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Sample records for hiv virus-like particles

  1. Virus-like-vaccines against HIV

    DEFF Research Database (Denmark)

    Andersson, Anne Marie C.; Schwerdtfeger, Melanie; Holst, Peter J.

    2018-01-01

    Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus-like-particle (......Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus...... of HIV. Such vaccines are immunologically perceived as viruses, as they infect cells and produce VLPs in situ, but they only resemble viruses, as the replication defective vectors and VLPs cannot propagate an infection. The inherent safety of such a platform, despite robust particle production...

  2. Effect of HIV-1 envelope cytoplasmic tail on adenovirus primed virus encoded virus-like particle immunizations

    DEFF Research Database (Denmark)

    Andersson, Anne Marie C; Ragonnaud, Emeline; Seaton, Kelly E.

    2016-01-01

    were found between the different priming regimens as both induced high titered tier 1 neutralizing antibodies, but no tier 2 antibodies, possibly reflecting the similar presentation of trimer specific antibody epitopes. The described vaccine regimens provide insight into the effects of the HIV-1 Env......The low number of envelope (Env) spikes presented on native HIV-1 particles is a major impediment for HIV-1 prophylactic vaccine development. We designed virus-like particle encoding adenoviral vectors utilizing SIVmac239 Gag as an anchor for full length and truncated HIV-1 M consensus Env...

  3. Selective elimination of HIV-1-infected cells by Env-directed, HIV-1-based virus-like particles

    International Nuclear Information System (INIS)

    Peretti, Silvia; Schiavoni, Ilaria; Pugliese, Katherina; Federico, Maurizio

    2006-01-01

    We recently showed that both replicating and resting cells cultivated with ganciclovir (GCV) were killed when challenged with vesicular stomatitis virus G glycoprotein pseudotyped HIV-1-based virus-like particles (VLPs) carrying the Nef7 (i.e., an HIV-1 Nef mutant incorporating in virions at high levels)/herpes simplex virus-1 thymidine kinase (HSV-TK) fusion product. On this basis, a novel anti-HIV therapeutic approach based on Nef7/TK VLPs expressing X4 or R5 HIV cell receptor complexes has been attempted. We here report that (CD4-CXCR4) and (CD4-CCR5) Nef7-based VLPs efficiently enter cells infected by X4- or R5-tropic HIV-1 strains, respectively. Importantly, the delivery of the VLP-associated Nef7/TK led to cell death upon GCV treatment. Of interest, VLPs were effective also against non-replicating, HIV-1-infected primary human monocyte-derived macrophages. HIV-targeted VLPs represent a promising candidate for the treatment of persistently HIV-1-infected cells that are part of virus reservoirs resistant to HAART therapies

  4. HIV-specific humoral and cellular immunity in rabbits vaccinated with recombinant human immunodeficiency virus-like gag-env particles

    International Nuclear Information System (INIS)

    Haffar, O.K.; Smithgall, M.D.; Moran, P.A.; Travis, B.M.; Zarling, J.M.; Hu, S.L.

    1991-01-01

    Recombinant human immunodeficiency virus type-1 (HIV-1)-like gag-env particles produced in mammalian cells were inoculated into two New Zealand white rabbits. In parallel, two control rabbits were inoculated with the homologous HIV-1 virions inactivated by ultraviolet light (uv) and psoralen treatments. The humoral and cellular immune responses to HIV-1 were evaluated for both groups of animals. Recombinant particles elicited humoral immunity that was specific for all the viral structural proteins. The antibodies recognized both denatured and nondenatured proteins. Moreover, the sera neutralized the in vitro infectivity of the homologous virus in CEM cells. Importantly, the recombinant particles also generated a T helper response by priming with the HIV proteins. Similar results were observed with inactivated virus immunization. Therefore, the authors results suggest that the recombinant HIV-like particles elicit functional humoral immunity as well as cellular immunity and represent a novel vaccine candidate for AIDS

  5. Virus-Like-Vaccines against HIV.

    Science.gov (United States)

    Andersson, Anne-Marie C; Schwerdtfeger, Melanie; Holst, Peter J

    2018-02-11

    Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus-like-particle (VLP) vaccines have emerged as potent inducers of antibody and helper T cell responses, while replication-deficient viral vectors have yielded potent cytotoxic T cell responses. Here, we review the emerging concept of merging these two technologies into virus-like-vaccines (VLVs) for the targeting of HIV. Such vaccines are immunologically perceived as viruses, as they infect cells and produce VLPs in situ, but they only resemble viruses, as the replication defective vectors and VLPs cannot propagate an infection. The inherent safety of such a platform, despite robust particle production, is a distinct advantage over live-attenuated vaccines that must balance safety and immunogenicity. Previous studies have delivered VLVs encoded in modified Vaccinia Ankara vectors and we have developed the concept into a single-reading adenovirus-based technology capable of eliciting robust CD8⁺ and CD4⁺ T cells responses and trimer binding antibody responses. Such vaccines offer the potential to display the naturally produced immunogen directly and induce an integrated humoral and cellular immune response.

  6. Live attenuated measles vaccine expressing HIV-1 Gag virus like particles covered with gp160ΔV1V2 is strongly immunogenic

    International Nuclear Information System (INIS)

    Guerbois, Mathilde; Moris, Arnaud; Combredet, Chantal; Najburg, Valerie; Ruffie, Claude; Fevrier, Michele; Cayet, Nadege; Brandler, Samantha; Schwartz, Olivier; Tangy, Frederic

    2009-01-01

    Although a live attenuated HIV vaccine is not currently considered for safety reasons, a strategy inducing both T cells and neutralizing antibodies to native assembled HIV-1 particles expressed by a replicating virus might mimic the advantageous characteristics of live attenuated vaccine. To this aim, we generated a live attenuated recombinant measles vaccine expressing HIV-1 Gag virus-like particles (VLPs) covered with gp160ΔV1V2 Env protein. The measles-HIV virus replicated efficiently in cell culture and induced the intense budding of HIV particles covered with Env. In mice sensitive to MV infection, this recombinant vaccine stimulated high levels of cellular and humoral immunity to both MV and HIV with neutralizing activity. The measles-HIV virus infected human professional antigen-presenting cells, such as dendritic cells and B cells, and induced efficient presentation of HIV-1 epitopes and subsequent activation of human HIV-1 Gag-specific T cell clones. This candidate vaccine will be next tested in non-human primates. As a pediatric vaccine, it might protect children and adolescents simultaneously from measles and HIV.

  7. A heterologous prime-boosting strategy with replicating Vaccinia virus vectors and plant-produced HIV-1 Gag/dgp41 virus-like particles

    Energy Technology Data Exchange (ETDEWEB)

    Meador, Lydia R. [Ira A. Fulton School of Engineering, Arizona State University, Tempe, AZ (United States); Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ (United States); Kessans, Sarah A. [Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ (United States); School of Life Sciences, Arizona State University, Tempe, AZ (United States); Kilbourne, Jacquelyn; Kibler, Karen V. [Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ (United States); Pantaleo, Giuseppe [Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne (Switzerland); Swiss Vaccine Research Institute, Lausanne (Switzerland); Roderiguez, Mariano Esteban [Department of Molecular and Cellular Biology, Centro Nacional de Biotecnologia – CSIC, Madrid (Spain); Blattman, Joseph N. [Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ (United States); School of Life Sciences, Arizona State University, Tempe, AZ (United States); Jacobs, Bertram L., E-mail: bjacobs@asu.edu [Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ (United States); School of Life Sciences, Arizona State University, Tempe, AZ (United States); Mor, Tsafrir S., E-mail: tsafrir.mor@asu.edu [Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ (United States); School of Life Sciences, Arizona State University, Tempe, AZ (United States)

    2017-07-15

    Showing modest efficacy, the RV144 HIV-1 vaccine clinical trial utilized a non-replicating canarypox viral vector and a soluble gp120 protein boost. Here we built upon the RV144 strategy by developing a novel combination of a replicating, but highly-attenuated Vaccinia virus vector, NYVAC-KC, and plant-produced HIV-1 virus-like particles (VLPs). Both components contained the full-length Gag and a membrane anchored truncated gp41 presenting the membrane proximal external region with its conserved broadly neutralizing epitopes in the pre-fusion conformation. We tested different prime/boost combinations of these components in mice and showed that the group primed with NYVAC-KC and boosted with both the viral vectors and plant-produced VLPs have the most robust Gag-specific CD8 T cell responses, at 12.7% of CD8 T cells expressing IFN-γ in response to stimulation with five Gag epitopes. The same immunization group elicited the best systemic and mucosal antibody responses to Gag and dgp41 with a bias towards IgG1. - Highlights: • We devised a prime/boost anti HIV-1 vaccination strategy modeled after RV144. • We used plant-derived virus-like particles (VLPs) consisting of Gag and dgp41. • We used attenuated, replicating vaccinia virus vectors expressing the same antigens. • The immunogens elicited strong cellular and humoral immune responses.

  8. Co-expression of HIV-1 virus-like particles and granulocyte-macrophage colony stimulating factor by GEO-D03 DNA vaccine

    Science.gov (United States)

    Hellerstein, Michael; Xu, Yongxian; Marino, Tracie; Lu, Shan; Yi, Hong; Wright, Elizabeth R.; Robinson, Harriet L.

    2012-01-01

    Here, we report on GEO-D03, a DNA vaccine that co-expresses non-infectious HIV-1 virus-like particles (VLPs) and the human cytokine, granulocyte-macrophage colony-stimulating factor (GM-CSF). The virus-like particles display the native gp160 form of the HIV-1 Envelope glycoprotein (Env) and are designed to elicit antibody against the natural form of Env on virus and virus-infected cells. The DNA-expressed HIV Gag, Pol and Env proteins also have the potential to elicit virus-specific CD4 and CD8 T cells. The purpose of the co-expressed GM-CSF is to target a cytokine that recruits, expands and differentiates macrophages and dendritic cells to the site of VLP expression. The GEO-D03 DNA vaccine is currently entered into human trials as a prime for a recombinant modified vaccinia Ankara (MVA) boost. In preclinical studies in macaques using an SIV prototype vaccine, this vaccination regimen elicited both anti-viral T cells and antibody, and provided 70% protection against acquisition during 12 weekly rectal exposures with a heterologous SIV. Higher avidity of the Env-specific Ab for the native form of the Env in the challenge virus correlated with lower likelihood of SIV infection. PMID:23111169

  9. Immunogenicity and efficacy of immunodeficiency virus-like particles pseudotyped with the G protein of vesicular stomatitis virus

    International Nuclear Information System (INIS)

    Kuate, Seraphin; Stahl-Hennig, Christiane; Stoiber, Heribert; Nchinda, Godwin; Floto, Anja; Franz, Monika; Sauermann, Ulrike; Bredl, Simon; Deml, Ludwig; Ignatius, Ralf; Norley, Steve; Racz, Paul; Tenner-Racz, Klara; Steinman, Ralph M.; Wagner, Ralf; Uberla, Klaus

    2006-01-01

    Vaccination with exogenous antigens such as recombinant viral proteins, immunodeficiency virus-derived whole inactivated virus particles, or virus-like particles (VLP) has generally failed to provide sufficient protection in animal models for AIDS. Pseudotyping VLPs with the vesicular stomatitis virus G protein (VSV-G), which is known to mediate entry into dendritic cells, might allow more efficient stimulation of immune responses. Therefore, we pseudotyped noninfectious immunodeficiency virus-like particles with VSV-G and carried out a preliminary screen of their immunogenicity and vaccination efficacy. Incorporation of VSV-G into HIV-1 VLPs led to hundred-fold higher antibody titers to HIV-1 Gag and enhancement of T cell responses in mice. Repeated vaccination of rhesus monkeys for 65 weeks with VSV-G pseudotyped simian immunodeficiency virus (SIV)-like particles (VLP[G]) provided initial evidence for efficient suppression of viral load after mucosal challenge with the SIVmac239 virus. Challenge of monkeys after a 28 week vaccination regimen with VLP[G] led to a reduction in peak viremia, but persistent suppression of viral load was not achieved. Due to limitations in the number of animals available for this study, improved efficacy of VSV-G pseudotyped VLPs in nonhuman primates could not be demonstrated. However, mouse experiments revealed that pseudotyping of VLPs with fusion-competent VSV-G clearly improves their immunogenicity. Additional strategies, particularly adjuvants, should be considered to provide greater protection against a challenge with pathogenic immunodeficiency virus

  10. Generation and characterization of a stable cell population releasing fluorescent HIV-1-based Virus Like Particles in an inducible way

    Directory of Open Access Journals (Sweden)

    Bosch Valerie

    2006-12-01

    Full Text Available Abstract Background The availability of cell lines releasing fluorescent viral particles can significantly support a variety of investigations, including the study of virus-cell interaction and the screening of antiviral compounds. Regarding HIV-1, the recovery of such biologic reagents represents a very hard challenge due to the intrinsic cytotoxicity of many HIV-1 products. We sought to overcome such a limitation by using a cell line releasing HIV-1 particles in an inducible way, and by exploiting the ability of a HIV-1 Nef mutant to be incorporated in virions at quite high levels. Results Here, we report the isolation and characterization of a HIV-1 packaging cell line, termed 18-4s, able to release valuable amounts of fluorescent HIV-1 based Virus-Like Particles (VLPs in an inducible way. 18-4s cells were recovered by constitutively expressing the HIV-1 NefG3C mutant fused with the enhanced-green fluorescent protein (NefG3C-GFP in a previously isolated inducible HIV-1 packaging cell line. The G3C mutation creates a palmitoylation site which results in NefG3C-GFP incorporation into virions greatly exceeding that of the wild type counterpart. Upon induction of 18-4s cells with ponasterone A and sodium butyrate, up to 4 μg/ml of VLPs, which had incorporated about 150 molecules of NefG3C-GFP per viral particle, were released into the culture supernatant. Due to their intrinsic strong fluorescence, the 18-4s VLPs were easily detectable by a novel cytofluorometric-based assay developed here. The treatment of target cells with fluorescent 18-4 VLPs pseudotyped with different glycoprotein receptors resulted in these becoming fluorescent as early as two hours post-challenge. Conclusion We created a stable cell line releasing fluorescent HIV-1 based VLPs upon induction useful for several applications including the study of virus-cell interactions and the screening of antiviral compounds.

  11. Virus-like particles as nanovaccine candidates

    International Nuclear Information System (INIS)

    Guillen, G; Aguilar, J C; Dueñas, S; Hermida, L; Iglesias, E; Penton, E; Lobaina, Y; Lopez, M; Mussachio, A; Falcon, V; Alvarez, L; Martinez, G; Gil, L; Valdes, I; Izquierdo, A; Lazo, L; Marcos, E; Guzman, G; Muzio, V; Herrera, L

    2013-01-01

    The existing vaccines are mainly limited to the microorganisms we are able to culture and produce and/or to those whose killing is mediated by humoral response (antibody mediated). It has been more difficult to develop vaccines capable of inducing a functional cellular response needed to prevent or cure chronic diseases. New strategies should be taken into account in the improvement of cell-based immune responses in order to prevent and control the infections and eventually clear the virus. Preclinical and clinical results with vaccine candidates developed as a vaccine platform based on virus-like particles (VLPs) evidenced their ability to stimulate mucosal as well as systemic immunity. Particles based on envelope, membrane or nucleocapsid microbial proteins induce a strong immune response after nasal or parenteral administration in mice, non-human primates and humans. In addition, the immune response obtained was modulated in a Th1 sense. The VLPs were also able to immunoenhance the humoral and cellular immune responses against several viral pathogens. Studies in animals and humans with nasal and systemic formulations evidenced that it is possible to induce functional immune response against HBV, HCV, HIV and dengue virus. (paper)

  12. Particle-based vaccines for HIV-1 infection.

    Science.gov (United States)

    Young, Kelly R; Ross, Ted M

    2003-06-01

    The use of live-attenuated viruses as vaccines has been successful for the control of viral infections. However, the development of an effective vaccine against the human immunodeficiency virus (HIV) has proven to be a challenge. HIV infects cells of the immune system and results in a severe immunodeficiency. In addition, the ability of the virus to adapt to immune pressure and the ability to reside in an integrated form in host cells present hurdles for vaccinologists to overcome. A particle-based vaccine strategy has promise for eliciting high titer, long-lived, immune responses to a diverse number of viral epitopes from different HIV antigens. Live-attenuated viruses are effective at generating both cellular and humoral immunity, however, a live-attenuated vaccine for HIV is problematic. The possibility of a live-attenuated vaccine to revert to a pathogenic form or recombine with a wild-type or defective virus in an infected individual is a drawback to this approach. Therefore, these vaccines are currently only being tested in non-human primate models. Live-attenuated vaccines are effective in stimulating immunity, however challenged animals rarely clear viral infection and the degree of attenuation directly correlates with the protection of animals from disease. Another particle-based vaccine approach for HIV involves the use of virus-like particles (VLPs). VLPs mimic the viral particle without causing an immunodeficiency disease. HIV-like particles (HIV-LP) are defined as self-assembling, non-replicating, nonpathogenic, genomeless particles that are similar in size and conformation to intact virions. A variety of VLPs for both HIV and SIV are currently in pre-clinical and clinical trials. This review focuses on the current knowledge regarding the immunogenicity and safety of particle-based vaccine strategies for HIV-1.

