high after one vaccine dose (cLIA/SEAP-NA ρ=0.91 (HPV16 and ρ=0.86 (HPV18; cLIA/ELISA ρ=0.84 (HPV16 and ρ=0.74 (HPV18; all p<0.001 and remained high through month 36. Ratios of mean antibody levels to seropositivity cutoffs at month 36 were lower for cLIA than for SEAP-NA or ELISA, particularly for HPV18 (HPV18 ratio for cLIA 1.9, SEAP-NA 3.5, ELISA 3.4.Conclusion: Though correlation between cLIA and SEAP-NA/ELISA is high and stable after vaccination, the assays differ in scale and sensitivity, with notable differences after 1 vaccine dose and for HPV18. Our results demonstrate that comparisons of antibody responses to HPV vaccination measured by different assays are approximate, and must consider biological and technical differences between assays.

Immunogenicity of therapeutic antibodies : Immunological mechanisms & clinical consequences

NARCIS (Netherlands)

van Schie, K.A.J.

2017-01-01

Monoclonal antibody therapy has revolutionized the treatment of many diseases, including chronic inflammatory diseases and cancer. Antibody therapy can unfortunately also elicit an unwanted immune response, leading to anti-drug antibodies (ADA). It is well known that ADA can lower the level of free

Immunoglobulin M and G antibody responses to Plasmodium falciparum glutamate-rich protein

DEFF Research Database (Denmark)

Dziegiel, Morten Hanefeld; Rowe, P; Bennett, S

1993-01-01

were measured with a recombinant fusion protein consisting of the carboxy-terminal 783 amino acids of the GLURP. Samples for the study were obtained during a longitudinal malaria morbidity survey performed in The Gambia; cross-sectional surveys were performed at the beginning of the transmission season......The aims of the present study were to describe the age-related immunoglobulin M (IgM) and IgG response to part of a 220-kDa glutamate-rich protein (GLURP) from Plasmodium falciparum and to determine possible correlations of possession of these antibodies with malaria morbidity. IgM and IgG levels...

Centile estimation for a proportion response variable.

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Hossain, Abu; Rigby, Robert; Stasinopoulos, Mikis; Enea, Marco

2016-03-15

This paper introduces two general models for computing centiles when the response variable Y can take values between 0 and 1, inclusive of 0 or 1. The models developed are more flexible alternatives to the beta inflated distribution. The first proposed model employs a flexible four parameter logit skew Student t (logitSST) distribution to model the response variable Y on the unit interval (0, 1), excluding 0 and 1. This model is then extended to the inflated logitSST distribution for Y on the unit interval, including 1. The second model developed in this paper is a generalised Tobit model for Y on the unit interval, including 1. Applying these two models to (1-Y) rather than Y enables modelling of Y on the unit interval including 0 rather than 1. An application of the new models to real data shows that they can provide superior fits. Copyright © 2015 John Wiley & Sons, Ltd.

Affinity of antibody secreted by a single cell

International Nuclear Information System (INIS)

Doran, D.M.

1978-01-01

It was the intention of this research to measure the affinity of antibody secreted by a single cell, and to describe the spectrum of affinities displayed in response to antigenic stimulation. The single cell secreting specific antibody was isolated by means of the hemolytic plaque assay. The amount of antibody secreted by the cell was to be measured through the use of a solid phase radioimmunoassay. The affinity of the antibody would be estimated by comparing the diameter of the plaque, and the amount of antibody secreted, with a mathematical theory of the formation of a plaque in agar. As a test system, a solid phase radioimmunoassay was developed for human serum albumin using antibody coupled to Sephadex. A sensitivity of 1 nanogram was attained with this assay. A solid phase radioimmunoassay for mouse immunoglobulin M was developed, using antibody coupled to Sepharose. The sensitivity attained with this assay was only on the order of 10 micrograms. The mouse immunoglobulin M radioimmunoassay was not sensitive enough to measure the amount of antibody secreted by a single cell. From a theoretical equation, the relationship between antibody affinity, plaque diameter and antibody secretion rate was calculated for the experimental conditions used in this research. By assuming a constant antibody secretion rate, an effective binding constant for the antibody was estimated from the average plaque diameters. This effective binding constant was observed to increase during the immune response

Subsets of memory CD4+ T cell and bactericidal antibody response to Neisseria meningitidis serogroup C after immunization of HIV-infected children and adolescents.

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Lucimar G Milagres

Full Text Available Meningococcal disease is endemic in Brazil, with periodic outbreaks and case fatality rates reach as high as 18 to 20% of cases. Conjugate vaccines against meningococci are immunogenic in healthy children. However, we have previously shown a poor bactericidal antibody response to a Men C conjugate vaccine in Brazilian HIV-infected children and adolescents after a single vaccine administration. The goal of the present work was to investigate associations between bactericidal antibody response induced by MenC vaccine and the frequency and activation profile (expression of CD38, HLA-DR and CCR5 molecules of total CD4+ memory T cell sub-populations in HIV-1-infected children and adolescents. Responders to vaccination against MenC had a predominance (about 44% of CD4+ TINTERMEDIATE subset followed by TTRANSITIONAL memory subset (23 to 26%. Importantly, CD4+ TINT frequency was positively associated with bactericidal antibody response induced by vaccination. The positive correlation persisted despite the observation that the frequency TINT CD38+HLA-DR+ was higher in responders. In contrast, CD4+ TCENTRAL MEMORY (TCM subset negatively correlated with bactericidal antibodies. In conclusion, these data indicate that less differentiated CD+ T cells, like TCM may be constantly differentiating into intermediate and later differentiated CD4+ T cell subsets. These include CD4 TINT subset which showed a positive association with bactericidal antibodies.

The intestinal flora is required to support antibody responses to systemic immunization in infant and germ free mice.

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Lamousé-Smith, Esi S; Tzeng, Alice; Starnbach, Michael N

2011-01-01

The presence of a complex and diverse intestinal flora is functionally important for regulating intestinal mucosal immune responses. However, the extent to which a balanced intestinal flora regulates systemic immune responses is still being defined. In order to specifically examine whether the acquisition of a less complex flora influences responses to immunization in the pre-weaning stages of life, we utilize a model in which infant mice acquire an intestinal flora from their mothers that has been altered by broad-spectrum antibiotics. In this model, pregnant dams are treated with a cocktail of antibiotics that alters both the density and microbial diversity of the intestinal flora. After challenge with a subcutaneous immunization, the antibiotic altered flora infant mice have lower antigen specific antibody titers compared to control age-matched mice. In a second model, we examined germ free (GF) mice to analyze how the complete lack of flora influences the ability to mount normal antibody responses following subcutaneous immunization. GF mice do not respond well to immunization and introduction of a normal flora into GF mice restores the capacity of these mice to respond. These results indicate that a gastrointestinal flora reduced in density and complexity at critical time points during development adversely impacts immune responses to systemic antigens.