  13. CCL28 induces mucosal homing of HIV-1-specific IgA-secreting plasma cells in mice immunized with HIV-1 virus-like particles.

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    Veronica Rainone

    Full Text Available Mucosae-associated epithelial chemokine (MEC or CCL28 binds to CCR3 and CCR10 and recruits IgA-secreting plasma cells (IgA-ASCs in the mucosal lamina propria. The ability of this chemokine to enhance migration of IgA-ASCs to mucosal sites was assessed in a mouse immunization model using HIV-1(IIIB Virus-like particles (VLPs. Mice receiving either HIV-1(IIIB VLPs alone, CCL28 alone, or the irrelevant CCL19 chemokine were used as controls. Results showed a significantly increased CCR3 and CCR10 expression on CD19(+ splenocytes of HIV-1(IIIB VPL-CCL28-treated mice. HIV-1 Env-specific IFN-γ, IL-4 and IL-5 production, total IgA, anti-Env IgA as well as gastro-intestinal mucosal IgA-secreting plasma cells were also significantly augmented in these mice. Notably, sera and vaginal secretions from HIV-1(IIIB VLP-CCL28-treated mice exhibited an enhanced neutralizing activity against both a HIV-1/B-subtype laboratory strain and a heterologous HIV-1/C-subtype primary isolate. These data suggest that CCL28 could be useful in enhancing the IgA immune response that will likely play a pivotal role in prophylactic HIV vaccines.

  14. Human immunodeficiency virus-like particles activate multiple types of immune cells

    International Nuclear Information System (INIS)

    Sailaja, Gangadhara; Skountzou, Ioanna; Quan, Fu-Shi; Compans, Richard W.; Kang, Sang-Moo

    2007-01-01

    The rapid spread of human immunodeficiency virus (HIV) worldwide makes it a high priority to develop an effective vaccine. Since live attenuated or inactivated HIV is not likely to be approved as a vaccine due to safety concerns, HIV virus like particles (VLPs) offer an attractive alternative because they are safe due to the lack of a viral genome. Although HIV VLPs have been shown to induce humoral and cellular immune responses, it is important to understand the mechanisms by which they induce such responses and to improve their immunogenicity. We generated HIV VLPs, and VLPs containing Flt3 ligand (FL), a dendritic cell growth factor, to target VLPs to dendritic cells, and investigated the roles of these VLPs in the initiation of adaptive immune responses in vitro and in vivo. We found that HIV-1 VLPs induced maturation of dendritic cells and monocyte/macrophage populations in vitro and in vivo, with enhanced expression of maturation markers and cytokines. Dendritic cells pulsed with VLPs induced activation of splenocytes resulting in increased production of cytokines. VLPs containing FL were found to increase dendritic cells and monocyte/macrophage populations in the spleen when administered to mice. Administration of VLPs induced acute activation of multiple types of cells including T and B cells as indicated by enhanced expression of the early activation marker CD69 and down-regulation of the homing receptor CD62L. VLPs containing FL were an effective form of antigen in activating immune cells via dendritic cells, and immunization with HIV VLPs containing FL resulted in enhanced T helper type 2-like immune responses

  15. Double-labelled HIV-1 particles for study of virus-cell interaction

    International Nuclear Information System (INIS)

    Lampe, Marko; Briggs, John A.G.; Endress, Thomas; Glass, Baerbel; Riegelsberger, Stefan; Kraeusslich, Hans-Georg; Lamb, Don C.; Braeuchle, Christoph; Mueller, Barbara

    2007-01-01

    Human immunodeficiency virus (HIV) delivers its genome to a host cell through fusion of the viral envelope with a cellular membrane. While the viral and cellular proteins involved in entry have been analyzed in detail, the dynamics of virus-cell fusion are largely unknown. Single virus tracing (SVT) provides the unique opportunity to visualize viral particles in real time allowing direct observation of the dynamics of this stochastic process. For this purpose, we developed a double-coloured HIV derivative carrying a green fluorescent label attached to the viral matrix protein combined with a red label fused to the viral Vpr protein designed to distinguish between complete virions and subviral particles lacking MA after membrane fusion. We present here a detailed characterization of this novel tool together with exemplary live cell imaging studies, demonstrating its suitability for real-time analyses of HIV-cell interaction

  16. A novel self-replicating chimeric lentivirus-like particle.

    Science.gov (United States)

    Jurgens, Christy K; Young, Kelly R; Madden, Victoria J; Johnson, Philip R; Johnston, Robert E

    2012-01-01

    Successful live attenuated vaccines mimic natural exposure to pathogens without causing disease and have been successful against several viruses. However, safety concerns prevent the development of attenuated human immunodeficiency virus (HIV) as a vaccine candidate. If a safe, replicating virus vaccine could be developed, it might have the potential to offer significant protection against HIV infection and disease. Described here is the development of a novel self-replicating chimeric virus vaccine candidate that is designed to provide natural exposure to a lentivirus-like particle and to incorporate the properties of a live attenuated virus vaccine without the inherent safety issues associated with attenuated lentiviruses. The genome from the alphavirus Venezuelan equine encephalitis virus (VEE) was modified to express SHIV89.6P genes encoding the structural proteins Gag and Env. Expression of Gag and Env from VEE RNA in primate cells led to the assembly of particles that morphologically and functionally resembled lentivirus virions and that incorporated alphavirus RNA. Infection of CD4⁺ cells with chimeric lentivirus-like particles was specific and productive, resulting in RNA replication, expression of Gag and Env, and generation of progeny chimeric particles. Further genome modifications designed to enhance encapsidation of the chimeric virus genome and to express an attenuated simian immunodeficiency virus (SIV) protease for particle maturation improved the ability of chimeric lentivirus-like particles to propagate in cell culture. This study provides proof of concept for the feasibility of creating chimeric virus genomes that express lentivirus structural proteins and assemble into infectious particles for presentation of lentivirus immunogens in their native and functional conformation.

  17. Heterologous prime-boost vaccination with DNA and MVA vaccines, expressing HIV-1 subtype C mosaic Gag virus-like particles, is highly immunogenic in mice.

    Directory of Open Access Journals (Sweden)

    Ros Chapman

    Full Text Available In an effort to make affordable vaccines suitable for the regions most affected by HIV-1, we have constructed stable vaccines that express an HIV-1 subtype C mosaic Gag immunogen (BCG-GagM, MVA-GagM and DNA-GagM. Mosaic immunogens have been designed to address the tremendous diversity of this virus. Here we have shown that GagM buds from cells infected and transfected with MVA-GagM and DNA-GagM respectively and forms virus-like particles. Previously we showed that a BCG-GagM prime MVA-GagM boost generated strong cellular immune responses in mice. In this study immune responses to the DNA-GagM and MVA-GagM vaccines were evaluated in homologous and heterologous prime-boost vaccinations. The DNA homologous prime boost vaccination elicited predominantly CD8+ T cells while the homologous MVA vaccination induced predominantly CD4+ T cells. A heterologous DNA-GagM prime MVA-GagM boost induced strong, more balanced Gag CD8+ and CD4+ T cell responses and that were predominantly of an effector memory phenotype. The immunogenicity of the mosaic Gag (GagM was compared to a naturally occurring subtype C Gag (GagN using a DNA homologous vaccination regimen. DNA-GagN expresses a natural Gag with a sequence that was closest to the consensus sequence of subtype C viruses sampled in South Africa. DNA-GagM homologous vaccination induced cumulative HIV-1 Gag-specific IFN-γ ELISPOT responses that were 6.5-fold higher than those induced by the DNA-GagN vaccination. Similarly, DNA-GagM vaccination generated 7-fold higher levels of cytokine-positive CD8+ T cells than DNA-GagN, indicating that this subtype C mosaic Gag elicits far more potent immune responses than a consensus-type Gag. Cells transfected and infected with DNA-GagM and MVA-GagM respectively, expressed high levels of GagM and produced budding virus-like particles. Our data indicates that a heterologous prime boost regimen using DNA and MVA vaccines expressing HIV-1 subtype C mosaic Gag is highly

  18. ESCRT-independent budding of HIV-1 gag virus-like particles from Saccharomyces cerevisiae spheroplasts.

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    Andrew P Norgan

    Full Text Available Heterologous expression of HIV-1 Gag in a variety of host cells results in its packaging into virus-like particles (VLPs that are subsequently released into the extracellular milieu. This phenomenon represents a useful tool for probing cellular factors required for viral budding and has contributed to the discovery of roles for ubiquitin ligases and the endosomal sorting complexes required for transport (ESCRTs in viral budding. These factors are highly conserved throughout eukaryotes and have been studied extensively in the yeast Saccharomyces cerevisiae, a model eukaryote previously utilized as a host for the production of VLPs. We used heterologous expression of HIV Gag in yeast spheroplasts to examine the role of ESCRTs and associated factors (Rsp5, a HECT ubiquitin ligase of the Nedd4 family; Bro1, a homolog of Alix; and Vps4, the AAA-ATPase required for ESCRT function in all contexts/organisms investigated in the generation of VLPs. Our data reveal: 1 characterized Gag-ESCRT interaction motifs (late domains are not required for VLP budding, 2 loss of function alleles of the essential HECT ubiquitin ligase Rsp5 do not display defects in VLP formation, and 3 ESCRT function is not required for VLP formation from spheroplasts. These results suggest that the egress of HIV Gag from yeast cells is distinct from the most commonly described mode of exit from mammalian cells, instead mimicking ESCRT-independent VLP formation observed in a subset of mammalian cells. As such, budding of Gag from yeast cells appears to represent ESCRT-independent budding relevant to viral replication in at least some situations. Thus the myriad of genetic and biochemical tools available in the yeast system may be of utility in the study of this aspect of viral budding.

  19. Vaccine potential of Nipah virus-like particles.

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    Pramila Walpita

    2011-04-01

    Full Text Available Nipah virus (NiV was first recognized in 1998 in a zoonotic disease outbreak associated with highly lethal febrile encephalitis in humans and a predominantly respiratory disease in pigs. Periodic deadly outbreaks, documentation of person-to-person transmission, and the potential of this virus as an agent of agroterror reinforce the need for effective means of therapy and prevention. In this report, we describe the vaccine potential of NiV virus-like particles (NiV VLPs composed of three NiV proteins G, F and M. Co-expression of these proteins under optimized conditions resulted in quantifiable amounts of VLPs with many virus-like/vaccine desirable properties including some not previously described for VLPs of any paramyxovirus: The particles were fusogenic, inducing syncytia formation; PCR array analysis showed NiV VLP-induced activation of innate immune defense pathways; the surface structure of NiV VLPs imaged by cryoelectron microscopy was dense, ordered, and repetitive, and consistent with similarly derived structure of paramyxovirus measles virus. The VLPs were composed of all the three viral proteins as designed, and their intracellular processing also appeared similar to NiV virions. The size, morphology and surface composition of the VLPs were consistent with the parental virus, and importantly, they retained their antigenic potential. Finally, these particles, formulated without adjuvant, were able to induce neutralizing antibody response in Balb/c mice. These findings indicate vaccine potential of these particles and will be the basis for undertaking future protective efficacy studies in animal models of NiV disease.

  20. Virus like particle-based vaccines against emerging infectious disease viruses.

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    Liu, Jinliang; Dai, Shiyu; Wang, Manli; Hu, Zhihong; Wang, Hualin; Deng, Fei

    2016-08-01

    Emerging infectious diseases are major threats to human health. Most severe viral disease outbreaks occur in developing regions where health conditions are poor. With increased international travel and business, the possibility of eventually transmitting infectious viruses between different countries is increasing. The most effective approach in preventing viral diseases is vaccination. However, vaccines are not currently available for numerous viral diseases. Virus-like particles (VLPs) are engineered vaccine candidates that have been studied for decades. VLPs are constructed by viral protein expression in various expression systems that promote the selfassembly of proteins into structures resembling virus particles. VLPs have antigenicity similar to that of the native virus, but are non-infectious as they lack key viral genetic material. VLP vaccines have attracted considerable research interest because they offer several advantages over traditional vaccines. Studies have shown that VLP vaccines can stimulate both humoral and cellular immune responses, which may offer effective antiviral protection. Here we review recent developments with VLP-based vaccines for several highly virulent emerging or re-emerging infectious diseases. The infectious agents discussed include RNA viruses from different virus families, such as the Arenaviridae, Bunyaviridae, Caliciviridae, Coronaviridae, Filoviridae, Flaviviridae, Orthomyxoviridae, Paramyxoviridae, and Togaviridae families.

  1. Enveloped virus-like particles as vaccines against pathogenic arboviruses

    NARCIS (Netherlands)

    Pijlman, G.P.

    2015-01-01

    Arthropod-borne arboviruses form a continuous threat to human and animal health, but few arboviral vaccines are currently available. Advances in expression technology for complex, enveloped virus-like particles (eVLPs) create new opportunities to develop potent vaccines against pathogenic

  2. Zika virus-like particle (VLP) based vaccine

    Science.gov (United States)

    Boigard, Hélène; Alimova, Alexandra; Martin, George R.; Katz, Al; Gottlieb, Paul

    2017-01-01

    The newly emerged mosquito-borne Zika virus poses a major public challenge due to its ability to cause significant birth defects and neurological disorders. The impact of sexual transmission is unclear but raises further concerns about virus dissemination. No specific treatment or vaccine is currently available, thus the development of a safe and effective vaccine is paramount. Here we describe a novel strategy to assemble Zika virus-like particles (VLPs) by co-expressing the structural (CprME) and non-structural (NS2B/NS3) proteins, and demonstrate their effectiveness as vaccines. VLPs are produced in a suspension culture of mammalian cells and self-assembled into particles closely resembling Zika viruses as shown by electron microscopy studies. We tested various VLP vaccines and compared them to analogous compositions of an inactivated Zika virus (In-ZIKV) used as a reference. VLP immunizations elicited high titers of antibodies, as did the In-ZIKV controls. However, in mice the VLP vaccine stimulated significantly higher virus neutralizing antibody titers than comparable formulations of the In-ZIKV vaccine. The serum neutralizing activity elicited by the VLP vaccine was enhanced using a higher VLP dose and with the addition of an adjuvant, reaching neutralizing titers greater than those detected in the serum of a patient who recovered from a Zika infection in Brazil in 2015. Discrepancies in neutralization levels between the VLP vaccine and the In-ZIKV suggest that chemical inactivation has deleterious effects on neutralizing epitopes within the E protein. This along with the inability of a VLP vaccine to cause infection makes it a preferable candidate for vaccine development. PMID:28481898

  3. Production of Novel Ebola Virus-Like Particles from cDNAs: an Alternative to Ebola Virus Generation by Reverse Genetics

    OpenAIRE

    Watanabe, Shinji; Watanabe, Tokiko; Noda, Takeshi; Takada, Ayato; Feldmann, Heinz; Jasenosky, Luke D.; Kawaoka, Yoshihiro

    2004-01-01

    We established a plasmid-based system for generating infectious Ebola virus-like particles (VLPs), which contain an Ebola virus-like minigenome consisting of a negative-sense copy of the green fluorescent protein gene. This system produced nearly 103 infectious particles per ml of supernatant, equivalent to the titer of Ebola virus generated by a reverse genetics system. Interestingly, infectious Ebola VLPs were generated, even without expression of VP24. Transmission and scanning electron mi...

  4. Feasibility of Cowpea chlorotic mottle virus-like particles as scaffold for epitope presentations

    NARCIS (Netherlands)

    Hassani-Mehraban, A.; Creutzburg, S.; Heereveld, van L.; Kormelink, R.J.M.

    2015-01-01

    Within the last decade Virus-Like Particles (VLPs) have increasingly received attention from scientists for their use as a carrier of (peptide) molecules or as scaffold to present epitopes for use in subunit vaccines. To test the feasibility of Cowpea chlorotic mottle virus (CCMV) particles as a

  5. Dengue virus-like particles mimic the antigenic properties of the infectious dengue virus envelope.

    Science.gov (United States)

    Metz, Stefan W; Thomas, Ashlie; White, Laura; Stoops, Mark; Corten, Markus; Hannemann, Holger; de Silva, Aravinda M

    2018-04-02

    The 4 dengue serotypes (DENV) are mosquito-borne pathogens that are associated with severe hemorrhagic disease. DENV particles have a lipid bilayer envelope that anchors two membrane glycoproteins prM and E. Two E-protein monomers form head-to-tail homodimers and three E-dimers align to form "rafts" that cover the viral surface. Some human antibodies that strongly neutralize DENV bind to quaternary structure epitopes displayed on E protein dimers or higher order structures forming the infectious virus. Expression of prM and E in cell culture leads to the formation of DENV virus-like particles (VLPs) which are smaller than wildtype virus particles and replication defective due to the absence of a viral genome. There is no data available that describes the antigenic landscape on the surface of flavivirus VLPs in comparison to the better studied infectious virion. A large panel of well characterized antibodies that recognize epitope of ranging complexity were used in biochemical analytics to obtain a comparative antigenic surface view of VLPs in respect to virus particles. DENV patient serum depletions were performed the show the potential of VLPs in serological diagnostics. VLPs were confirmed to be heterogeneous in size morphology and maturation state. Yet, we show that many highly conformational and quaternary structure-dependent antibody epitopes found on virus particles are efficiently displayed on DENV1-4 VLP surfaces as well. Additionally, DENV VLPs can efficiently be used as antigens to deplete DENV patient sera from serotype specific antibody populations. This study aids in further understanding epitopic landscape of DENV VLPs and presents a comparative antigenic surface view of VLPs in respect to virus particles. We propose the use VLPs as a safe and practical alternative to infectious virus as a vaccine and diagnostic antigen.