Nanobodies and Nanobody-Based Human Heavy Chain Antibodies As Antitumor Therapeutics

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Peter Bannas

2017-11-01

Full Text Available Monoclonal antibodies have revolutionized cancer therapy. However, delivery to tumor cells in vivo is hampered by the large size (150 kDa of conventional antibodies. The minimal target recognition module of a conventional antibody is composed of two non-covalently associated variable domains (VH and VL. The proper orientation of these domains is mediated by their hydrophobic interface and is stabilized by their linkage to disulfide-linked constant domains (CH1 and CL. VH and VL domains can be fused via a genetic linker into a single-chain variable fragment (scFv. scFv modules in turn can be fused to one another, e.g., to generate a bispecific T-cell engager, or they can be fused in various orientations to antibody hinge and Fc domains to generate bi- and multispecific antibodies. However, the inherent hydrophobic interaction of VH and VL domains limits the stability and solubility of engineered antibodies, often causing aggregation and/or mispairing of V-domains. Nanobodies (15 kDa and nanobody-based human heavy chain antibodies (75 kDa can overcome these limitations. Camelids naturally produce antibodies composed only of heavy chains in which the target recognition module is composed of a single variable domain (VHH or Nb. Advantageous features of nanobodies include their small size, high solubility, high stability, and excellent tissue penetration in vivo. Nanobodies can readily be linked genetically to Fc-domains, other nanobodies, peptide tags, or toxins and can be conjugated chemically at a specific site to drugs, radionuclides, photosensitizers, and nanoparticles. These properties make them particularly suited for specific and efficient targeting of tumors in vivo. Chimeric nanobody-heavy chain antibodies combine advantageous features of nanobodies and human Fc domains in about half the size of a conventional antibody. In this review, we discuss recent developments and perspectives for applications of nanobodies and nanobody

Nanobodies and Nanobody-Based Human Heavy Chain Antibodies As Antitumor Therapeutics.

Science.gov (United States)

Bannas, Peter; Hambach, Julia; Koch-Nolte, Friedrich

2017-01-01

Monoclonal antibodies have revolutionized cancer therapy. However, delivery to tumor cells in vivo is hampered by the large size (150 kDa) of conventional antibodies. The minimal target recognition module of a conventional antibody is composed of two non-covalently associated variable domains (VH and VL). The proper orientation of these domains is mediated by their hydrophobic interface and is stabilized by their linkage to disulfide-linked constant domains (CH1 and CL). VH and VL domains can be fused via a genetic linker into a single-chain variable fragment (scFv). scFv modules in turn can be fused to one another, e.g., to generate a bispecific T-cell engager, or they can be fused in various orientations to antibody hinge and Fc domains to generate bi- and multispecific antibodies. However, the inherent hydrophobic interaction of VH and VL domains limits the stability and solubility of engineered antibodies, often causing aggregation and/or mispairing of V-domains. Nanobodies (15 kDa) and nanobody-based human heavy chain antibodies (75 kDa) can overcome these limitations. Camelids naturally produce antibodies composed only of heavy chains in which the target recognition module is composed of a single variable domain (VHH or Nb). Advantageous features of nanobodies include their small size, high solubility, high stability, and excellent tissue penetration in vivo . Nanobodies can readily be linked genetically to Fc-domains, other nanobodies, peptide tags, or toxins and can be conjugated chemically at a specific site to drugs, radionuclides, photosensitizers, and nanoparticles. These properties make them particularly suited for specific and efficient targeting of tumors in vivo . Chimeric nanobody-heavy chain antibodies combine advantageous features of nanobodies and human Fc domains in about half the size of a conventional antibody. In this review, we discuss recent developments and perspectives for applications of nanobodies and nanobody-based human heavy

Antibody responses against xenotropic murine leukemia virus-related virus envelope in a murine model.

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Natalia Makarova

2011-04-01

Full Text Available Xenotropic murine leukemia virus-related virus (XMRV was recently discovered to be the first human gammaretrovirus that is associated with chronic fatigue syndrome and prostate cancer (PC. Although a mechanism for XMRV carcinogenesis is yet to be established, this virus belongs to the family of gammaretroviruses well known for their ability to induce cancer in the infected hosts. Since its original identification XMRV has been detected in several independent investigations; however, at this time significant controversy remains regarding reports of XMRV detection/prevalence in other cohorts and cell type/tissue distribution. The potential risk of human infection, coupled with the lack of knowledge about the basic biology of XMRV, warrants further research, including investigation of adaptive immune responses. To study immunogenicity in vivo, we vaccinated mice with a combination of recombinant vectors expressing codon-optimized sequences of XMRV gag and env genes and virus-like particles (VLP that had the size and morphology of live infectious XMRV.Immunization elicited Env-specific binding and neutralizing antibodies (NAb against XMRV in mice. The peak titers for ELISA-binding antibodies and NAb were 1:1024 and 1:464, respectively; however, high ELISA-binding and NAb titers were not sustained and persisted for less than three weeks after immunizations.Vaccine-induced XMRV Env antibody titers were transiently high, but their duration was short. The relatively rapid diminution in antibody levels may in part explain the differing prevalences reported for XMRV in various prostate cancer and chronic fatigue syndrome cohorts. The low level of immunogenicity observed in the present study may be characteristic of a natural XMRV infection in humans.

A plant’s perspective of extremes: Terrestrial plant responses to changing climatic variability

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Reyer, C.; Leuzinger, S.; Rammig, A.; Wolf, A.; Bartholomeus, R. P.; Bonfante, A.; de Lorenzi, F.; Dury, M.; Gloning, P.; Abou Jaoudé, R.; Klein, T.; Kuster, T. M.; Martins, M.; Niedrist, G.; Riccardi, M.; Wohlfahrt, G.; de Angelis, P.; de Dato, G.; François, L.; Menzel, A.; Pereira, M.

2013-01-01

We review observational, experimental and model results on how plants respond to extreme climatic conditions induced by changing climatic variability. Distinguishing between impacts of changing mean climatic conditions and changing climatic variability on terrestrial ecosystems is generally underrated in current studies. The goals of our review are thus (1) to identify plant processes that are vulnerable to changes in the variability of climatic variables rather than to changes in their mean, and (2) to depict/evaluate available study designs to quantify responses of plants to changing climatic variability. We find that phenology is largely affected by changing mean climate but also that impacts of climatic variability are much less studied but potentially damaging. We note that plant water relations seem to be very vulnerable to extremes driven by changes in temperature and precipitation and that heatwaves and flooding have stronger impacts on physiological processes than changing mean climate. Moreover, interacting phenological and physiological processes are likely to further complicate plant responses to changing climatic variability. Phenological and physiological processes and their interactions culminate in even more sophisticated responses to changing mean climate and climatic variability at the species and community level. Generally, observational studies are well suited to study plant responses to changing mean climate, but less suitable to gain a mechanistic understanding of plant responses to climatic variability. Experiments seem best suited to simulate extreme events. In models, temporal resolution and model structure are crucial to capture plant responses to changing climatic variability. We highlight that a combination of experimental, observational and /or modeling studies have the potential to overcome important caveats of the respective individual approaches. PMID:23504722

Reshaping Human Antibodies: Grafting an Antilysozyme Activity

Science.gov (United States)

Verhoeyen, Martine; Milstein, Cesar; Winter, Greg

1988-03-01

The production of therapeutic human monoclonal antibodies by hybridoma technology has proved difficult, and this has prompted the ``humanizing'' of mouse monoclonal antibodies by recombinant DNA techniques. It was shown previously that the binding site for a small hapten could be grafted from the heavy-chain variable domain of a mouse antibody to that of a human myeloma protein by transplanting the hypervariable loops. It is now shown that a large binding site for a protein antigen (lysozyme) can also be transplanted from mouse to human heavy chain. The success of such constructions may be facilitated by an induced-fit mechanism.