  6. Towards the directed evolution of virus-like particles derived from polyomaviruses

    NARCIS (Netherlands)

    Teunissen, E.A.

    2014-01-01

    Virus-like particles (VLPs) are assemblies of viral structural proteins. These particles resemble the native viral capsid in structure, tropism, and transduction efficiency, but do not contain any viral genetic material. This makes them a safer alternative to viral vectors for gene therapy, and

  7. Virus-Like Particles That Can Deliver Proteins and RNA | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The present invention describes novel virus-like particles (VLPs) that are capable of binding to and replicating within a target mammalian cell, including human cells. The claimed VLPs are safer than viral delivery because they are incapable of re-infecting target cells. The National Cancer Institute's Protein Expression Laboratory seeks parties interested in licensing the novel delivery of RNA to mammalian cells using virus-like particles.

  8. A simple fluorescence based assay for quantification of human immunodeficiency virus particle release

    Directory of Open Access Journals (Sweden)

    Heuser Anke-Mareil

    2010-04-01

    Full Text Available Abstract Background The assembly and release of human immunodeficiency virus (HIV particles from infected cells represent attractive, but not yet exploited targets for antiretroviral therapy. The availability of simple methods to measure the efficiency of these replication steps in tissue culture would facilitate the identification of host factors essential for these processes as well as the screening for lead compounds acting as specific inhibitors of particle formation. We describe here the development of a rapid cell based assay for quantification of human immunodeficiency virus type 1 (HIV-1 particle assembly and/or release. Results Using a fluorescently labelled HIV-derivative, which carries an eYFP domain within the main viral structural protein Gag in the complete viral protein context, the release of virus like particles could be monitored by directly measuring the fluorescence intensity of the tissue culture supernatant. Intracellular Gag was quantitated in parallel by direct fluorescence analysis of cell lysates, allowing us to normalize for Gag expression efficiency. The assay was validated by comparison with p24 capsid ELISA measurements, a standard method for quantifying HIV-1 particles. Optimization of conditions allowed the robust detection of particle amounts corresponding to 50 ng p24/ml in medium by fluorescence spectroscopy. Further adaptation to a multi-well format rendered the assay suitable for medium or high throughput screening of siRNA libraries to identify host cell factors involved in late stages of HIV replication, as well as for random screening approaches to search for potential inhibitors of HIV-1 assembly or release. Conclusions The fast and simple fluorescence based quantification of HIV particle release yielded reproducible results which were comparable to the well established ELISA measurements, while in addition allowing the parallel determination of intracellular Gag expression. The protocols described here

  9. Maize rayado fino virus capsid proteins assemble into virus-like particles in Escherichia coli.

    Science.gov (United States)

    Hammond, Rosemarie W; Hammond, John

    2010-02-01

    Maize rayado fino virus (MRFV; genus Marafivirus; family Tymoviridae) is an isometric plant virus of 30 nm containing two components: empty shells and complete virus particles (encapsidating the 6.3 kb genomic RNA). Both particles are composed of two serologically related, carboxy co-terminal, coat proteins (CP) of apparent molecular mass 21-22 kDa (CP2) and 24-28 kDa (CP1) in a molar ratio of 3:1, respectively; CP1 contains a 37 amino acid amino terminal extension of CP2. In our study, expression of CP1 or CP2 in Escherichia coli resulted in assembly of each capsid protein into virus-like particles (VLPs), appearing in electron microscopy as stain-permeable (CP2) or stain-impermeable particles (CP1). CP1 VLPs encapsidated bacterial 16S ribosomal RNA, but not CP mRNA, while CP2 VLPs encapsidated neither CP mRNA nor 16S ribosomal RNA. Expression of CP1 and CP2 in E. coli using a co-expression vector resulted in the assembly of VLPs which were stain-impermeable and encapsidated CP mRNA. These results suggest that the N-terminal 37 amino acid residues of CP1, although not required for particle formation, may be involved in the assembly of complete virions and that the presence of both CP1 and CP2 in the particle is required for specific encapsidation of MRFV CP mRNA. (c) 2009 Elsevier B.V. All rights reserved.

  10. Characterization of chikungunya virus-like particles.

    Directory of Open Access Journals (Sweden)

    Nitchakarn Noranate

    Full Text Available Chikungunya virus (CHIKV is becoming a global concern due to the increasing number of outbreaks throughout the world and the absence of any CHIKV-specific vaccine or treatment. Virus-like particles (VLPs are multistructured proteins that mimic the organization and conformation of native viruses but lack the viral genome. They are noninfectious and potentially safer vaccine candidates. Recent studies demonstrated that the yield of CHIKV VLPs varies depending on the strains, despite the 95% amino acid similarity of the strains. This might be due to the codon usage, since protein expression is differently controlled by different organisms. We optimized the region encoding CHIKV structural proteins, C-E3-E2-6k-E1, inserted it into a mammalian expression vector, and used the resulting construct to transfect 293 cells. We detected 50-kDa proteins corresponding to E1 and/or E2 in the cell lysate and the supernatant. Transmission electron microscopy revealed spherical particles with a 50- to 60-nm diameter in the supernatant that resembled the native CHIKV virions. The buoyant density of the VLPs was 1.23 g/mL, and the yield was 20 µg purified VLPs per 108 cells. The VLPs aggregated when mixed with convalescent sera from chikungunya patients, indicating that their antigenicity is similar to that of native CHIKV. Antibodies elicited with the VLPs were capable of detecting native CHIKV, demonstrating that the VLPs retain immunogenicity similar to that of the native virion. These results indicated that CHIKV VLPs are morphologically, antigenically, and immunologically similar to the native CHIKV, suggesting that they have potential for use in chikungunya vaccines.

  11. Exploiting Fluorescent Polymers To Probe the Self-Assembly of Virus-like Particles

    DEFF Research Database (Denmark)

    Caden-Nava, Ruben D.; Hu, Yufang; Garmann, Rees F.

    2011-01-01

    , for example, poly(styrene sulfonate) (PSS), forming virus-like particles (VLPs). We have demonstrated recently that the VLPs formed from cowpea chlorotic mottle virus (CCMV) capsid protein increase in size (from T = 2 to T = 3 structures) upon increase in PSS molecular weight (from 400 kDa to 3.4MDa...

  12. Optimisation of secretion of recombinant HBsAg virus-like particles: Impact on the development of HIV-1/HBV bivalent vaccines

    NARCIS (Netherlands)

    Michel, Marie; Lone, Yu-Chun; Centlivre, Mireille; Roux, Pascal; Wain-Hobson, Simon; Sala, Monica

    2007-01-01

    The hepatitis B surface antigen (HBsAg) assembles into virus-like particles (VLPs) that can be used as carrier of immunogenic peptides for the development of bivalent vaccine candidates. It is shown here that by respecting certain qualitative features of mammalian preS1 and preS2 protein domains

  13. An efficient plant viral expression system generating orally immunogenic Norwalk virus-like particles.

    Science.gov (United States)

    Santi, Luca; Batchelor, Lance; Huang, Zhong; Hjelm, Brooke; Kilbourne, Jacquelyn; Arntzen, Charles J; Chen, Qiang; Mason, Hugh S

    2008-03-28

    Virus-like particles (VLPs) derived from enteric pathogens like Norwalk virus (NV) are well suited to study oral immunization. We previously described stable transgenic plants that accumulate recombinant NV-like particles (rNVs) that were orally immunogenic in mice and humans. The transgenic approach suffers from long generation time and modest level of antigen accumulation. We now overcome these constraints with an efficient tobacco mosaic virus (TMV)-derived transient expression system using leaves of Nicotiana benthamiana. We produced properly assembled rNV at 0.8 mg/g leaf 12 days post-infection (dpi). Oral immunization of CD1 mice with 100 or 250 microg/dose of partially purified rNV elicited systemic and mucosal immune responses. We conclude that the plant viral transient expression system provides a robust research tool to generate abundant quantities of rNV as enriched, concentrated VLP preparations that are orally immunogenic.

  14. Comparative analysis of rabbit hemorrhagic disease virus (RHDV) and new RHDV2 virus antigenicity, using specific virus-like particles

    OpenAIRE

    Bárcena, Juan; Guerra, Beatriz; Angulo, Iván; González, Julia; Valcárcel, Félix; Mata, Carlos P.; Castón, José R.; Blanco, Esther; Alejo, Alí

    2015-01-01

    International audience; In 2010 a new Lagovirus related to rabbit haemorrhagic disease virus (RHDV) emerged in France and has since rapidly spread throughout domestic and wild rabbit populations of several European countries. The new virus, termed RHDV2, exhibits distinctive genetic, antigenic and pathogenic features. Notably, RHDV2 kills rabbits previously vaccinated with RHDV vaccines. Here we report for the first time the generation and characterization of RHDV2-specific virus-like particl...

  15. Nef enhances HIV-1 infectivity via association with the virus assembly complex

    International Nuclear Information System (INIS)

    Qi Mingli; Aiken, Christopher

    2008-01-01

    The HIV-1 accessory protein Nef enhances virus infectivity by facilitating an early post-entry step of infection. Nef acts in the virus producer cell, leading to a beneficial modification to HIV-1 particles. Nef itself is incorporated into HIV-1 particles, where it is cleaved by the viral protease during virion maturation. To probe the role of virion-associated Nef in HIV-1 infection, we generated a fusion protein consisting of the host protein cyclophilin A (CypA) linked to the amino terminus of Nef. The resulting CypA-Nef protein enhanced the infectivity of Nef-defective HIV-1 particles and was specifically incorporated into the virions via association with Gag during particle assembly. Pharmacologic or genetic inhibition of CypA-Nef binding to Gag prevented incorporation of CypA-Nef into virions and inhibited infectivity enhancement. Our results indicate that infectivity enhancement by Nef requires its association with a component of the assembling HIV-1 particle

  16. Enhancement of mucosal immune responses by chimeric influenza HA/SHIV virus-like particles

    International Nuclear Information System (INIS)

    Guo Lizheng; Lu Xiaoyan; Kang, S.-M.; Chen Changyi; Compans, Richard W.; Yao Qizhi

    2003-01-01

    To enhance mucosal immune responses using simian/human immunodeficiency virus-like particles (SHIV VLPs), we have produced novel phenotypically mixed chimeric influenza HA/SHIV VLPs and used them to immunize C57BL/6J mice intranasally. Antibody and cytotoxic T-cell (CTL) responses as well as cytokine production in both systemic and mucosal sites were compared after immunization with SHIV VLPs or chimeric HA/SHIV VLPs. By using enzyme-linked immunosorbent assay (ELISA), the levels of serum IgG and mucosal IgA to the HIV envelope protein (Env) were found to be highest in the group immunized with chimeric HA/SHIV VLPs. Furthermore, the highest titer of serum neutralizing antibody against HIV Env was found with the group immunized with chimeric HA/SHIV VLPs. Analysis of the IgG1/IgG2a ratio indicated that a T H 1-oriented immune response resulted from these VLP immunizations. HA/SHIV VLP-immunized mice also showed significantly higher CTL responses than those observed in SHIV VLP-immunized mice. Moreover, a MHC class I restricted T-cell activation ELISPOT assay showed a mixed type of T H 1/T H 2 cytokines in the HA/SHIV VLP-immunized mice, indicating that the chimeric VLPs can enhance both humoral and cellular immune responses to the HIV Env protein at multiple mucosal and systemic sites. The results indicate that incorporation of influenza HA into heterotypic VLPs may be highly effective for targeting vaccines to mucosal surfaces

  17. Ebola virus-like particles produced in insect cells exhibit dendritic cell stimulating activity and induce neutralizing antibodies

    International Nuclear Information System (INIS)

    Ye Ling; Lin Jianguo; Sun Yuliang; Bennouna, Soumaya; Lo, Michael; Wu Qingyang; Bu Zhigao; Pulendran, Bali; Compans, Richard W.; Yang Chinglai

    2006-01-01

    Recombinant baculoviruses (rBV) expressing Ebola virus VP40 (rBV-VP40) or GP (rBV-GP) proteins were generated. Infection of Sf9 insect cells by rBV-VP40 led to assembly and budding of filamentous particles from the cell surface as shown by electron microscopy. Ebola virus-like particles (VLPs) were produced by coinfection of Sf9 cells with rBV-VP40 and rBV-GP, and incorporation of Ebola GP into VLPs was demonstrated by SDS-PAGE and Western blot analysis. Recombinant baculovirus infection of insect cells yielded high levels of VLPs, which were shown to stimulate cytokine secretion from human dendritic cells similar to VLPs produced in mammalian cells. The immunogenicity of Ebola VLPs produced in insect cells was evaluated by immunization of mice. Analysis of antibody responses showed that most of the GP-specific antibodies were of the IgG2a subtype, while no significant level of IgG1 subtype antibodies specific for GP was induced, indicating the induction of a Th1-biased immune response. Furthermore, sera from Ebola VLP immunized mice were able to block infection by Ebola GP pseudotyped HIV virus in a single round infection assay, indicating that a neutralizing antibody against the Ebola GP protein was induced. These results show that production of Ebola VLPs in insect cells using recombinant baculoviruses represents a promising approach for vaccine development against Ebola virus infection

  18. Self-assembly of virus-like particles of canine parvovirus capsid protein expressed from Escherichia coli and application as virus-like particle vaccine.

    Science.gov (United States)

    Xu, Jin; Guo, Hui-Chen; Wei, Yan-Quan; Dong, Hu; Han, Shi-Chong; Ao, Da; Sun, De-Hui; Wang, Hai-Ming; Cao, Sui-Zhong; Sun, Shi-Qi

    2014-04-01

    Canine parvovirus disease is an acute infectious disease caused by canine parvovirus (CPV). Current commercial vaccines are mainly attenuated and inactivated; as such, problems concerning safety may occur. To resolve this problem, researchers developed virus-like particles (VLPs) as biological nanoparticles resembling natural virions and showing high bio-safety. This property allows the use of VLPs for vaccine development and mechanism studies of viral infections. Tissue-specific drug delivery also employs VLPs as biological nanomaterials. Therefore, VLPs derived from CPV have a great potential in medicine and diagnostics. In this study, small ubiquitin-like modifier (SUMO) fusion motif was utilized to express a whole, naturalVP2 protein of CPV in Escherichia coli. After the cleavage of the fusion motif, the CPV VP2 protein has self-assembled into VLPs. The VLPs had a size and shape that resembled the authentic virus capsid. However, the self-assembly efficiency of VLPs can be affected by different pH levels and ionic strengths. The mice vaccinated subcutaneously with CPV VLPs and CPV-specific immune responses were compared with those immunized with the natural virus. This result showed that VLPs can effectively induce anti-CPV specific antibody and lymphocyte proliferation as a whole virus. This result further suggested that the antigen epitope of CPV was correctly present on VLPs, thereby showing the potential application of a VLP-based CPV vaccine.

  19. Hantavirus Gn and Gc glycoproteins self-assemble into virus-like particles.

    Science.gov (United States)

    Acuña, Rodrigo; Cifuentes-Muñoz, Nicolás; Márquez, Chantal L; Bulling, Manuela; Klingström, Jonas; Mancini, Roberta; Lozach, Pierre-Yves; Tischler, Nicole D

    2014-02-01

    How hantaviruses assemble and exit infected cells remains largely unknown. Here, we show that the expression of Andes (ANDV) and Puumala (PUUV) hantavirus Gn and Gc envelope glycoproteins lead to their self-assembly into virus-like particles (VLPs) which were released to cell supernatants. The viral nucleoprotein was not required for particle formation. Further, a Gc endodomain deletion mutant did not abrogate VLP formation. The VLPs were pleomorphic, exposed protrusions and reacted with patient sera.

  20. Evidences of Changes in Surface Electrostatic Charge Distribution during Stabilization of HPV16 Virus-Like Particles.