Characterization of isotypes of antibody response against leishmania parasite

International Nuclear Information System (INIS)

Elassad, Asma M.S.; Ghalib, Hashim W.; Younis, Saddia A.

1994-01-01

In this study an enzyme linked immunosorbent assay (ELIZA) was developed to detect IgG,IgM and IgA response in visceral leishmaniasis patients (VL) against L.donovain and L. major antigens compared to control groups; cutaneous leishmaniasis patients (CL), mucosal leishmaniasis patients (ML), patients with other tropical diseases and healthy controls.Highly specific IgG were found in VL patients with test specificity (93.7%) and sensitivity(93.4%). A moderate IgG were found in VL patients but non-specific while no IgA were detected in all studied groups. Also VL patients showed high specificity and sensitivity (95.2 and 96.6% respectively) against L.major antigen.The distribution of IgG subclasses (IgG1,IgG2,IgG3 and IgG4) antibodies in VL patients were assayed.IgG3 showed the highest specificity and sensitivity and titers followed by IgG1.Also the diagnostic value of ELIZA test for different leishmaniasis forms were discussed. (Author)

Serotype-specific immunoglobulin G antibody responses to pneumococcal polysaccharide vaccine in children with sickle cell anemia : Effects of continued penicillin prophylaxis

NARCIS (Netherlands)

Bjornson, AB; Falletta, JM; Verter, JI; Buchanan, GR; Miller, ST; Pegelow, CH; Iyer, RV; Johnstone, HS; DeBaun, MR; Wethers, DL; Woods, GM; Holbrook, CT; Becton, DL; Kinney, TR; Reaman, GH; Kalinyak, K; Grossman, NJ; Vichinsky, E; Reid, CD

1996-01-01

Objectives: (1) To determine serotype-specific IgG antibody responses to reimmunization with pneumococcal polysaccharide vaccine at age 5 years ski children with sickle cell anemia and (2) to determine whether continued penicillin prophylaxis had any adverse effects on these responses. Study design:

Generation of a rabbit single-chain fragment variable (scFv) antibody for specific detection of Bradyrhizobium sp. DOA9 in both free-living and bacteroid forms.

Science.gov (United States)

Vu, Nguyen Xuan; Pruksametanan, Natcha; Srila, Witsanu; Yuttavanichakul, Watcharin; Teamtisong, Kamonluck; Teaumroong, Neung; Boonkerd, Nantakorn; Tittabutr, Panlada; Yamabhai, Montarop

2017-01-01

A simple and reliable method for the detection of specific nitrogen-fixing bacteria in both free-living and bacteroid forms is essential for the development and application of biofertilizer. Traditionally, a polyclonal antibody generated from an immunized rabbit was used for detection. However, the disadvantages of using a polyclonal antibody include limited supply and cross-reactivity to related bacterial strains. This is the first report on the application of phage display technology for the generation of a rabbit recombinant monoclonal antibody for specific detection and monitoring of nitrogen-fixing bacteria in both free-living form and in plant nodules. Bradyrhizobium sp. DOA9, a broad host range soil bacteria, originally isolated from the root nodules of Aeschynomene americana in Thailand was used as a model in this study. A recombinant single-chain fragment variable (scFv) antibody library was constructed from the spleen of a rabbit immunized with DOA9. After three rounds of biopanning, one specific phage-displayed scFv antibody, designated bDOA9rb8, was identified. Specific binding of this antibody was confirmed by phage enzyme-linked immunosorbent assay (phage ELISA). The phage antibody could bind specifically to DOA9 in both free-living cells (pure culture) and bacteroids inside plant nodules. In addition to phage ELISA, specific and robust immunofluorescence staining of both free-living and bacteroid forms could also be observed by confocal-immunofluorescence imaging, without cross-reactivity with other tested bradyrhizobial strains. Moreover, specific binding of free scFv to DOA9 was also demonstrated by ELISA. This recombinant antibody can also be used for the study of the molecular mechanism of plant-microbe interactions in the future.

Serum Antibody Response to Koala Retrovirus Antigens Varies in Free-Ranging Koalas ( Phascolarctos cinereus ) in Australia: Implications for Vaccine Design.

Science.gov (United States)

Waugh, Courtney; Gillett, Amber; Polkinghorne, Adam; Timms, Peter

2016-04-28

Little is known about the immune response in the koala ( Phascolarctos cinereus ) to its retroviruses. Koala retroviruses (KoRVs) have been linked to neoplasia in wild and captive koalas, but there is no treatment available. We tested the KoRV-specific serum immunoglobulin G antibody response in nonimmunized and immunized koalas.

Persistence of hepatitis A virus antibodies after primary immunization and response to revaccination in children and adolescents with perinatal HIV exposure

Science.gov (United States)

Gouvêa, Aída de Fátima Thomé Barbosa; Pinto, Maria Isabel de Moraes; Miyamoto, Maristela; Machado, Daisy Maria; Pessoa, Silvana Duarte; do Carmo, Fabiana Bononi; Beltrão, Suênia Cordeiro de Vasconcelos; Succi, Regina Célia de Menezes

2015-01-01

OBJECTIVE: To assess possible factors associated with the loss of antibodies to hepatitis A 7 years after the primary immunization in children of HIV-infected mothers and the response to revaccination in patients seronegative for hepatitis A. METHODS: Quantification of HAV antibodies by electrochemiluminescence was performed in 39 adolescents followed up at the Pediatric Aids Clinic of Federal University of São Paulo (Unifesp): 29 HIV-infected (HIV group) (median age: 12.8 years) and 10 HIV-exposed but non-infected (ENI group) (median age: 13.4 years). All of them received two doses of HAV vaccine (Havrix(r)) in 2002. RESULTS: The median age at primary immunization (PI) was 5.4 years for HIV group and 6.5 years for ENI group. All children, from both groups, had antibodies to HAV >20 mIU/mL after PI. Seven years later, the ENI group showed a median concentration of antibodies = 253.5 mIU/mL, while the HIV group = 113.0 mIU/mL (Mann-Whitney test, p=0.085). All ENI group and 23/29 (79.3%) from HIV group mantained HAV antibodies 7 years after PI. The levels of hepatitis A antibodies in the primary vaccination were the only factor independently associated with maintaining these antibodies for 7 years. The group that lost HAV seropositivity was revaccinated and 83.3% (5/6) responded with antibodies >20 mUI/mL. CONCLUSIONS: The antibodies levels acquired in the primary vaccination in the HIV group were the main factor associated with antibodies loss after HAV immunization. PMID:25918013

Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route.

Science.gov (United States)

Carey, John B; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V S; Draper, Simon J; Moore, Anne C

2014-08-21

Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP1₄₂, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delivery. Microneedle-mediated vaccine priming and resultant induction of low anti-vector antibody titres permitted repeated use of the same adenovirus vaccine vector. This resulted in significantly increased antigen-specific antibody responses in these mice compared to ID-treated mice. Boosting with a heterologous vaccine; MVA-PyMSP1₄₂ also resulted in significantly greater antibody responses in mice primed with HAdV5-PyMSP1₄₂ using MN compared to the ID route. The highest protection against blood-stage malaria challenge was observed when a heterologous route of immunization (MN/ID) was used. Therefore, microneedle-mediated immunization has potential to both overcome some of the logistic obstacles surrounding needle-and-syringe-based immunization as well as to facilitate the repeated use of the same adenovirus vaccine thereby potentially reducing manufacturing costs of multiple vaccines. This could have important benefits in the clinical ease of use of adenovirus-based immunization strategies.

Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route

Science.gov (United States)

Carey, John B.; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V. S.; Draper, Simon J.; Moore, Anne C.

2014-01-01

Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP142, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delivery. Microneedle-mediated vaccine priming and resultant induction of low anti-vector antibody titres permitted repeated use of the same adenovirus vaccine vector. This resulted in significantly increased antigen-specific antibody responses in these mice compared to ID-treated mice. Boosting with a heterologous vaccine; MVA-PyMSP142 also resulted in significantly greater antibody responses in mice primed with HAdV5-PyMSP142 using MN compared to the ID route. The highest protection against blood-stage malaria challenge was observed when a heterologous route of immunization (MN/ID) was used. Therefore, microneedle-mediated immunization has potential to both overcome some of the logistic obstacles surrounding needle-and-syringe-based immunization as well as to facilitate the repeated use of the same adenovirus vaccine thereby potentially reducing manufacturing costs of multiple vaccines. This could have important benefits in the clinical ease of use of adenovirus-based immunization strategies. PMID:25142082

Impaired Epstein-Barr Virus-Specific Neutralizing Antibody Response during Acute Infectious Mononucleosis Is Coincident with Global B-Cell Dysfunction.

Science.gov (United States)

Panikkar, Archana; Smith, Corey; Hislop, Andrew; Tellam, Nick; Dasari, Vijayendra; Hogquist, Kristin A; Wykes, Michelle; Moss, Denis J; Rickinson, Alan; Balfour, Henry H; Khanna, Rajiv

2015-09-01

Here we present evidence for previously unappreciated B-cell immune dysregulation during acute Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM). Longitudinal analyses revealed that patients with acute IM have undetectable EBV-specific neutralizing antibodies and gp350-specific B-cell responses, which were associated with a significant reduction in memory B cells and no evidence of circulating antibody-secreting cells. These observations correlate with dysregulation of tumor necrosis factor family members BAFF and APRIL and increased expression of FAS on circulating B cells. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Pulmonary biology of anti-interleukin 5 antibodies

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RW Egan

1997-12-01

Full Text Available Interleukin 5 (IL-5 is a critical cytokine for the maturation of eosinophil precursors to eosinophils in the bone marrow and those eosinophils then accumulate in the lungs during asthma. We have studied anti IL-5 antibodies on allergic responses in mice, guinea pigs and monkeys and are extending this experiment into humans with a humanized antibody. In a monkey model of pulmonary inflammation and airway hyperreactivity, we found that the TRFK-5 antibody blocked both responses for three months following a single dose of 0.3 mg/kg, i.v. This antibody also blocked lung eosinophilia in mice by inhibiting release from the bone marrow. To facilitate multiple dosing and to reduce immunogenicity in humans, we prepared Sch 55700, a humanized antibody against IL-5. Sch 55700 was also active against lung eosinophilia in allergic monkeys and mice and against pulmonary eosinophilia and airway hyperresponsiveness in guinea pigs. Furthermore, as opposed to steroids, Sch 55700 did not cause immunosuppression in guinea pigs. Studies with this antibody in humans will be critical to establishing the therapeutic potential of IL-5 inhibition.

Antigenic sites on the HN domain of botulinum neurotoxin A stimulate protective antibody responses against active toxin.

Science.gov (United States)

Ayyar, B Vijayalakshmi; Tajhya, Rajeev B; Beeton, Christine; Atassi, M Zouhair

2015-10-28

Botulinum neurotoxins (BoNTs) are the most toxic substances known. BoNT intoxicates cells in a highly programmed fashion initiated by binding to the cell surface, internalization and enzymatic cleavage of substrate, thus, inhibiting synaptic exocytosis. Over the past two decades, immunological significance of BoNT/A C-terminal heavy chain (HC) and light chain (LC) domains were investigated extensively leading to important findings. In the current work, we explored the significance of BoNT/A heavy chain N-terminal (HN) region as a vaccine candidate. Mice were immunized with recombinant HN519-845 generating antibodies (Abs) that were found to be protective against lethal dose of BoNT/A. Immuno-dominant regions of HN519-845 were identified and individually investigated for antibody response along with synthetic peptides within those regions, using in vivo protection assays against BoNT/A. Results were confirmed by patch-clamp analysis where anti-HN antibodies were studied for the ability to block toxin-induced channel formation. This data strongly indicated that HN519-593 is an important region in generating protective antibodies and should be valuable in a vaccine design. These results are the first to describe and dissect the protective activity of the BoNT/A HN domain.

Performance of high titre attenuated canine parvovirus vaccine in pups with maternally derived antibody.

Science.gov (United States)

Burtonboy, S; Charlier, P; Hertoghs, J; Lobmann, M; Wiseman, A; Woods, S

1991-04-20

The performance of live, attenuated, homologous, canine parvovirus vaccines was studied in 140 puppies aged from four to 11 weeks. In the presence of maternally derived antibody the ability of the vaccines to elicit a serological response, as determined by the haemagglutination inhibition test and a standardised ELISA, was found to be dose (infectious titre) related. An experimental vaccine containing 10(7.0) TCID50 of virus induced seroconversion rates of 95, 89, 82 and 44 per cent in dogs with haemagglutination inhibition antibody titres of less than or equal to 8, 16, 32 and greater than 32, respectively. The standardised ELISA appeared to be better than the haemagglutination inhibition test with respect to variability and subjectivity, especially when titres were low.

Antibody responses of Macaca fascicularis against a new inactivated polio vaccine derived from Sabin strains (sIPV) in DTaP-sIPV vaccine.