    Directory of Open Access Journals (Sweden)

    Juan F Vega

    Full Text Available The stabilization of human papillomavirus type 16 virus-like particles has been examined by means of different techniques including dynamic and static light scattering, transmission electron microscopy and electrophoretic mobility. All these techniques provide different and often complementary perspectives about the aggregation process and generation of stabilized virus-like particles after a period of time of 48 hours at a temperature of 298 K. Interestingly, static light scattering results point towards a clear colloidal instability in the initial systems, as suggested by a negative value of the second virial coefficient. This is likely related to small repulsive electrostatic interactions among the particles, and in agreement with relatively small absolute values of the electrophoretic mobility and, hence, of the net surface charges. At this initial stage the small repulsive interactions are not able to compensate binding interactions, which tend to aggregate the particles. As time proceeds, an increase of the size of the particles is accompanied by strong increases, in absolute values, of the electrophoretic mobility and net surface charge, suggesting enhanced repulsive electrostatic interactions and, consequently, a stabilized colloidal system. These results show that electrophoretic mobility is a useful methodology that can be applied to screen the stabilization factors for virus-like particles during vaccine development.

  1. Stability and assembly in vitro of bacteriophage PP7 virus-like particles

    Directory of Open Access Journals (Sweden)

    Peabody David S

    2007-11-01

    Full Text Available Abstract Background The stability of a virus-like particle (VLP is an important consideration for its use in nanobiotechnology. The icosahedral capsid of the RNA bacteriophage PP7 is cross-linked by disulfide bonds between coat protein dimers at its 5-fold and quasi-6-fold symmetry axes. This work determined the effects of these disulfides on the VLP's thermal stability. Results Measurements of the thermal denaturation behavior of PP7 VLPs in the presence and absence of a reducing agent show that disulfide cross-links substantially stabilize them against thermal denaturation. Although dimers in the capsid are linked to one another by disulfides, the two subunits of dimers themselves are held together only by non-covalent interactions. In an effort to confer even greater stability a new cross-link was introduced by genetically fusing two coat protein monomers, thus producing a "single-chain dimer" that assembles normally into a completely cross-linked VLP. However, subunit fusion failed to increase the thermal stability of the particles, even though it stabilized the isolated dimer. As a step toward gaining control of the internal composition of the capsid, conditions that promote the assembly of PP7 coat protein dimers into virus-like particles in vitro were established. Conclusion The presence of inter-dimer disulfide bonds greatly stabilizes the PP7 virus-like particle against thermal denaturation. Covalently cross-linking the subunits of the dimers themselves by genetically fusing them through a dipeptide linker sequence, offers no further stabilization of the VLP, although it does stabilize the dimer. PP7 capsids readily assemble in vitro in a reaction that requires RNA.

  2. Three-dimensional visualization of forming Hepatitis C virus-like particles by electron-tomography

    Energy Technology Data Exchange (ETDEWEB)

    Badia-Martinez, Daniel; Peralta, Bibiana [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); Andres, German; Guerra, Milagros [Electron Microscopy Unit, Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, Campus Cantoblanco, 28049 Madrid (Spain); Gil-Carton, David [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); Abrescia, Nicola G.A., E-mail: nabrescia@cicbiogune.es [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

    2012-09-01

    Hepatitis C virus infects almost 170 million people per year but its assembly pathway, architecture and the structures of its envelope proteins are poorly understood. Using electron tomography of plastic-embedded sections of insect cells, we have visualized the morphogenesis of recombinant Hepatitis C virus-like particles. Our data provide a three-dimensional sketch of viral assembly at the endoplasmic reticulum showing different budding stages and contiguity of buds. This latter phenomenon could play an important role during the assembly of wt-HCV and explain the size-heterogeneity of its particles.

  3. Three-dimensional visualization of forming Hepatitis C virus-like particles by electron-tomography

    International Nuclear Information System (INIS)

    Badia-Martinez, Daniel; Peralta, Bibiana; Andrés, German; Guerra, Milagros; Gil-Carton, David; Abrescia, Nicola G.A.

    2012-01-01

    Hepatitis C virus infects almost 170 million people per year but its assembly pathway, architecture and the structures of its envelope proteins are poorly understood. Using electron tomography of plastic-embedded sections of insect cells, we have visualized the morphogenesis of recombinant Hepatitis C virus-like particles. Our data provide a three-dimensional sketch of viral assembly at the endoplasmic reticulum showing different budding stages and contiguity of buds. This latter phenomenon could play an important role during the assembly of wt-HCV and explain the size-heterogeneity of its particles.

  4. Comparative analysis of rabbit hemorrhagic disease virus (RHDV) and new RHDV2 virus antigenicity, using specific virus-like particles.

    Science.gov (United States)

    Bárcena, Juan; Guerra, Beatriz; Angulo, Iván; González, Julia; Valcárcel, Félix; Mata, Carlos P; Castón, José R; Blanco, Esther; Alejo, Alí

    2015-09-24

    In 2010 a new Lagovirus related to rabbit haemorrhagic disease virus (RHDV) emerged in France and has since rapidly spread throughout domestic and wild rabbit populations of several European countries. The new virus, termed RHDV2, exhibits distinctive genetic, antigenic and pathogenic features. Notably, RHDV2 kills rabbits previously vaccinated with RHDV vaccines. Here we report for the first time the generation and characterization of RHDV2-specific virus-like particles (VLPs). Our results further confirmed the differential antigenic properties exhibited by RHDV and RHDV2, highlighting the need of using RHDV2-specific diagnostic assays to monitor the spread of this new virus.

  5. Crystallization and preliminary X-ray diffraction analysis of recombinant hepatitis E virus-like particle

    International Nuclear Information System (INIS)

    Wang, Che-Yen; Miyazaki, Naoyuki; Yamashita, Tetsuo; Higashiura, Akifumi; Nakagawa, Atsushi; Li, Tian-Cheng; Takeda, Naokazu; Xing, Li; Hjalmarsson, Erik; Friberg, Claes; Liou, Der-Ming; Sung, Yen-Jen; Tsukihara, Tomitake; Matsuura, Yoshiharu; Miyamura, Tatsuo; Cheng, R. Holland

    2008-01-01

    A recombinant virus-like particle that is a potential oral hepatitis E vaccine was crystallized. Diffraction data were collected to 8.3 Å resolution and the X-ray structure was phased with the aid of a low-resolution density map determined using cryo-electron microscopy data. Hepatitis E virus (HEV) accounts for the majority of enterically transmitted hepatitis infections worldwide. Currently, there is no specific treatment for or vaccine against HEV. The major structural protein is derived from open reading frame (ORF) 2 of the viral genome. A potential oral vaccine is provided by the virus-like particles formed by a protein construct of partial ORF3 protein (residue 70–123) fused to the N-terminus of the ORF2 protein (residues 112–608). Single crystals obtained by the hanging-drop vapour-diffusion method at 293 K diffract X-rays to 8.3 Å resolution. The crystals belong to space group P2 1 2 1 2 1 , with unit-cell parameters a = 337, b = 343, c = 346 Å, α = β = γ = 90°, and contain one particle per asymmetric unit

  6. Noninfectious virus-like particles produced by Moloney murine leukemia virus-based retrovirus packaging cells deficient in viral envelope become infectious in the presence of lipofection reagents

    Science.gov (United States)

    Sharma, Sanjai; Murai, Fukashi; Miyanohara, Atsushi; Friedmann, Theodore

    1997-01-01

    Retrovirus packaging cell lines expressing the Moloney murine leukemia virus gag and pol genes but lacking virus envelope genes produce virus-like particles constitutively, whether or not they express a transcript from an integrated retroviral provirus. In the absence of a proviral transcript, the assembled particles contain processed gag and reverse transcriptase, and particles made by cells expressing an integrated lacZ provirus also contain viral RNA. The virus-like particles from both cell types are enveloped and are secreted/budded into the extracellular space but are noninfectious. Their physicochemical properties are similar to those of mature retroviral particles. The noninfectious gag pol RNA particles can readily be made infectious by the addition of lipofection reagents to produce preparations with titers of up to 105 colony-forming units per ml. PMID:9380714

  7. Noninfectious virus-like particles produced by Moloney murine leukemia virus-based retrovirus packaging cells deficient in viral envelope become infectious in the presence of lipofection reagents.

    Science.gov (United States)

    Sharma, S; Murai, F; Miyanohara, A; Friedmann, T

    1997-09-30

    Retrovirus packaging cell lines expressing the Moloney murine leukemia virus gag and pol genes but lacking virus envelope genes produce virus-like particles constitutively, whether or not they express a transcript from an integrated retroviral provirus. In the absence of a proviral transcript, the assembled particles contain processed gag and reverse transcriptase, and particles made by cells expressing an integrated lacZ provirus also contain viral RNA. The virus-like particles from both cell types are enveloped and are secreted/budded into the extracellular space but are noninfectious. Their physicochemical properties are similar to those of mature retroviral particles. The noninfectious gag pol RNA particles can readily be made infectious by the addition of lipofection reagents to produce preparations with titers of up to 10(5) colony-forming units per ml.

  8. Virus-like particles suppress growth of the red-tide-forming marine dinoflagellate Gymnodinium mikimotoi.

    Science.gov (United States)

    Onji, Masashi; Nakano, Shin-ichi; Suzuki, Satoru

    2003-01-01

    We isolated 2 virus-like agents that suppressed growth of Gymnodinium mikimotoi from coastal waters of the Uwa Sea, Japan. The agents found in the flagellate cells, named GM6 and GM7, were filterable in a 0.22-microm-pore filter with approximately 100-nm shapes. Electron microscopic observation showed the presence of virus-like particles in severely damaged G. mikimotoi cells infected by GM6. The growth-suppression activity of the agents (GM6 or GM7) was lost by heating at 50 degrees C, with treatments of DNase and protease, and filtration through a 0.05-microm filter. Our results suggest that the agents are DNA viruses infectious to and virulent for G. mikimotoi. This is the first report of a virus-like agent specific to G. mikimotoi.

  9. Replacement of the murine leukemia virus (MLV) envelope gene with a truncated HIV envelope gene in MLV generates a virus with impaired replication capacity

    International Nuclear Information System (INIS)

    Nack, Ursula; Schnierle, Barbara S.

    2003-01-01

    Murine leukemia virus (MLV) capsid particles can be efficiently pseudotyped with a variant of the HIV-1 envelope protein (Env) containing the surface glycoprotein gp120-SU and a carboxyl-terminally truncated transmembrane (TM) protein, with only seven cytoplasmic amino acids. MLV/HIV pseudotyped vector particles acquire the natural host tropism of HIV-1 and their entry is dependent on the presence of CD4 and an appropriate co-receptor on the surface of the target cell. We describe here the construction of chimeric MLV/HIV proviruses containing the truncated HIV envelope gene. The MLV/HIV provirus was generated by direct replacement of the MLV envelope gene with HIV Env coding sequences either with or without the additional inclusion of the woodchuck hepatitis virus posttranscriptional regulatory element (WPRE). Chimeric MLV/HIV particles could be generated from transfected 293T cells and were able to infect CD4/CXCR4-positive target cells. However, the second round of infection of target cells was severely impaired, despite the fact that the WPRE element enhanced the amount of viral mRNA detected. Viral particles released from infected cells showed reduced HIV Env incorporation, indicating that additional factors required for efficient replication of MLV/HIV pseudotyped viruses are missing

  10. Oligonucleotide Length-Dependent Formation of Virus-Like Particles.

    Science.gov (United States)

    Maassen, Stan J; de Ruiter, Mark V; Lindhoud, Saskia; Cornelissen, Jeroen J L M

    2018-05-23

    Understanding the assembly pathway of viruses can contribute to creating monodisperse virus-based materials. In this study, the cowpea chlorotic mottle virus (CCMV) is used to determine the interactions between the capsid proteins of viruses and their cargo. The assembly of the capsid proteins in the presence of different lengths of short, single-stranded (ss) DNA is studied at neutral pH, at which the protein-protein interactions are weak. Chromatography, electrophoresis, microscopy, and light scattering data show that the assembly efficiency and speed of the particles increase with increasing length of oligonucleotides. The minimal length required for assembly under the conditions used herein is 14 nucleotides. Assembly of particles containing such short strands of ssDNA can take almost a month. This slow assembly process enabled the study of intermediate states, which confirmed a low cooperative assembly for CCMV and allowed for further expansion of current assembly theories. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. RNA packaging of MRFV virus-like particles: The interplay between RNA pools and capsid coat protein

    Science.gov (United States)

    Virus-like particles (VLPs) can be produced through self-assembly of capsid protein (CP) into particles with discrete shapes and sizes and containing different types of RNA molecules. The general principle that governs particle assembly and RNA packaging is determined by unique interactions between ...

  12. Two proteins with reverse transcriptase activities associated with hepatitis B virus-like particles

    International Nuclear Information System (INIS)

    Bavand, M.R.; Laub, O.

    1988-01-01

    Recent studies suggest that hepatitis B virus (HBV), despite being a DNA virus, replicates via an RNA intermediate. The HBV life cycle is therefore a permuted version of the RNA retroviral life cycle. Sequence homology between retroviral reverse transcriptase and the putative HBV polymerase gene product suggests the presence of an HBV reverse transcriptase. As yet, there has been no direct evidence that reverse transcriptase activity is present in the viral particle. The authors used activity gel analysis to detect the in situ catalytic activities of DNA polymerases after sodium dodecyl sulfate-polyacrylamide gel electrophorsis. These studies demonstrated that HBV-like particles secreted by a differentiated human hepatoma cell line tranfected with genomic HBV DNA contain two major polymerase activities which migrate as ∼90- and ∼70-kilodalton (kDa) proteins. This demonstrated, for the first time, that HBV-like particles contain a novel DNA polymerase-reverse transcriptase activity. Furthermore, they propose that the 70-kDa reverse transcriptase may be produced by proteolytic self-cleavage of the 90-kDa precursor protein

  13. Production and immunogenicity of chimeric virus-like particles containing the spike glycoprotein of infectious bronchitis virus.

    Science.gov (United States)

    Lv, Lishan; Li, Xiaoming; Liu, Genmei; Li, Ran; Liu, Qiliang; Shen, Huifang; Wang, Wei; Xue, Chunyi; Cao, Yongchang

    2014-01-01

    Infectious bronchitis virus (IBV) poses a severe threat to the poultry industry and causes heavy economic losses worldwide. Vaccination is the most effective method of preventing infection and controlling the spread of IBV, but currently available inactivated and attenuated virus vaccines have some disadvantages. We developed a chimeric virus-like particle (VLP)-based candidate vaccine for IBV protection. The chimeric VLP was composed of matrix 1 protein from avian influenza H5N1 virus and a fusion protein neuraminidase (NA)/spike 1 (S1) that was generated by fusing IBV S1 protein to the cytoplasmic and transmembrane domains of NA protein of avian influenza H5N1 virus. The chimeric VLPs elicited significantly higher S1-specific antibody responses in intramuscularly immunized mice and chickens than inactivated IBV viruses. Furthermore, the chimeric VLPs induced significantly higher neutralization antibody levels than inactivated H120 virus in SPF chickens. Finally, the chimeric VLPs induced significantly higher IL-4 production in mice. These results demonstrate that chimeric VLPs have the potential for use in vaccines against IBV infection.

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

    International Nuclear Information System (INIS)

    Blokhina, Elena A.; Kuprianov, Victor V.; Stepanova, Ludmila A.; Tsybalova, Ludmila M.; Kiselev, Oleg I.; Ravin, Nikolai V.; Skryabin, Konstantin G.

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-20

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

  16. Rotavirus Virus-Like Particles as Surrogates in Environmental Persistence and Inactivation Studies

    Science.gov (United States)

    Caballero, Santiago; Abad, F. Xavier; Loisy, Fabienne; Le Guyader, Françoise S.; Cohen, Jean; Pintó, Rosa M.; Bosch, Albert

    2004-01-01

    Virus-like particles (VLPs) with the full-length VP2 and VP6 rotavirus capsid proteins, produced in the baculovirus expression system, have been evaluated as surrogates of human rotavirus in different environmental scenarios. Green fluorescent protein-labeled VLPs (GFP-VLPs) and particles enclosing a heterologous RNA (pseudoviruses), whose stability may be monitored by flow cytometry and antigen capture reverse transcription-PCR, respectively, were used. After 1 month in seawater at 20°C, no significant differences were observed between the behaviors of GFP-VLPs and of infectious rotavirus, whereas pseudovirus particles showed a higher decay rate. In the presence of 1 mg of free chlorine (FC)/liter both tracers persisted longer in freshwater at 20°C than infectious viruses, whereas in the presence of 0.2 mg of FC/liter no differences were observed between tracers and infectious rotavirus at short contact times. However, from 30 min of contact with FC onward, the decay of infectious rotavirus was higher than that of recombinant particles. The predicted Ct value for a 90% reduction of GFP-VLPs or pseudoviruses induces a 99.99% inactivation of infectious rotavirus. Both tracers were more resistant to UV light irradiation than infectious rotavirus in fresh and marine water. The effect of UV exposure was more pronounced on pseudovirus than in GFP-VLPs. In all types of water, the UV dose to induce a 90% reduction of pseudovirus ensures a 99.99% inactivation of infectious rotavirus. Recombinant virus surrogates open new possibilities for the systematic validation of virus removal practices in actual field situations where pathogenic agents cannot be introduced. PMID:15240262

  17. Binding of human papilloma virus L1 virus-like particles to dendritic cells is mediated through heparan sulfates and induces immune activation

    NARCIS (Netherlands)

    de Witte, Lot; Zoughlami, Younes; Aengeneyndt, Birgit; David, Guido; van Kooyk, Yvette; Gissmann, Lutz; Geijtenbeek, Teunis B. H.

    2007-01-01

    Immunization using human papilloma virus (HPV)-L1 virus-like particles (VLPs) induces a robust and effective immune response, which has recently resulted in the implementation of the HPV-L1 VLP vaccination in health programs. However, during infection, HPV can escape immune surveillance leading to

  18. Virus-Like Particle Engineering: From Rational Design to Versatile Applications.

    Science.gov (United States)

    Ding, Xuanwei; Liu, Dong; Booth, George; Gao, Wei; Lu, Yuan

    2018-05-01

    As mimicking natural virus structures, virus-like particles (VLPs) have evolved to become a widely accepted technology used for humans which are safe, highly efficacious, and profitable. Several remarkable advantages have been achieved to revolutionize the molecule delivery for diverse applications in nanotechnology, biotechnology, and medicine. Here, the rational structure design, manufacturing process, functionalization strategy, and emerging applications of VLPs is reviewed. The situation and challenges in the VLP engineering, the key development orientation, and future applications have been discussed. To develop a good VLP design concept, the virus/VLP-host interactions need to be examined and the screening methods of the VLP stabilization factors need to be established. The functionalization toolbox can be expanded to fabricate smart, robust, and multifunctional VLPs. Novel robust VLP manufacturing platforms are required to deliver vaccines in resource-poor regions with a significant reduction in the production time and cost. The future applications of VLPs are always driven by the development of emerging technologies and new requirements of modern life. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Toll-Like Receptor 2 Ligation Enhances HIV-1 Replication in Activated CCR6+ CD4+ T Cells by Increasing Virus Entry and Establishing a More Permissive Environment to Infection.

    Science.gov (United States)

    Bolduc, Jean-François; Ouellet, Michel; Hany, Laurent; Tremblay, Michel J

    2017-02-15

    In this study, we investigated the effect of Toll-like receptor 2 (TLR2) ligation on the permissiveness of activated CD4 + T cells to HIV-1 infection by focusing our experiments on the relative susceptibility of cell subsets based on their expression of CCR6. Purified primary human CD4 + T cells were first subjected to a CD3/CD28 costimulation before treatment with the TLR2 agonist Pam3CSK4. Finally, cells were inoculated with R5-tropic HIV-1 particles that permit us to study the effect of TLR2 triggering on virus production at both population and single-cell levels. We report here that HIV-1 replication is augmented in CD3/CD28-costimulated CCR6 + CD4 + T cells upon engagement of the cell surface TLR2. Additional studies indicate that a higher virus entry and polymerization of the cortical actin are seen in this cell subset following TLR2 stimulation. A TLR2-mediated increase in the level of phosphorylated NF-κB p65 subunit was also detected in CD3/CD28-costimulated CCR6 + CD4 + T cells. We propose that, upon antigenic presentation, an engagement of TLR2 acts specifically on CCR6 + CD4 + T cells by promoting virus entry in an intracellular milieu more favorable for productive HIV-1 infection. Following primary infection, HIV-1 induces an immunological and structural disruption of the gut mucosa, leading to bacterial translocation and release of microbial components in the bloodstream. These pathogen-derived constituents include several agonists of Toll-like receptors that may affect gut-homing CD4 + T cells, such as those expressing the chemokine receptor CCR6, which are highly permissive to HIV-1 infection. We demonstrate that TLR2 ligation in CD3/CD28-costimulated CCR6 + CD4 + T cells leads to enhanced virus production. Our results highlight the potential impact of bacterial translocation on the overall permissiveness of CCR6 + CD4 + T cells to productive HIV-1 infection. Copyright © 2017 American Society for Microbiology.

  20. Coronavirus-like particles in laboratory rabbits with different syndromes in The Netherlands (Coronavirus-like particles in rabbits).

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert); J.S. Teppema; G. van Steenis (Bert)

    1982-01-01

    textabstractVirus-like particles were identified from the plasma of rabbits which developed pleural effusion disease after inoculation with different strains of Treponema pallidum. These particles were considered coronavirus-like on the basis of their size, morphology, and buoyant density. Clinical

  1. Enhanced light microscopy visualization of virus particles from Zika virus to filamentous ebolaviruses.

    Directory of Open Access Journals (Sweden)

    George G Daaboul

    Full Text Available Light microscopy is a powerful tool in the detection and analysis of parasites, fungi, and prokaryotes, but has been challenging to use for the detection of individual virus particles. Unlabeled virus particles are too small to be visualized using standard visible light microscopy. Characterization of virus particles is typically performed using higher resolution approaches such as electron microscopy or atomic force microscopy. These approaches require purification of virions away from their normal millieu, requiring significant levels of expertise, and can only enumerate small numbers of particles per field of view. Here, we utilize a visible light imaging approach called Single Particle Interferometric Reflectance Imaging Sensor (SP-IRIS that allows automated counting and sizing of thousands of individual virions. Virions are captured directly from complex solutions onto a silicon chip and then detected using a reflectance interference imaging modality. We show that the use of different imaging wavelengths allows the visualization of a multitude of virus particles. Using Violet/UV illumination, the SP-IRIS technique is able to detect individual flavivirus particles (~40 nm, while green light illumination is capable of identifying and discriminating between vesicular stomatitis virus and vaccinia virus (~360 nm. Strikingly, the technology allows the clear identification of filamentous infectious ebolavirus particles and virus-like particles. The ability to differentiate and quantify unlabeled virus particles extends the usefulness of traditional light microscopy and can be embodied in a straightforward benchtop approach allowing widespread applications ranging from rapid detection in biological fluids to analysis of virus-like particles for vaccine development and production.

  2. Maturation of the viral core enhances the fusion of HIV-1 particles with primary human T cells and monocyte-derived macrophages

    International Nuclear Information System (INIS)

    Jiang Jiyang; Aiken, Christopher

    2006-01-01

    HIV-1 infection requires fusion of viral and cellular membranes in a reaction catalyzed by the viral envelope proteins gp120 and gp41. We recently reported that efficient HIV-1 particle fusion with target cells is linked to maturation of the viral core by an activity of the gp41 cytoplasmic domain. Here, we show that maturation enhances the fusion of a variety of recombinant viruses bearing primary and laboratory-adapted Env proteins with primary human CD4 + T cells. Overall, HIV-1 fusion was more dependent on maturation for viruses bearing X4-tropic envelope proteins than for R5-tropic viruses. Fusion of HIV-1 with monocyte-derived macrophages was also dependent on particle maturation. We conclude that the ability to couple fusion to particle maturation is a common feature of HIV-1 Env proteins and may play an important role during HIV-1 replication in vivo

  3. Effective chikungunya virus-like particle vaccine produced in insect cells.

    Directory of Open Access Journals (Sweden)

    Stefan W Metz

    Full Text Available The emerging arthritogenic, mosquito-borne chikungunya virus (CHIKV causes severe disease in humans and represents a serious public health threat in countries where Aedes spp mosquitoes are present. This study describes for the first time the successful production of CHIKV virus-like particles (VLPs in insect cells using recombinant baculoviruses. This well-established expression system is rapidly scalable to volumes required for epidemic responses and proved well suited for processing of CHIKV glycoproteins and production of enveloped VLPs. Herein we show that a single immunization with 1 µg of non-adjuvanted CHIKV VLPs induced high titer neutralizing antibody responses and provided complete protection against viraemia and joint inflammation upon challenge with the Réunion Island CHIKV strain in an adult wild-type mouse model of CHIKV disease. CHIKV VLPs produced in insect cells using recombinant baculoviruses thus represents as a new, safe, non-replicating and effective vaccine candidate against CHIKV infections.

  4. A novel recombinant virus-like particle vaccine for prevention of porcine parvovirus-induced reproductive failure

    NARCIS (Netherlands)

    Antonis, A.F.G.; Bruschke, C.J.M.; Rueda, P.; Maranga, L.; Casal, J.; Vela, C.; Hilgers, L.A.T.; Belt, P.B.G.M.; Weerdmeester, K.; Carrondo, M.J.; Langeveld, J.P.M.

    2006-01-01

    A novel vaccine against porcine parvovirus (PPV), composed of recombinant virus-like particles (PPV-VLPs) produced with the baculovirus expression vector system (BEVS) at industrial scale, was tested for its immunogenicity and protective potency. A formulation of submicrogram amounts of PPV-VLPs in

  5. Genotype I of Japanese Encephalitis Virus Virus-like Particles Elicit Sterilizing Immunity against Genotype I and III Viral Challenge in Swine.

    Science.gov (United States)

    Fan, Yi-Chin; Chen, Jo-Mei; Lin, Jen-Wei; Chen, Yi-Ying; Wu, Guan-Hong; Su, Kuan-Hsuan; Chiou, Ming-Tang; Wu, Shang-Rung; Yin, Ji-Hang; Liao, Jiunn-Wang; Chang, Gwong-Jen J; Chiou, Shyan-Song

    2018-05-10

    Swine are a critical amplifying host involved in human Japanese encephalitis (JE) outbreaks. Cross-genotypic immunogenicity and sterile protection are important for the current genotype III (GIII) virus-derived vaccines in swine, especially now that emerging genotype I (GI) JE virus (JEV) has replaced GIII virus as the dominant strain. Herein, we aimed to develop a system to generate GI JEV virus-like particles (VLPs) and evaluate the immunogenicity and protection of the GI vaccine candidate in mice and specific pathogen-free swine. A CHO-heparan sulfate-deficient (CHO-HS(-)) cell clone, named 51-10 clone, stably expressing GI-JEV VLP was selected and continually secreted GI VLPs without signs of cell fusion. 51-10 VLPs formed a homogeneously empty-particle morphology and exhibited similar antigenic activity as GI virus. GI VLP-immunized mice showed balanced cross-neutralizing antibody titers against GI to GIV viruses (50% focus-reduction micro-neutralization assay titers 71 to 240) as well as potent protection against GI or GIII virus infection. GI VLP-immunized swine challenged with GI or GIII viruses showed no fever, viremia, or viral RNA in tonsils, lymph nodes, and brains as compared with phosphate buffered saline-immunized swine. We thus conclude GI VLPs can provide sterile protection against GI and GIII viruses in swine.

  6. Generation and Characterization of a Defective HIV-1 Virus as an Immunogen for a Therapeutic Vaccine

    Science.gov (United States)

    García-Pérez, Javier; García, Felipe; Blanco, Julia; Escribà-García, Laura; Gatell, Jose Maria; Alcamí, Jose; Plana, Montserrat; Sánchez-Palomino, Sonsoles

    2012-01-01

    Background The generation of new immunogens able to elicit strong specific immune responses remains a major challenge in the attempts to obtain a prophylactic or therapeutic vaccine against HIV/AIDS. We designed and constructed a defective recombinant virus based on the HIV-1 genome generating infective but non-replicative virions able to elicit broad and strong cellular immune responses in HIV-1 seropositive individuals. Results Viral particles were generated through transient transfection in producer cells (293-T) of a full length HIV-1 DNA carrying a deletion of 892 base pairs (bp) in the pol gene encompassing the sequence that codes for the reverse transcriptase (NL4-3/ΔRT clone). The viral particles generated were able to enter target cells, but due to the absence of reverse transcriptase no replication was detected. The immunogenic capacity of these particles was assessed by ELISPOT to determine γ-interferon production in a cohort of 69 chronic asymptomatic HIV-1 seropositive individuals. Surprisingly, defective particles produced from NL4-3/ΔRT triggered stronger cellular responses than wild-type HIV-1 viruses inactivated with Aldrithiol-2 (AT-2) and in a larger proportion of individuals (55% versus 23% seropositive individuals tested). Electron microscopy showed that NL4-3/ΔRT virions display immature morphology. Interestingly, wild-type viruses treated with Amprenavir (APV) to induce defective core maturation also induced stronger responses than the same viral particles generated in the absence of protease inhibitors. Conclusions We propose that immature HIV-1 virions generated from NL4-3/ΔRT viral clones may represent new prototypes of immunogens with a safer profile and stronger capacity to induce cellular immune responses than wild-type inactivated viral particles. PMID:23144996

  7. Induction of ebolavirus cross-species immunity using retrovirus-like particles bearing the Ebola virus glycoprotein lacking the mucin-like domain.

    Science.gov (United States)

    Ou, Wu; Delisle, Josie; Jacques, Jerome; Shih, Joanna; Price, Graeme; Kuhn, Jens H; Wang, Vivian; Verthelyi, Daniela; Kaplan, Gerardo; Wilson, Carolyn A

    2012-01-25

    The genus Ebolavirus includes five distinct viruses. Four of these viruses cause hemorrhagic fever in humans. Currently there are no licensed vaccines for any of them; however, several vaccines are under development. Ebola virus envelope glycoprotein (GP1,2) is highly immunogenic, but antibodies frequently arise against its least conserved mucin-like domain (MLD). We hypothesized that immunization with MLD-deleted GP1,2 (GPΔMLD) would induce cross-species immunity by making more conserved regions accessible to the immune system. To test this hypothesis, mice were immunized with retrovirus-like particles (retroVLPs) bearing Ebola virus GPΔMLD, DNA plasmids (plasmo-retroVLP) that can produce such retroVLPs in vivo, or plasmo-retroVLP followed by retroVLPs. Cross-species neutralizing antibody and GP1,2-specific cellular immune responses were successfully induced. Our findings suggest that GPΔMLD presented through retroVLPs may provide a strategy for development of a vaccine against multiple ebolaviruses. Similar vaccination strategies may be adopted for other viruses whose envelope proteins contain highly variable regions that may mask more conserved domains from the immune system.

  8. Cellular Antiviral Factors that Target Particle Infectivity of HIV-1.

    Science.gov (United States)

    Goffinet, Christine

    2016-01-01

    In the past decade, the identification and characterization of antiviral genes with the ability to interfere with virus replication has established cell-intrinsic innate immunity as a third line of antiviral defense in addition to adaptive and classical innate immunity. Understanding how cellular factors have evolved to inhibit HIV-1 reveals particularly vulnerable points of the viral replication cycle. Many, but not all, antiviral proteins share type I interferon-upregulated expression and sensitivity to viral counteraction or evasion measures. Whereas well-established restriction factors interfere with early post-entry steps and release of HIV-1, recent research has revealed a diverse set of proteins that reduce the infectious quality of released particles using individual, to date poorly understood modes of action. These include induction of paucity of mature glycoproteins in nascent virions or self-incorporation into the virus particle, resulting in poor infectiousness of the virion and impaired spread of the infection. A better understanding of these newly discovered antiviral factors may open new avenues towards the design of drugs that repress the spread of viruses whose genomes have already integrated.

  9. Remarkable morphological diversity of viruses and virus-like particles in hot terrestrial environments.

    Science.gov (United States)

    Rachel, R; Bettstetter, M; Hedlund, B P; Häring, M; Kessler, A; Stetter, K O; Prangishvili, D

    2002-12-01

    Electron microscopic studies of the viruses in two hot springs (85 degrees C, pH 1.5-2.0, and 75-93 degrees C, pH 6.5) in Yellowstone National Park revealed particles with twelve different morphotypes. This diversity encompassed known viruses of hyperthermophilic archaea, filamentous Lipothrixviridae, rod-shaped Rudiviridae, and spindle-shaped Fuselloviridae, and novel morphotypes previously not observed in nature. Two virus types resembled head-and-tail bacteriophages from the families Siphoviridae and Podoviridae, and constituted the first observation of these viruses in a hydrothermal environment. Viral hosts in the acidic spring were members of the hyperthermophilic archaeal genus Acidianus.

  10. Promising MS2 mediated virus-like particle vaccine against foot-and-mouth disease.

    Science.gov (United States)

    Dong, Yan-mei; Zhang, Guo-guang; Huang, Xiao-jun; Chen, Liang; Chen, Hao-tai

    2015-05-01

    Foot-and-mouth disease (FMD) has caused severe economic losses to millions of farmers worldwide. In this work, the coding genes of 141-160 epitope peptide (EP141-160) of VP1 were inserted into the coat protein (CP) genes of MS2 in prokaryotic expression vector, and the recombinant protein self-assembled into virus-like particles (VLP). Results showed that the CP-EP141-160 VLP had a strong immunoreaction with the FMD virus (FMDV) antigen in vitro, and also had an effective immune response in mice. Further virus challenge tests were carried out on guinea pigs and swine, high-titer neutralizing antibodies were produced and the CP-EP141-160 VLP vaccine could protect most of the animals against FMDV. Copyright © 2015. Published by Elsevier B.V.