Science.gov (United States)

Sato, Y; Shiosaki, K; Goto, Y; Sonoda, K; Kino, Y

2013-05-01

Antibody responses of Macaca fascicularis against a new tetravalent vaccine composed of diphtheria toxoid, tetanus toxoid, acellular pertussis antigens, and inactivated poliovirus derived from Sabin strains (sIPV) was investigated to predict an optimal dose of sIPV in a new tetravalent vaccine (DTaP-sIPV) prior to conducting a dose-defined clinical study. Monkeys were inoculated with DTaP-sIPVs containing three different antigen units of sIPVs: Vaccine A (types 1:2:3 = 3:100:100 DU), Vaccine B (types 1:2:3 = 1.5:50:50 DU), and Vaccine C (types 1:2:3 = 0.75:25:25 DU). There was no difference in the average titers of neutralizing antibody against the attenuated or virulent polioviruses between Vaccines A and B. The average neutralizing antibody titers of Vaccine C tended to be lower than those of Vaccines A and B. The sIPV antigens did not affect the anti-diphtheria or anti-tetanus antibody titers of DTaP-sIPV. Furthermore, the average neutralizing antibody titers of Vaccine A against the attenuated and virulent polioviruses were comparable between M. fascicularis and humans. These results suggest that M. fascicularis may be a useful animal model for predicting the antibody responses to sIPVs in humans, and that it may be likely to reduce the amount of sIPVs contained in DTaP-sIPVs, even for humans. Copyright © 2013 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

The initial antibody response to HIV-1: induction of ineffective early B cell responses against GP41 by the transmitted/founder virus

Energy Technology Data Exchange (ETDEWEB)

Chavez, Leslie L [Los Alamos National Laboratory; Perelson, Alan [Los Alamos National Laboratory

2008-01-01

A window of opportunity for immune responses to extinguish HIV -1 exists from the moment of transmission through establishment of the latent pool of HIV -I-infected cells. A critical time to study the initial immune responses to the transmitted/founder virus is the eclipse phase of HIV-1 infection (time from transmission to the first appearance of plasma virus) but, to date, this period has been logistically difficult to analyze. Studies in non-human primates challenged with chimeric simianhuman immunodeficiency virus have shown that neutralizing antibodies, when present at the time of infection, can prevent virus infection.

Seasonal variations in antibody response to a Plasmodium ...

African Journals Online (AJOL)

An Enzyme Linked Immunosorbent Assay (ELISA), employing a recombinant peptide capture antigen (R32tet32) was used to detect antibodies against the circumsporozoite protein (CSP) of the malaria parasite, Plasmodium falciparum in 169 ...

Genetically engineered multivalent single chain antibody constructs for cancer therapy

International Nuclear Information System (INIS)

Surinder Batra

2006-01-01

increase its tumor: normal tissue ratio for improved therapeutic index, we engineered a variety antibody constructs. These constructs were evaluated using novel approaches like special radionuclides, pretargeting and optimization. Due to the smaller size, the engineered antibody molecules should penetrate better throughout a tumor mass, with less dose heterogeneity, than is the case with intact IgG. Multivalent scFvs with an appropriate radionuclide, therefore, hold promising prospects for cancer therapy and clinical imaging in MAb-based radiopharmaceuticals. In addition, the human anti-mouse antibodies (HAMA) responses in patients against antibody-based therapy are usually directed against the immunoglobulin constant regions; however, anti-idiotypic responses can also be detected. The HAMA responses reduce the efficacy of treatment by removing the circulating antibody molecules, fragments, and possibly scFvs by altering the pharmacokinetic properties of the antibody. HAMA responses against divalent IgG, divalent Ig fragments, and possibly multimeric scFvs could cause immune complex formation with hypersensitivity or allergic reactions that could be harmful to patients. The use of small molecules, such as scFvs (monomeric as well as multimeric), with their shorter biological half-lives and the lack of the constant regions and humanized variable (binding regions) performed in our studies should reduce the development of HAMA. The generation of humanized and fully human scFvs should further reduce the development of HAMA. Specific accomplishments on the project are the production of large amounts of recombinant antibodies as they are required in large amounts for cancer diagnosis and therapy. A variety of single-chain Fv (scFv) constructs were engineered for the desired pharmacokinetic properties. Tetrameric and dimeric scFvs showed a two-fold advantage: (1) there was a considerable gain in avidity as compared to smaller fragments, and (2) the biological half-life was more

A simple method for assessment of human anti-Neu5Gc antibodies applied to Kawasaki disease.

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Vered Padler-Karavani

Full Text Available N-glycolylneuraminic acid (Neu5Gc is an immunogenic sugar of dietary origin that metabolically incorporates into diverse native glycoconjugates in humans. Anti-Neu5Gc antibodies are detected in all human sera, though with variable levels and epitope-recognition profiles. These antibodies likely play a role in several inflammation-mediated pathologies including cardiovascular diseases and cancer. In cancer, they have dualistic and opposing roles, either stimulating or repressing disease, as a function of their dose, and some of these antibodies serve as carcinoma biomarkers. Thus, anti-Neu5Gc antibodies may signify risk of inflammation-mediated diseases, and changes in their levels could potentially be used to monitor disease progression and/or response to therapy. Currently, it is difficult to determine levels of anti-Neu5Gc antibodies in individual human samples because these antibodies recognize multiple Neu5Gc-epitopes. Here we describe a simple and specific method for detection and overall estimation of human anti-Neu5Gc antibodies. We exploit the difference between two mouse models that differ only by Neu5Gc-presence (wild-type or Neu5Gc-absence (Cmah(-/- knockout. We characterize mouse serum from both strains by HPLC, lectin and mass-spectrometry analysis and show the target Neu5Gc-epitopes. We then use Cmah(-/- knockout sera to inhibit all non-Neu5Gc-reactivity followed by binding to wild-type sera to detect overall anti-Neu5Gc response in a single assay. We applied this methodology to characterize and quantify anti-Neu5Gc IgG and IgA in sera of patients with Kawasaki disease (KD at various stages compared to controls. KD is an acute childhood febrile disease characterized by inflammation of coronary arteries that untreated may lead to coronary artery aneurysms with risk of thrombosis and myocardial infarction. This estimated response is comparable to the average of detailed anti-Neu5Gc IgG profile analyzed by a sialoglycan microarray

Binding of HIV-1 gp41-directed neutralizing and non-neutralizing fragment antibody binding domain (Fab and single chain variable fragment (ScFv antibodies to the ectodomain of gp41 in the pre-hairpin and six-helix bundle conformations.

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John M Louis

Full Text Available We previously reported a series of antibodies, in fragment antigen binding domain (Fab formats, selected from a human non-immune phage library, directed against the internal trimeric coiled-coil of the N-heptad repeat (N-HR of HIV-1 gp41. Broadly neutralizing antibodies from that series bind to both the fully exposed N-HR trimer, representing the pre-hairpin intermediate state of gp41, and to partially-exposed N-HR helices within the context of the gp41 six-helix bundle. While the affinities of the Fabs for pre-hairpin intermediate mimetics vary by only 2 to 20-fold between neutralizing and non-neutralizing antibodies, differences in inhibition of viral entry exceed three orders of magnitude. Here we compare the binding of neutralizing (8066 and non-neutralizing (8062 antibodies, differing in only four positions within the CDR-H2 binding loop, in Fab and single chain variable fragment (ScFv formats, to several pre-hairpin intermediate and six-helix bundle constructs of gp41. Residues 56 and 58 of the mini-antibodies are shown to be crucial for neutralization activity. There is a large differential (≥ 150-fold in binding affinity between neutralizing and non-neutralizing antibodies to the six-helix bundle of gp41 and binding to the six-helix bundle does not involve displacement of the outer C-terminal helices of the bundle. The binding stoichiometry is one six-helix bundle to one Fab or three ScFvs. We postulate that neutralization by the 8066 antibody is achieved by binding to a continuum of states along the fusion pathway from the pre-hairpin intermediate all the way to the formation of the six-helix bundle, but prior to irreversible fusion between viral and cellular membranes.

Antigenic specificity of serum antibodies in mice fed soy protein

DEFF Research Database (Denmark)

Christensen, Hanne Risager; Bruun, S.W.; Frøkiær, Hanne

2003-01-01

Background: Soybean protein is used in a number of food products but unfortunately is also a common cause of food allergy. Upon ingestion of soy protein, healthy mice like other animals and humans generate a soy-specific antibody response in the absence of signs of illness. Not much is known about...... the relationship between the immunogenic proteins involved in this nondeleterious antibody response and the pathological response associated with food allergy. The objective of the present study was to characterize the antigenic specificity of the soy protein-specific antibody response generated in healthy mice...... ingesting soy protein. Methods: Blood from mice fed a soy-containing diet was analyzed using ELISA and immunoblot for antibody reactivity towards various soy protein fractions and pure soy proteins/subunits. Mice bred on a soy-free diet were used as controls. Results: The detectable antigenic specificity...

Sensitivity of some Immunoglobulin G class and subclass antibodies ...

African Journals Online (AJOL)

Indirect sandwich enzyme-linked immunosorbent assay (ELISA) was used to measure serum antibody responses in onchocerciasis patients. Apparently, IgG antibody class was more sensitive than IgG1, IgG3 and IgG4 responses to Onchocerca volvulus adult worms sodium duodecyl sulphate (SDS) extracted crude ...

Molecular evolution of broadly neutralizing Llama antibodies to the CD4-binding site of HIV-1.

Science.gov (United States)

McCoy, Laura E; Rutten, Lucy; Frampton, Dan; Anderson, Ian; Granger, Luke; Bashford-Rogers, Rachael; Dekkers, Gillian; Strokappe, Nika M; Seaman, Michael S; Koh, Willie; Grippo, Vanina; Kliche, Alexander; Verrips, Theo; Kellam, Paul; Fassati, Ariberto; Weiss, Robin A

2014-12-01

To date, no immunization of humans or animals has elicited broadly neutralizing sera able to prevent HIV-1 transmission; however, elicitation of broad and potent heavy chain only antibodies (HCAb) has previously been reported in llamas. In this study, the anti-HIV immune responses in immunized llamas were studied via deep sequencing analysis using broadly neutralizing monoclonal HCAbs as a guides. Distinct neutralizing antibody lineages were identified in each animal, including two defined by novel antibodies (as variable regions called VHH) identified by robotic screening of over 6000 clones. The combined application of five VHH against viruses from clades A, B, C and CRF_AG resulted in neutralization as potent as any of the VHH individually and a predicted 100% coverage with a median IC50 of 0.17 µg/ml for the panel of 60 viruses tested. Molecular analysis of the VHH repertoires of two sets of immunized animals showed that each neutralizing lineage was only observed following immunization, demonstrating that they were elicited de novo. Our results show that immunization can induce potent and broadly neutralizing antibodies in llamas with features similar to human antibodies and provide a framework to analyze the effectiveness of immunization protocols.

[Persistence of hepatitis A virus antibodies after primary immunization and response to revaccination in children and adolescents with perinatal HIV exposure].

Science.gov (United States)

Gouvêa, Aída de Fátima Thomé Barbosa; Pinto, Maria Isabel de Moraes; Miyamoto, Maristela; Machado, Daisy Maria; Pessoa, Silvana Duarte; Carmo, Fabiana Bononi do; Beltrão, Suênia Cordeiro de Vasconcelos; Succi, Regina Célia de Menezes

2015-01-01

To assess possible factors associated with the loss of antibodies to hepatitis A 7 years after the primary immunization in children of HIV-infected mothers and the response to revaccination in patients seronegative for hepatitis A. Quantification of HAV antibodies by electrochemiluminescence was performed in 39 adolescents followed up at the Pediatric Aids Clinic of Federal University of São Paulo (Unifesp): 29 HIV-infected (HIVgroup) (median age: 12.8 years) and 10 HIV-exposed but non-infected (ENI group) (median age: 13.4 years). All of them received two doses of HAV vaccine (Havrix(®)) in 2002. The median age at primary immunization (PI) was 5.4 years for HIV group and 6.5 years for ENI group. All children, from both groups, had antibodies to HAV >20 mIU/mL after PI. Seven years later, the ENI group showed a median concentration of antibodies = 253.5 mIU/mL, while the HIV group = 113.0 mIU/mL (Mann-Whitney test, p=0.085). All ENI group and 23/29 (79.3%) from HIV group mantained HAV antibodies 7 years after PI. The levels of hepatitis A antibodies in the primary vaccination were the only factor independently associated with maintaining these antibodies for 7 years. The group that lost HAV seropositivity was revaccinated and 83.3% (5/6) responded with antibodies >20 mUI/mL. The antibodies levels acquired in the primary vaccination in the HIV group were the main factor associated with antibodies loss after HAV immunization. Copyright © 2015 Associação de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

Avian Diagnostic and Therapeutic Antibodies

Energy Technology Data Exchange (ETDEWEB)

Bradley, David Sherman [UND SMHS

2012-12-31

A number of infectious agents have the potential of causing significant clinical symptomology and even death, but dispite this, the number of incidence remain below the level that supports producing a vaccine. Therapeutic antibodies provide a viable treatment option for many of these diseases. We proposed that antibodies derived from West Nile Virus (WNV) immunized geese would be able to treat WNV infection in mammals and potential humans. We demonstrated that WNV specific goose antibodies are indeed successful in treating WNV infection both prophylactically and therapeutically in a golden hamster model. We demonstrated that the goose derived antibodies are non-reactogenic, i.e. do not cause an inflammatory response with multiple exposures in mammals. We also developed both a specific pathogen free facility to house the geese during the antibody production phase and a patent-pending purification process to purify the antibodies to greater than 99% purity. Therefore, the success of these study will allow a cost effective rapidly producible therapeutic toward clinical testing with the necessary infrastructure and processes developed and in place.

Peripheral neuropathies associated with antibodies directed to intracellular neural antigens.