  11. Biomedical and Catalytic Opportunities of Virus-Like Particles in Nanotechnology.

    Science.gov (United States)

    Schwarz, B; Uchida, M; Douglas, T

    2017-01-01

    Within biology, molecules are arranged in hierarchical structures that coordinate and control the many processes that allow for complex organisms to exist. Proteins and other functional macromolecules are often studied outside their natural nanostructural context because it remains difficult to create controlled arrangements of proteins at this size scale. Viruses are elegantly simple nanosystems that exist at the interface of living organisms and nonliving biological machines. Studied and viewed primarily as pathogens to be combatted, viruses have emerged as models of structural efficiency at the nanoscale and have spurred the development of biomimetic nanoparticle systems. Virus-like particles (VLPs) are noninfectious protein cages derived from viruses or other cage-forming systems. VLPs provide incredibly regular scaffolds for building at the nanoscale. Composed of self-assembling protein subunits, VLPs provide both a model for studying materials' assembly at the nanoscale and useful building blocks for materials design. The robustness and degree of understanding of many VLP structures allow for the ready use of these systems as versatile nanoparticle platforms for the conjugation of active molecules or as scaffolds for the structural organization of chemical processes. Lastly the prevalence of viruses in all domains of life has led to unique activities of VLPs in biological systems most notably the immune system. Here we discuss recent efforts to apply VLPs in a wide variety of applications with the aim of highlighting how the common structural elements of VLPs have led to their emergence as paradigms for the understanding and design of biological nanomaterials. © 2017 Elsevier Inc. All rights reserved.

  12. Human transbodies to VP40 inhibit cellular egress of Ebola virus-like particles

    International Nuclear Information System (INIS)

    Teimoori, Salma; Seesuay, Watee; Jittavisutthikul, Surasak; Chaisri, Urai; Sookrung, Nitat; Densumite, Jaslan; Saelim, Nawannaporn; Chulanetra, Monrat; Maneewatch, Santi; Chaicumpa, Wanpen

    2016-01-01

    A direct acting anti-Ebola agent is needed. VP40, a conserved protein across Ebolavirus (EBOV) species has several pivotal roles in the virus life cycle. Inhibition of VP40 functions would lessen the virion integrity and interfere with the viral assembly, budding, and spread. In this study, cell penetrable human scFvs (HuscFvs) that bound to EBOV VP40 were produced by phage display technology. Gene sequences coding for VP40-bound-HuscFvs were subcloned from phagemids into protein expression plasmids downstream to a gene of cell penetrating peptide, i.e., nonaarginine (R9). By electron microscopy, transbodies from three clones effectively inhibited egress of the Ebola virus-like particles from human hepatic cells transduced with pseudo-typed-Lentivirus particles carrying EBOV VP40 and GP genes. Computerized simulation indicated that the effective HuscFvs bound to multiple basic residues in the cationic patch of VP40 C-terminal domain which are important in membrane-binding for viral matrix assembly and virus budding. The transbodies bound also to VP40 N-terminal domain and L domain peptide encompassed the PTAPPEY (WW binding) motif, suggesting that they might confer VP40 function inhibition through additional mechanism(s). The generated transbodies are worthwhile tested with authentic EBOV before developing to direct acting anti-Ebola agent for preclinical and clinical trials. - Highlights: • Cell penetrable human scFvs (transbodies) to Ebolavirus (EBOV) VP40 were produced. • The transbodies inhibited egress of EBOV-like particles (VLPs) from human hepatocytes. • They interacted with VP40 CTD basic residues important for plasma membrane binding. • And hence interfere with viral matrix assembly and viral progeny budding. • This is the first report on human antibodies that target intracellular EBOV VP40.

  13. Protein-based polymers that bond to DNA : design of virus-like particles and supramolecular nanostructures

    NARCIS (Netherlands)

    Hernandez Garcia, A.

    2014-01-01

    In this thesis it is demonstrated that it is possible to use Protein-based Polymers (PbPs) as synthetic binders of DNA (or any other negatively charged polyelectrolyte). The PbPs co-assemble with their DNA templates to form highly organized virus-like particles and supramolecular structures. A

  14. Virus-like particle vaccine primes immune responses preventing inactivated-virus vaccine-enhanced disease against respiratory syncytial virus.

    Science.gov (United States)

    Hwang, Hye Suk; Lee, Young-Tae; Kim, Ki-Hye; Ko, Eun-Ju; Lee, Youri; Kwon, Young-Man; Kang, Sang-Moo

    2017-11-01

    Formalin inactivated respiratory syncytial virus (FI-RSV) vaccination caused vaccine-enhanced respiratory disease (ERD) upon exposure to RSV in children. Virus-like particles presenting RSV F fusion protein (F VLP) are known to increase T helper type-1 (Th1) immune responses and avoid ERD in animal models. We hypothesized that F VLP would prime immune responses preventing ERD upon subsequent exposure to ERD-prone FI-RSV. Here, we demonstrated that heterologous F VLP priming and FI-RSV boosting of mice prevented FI-RSV vaccine-enhanced lung inflammation and eosinophilia upon RSV challenge. F VLP priming redirected pulmonary T cells toward effector CD8 T cells producing Th1 cytokines and significantly suppressed pulmonary Th2 cytokines. This study suggests that RSV F VLP priming would modulate and shift immune responses to subsequent exposure to ERD-prone FI-RSV vaccine and RSV infection, suppressing Th2 immune-mediated pulmonary histopathology and eosinophilia. Copyright © 2017. Published by Elsevier Inc.

  15. Coinfecting viruses as determinants of HIV disease.

    Science.gov (United States)

    Lisco, Andrea; Vanpouille, Christophe; Margolis, Leonid

    2009-02-01

    The human body constitutes a balanced ecosystem of its own cells together with various microbes ("host-microbe ecosystem"). The transmission of HIV-1 and the progression of HIV disease in such an ecosystem are accompanied by de novo infection by other microbes or by activation of microbes that were present in the host in homeostatic equilibrium before HIV-1 infection. In recent years, data have accumulated on the interactions of these coinfecting microbes-viruses in particular-with HIV. Coinfecting viruses generate negative and positive signals that suppress or upregulate HIV-1. We suggest that the signals generated by these viruses may largely affect HIV transmission, pathogenesis, and evolution. The study of the mechanisms of HIV interaction with coinfecting viruses may indicate strategies to suppress positive signals, enhance negative signals, and lead to the development of new and original anti-HIV therapies.

  16. Induction of ebolavirus cross-species immunity using retrovirus-like particles bearing the Ebola virus glycoprotein lacking the mucin-like domain

    Directory of Open Access Journals (Sweden)

    Ou Wu

    2012-01-01

    Full Text Available Abstract Background The genus Ebolavirus includes five distinct viruses. Four of these viruses cause hemorrhagic fever in humans. Currently there are no licensed vaccines for any of them; however, several vaccines are under development. Ebola virus envelope glycoprotein (GP1,2 is highly immunogenic, but antibodies frequently arise against its least conserved mucin-like domain (MLD. We hypothesized that immunization with MLD-deleted GP1,2 (GPΔMLD would induce cross-species immunity by making more conserved regions accessible to the immune system. Methods To test this hypothesis, mice were immunized with retrovirus-like particles (retroVLPs bearing Ebola virus GPΔMLD, DNA plasmids (plasmo-retroVLP that can produce such retroVLPs in vivo, or plasmo-retroVLP followed by retroVLPs. Results Cross-species neutralizing antibody and GP1,2-specific cellular immune responses were successfully induced. Conclusion Our findings suggest that GPΔMLD presented through retroVLPs may provide a strategy for development of a vaccine against multiple ebolaviruses. Similar vaccination strategies may be adopted for other viruses whose envelope proteins contain highly variable regions that may mask more conserved domains from the immune system.

  17. Visualization of Content Release from Cell Surface-Attached Single HIV-1 Particles Carrying an Extra-Viral Fluorescent pH-Sensor.

    Science.gov (United States)

    Sood, Chetan; Marin, Mariana; Mason, Caleb S; Melikyan, Gregory B

    2016-01-01

    HIV-1 fusion leading to productive entry has long been thought to occur at the plasma membrane. However, our previous single virus imaging data imply that, after Env engagement of CD4 and coreceptors at the cell surface, the virus enters into and fuses with intracellular compartments. We were unable to reliably detect viral fusion at the plasma membrane. Here, we implement a novel virus labeling strategy that biases towards detection of virus fusion that occurs in a pH-neutral environment-at the plasma membrane or, possibly, in early pH-neutral vesicles. Virus particles are co-labeled with an intra-viral content marker, which is released upon fusion, and an extra-viral pH sensor consisting of ecliptic pHluorin fused to the transmembrane domain of ICAM-1. This sensor fully quenches upon virus trafficking to a mildly acidic compartment, thus precluding subsequent detection of viral content release. As an interesting secondary observation, the incorporation of the pH-sensor revealed that HIV-1 particles occasionally shuttle between neutral and acidic compartments in target cells expressing CD4, suggesting a small fraction of viral particles is recycled to the plasma membrane and re-internalized. By imaging viruses bound to living cells, we found that HIV-1 content release in neutral-pH environment was a rare event (~0.4% particles). Surprisingly, viral content release was not significantly reduced by fusion inhibitors, implying that content release was due to spontaneous formation of viral membrane defects occurring at the cell surface. We did not measure a significant occurrence of HIV-1 fusion at neutral pH above this defect-mediated background loss of content, suggesting that the pH sensor may destabilize the membrane of the HIV-1 pseudovirus and, thus, preclude reliable detection of single virus fusion events at neutral pH.

  18. Visualization of Content Release from Cell Surface-Attached Single HIV-1 Particles Carrying an Extra-Viral Fluorescent pH-Sensor.

    Directory of Open Access Journals (Sweden)

    Chetan Sood

    Full Text Available HIV-1 fusion leading to productive entry has long been thought to occur at the plasma membrane. However, our previous single virus imaging data imply that, after Env engagement of CD4 and coreceptors at the cell surface, the virus enters into and fuses with intracellular compartments. We were unable to reliably detect viral fusion at the plasma membrane. Here, we implement a novel virus labeling strategy that biases towards detection of virus fusion that occurs in a pH-neutral environment-at the plasma membrane or, possibly, in early pH-neutral vesicles. Virus particles are co-labeled with an intra-viral content marker, which is released upon fusion, and an extra-viral pH sensor consisting of ecliptic pHluorin fused to the transmembrane domain of ICAM-1. This sensor fully quenches upon virus trafficking to a mildly acidic compartment, thus precluding subsequent detection of viral content release. As an interesting secondary observation, the incorporation of the pH-sensor revealed that HIV-1 particles occasionally shuttle between neutral and acidic compartments in target cells expressing CD4, suggesting a small fraction of viral particles is recycled to the plasma membrane and re-internalized. By imaging viruses bound to living cells, we found that HIV-1 content release in neutral-pH environment was a rare event (~0.4% particles. Surprisingly, viral content release was not significantly reduced by fusion inhibitors, implying that content release was due to spontaneous formation of viral membrane defects occurring at the cell surface. We did not measure a significant occurrence of HIV-1 fusion at neutral pH above this defect-mediated background loss of content, suggesting that the pH sensor may destabilize the membrane of the HIV-1 pseudovirus and, thus, preclude reliable detection of single virus fusion events at neutral pH.

  19. Viruses & kidney disease: beyond HIV

    Science.gov (United States)

    Waldman, Meryl; Marshall, Vickie; Whitby, Denise; Kopp, Jeffrey B.

    2008-01-01

    HIV-infected patients may acquire new viral co-infections; they may also experience the reactivation or worsening of existing viral infections, including active, smoldering, or latent infections. HIV-infected patients may be predisposed to these viral infections due to immunodeficiency or to risk factors common to HIV and other viruses. A number of these affect the kidney, either by direct infection or by deposition of immune complexes. In this review we discuss the renal manifestations and treatment of hepatitis C virus, BK virus, adenovirus, cytomegalovirus, and parvovirus B19 in patients with HIV disease. We also discuss an approach to the identification of new viral renal pathogens, using a viral gene chip to identify viral DNA or RNA. PMID:19013331

  20. Viruses and kidney disease: beyond HIV.

    Science.gov (United States)

    Waldman, Meryl; Marshall, Vickie; Whitby, Denise; Kopp, Jeffrey B

    2008-11-01

    Human immunodeficiency virus (HIV)-infected patients may acquire new viral co-infections; they also may experience the reactivation or worsening of existing viral infections, including active, smoldering, or latent infections. HIV-infected patients may be predisposed to these viral infections owing to immunodeficiency or risk factors common to HIV and other viruses. A number of these affect the kidney, either by direct infection or by deposition of immune complexes. In this review we discuss the renal manifestations and treatment of hepatitis C virus, BK virus, adenovirus, cytomegalovirus, and parvovirus B19 in patients with HIV disease. We also discuss an approach to the identification of new viral renal pathogens, using a viral gene chip to identify viral DNA or RNA.

  1. Characterization of a Latent Virus-Like Infection of Symbiotic Zooxanthellae▿

    Science.gov (United States)

    Lohr, Jayme; Munn, Colin B.; Wilson, William H.

    2007-01-01

    A latent virus-like agent, which we designated zooxanthella filamentous virus 1 (ZFV1), was isolated from Symbiodinium sp. strain CCMP 2465 and characterized. Transmission electron microscopy and analytical flow cytometry revealed the presence of a new group of distinctive filamentous virus-like particles after exposure of the zooxanthellae to UV light. Examination of thin sections of the zooxanthellae revealed the formation and proliferation of filamentous virus-like particles in the UV-induced cells. Assessment of Symbiodinium sp. cultures was used here as a model to show the effects of UV irradiance and induction of potential latent viruses. The unique host-virus system described here provides insight into the role of latent infections in zooxanthellae through environmentally regulated viral induction mechanisms. PMID:17351090

  2. Characterization of a latent virus-like infection of symbiotic zooxanthellae.

    Science.gov (United States)

    Lohr, Jayme; Munn, Colin B; Wilson, William H

    2007-05-01

    A latent virus-like agent, which we designated zooxanthella filamentous virus 1 (ZFV1), was isolated from Symbiodinium sp. strain CCMP 2465 and characterized. Transmission electron microscopy and analytical flow cytometry revealed the presence of a new group of distinctive filamentous virus-like particles after exposure of the zooxanthellae to UV light. Examination of thin sections of the zooxanthellae revealed the formation and proliferation of filamentous virus-like particles in the UV-induced cells. Assessment of Symbiodinium sp. cultures was used here as a model to show the effects of UV irradiance and induction of potential latent viruses. The unique host-virus system described here provides insight into the role of latent infections in zooxanthellae through environmentally regulated viral induction mechanisms.

  3. Detection of a human intracisternal A-type retroviral particle antigenically related to HIV

    Science.gov (United States)

    Garry, R. F.; Fermin, C. D.; Hart, D. J.; Alexander, S. S.; Donehower, L. A.; Luo-Zhang, H.

    1990-01-01

    Sjogren's syndrome is an autoimmune disease that is characterized by dryness of the mouth and eyes. The loss of salivary and lacrimal gland function is accompanied by lymphocytic infiltration. Because similar symptoms and glandular pathology are observed in certain persons infected with human immunodeficiency virus (HIV), a search was initiated for a possible retroviral etiology in this syndrome. A human intracisternal A-type retroviral particle that is antigenically related to HIV was detected in lymphoblastoid cells exposed to homogenates of salivary tissue from patients with Sjogren's syndrome. Comparison of this retroviral particle to HIV indicates that they are distinguishable by several ultrastructural, physical, and enzymatic criteria.

  4. A predominance of R5-like HIV genotypes in vaginal secretions is associated with elevated plasma HIV-1 RNA levels and the absence of anti-retroviral therapy

    Directory of Open Access Journals (Sweden)

    Lacour Nedra

    2008-07-01

    Full Text Available Abstract HIV expressed in genital secretions provides the inoculum from which transmitting variants are selected, both in sexual transmission and mother-to-infant transmission during partuition. Characterization of HIV levels and genotypes found in vaginal secretions and the impact of anti-retroviral therapy (ART on this virus can provide valuable insight for the prevention of HIV transmission. Vaginal HIV was evaluated in a cohort of 43 women attending a New Orleans HIV outpatient clinic. Predominant vaginal genotypes were characterized as R5- or X4-like by heteroduplex tracking analyses of the envelope V3 region. Most women (67.4% shed R5-like genotypes in vaginal secretions which was associated with elevated plasma HIV levels (≥ 10,000 copies HIV-RNA/mL and absence of ART. Because R5-like genotypes are more frequently associated with transmission, these observations suggest that the majority of women shedding HIV in genital secretions present a transmission risk. The levels of vaginal virus were similar between both groups, but shedding of X4-like genotypes was associated with lower plasma viral loads and the use of ART, suggesting that ART use may impact the genotypes of virus found in the female genital compartment.