Science.gov (United States)

Antoine, J-C

2014-10-01

Antibodies directed to intracellular neural antigens have been mainly described in paraneoplastic peripheral neuropathies and mostly includes anti-Hu and anti-CV2/CRMP5 antibodies. These antibodies occur with different patterns of neuropathy. With anti-Hu antibody, the most frequent manifestation is sensory neuronopathy with frequent autonomic involvement. With anti-CV2/CRMP5 the neuropathy is more frequently sensory and motor with an axonal or mixed demyelinating and axonal electrophysiological pattern. The clinical pattern of these neuropathies is in keeping with the cellular distribution of HuD and CRMP5 in the peripheral nervous system. Although present in high titer, these antibodies are probably not directly responsible for the neuropathy. Pathological and experimental studies indicate that cytotoxic T-cells are probably the main effectors of the immune response. These disorders contrast with those in which antibodies recognize a cell surface antigen and are probably responsible for the disease. The neuronal cell death and axonal degeneration which result from T-cell mediated immunity explains why treating these disorders remains challenging. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Detection systems for antibody responses against herpes B virus

OpenAIRE

Pöhlmann, Stefan; Krüger, Astrid; Hafezi, Wali; Schneider, Stefan; Gruber, Jens; Winkler, Michael; Kaul, Artur

2017-01-01

Herpes B virus (BV) infection is highly prevalent among adult Asian macaques and rarely causes severe disease in infected animals. In contrast, BV infection of humans can induce fatal encephalitis in the absence of treatment. Therefore, the development of diagnostic tests for specific and sensitive detection of antibodies against BV is an important task. The cross-reactivity of antibodies against BV with related simplex viruses of other primates may afford an opportunity to ...

A Strategy for Generating a Broad-Spectrum Monoclonal Antibody and Soluble Single-Chain Variable Fragments against Plant Potyviruses

Science.gov (United States)

Liu, Han-Lin; Lin, Wei-Fang; Hu, Wen-Chi; Lee, Yung-An

2015-01-01

Potyviruses are major pathogens that often cause mixed infection in calla lilies. To reduce the time and cost of virus indexing, a detection method for the simultaneous targeting of multiple potyviruses was developed by generating a broad-spectrum monoclonal antibody (MAb) for detecting the greatest possible number of potyviruses. The conserved 121-amino-acid core regions of the capsid proteins of Dasheen mosaic potyvirus (DsMV), Konjak mosaic potyvirus (KoMV), and Zantedeschia mild mosaic potyvirus (ZaMMV) were sequentially concatenated and expressed as a recombinant protein for immunization. After hybridoma cell fusion and selection, one stable cell line that secreted a group-specific antibody, named C4 MAb, was selected. In the reaction spectrum test, the C4 MAb detected at least 14 potyviruses by indirect enzyme-linked immunosorbent assay (I-ELISA) and Western blot analysis. Furthermore, the variable regions of the heavy (VH) and light (VL) chains of the C4 MAb were separately cloned and constructed as single-chain variable fragments (scFvs) for expression in Escherichia coli. Moreover, the pectate lyase E (PelE) signal peptide of Erwinia chrysanthemi S3-1 was added to promote the secretion of C4 scFvs into the medium. According to Western blot analysis and I-ELISA, the soluble C4 scFv (VL-VH) fragment showed a binding specificity similar to that of the C4 MAb. Our results demonstrate that a recombinant protein derived from fusion of the conserved regions of viral proteins has the potential to produce a broad-spectrum MAb against a large group of viruses and that the PelE signal peptide can improve the secretion of scFvs in E. coli. PMID:26209665

Glycosylation profiles of therapeutic antibody pharmaceuticals.

Science.gov (United States)

Wacker, Christoph; Berger, Christoph N; Girard, Philippe; Meier, Roger

2011-11-01

Recombinant antibodies specific for human targets are often used as therapeutics and represent a major class of drug products. Their therapeutic efficacy depends on the formation of antibody complexes resulting in the elimination of a target molecule or the modulation of specific signalling pathways. The physiological effects of antibody therapeutics are known to depend on the structural characteristics of the antibody molecule, specifically on the glycosylation which is the result of posttranslational modifications. Hence, production of therapeutic antibodies with a defined and consistent glycoform profile is needed which still remains a considerable challenge to the biopharmaceutical industry. To provide an insight into the industries capability to control their manufacturing process and to provide antibodies of highest quality, we conducted a market surveillance study and compared major oligosaccharide profiles of a number of monoclonal antibody pharmaceuticals sampled on the Swiss market. Product lot-to-lot variability was found to be generally low, suggesting that a majority of manufacturers have implemented high quality standards in their production processes. However, proportions of G0, G1 and G2 core-fucosylated chains derived from different products varied considerably and showed a bias towards the immature agalactosidated G0 form. Interestingly, differences in glycosylation caused by the production cell type seem to be of less importance compared with process related parameters such as cell growth. Copyright © 2011 Elsevier B.V. All rights reserved.

Antibody-independent control of gamma-herpesvirus latency via B cell induction of anti-viral T cell responses.

Directory of Open Access Journals (Sweden)

Kelly B McClellan

2006-06-01

Full Text Available B cells can use antibody-dependent mechanisms to control latent viral infections. It is unknown whether this represents the sole function of B cells during chronic viral infection. We report here that hen egg lysozyme (HEL-specific B cells can contribute to the control of murine gamma-herpesvirus 68 (gammaHV68 latency without producing anti-viral antibody. HEL-specific B cells normalized defects in T cell numbers and proliferation observed in B cell-/- mice during the early phase of gammaHV68 latency. HEL-specific B cells also reversed defects in CD8 and CD4 T cell cytokine production observed in B cell-/- mice, generating CD8 and CD4 T cells necessary for control of latency. Furthermore, HEL-specific B cells were able to present virally encoded antigen to CD8 T cells. Therefore, B cells have antibody independent functions, including antigen presentation, that are important for control of gamma-herpesvirus latency. Exploitation of this property of B cells may allow enhanced vaccine responses to chronic virus infection.

Study of the immune response by antibodies against the Bothrops asper venom for the elaboration of a antiophidic vaccine for bovines

International Nuclear Information System (INIS)

Gonzalez Rojas, Katherine

2014-01-01

Active immunization has determined against Bothrops asper snake venom (tested in murine and bovine models) a induced response by antibody able to prevent in immunized animals. A coagulopathy or death is developed after of be administered with adequate doses of poison. The amount of B. asper venom has defined the poisoning induced in bovine and murine models. The plasmatic concentration of equine antibodies against B. asper venom is specified to prevent coagulopathy and lethality induced by this venom in murine and bovine models. Murine and bovine models have verified the active immunization reached in a concentration of antibodies against B. asper venom equal or greater to the maximum concentration achieved by intravenous administration of antivenoms from equine origin. The concentration of antibodies induced by the active immunization is evaluated against B. asper venom to prevent the development of coagulopathy and lethality induced by the venom in murine and bovine models [es

Eyewitness Accounts on Climate Variability and the Responses: Perspectives from Farmers

Directory of Open Access Journals (Sweden)

Jiban Mani Poudel

2012-06-01

Full Text Available People with different socio-cultural arrangements havedifferent experiences and responses to climatic variability. The place specific experiences and responses at community level still remain a little explored issue in the discourse of climate change research. This paper deals with local experiences of climatic variability which have been monitoring by locals in their lifetime, on the one hand, and, on the other, explore their responses or coping mechanisms which they have been practicing to mitigate with climatic risks. Moreover, farmers’ experiences were documented in term of observed climatic variability in their lifetime focusing on qualitative data. I have used eyewitness accounts and hearsays to document their experiences of climatic variability. Moreover, farmers have developed various coping mechanisms such as indigenous knowledge, utilize kinship based social network, environment friendly cropping practices, and use of alternative sources of water (water-tanker, well-water for irrigation, arrange rain-making ritual to cope with climatic uncertainty in their lifetime.DOI: http://dx.doi.org/10.3126/dsaj.v5i0.6362Dhaulagiri Journal of Sociology and Anthropology Vol. 5, 2011: 171-90

A heterologous prime-boost Ebola virus vaccine regimen induces durable neutralizing antibody response and prevents Ebola virus-like particle entry in mice.

Science.gov (United States)

Chen, Tan; Li, Dapeng; Song, Yufeng; Yang, Xi; Liu, Qingwei; Jin, Xia; Zhou, Dongming; Huang, Zhong

2017-09-01

Ebola virus (EBOV) is one of the most virulent pathogens known to humans. Neutralizing antibodies play a major role in the protection against EBOV infections. Thus, an EBOV vaccine capable of inducing a long-lasting neutralizing antibody response is highly desirable. We report here that a heterologous prime-boost vaccine regimen can elicit durable EBOV-neutralizing antibody response in mice. A chimpanzee serotype 7 adenovirus expressing EBOV GP (denoted AdC7-GP) was generated and used for priming. A truncated version of EBOV GP1 protein (denoted GP1t) was produced at high levels in Drosophila S2 cells and used for boosting. Mouse immunization studies showed that the AdC7-GP prime/GP1t boost vaccine regimen was more potent in eliciting neutralizing antibodies than either the AdC7-GP or GP1t alone. Neutralizing antibodies induced by the heterologous prime-boost regimen sustained at high titers for at least 18 weeks after immunization. Significantly, in vivo challenge studies revealed that the entry of reporter EBOV-like particles was efficiently blocked in mice receiving the heterologous prime-boost regimen even at 18 weeks after the final dose of immunization. These results suggest that this novel AdC7-GP prime/GP1t boost regimen represents an EBOV vaccine approach capable of establishing long-term protection, and therefore warrants further development. Copyright © 2017 Elsevier B.V. All rights reserved.

Augmentation of the antibody response of Atlantic salmon by oral administration of alginate-encapsulated IPNV antigens.

Directory of Open Access Journals (Sweden)

Lihan Chen

Full Text Available The objective of the present study was to assess the effect of alginate-encapsulated infectious pancreatic necrosis virus antigens in inducing the immune response of Atlantic salmon as booster vaccines. One year after intraperitoneal injection with an oil-adjuvanted vaccine, post-smolts were orally boosted either by 1 alginate-encapsulated IPNV antigens (ENCAP; 2 soluble antigens (UNENCAP or 3 untreated feed (control. This was done twice, seven weeks apart. Sampling was done twice, firstly at 7 weeks post 1st oral boost and the 2nd, at 4 weeks after the 2nd oral boost. Samples included serum, head kidney, spleen and hindgut. Serum antibodies were analyzed by ELISA while tissues were used to assess the expression of IgM, IgT, CD4, GATA3, FOXP3, TGF-β and IL-10 genes by quantitative PCR. Compared to controls, fish fed with ENCAP had a significant increase (p<0.04 in serum antibodies following the 1st boost but not after the 2nd boost. This coincided with significant up-regulation of CD4 and GATA3 genes. In contrast, serum antibodies in the UNENCAP group decreased both after the 1st and 2nd oral boosts. This was associated with significant up-regulation of FOXP3, TGF-β and IL-10 genes. The expression of IgT was not induced in the hindgut after the 1st oral boost but was significantly up-regulated following the 2nd one. CD4 and GATA3 mRNA expressions exhibited a similar pattern to IgT in the hindgut. IgM mRNA expression on the other hand was not differentially regulated at any of the times examined. Our findings suggest that 1 Parenteral prime with oil-adjuvanted vaccines followed by oral boost with ENCAP results in augmentation of the systemic immune response; 2 Symmetrical prime and boost (mucosal with ENCAP results in augmentation of mucosal immune response and 3 Symmetrical priming and boosting (mucosal with soluble antigens results in the induction of systemic immune tolerance.

The Variability of Neural Responses to Naturalistic Videos Change with Age and Sex.

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Petroni, Agustin; Cohen, Samantha S; Ai, Lei; Langer, Nicolas; Henin, Simon; Vanderwal, Tamara; Milham, Michael P; Parra, Lucas C

2018-01-01

Neural development is generally marked by an increase in the efficiency and diversity of neural processes. In a large sample ( n = 114) of human children and adults with ages ranging from 5 to 44 yr, we investigated the neural responses to naturalistic video stimuli. Videos from both real-life classroom settings and Hollywood feature films were used to probe different aspects of attention and engagement. For all stimuli, older ages were marked by more variable neural responses. Variability was assessed by the intersubject correlation of evoked electroencephalographic responses. Young males also had less-variable responses than young females. These results were replicated in an independent cohort ( n = 303). When interpreted in the context of neural maturation, we conclude that neural function becomes more variable with maturity, at least during the passive viewing of real-world stimuli.

Mathematical analysis of dengue virus antibody dynamics

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Perera, Sulanie; Perera, SSN

2018-03-01

Dengue is a mosquito borne viral disease causing over 390 million infections worldwide per annum. Even though information on how infection is controlled and eradicated from the body is lacking, antibodies are thought to play a major role in clearing the virus. In this paper, a non-linear conceptual dynamical model with humoral immune response and absorption effect has been proposed for primary dengue infection. We have included the absorption of pathogens into uninfected cells since this effect causes the virus density in the blood to decrease. The time delay that arises in the production of antibodies was accounted and is introduced through a continuous function. The basic reproduction number R0 is computed and a detailed stability analysis is done. Three equilibrium states, namely the infection free equilibrium, no immune equilibrium and the endemic equilibrium were identified and the existence and the stability conditions of these steady states were obtained. Numerical simulations proved the results that were obtained. By establishing the characteristic equation of the model at infection free equilibrium, it was observed that the infection free equilibrium is locally asymptotically stable if R0 1. Stability regions are identified for infection free equilibrium state with respect to the external variables and it is observed as the virus burst rate increases, the stability regions would decrease. These results implied that for higher virus burst rates, other conditions in the body must be strong enough to eliminate the disease completely from the host. The effect of time delay of antibody production on virus dynamics is discussed. It was seen that as the time delay in production of antibodies increases, the time for viral decline also increased. Also it was observed that the virus count goes to negligible levels within 7 - 14 days after the onset of symptoms as seen in dengue infections.

Characterization of isotypes of antibody response against leishmania parasite