  5. Interactions Between HIV-1 Gag and Viral RNA Genome Enhance Virion Assembly

    DEFF Research Database (Denmark)

    Dilley, Kari A; Nikolaitchik, Olga A; Galli, Andrea

    2017-01-01

    between Gag and viral RNA are required for the enhancement of particle production. Taken together, these studies are consistent with our previous hypothesis that specific dimeric viral RNA:Gag interactions are the nucleation event of infectious virion assembly, ensuring that one RNA dimer is packaged......Most HIV-1 virions contain two copies of full-length viral RNA, indicating that genome packaging is efficient and tightly regulated. However, the structural protein Gag is the only component required for the assembly of noninfectious virus-like particles and the viral RNA is dispensable...... in this process. The mechanism that allows HIV-1 to achieve such high efficiency of genome packaging when a packageable viral RNA is not required for virus assembly is currently unknown. In this report, we examined the role of HIV-1 RNA in virus assembly and found that packageable HIV-1 RNA enhances particle...

  6. Virus-like particles in venom of Meteorus pulchricornis induce host hemocyte apoptosis.

    Science.gov (United States)

    Suzuki, M; Tanaka, T

    2006-06-01

    Ultrastructural studies on the reproductive tract and venom apparatus of a female braconid, Meteorus pulchricornis, revealed that the parasitoid lacks the calyx region in its oviduct, but possesses a venom gland with two venom gland filaments and a venom reservoir filled with white and cloudy fluid. Its venom gland cell is concaved and has a lumen filled with numerous granules. Transmisson electron microscopic (TEM) observation revealed that virus-like particles (VLPs) were produced in venom gland cells. The virus-like particle observed in M. pulchricornis (MpVLP) is composed of membranous envelopes with two different parts: a high-density core and a whitish low-density part. The VLPs of M. pulchricornis is also found assembling ultimately in the lumen of venom gland cell. Microvilli were found thrusting into the lumen of the venom gland cell and seem to aid in driving the matured MpVLPs to the common duct of the venom gland filament. Injection of MpVLPs into non-parasitized Pseudaletia separata hosts induced apoptosis in hemocytes, particularly granulocytes (GRs). Rate of apoptosis induced in GRs peaked 48h after VLP injection. While a large part of the GR population collapsed due to apoptosis caused by MpVLPs, the plasmatocyte population was minimally affected. The capacity of MpVLPs to cause apoptosis in host's hemocytes was further demonstrated by a decrease ( approximately 10-fold) in ability of host hemocytes to encapsulate fluorescent latex beads when MpVLPs were present. Apparently, the reduced encapsulation ability was due to a decrease in the GR population resulting from MpVLP-induced apoptosis.

  7. Molecular and structural characterization of fluorescent human parvovirus B19 virus-like particles

    International Nuclear Information System (INIS)

    Gilbert, Leona; Toivola, Jouni; White, Daniel; Ihalainen, Teemu; Smith, Wesley; Lindholm, Laura; Vuento, Matti; Oker-Blom, Christian

    2005-01-01

    Although sharing a T = 1 icosahedral symmetry with other members of the Parvoviridae family, it has been suggested that the fivefold channel of the human parvovirus B19 VP2 capsids is closed at its outside end. To investigate the possibility of placing a relatively large protein moiety at this site of B19, fluorescent virus-like particles (fVLPs) of B19 were developed. The enhanced green fluorescent protein (EGFP) was inserted at the N-terminus of the structural protein VP2 and assembly of fVLPs from this fusion protein was obtained. Electron microscopy revealed that these fluorescent protein complexes were very similar in size when compared to wild-type B19 virus. Further, fluorescence correlation spectroscopy showed that an average of nine EGFP domains were associated with these virus-like structures. Atomic force microscopy and immunoprecipitation studies showed that EGFP was displayed on the surface of these fVLPs. Confocal imaging indicated that these chimeric complexes were targeted to late endosomes when expressed in insect cells. The fVLPs were able to efficiently enter cancer cells and traffic to the nucleus via the microtubulus network. Finally, immunoglobulins present in human parvovirus B19 acute and past-immunity serum samples were able to detect antigenic epitopes present in these fVLPs. In summary, we have developed fluorescent virus-like nanoparticles displaying a large heterologous entity that should be of help to elucidate the mechanisms of infection and pathogenesis of human parvovirus B19. In addition, these B19 nanoparticles serve as a model in the development of targetable vehicles designed for delivery of biomolecules

  8. Preclinical Development and Production of Virus-Like Particles As Vaccine Candidates for Hepatitis C

    Directory of Open Access Journals (Sweden)

    Makutiro Ghislain Masavuli

    2017-12-01

    Full Text Available Hepatitis C Virus (HCV infects 2% of the world’s population and is the leading cause of liver disease and liver transplantation. It poses a serious and growing worldwide public health problem that will only be partially addressed with the introduction of new antiviral therapies. However, these treatments will not prevent re-infection particularly in high risk populations. The introduction of a HCV vaccine has been predicted, using simulation models in a high risk population, to have a significant effect on reducing the incidence of HCV. A vaccine with 50 to 80% efficacy targeted to high-risk intravenous drug users could dramatically reduce HCV incidence in this population. Virus like particles (VLPs are composed of viral structural proteins which self-assemble into non-infectious particles that lack genetic material and resemble native viruses. Thus, VLPs represent a safe and highly immunogenic vaccine delivery platform able to induce potent adaptive immune responses. Currently, many VLP-based vaccines have entered clinical trials, while licensed VLP vaccines for hepatitis B virus (HBV and human papilloma virus (HPV have been in use for many years. The HCV core, E1 and E2 proteins can self-assemble into immunogenic VLPs while inclusion of HCV antigens into heterogenous (chimeric VLPs is also a promising approach. These VLPs are produced using different expression systems such as bacterial, yeast, mammalian, plant, or insect cells. Here, this paper will review HCV VLP-based vaccines and their immunogenicity in animal models as well as the different expression systems used in their production.

  9. A chimeric measles virus with a lentiviral envelope replicates exclusively in CD4+/CCR5+ cells

    International Nuclear Information System (INIS)

    Mourez, Thomas; Mesel-Lemoine, Mariana; Combredet, Chantal; Najburg, Valerie; Cayet, Nadege; Tangy, Frederic

    2011-01-01

    We generated a replicating chimeric measles virus in which the hemagglutinin and fusion surface glycoproteins were replaced with the gp160 envelope glycoprotein of simian immunodeficiency virus (SIVmac239). Based on a previously cloned live-attenuated Schwarz vaccine strain of measles virus (MV), this chimera was rescued at high titers using reverse genetics in CD4+ target cells. Cytopathic effect consisted in the presence of large cell aggregates evolving to form syncytia, as observed during SIV infection. The morphology of the chimeric virus was identical to that of the parent MV particles. The presence of SIV gp160 as the only envelope protein on chimeric particles surface altered the cell tropism of the new virus from CD46+ to CD4+ cells. Used as an HIV candidate vaccine, this MV/SIVenv chimeric virus would mimic transient HIV-like infection, benefiting both from HIV-like tropism and the capacity of MV to replicate in dendritic cells, macrophages and lymphocytes.

  10. Protection against Multiple Subtypes of Influenza Viruses by Virus-Like Particle Vaccines Based on a Hemagglutinin Conserved Epitope

    Directory of Open Access Journals (Sweden)

    Shaoheng Chen

    2015-01-01

    Full Text Available We selected the conserved sequence in the stalk region of influenza virus hemagglutinin (HA trimmer, the long alpha helix (LAH, as the vaccine candidate sequence, and inserted it into the major immunodominant region (MIR of hepatitis B virus core protein (HBc, and, by using the E. coli expression system, we prepared a recombinant protein vaccine LAH-HBc in the form of virus-like particles (VLP. Intranasal immunization of mice with this LAH-HBc VLP plus cholera toxin B subunit with 0.2% of cholera toxin (CTB* adjuvant could effectively elicit humoral and cellular immune responses and protect mice against a lethal challenge of homologous influenza viruses (A/Puerto Rico/8/1934 (PR8 (H1N1. In addition, passage of the immune sera containing specific antibodies to naïve mice rendered them resistant against a lethal homologous challenge. Immunization with LAH-HBc VLP vaccine plus CTB* adjuvant could also fully protect mice against a lethal challenge of the 2009 pandemic H1N1 influenza virus or the avian H9N2 virus and could partially protect mice against a lethal challenge of the avian H5N1 influenza virus. This study demonstrated that the LAH-HBc VLP vaccine based on a conserved sequence of the HA trimmer stalk region is a promising candidate vaccine for developing a universal influenza vaccine against multiple influenza viruses infections.

  11. Seksuel transmission af hepatitis C-virus hos hiv-inficerede maend

    DEFF Research Database (Denmark)

    Peters, Lars; Weis, Nina M; Lindhardt, Bjarne Orskov

    2006-01-01

    Infections with the hepatitis C virus (HCV) occur primarily through percutaneous transmission, while sexual transmission seems to be rare. Recently, in some European cities, an increasing incidence of sexually transmitted HCV infection among HIV-infected homosexual males has been reported. We...... describe four cases of acute HCV infection among HIV-infected homosexual males, where sexual transmission was likely. Udgivelsesdato: 2006-Oct-16...

  12. Affinity selection of Nipah and Hendra virus-related vaccine candidates from a complex random peptide library displayed on bacteriophage virus-like particles

    Energy Technology Data Exchange (ETDEWEB)

    Peabody, David S.; Chackerian, Bryce; Ashley, Carlee; Carnes, Eric; Negrete, Oscar

    2017-01-24

    The invention relates to virus-like particles of bacteriophage MS2 (MS2 VLPs) displaying peptide epitopes or peptide mimics of epitopes of Nipah Virus envelope glycoprotein that elicit an immune response against Nipah Virus upon vaccination of humans or animals. Affinity selection on Nipah Virus-neutralizing monoclonal antibodies using random sequence peptide libraries on MS2 VLPs selected peptides with sequence similarity to peptide sequences found within the envelope glycoprotein of Nipah itself, thus identifying the epitopes the antibodies recognize. The selected peptide sequences themselves are not necessarily identical in all respects to a sequence within Nipah Virus glycoprotein, and therefore may be referred to as epitope mimics VLPs displaying these epitope mimics can serve as vaccine. On the other hand, display of the corresponding wild-type sequence derived from Nipah Virus and corresponding to the epitope mapped by affinity selection, may also be used as a vaccine.

  13. Production of FMDV virus-like particles by a SUMO fusion protein approach in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Liang Shu-Mei

    2009-08-01

    Full Text Available Abstract Virus-like particles (VLPs are formed by the self-assembly of envelope and/or capsid proteins from many viruses. Some VLPs have been proven successful as vaccines, and others have recently found applications as carriers for foreign antigens or as scaffolds in nanoparticle biotechnology. However, production of VLP was usually impeded due to low water-solubility of recombinant virus capsid proteins. Previous studies revealed that virus capsid and envelope proteins were often posttranslationally modified by SUMO in vivo, leading into a hypothesis that SUMO modification might be a common mechanism for virus proteins to retain water-solubility or prevent improper self-aggregation before virus assembly. We then propose a simple approach to produce VLPs of viruses, e.g., foot-and-mouth disease virus (FMDV. An improved SUMO fusion protein system we developed recently was applied to the simultaneous expression of three capsid proteins of FMDV in E. coli. The three SUMO fusion proteins formed a stable heterotrimeric complex. Proteolytic removal of SUMO moieties from the ternary complexes resulted in VLPs with size and shape resembling the authentic FMDV. The method described here can also apply to produce capsid/envelope protein complexes or VLPs of other disease-causing viruses.

  14. Virus-like particle nanoreactors: programmed en capsulation of the thermostable CelB glycosidase inside the P22 capsid

    NARCIS (Netherlands)

    Patterson, D.P.; Schwarz, B.; El-Boubbou, K.; Oost, van der J.; Prevelige, P.E.; Douglas, T.

    2012-01-01

    Self-assembling biological systems hold great potential for the synthetic construction of new active soft nanomaterials. Here we demonstrate the hierarchical bottom-up assembly of bacteriophage P22 virus-like particles (VLPs) that encapsulate the thermostable CelB glycosidase creating catalytically

  15. HIV-particles in spermatozoa of patients with AIDS and their transfer into the oocyte

    Science.gov (United States)

    Baccetti, B; Benedetto, A; Burrini, AG; Collodel, G; Ceccarini, EC; Crisa, N; Di Caro, A; Estenoz, M; Garbuglia, AR; Massacesi, A; Piomboni, P; Renieri, T; Solazzo, D

    1994-01-01

    By immunocytochemistry and in situ hybridization at the electron microscopy level, and by the PCR technique, we have shown that HIV-1 binds and enters normal sperm; that viral particles, their antigens, and nucleic acid are present in sperm from HIV-1 infected men; and that such sperm can transfer HIV-1 like particles to normal human oocytes. We also present evidence that a galactosylceramide-like compound is present on the sperm membrane and could function as an alternative receptor for HIV. PMID:7962075

  16. Bacterially produced recombinant influenza vaccines based on virus-like particles.

    Directory of Open Access Journals (Sweden)

    Andrea Jegerlehner

    Full Text Available Although current influenza vaccines are effective in general, there is an urgent need for the development of new technologies to improve vaccine production timelines, capacities and immunogenicity. Herein, we describe the development of an influenza vaccine technology which enables recombinant production of highly efficient influenza vaccines in bacterial expression systems. The globular head domain of influenza hemagglutinin, comprising most of the protein's neutralizing epitopes, was expressed in E. coli and covalently conjugated to bacteriophage-derived virus-like particles produced independently in E.coli. Conjugate influenza vaccines produced this way were used to immunize mice and found to elicit immune sera with high antibody titers specific for the native influenza hemagglutinin protein and high hemagglutination-inhibition titers. Moreover vaccination with these vaccines induced full protection against lethal challenges with homologous and highly drifted influenza strains.

  17. Single Dose of Consensus Hemagglutinin-Based Virus-Like Particles Vaccine Protects Chickens against Divergent H5 Subtype Influenza Viruses

    Directory of Open Access Journals (Sweden)

    Peipei Wu

    2017-11-01

    Full Text Available The H5 subtype highly pathogenic avian influenza (HPAI virus is one of the greatest threats to global poultry industry. To develop broadly protective H5 subunit vaccine, a recombinant consensus HA sequence (rHA was constructed and expressed in virus-like particles (rHA VLPs in the baculovirus-insect cell system. The efficacy of the rHA VLPs vaccine with or without immunopotentiator (CVCVA5 was assessed in chickens. Compared to the commercial Re6 or Re6-CVCVA5 vaccines, single dose immunization of chickens with rHA VLPs or rHA-CVCVA5 vaccines induced higher levels of serum hemagglutinin inhibition titers and neutralization titers, mucosal antibodies, IFN-γ and IL-4 cytokines in sera, and cytotoxic T lymphocyte responses. The rHA VLPs vaccine was superior to the commercial Re6 vaccine in conferring cross-protection against different clades of H5 subtype viruses. This study reports that H5 subtype consensus HA VLP single dose vaccination provides broad protection against HPAI virus in chickens.

  18. Particle size effects on protein and virus-like particle adsorption on perfusion chromatography media.

    Science.gov (United States)

    Wu, Yige; Abraham, Dicky; Carta, Giorgio

    2015-01-02

    The resin structure, chromatographic behavior, and adsorption kinetics of proteins and virus-like-particles (VLPs) are studied for POROS HS 20 and POROS HS 50 (23 and 52 μm mean diameter, respectively) to determine the effects of particle size on perfusion chromatography and to determine the predictive ability of available models. Transmission electron microscopy (TEM) and inverse size-exclusion chromatography (iSEC) show similar structures for the two resins, both containing 200-1000 nm pores that transect a network of much smaller pores. For non-binding conditions, trends of the height equivalent to a theoretical plate (HETP) as a function of reduced velocity are consistent with perfusion. The estimated intraparticle flow fractions for these conditions are 0.0018 and 0.00063 for POROS HS 20 and HS 50, respectively. For strong binding conditions, confocal laser scanning microscopy (CLSM) shows asymmetrical intraparticle concentrations profiles and enhanced rates of IgG adsorption on POROS HS 20 at 1000 cm/h. The corresponding effective diffusivity under flow is 2-3 times larger than for non-flow conditions and much larger than observed for POROS HS 50, consistent with available models. For VLPs, however, adsorption is confined to a thin layer near the particle surface for both resins, suggesting that the bound VLPs block the pores. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Epstein–Barr virus particles induce centrosome amplification and chromosomal instability

    Science.gov (United States)

    Shumilov, Anatoliy; Tsai, Ming-Han; Schlosser, Yvonne T.; Kratz, Anne-Sophie; Bernhardt, Katharina; Fink, Susanne; Mizani, Tuba; Lin, Xiaochen; Jauch, Anna; Mautner, Josef; Kopp-Schneider, Annette; Feederle, Regina; Hoffmann, Ingrid; Delecluse, Henri-Jacques

    2017-01-01

    Infections with Epstein–Barr virus (EBV) are associated with cancer development, and EBV lytic replication (the process that generates virus progeny) is a strong risk factor for some cancer types. Here we report that EBV infection of B-lymphocytes (in vitro and in a mouse model) leads to an increased rate of centrosome amplification, associated with chromosomal instability. This effect can be reproduced with virus-like particles devoid of EBV DNA, but not with defective virus-like particles that cannot infect host cells. Viral protein BNRF1 induces centrosome amplification, and BNRF1-deficient viruses largely lose this property. These findings identify a new mechanism by which EBV particles can induce chromosomal instability without establishing a chronic infection, thereby conferring a risk for development of tumours that do not necessarily carry the viral genome. PMID:28186092

  20. HIV-1 Envelope Glycoprotein Trafficking through the Endosomal Recycling Compartment Is Required for Particle Incorporation.

    Science.gov (United States)

    Kirschman, Junghwa; Qi, Mingli; Ding, Lingmei; Hammonds, Jason; Dienger-Stambaugh, Krista; Wang, Jaang-Jiun; Lapierre, Lynne A; Goldenring, James R; Spearman, Paul

    2018-03-01

    The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) encodes specific trafficking signals within its long cytoplasmic tail (CT) that regulate incorporation into HIV-1 particles. Rab11-family interacting protein 1C (FIP1C) and Rab14 are host trafficking factors required for Env particle incorporation, suggesting that Env undergoes sorting from the endosomal recycling compartment (ERC) to the site of particle assembly on the plasma membrane. We disrupted outward sorting from the ERC by expressing a C-terminal fragment of FIP1C (FIP1C 560-649 ) and examined the consequences on Env trafficking and incorporation into particles. FIP1C 560-649 reduced cell surface levels of Env and prevented its incorporation into HIV-1 particles. Remarkably, Env was trapped in an exaggerated perinuclear ERC in a CT-dependent manner. Mutation of either the Yxxϕ endocytic motif or the YW 795 motif in the CT prevented Env trapping in the ERC and restored incorporation into particles. In contrast, simian immunodeficiency virus SIVmac239 Env was not retained in the ERC, while substitution of the HIV-1 CT for the SIV CT resulted in SIV Env retention in this compartment. These results provide the first direct evidence that Env traffics through the ERC and support a model whereby HIV-1 Env is specifically targeted to the ERC prior to FIP1C- and CT-dependent outward sorting to the particle assembly site on the plasma membrane. IMPORTANCE The HIV envelope protein is an essential component of the viral particle. While many aspects of envelope protein structure and function have been established, the pathway it follows in the cell prior to reaching the site of particle assembly is not well understood. The envelope protein has a very long cytoplasmic tail that interacts with the host cell trafficking machinery. Here, we utilized a truncated form of the trafficking adaptor FIP1C protein to arrest the intracellular transport of the envelope protein, demonstrating that it becomes

  1. Biophysical analysis of HTLV-1 particles reveals novel insights into particle morphology and Gag stochiometry

    Directory of Open Access Journals (Sweden)

    Fogarty Keir H

    2010-09-01

    Full Text Available Abstract Background Human T-lymphotropic virus type 1 (HTLV-1 is an important human retrovirus that is a cause of adult T-cell leukemia/lymphoma. While an important human pathogen, the details regarding virus replication cycle, including the nature of HTLV-1 particles, remain largely unknown due to the difficulties in propagating the virus in tissue culture. In this study, we created a codon-optimized HTLV-1 Gag fused to an EYFP reporter as a model system to quantitatively analyze HTLV-1 particles released from producer cells. Results The codon-optimized Gag led to a dramatic and highly robust level of Gag expression as well as virus-like particle (VLP production. The robust level of particle production overcomes previous technical difficulties with authentic particles and allowed for detailed analysis of particle architecture using two novel methodologies. We quantitatively measured the diameter and morphology of HTLV-1 VLPs in their native, hydrated state using cryo-transmission electron microscopy (cryo-TEM. Furthermore, we were able to determine HTLV-1 Gag stoichiometry as well as particle size with the novel biophysical technique of fluorescence fluctuation spectroscopy (FFS. The average HTLV-1 particle diameter determined by cryo-TEM and FFS was 71 ± 20 nm and 75 ± 4 nm, respectively. These values are significantly smaller than previous estimates made of HTLV-1 particles by negative staining TEM. Furthermore, cryo-TEM reveals that the majority of HTLV-1 VLPs lacks an ordered structure of the Gag lattice, suggesting that the HTLV-1 Gag shell is very likely to be organized differently compared to that observed with HIV-1 Gag in immature particles. This conclusion is supported by our observation that the average copy number of HTLV-1 Gag per particle is estimated to be 510 based on FFS, which is significantly lower than that found for HIV-1 immature virions. Conclusions In summary, our studies represent the first quantitative biophysical

  2. Vaccination with dengue virus-like particles induces humoral and cellular immune responses in mice

    Directory of Open Access Journals (Sweden)

    Zhang Quanfu

    2011-06-01

    Full Text Available Abstract Background The incidence of dengue, an infectious disease caused by dengue virus (DENV, has dramatically increased around the world in recent decades and is becoming a severe public health threat. However, there is currently no specific treatment for dengue fever, and licensed vaccine against dengue is not available. Vaccination with virus-like particles (VLPs has shown considerable promise for many viral diseases, but the effect of DENV VLPs to induce specific immune responses has not been adequately investigated. Results By optimizing the expression plasmids, recombinant VLPs of four antigenically different DENV serotypes DENV1-4 were successfully produced in 293T cells. The vaccination effect of dengue VLPs in mice showed that monovalent VLPs of each serotype stimulated specific IgG responses and potent neutralizing antibodies against homotypic virus. Tetravalent VLPs efficiently enhanced specific IgG and neutralizing antibodies against all four serotypes of DENV. Moreover, vaccination with monovalent or tetravalent VLPs resulted in the induction of specific cytotoxic T cell responses. Conclusions Mammalian cell expressed dengue VLPs are capable to induce VLP-specific humoral and cellular immune responses in mice, and being a promising subunit vaccine candidate for prevention of dengue virus infection.

  3. Homologous and Heterologous Protection of Nonhuman Primates by Ebola and Sudan Virus-Like Particles

    Science.gov (United States)

    Warfield, Kelly L.; Dye, John M.; Wells, Jay B.; Unfer, Robert C.; Holtsberg, Frederick W.; Shulenin, Sergey; Vu, Hong; Swenson, Dana L.; Bavari, Sina; Aman, M. Javad

    2015-01-01

    Filoviruses cause hemorrhagic fever resulting in significant morbidity and mortality in humans. Several vaccine platforms that include multiple virus-vectored approaches and virus-like particles (VLPs) have shown efficacy in nonhuman primates. Previous studies have shown protection of cynomolgus macaques against homologous infection for Ebola virus (EBOV) and Marburg virus (MARV) following a three-dose vaccine regimen of EBOV or MARV VLPs, as well as heterologous protection against Ravn Virus (RAVV) following vaccination with MARV VLPs. The objectives of the current studies were to determine the minimum number of vaccine doses required for protection (using EBOV as the test system) and then demonstrate protection against Sudan virus (SUDV) and Taï Forest virus (TAFV). Using the EBOV nonhuman primate model, we show that one or two doses of VLP vaccine can confer protection from lethal infection. VLPs containing the SUDV glycoprotein, nucleoprotein and VP40 matrix protein provide complete protection against lethal SUDV infection in macaques. Finally, we demonstrate protective efficacy mediated by EBOV, but not SUDV, VLPs against TAFV; this is the first demonstration of complete cross-filovirus protection using a single component heterologous vaccine within the Ebolavirus genus. Along with our previous results, this observation provides strong evidence that it will be possible to develop and administer a broad-spectrum VLP-based vaccine that will protect against multiple filoviruses by combining only three EBOV, SUDV and MARV components. PMID:25793502

  4. Homologous and heterologous protection of nonhuman primates by Ebola and Sudan virus-like particles.

    Directory of Open Access Journals (Sweden)

    Kelly L Warfield

    Full Text Available Filoviruses cause hemorrhagic fever resulting in significant morbidity and mortality in humans. Several vaccine platforms that include multiple virus-vectored approaches and virus-like particles (VLPs have shown efficacy in nonhuman primates. Previous studies have shown protection of cynomolgus macaques against homologous infection for Ebola virus (EBOV and Marburg virus (MARV following a three-dose vaccine regimen of EBOV or MARV VLPs, as well as heterologous protection against Ravn Virus (RAVV following vaccination with MARV VLPs. The objectives of the current studies were to determine the minimum number of vaccine doses required for protection (using EBOV as the test system and then demonstrate protection against Sudan virus (SUDV and Taï Forest virus (TAFV. Using the EBOV nonhuman primate model, we show that one or two doses of VLP vaccine can confer protection from lethal infection. VLPs containing the SUDV glycoprotein, nucleoprotein and VP40 matrix protein provide complete protection against lethal SUDV infection in macaques. Finally, we demonstrate protective efficacy mediated by EBOV, but not SUDV, VLPs against TAFV; this is the first demonstration of complete cross-filovirus protection using a single component heterologous vaccine within the Ebolavirus genus. Along with our previous results, this observation provides strong evidence that it will be possible to develop and administer a broad-spectrum VLP-based vaccine that will protect against multiple filoviruses by combining only three EBOV, SUDV and MARV components.

  5. A novel recombinant virus-like particle vaccine for prevention of porcine parvovirus-induced reproductive failure.

    Science.gov (United States)

    Antonis, Adriaan F G; Bruschke, Christianne J M; Rueda, Paloma; Maranga, Luis; Casal, J Ignacio; Vela, Carmen; Hilgers, Luuk A Th; Belt, Peter B G M; Weerdmeester, Klaas; Carrondo, Manuel J T; Langeveld, Jan P M

    2006-06-29

    A novel vaccine against porcine parvovirus (PPV), composed of recombinant virus-like particles (PPV-VLPs) produced with the baculovirus expression vector system (BEVS) at industrial scale, was tested for its immunogenicity and protective potency. A formulation of submicrogram amounts of PPV-VLPs in a water-in-mineral oil adjuvant evoked high serum antibody titres in both guinea pigs, used as reference model, and target species, pigs. A single immunisation with 0.7microg of this antigen yielded complete foetal protection against PPV infection after challenge with a virulent strain of this virus. Furthermore, also in the presence of mild adjuvants the protective action of these PPV-VLPs is excellent. This recombinant subunit vaccine overcomes some of the drawbacks of classical PPV vaccines.

  6. Herpes viruses and HIV-1 drug resistance mutations influence the virologic and immunologic milieu of the male genital tract.

    Science.gov (United States)

    Gianella, Sara; Morris, Sheldon R; Anderson, Christy; Spina, Celsa A; Vargas, Milenka V; Young, Jason A; Richman, Douglas D; Little, Susan J; Smith, Davey M

    2013-01-02

    To further understand the role that chronic viral infections of the male genital tract play on HIV-1 dynamics and replication. Retrospective, observational study including 236 paired semen and blood samples collected from 115 recently HIV-1 infected antiretroviral naive men who have sex with men. In this study, we evaluated the association of seminal HIV-1 shedding to coinfections with seven herpes viruses, blood plasma HIV-1 RNA levels, CD4 T-cell counts, presence of transmitted drug resistance mutations (DRMs) in HIV-1 pol, participants' age and stage of HIV-infection using multivariate generalized estimating equation methods. Associations between herpes virus shedding, seminal HIV-1 levels, number and immune activation of seminal T-cells was also investigated (Mann-Whitney). Seminal herpes virus shedding was observed in 75.7% of individuals. Blood HIV-1 RNA levels (P herpes virus (HHV)-8 levels (P herpes viruses seminal shedding in our cohort. Shedding of CMV, EBV and HHV-8 and absence of DRM were associated with increased frequency of HIV-1 shedding and/or higher levels of HIV-1 RNA in semen, which are likely important cofactors for HIV-1 transmission.

  7. Prevalence of virus-like particles within a staghorn scleractinian coral ( Acropora muricata) from the Great Barrier Reef

    Science.gov (United States)

    Patten, N. L.; Harrison, P. L.; Mitchell, J. G.

    2008-09-01

    Transmission electron microscopy (TEM) was used to determine whether Acropora muricata coral colonies from the Great Barrier Reef (GBR), Australia, harboured virus-like particles (VLPs). VLPs were present in all coral colonies sampled at Heron Island (southern GBR) and in tagged coral colonies sampled in at least two of the three sampling periods at Lizard Island (northern GBR). VLPs were observed within gastrodermal and epidermal tissues, and on rarer occasions, within the mesoglea. These VLPs had similar morphologies to known prokaryotic and eukaryotic viruses in other systems. Icosahedral VLPs were observed most frequently, however, filamentous VLPs (FVLPs) and phage were also noted. There were no clear differences in VLP size, morphology or location within the tissues with respect to sample date, coral health status or site. The most common VLP morphotype exhibited icosahedral symmetry, 120-150 nm in diameter, with an electron-dense core and an electronlucent membrane. Larger VLPs of similar morphology were also common. VLPs occurred as single entities, in groups, or in dense clusters, either as free particles within coral tissues, or within membrane-bound vacuoles. VLPs were commonly observed within the perinuclear region, with mitochondria, golgi apparatus and crescent-shaped particles frequently observed within close proximity. The host(s) of these observed VLPs was not clear; however, the different sizes and morphologies of VLPs observed within A. muricata tissues suggest that viruses are infecting either the coral animal, zooxanthellae, intracellular bacteria and/or other coral-associated microbiota, or that the one host is susceptible to infection from more than one type of virus. These results add to the limited but emerging body of evidence that viruses represent another potentially important component of the coral holobiont.

  8. Prevalence of human immunodeficiency virus (HIV) infection among ...

    African Journals Online (AJOL)

    AJB SERVER

    2007-02-05

    Feb 5, 2007 ... associated virus (LAV, now HIV1.). In the same year,. Robert Gallo and colleagues, working at the National. Cancer Institute (NCI), USA made a similar discovery while in their quest to find cancer-causing viruses. In. 1986 a second closely related virus, termed HIV 2 was isolated from a patient from West ...

  9. Characterization of self-assembled virus-like particles of dromedary camel hepatitis e virus generated by recombinant baculoviruses.

    Science.gov (United States)

    Zhou, Xianfeng; Kataoka, Michiyo; Liu, Zheng; Takeda, Naokazu; Wakita, Takaji; Li, Tian-Cheng

    2015-12-02

    Dromedary camel hepatitis E virus (DcHEV), a novel hepatitis E virus, has been identified in dromedary camels in Dubai, United Arab Emirates. The antigenicity, pathogenicity and epidemiology of this virus have been unclear. Here we first used a recombinant baculovirus expression system to express the 13 and 111 N-terminus amino-acid-truncated DcHEV ORF2 protein in insect Tn5 cells, and we obtained two types of virus-like particles (VLPs) with densities of 1.300 g/cm(3) and 1.285 g/cm(3), respectively. The small VLPs (Dc4sVLPs) were estimated to be 24 nm in diameter, and were assembled by a protein with the molecular mass 53 kDa. The large VLPs (Dc3nVLPs and Dc4nVLPs) were 35 nm in diameter, and were assembled by a 64-kDa protein. An antigenic analysis demonstrated that DcHEV was cross-reactive with G1, G3-G6, ferret and rat HEVs, and DcHEV showed a stronger cross-reactivity to G1 G3-G6 HEV than it did to rat and ferret HEV. In addition, the antibody against DcHEV-LPs neutralized G1 and G3 HEV in a cell culture system, suggesting that the serotypes of these HEVs are identical. We also found that the amino acid residue Met-358 affects the small DcHEV-LPs assembly. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Characterization of virus-like particles by atomic force microscopy in ambient conditions

    International Nuclear Information System (INIS)

    Oropesa, Reinier; Ramos, Jorge R; Falcón, Viviana; Felipe, Ariel

    2013-01-01

    Recombinant virus-like particles (VLPs) are attractive candidates for vaccine design since they resemble native viroids in size and morphology, but they are non-infectious due to the absence of a viral genome. The visualization of surface morphologies and structures can be used to deepen the understanding of physical, chemical, and biological phenomena. Atomic force microscopy (AFM) is a useful tool for the visualization of soft biological samples in a nanoscale resolution. In this work we have investigated the morphology of recombinant surface antigens of hepatitis B (rHBsAg) VLPs from Cuban vaccine against hepatitis B. The rHBsAg VLPs sizes estimated by AFM between 15 and 30 nm are similar to those reported on previous transmission electron microscopy (TEM) studies. (paper)

  11. Chimeric SV40 virus-like particles induce specific cytotoxicity and protective immunity against influenza A virus without the need of adjuvants.

    Science.gov (United States)

    Kawano, Masaaki; Morikawa, Katsuma; Suda, Tatsuya; Ohno, Naohito; Matsushita, Sho; Akatsuka, Toshitaka; Handa, Hiroshi; Matsui, Masanori

    2014-01-05

    Virus-like particles (VLPs) are a promising vaccine platform due to the safety and efficiency. However, it is still unclear whether polyomavirus-based VLPs are useful for this purpose. Here, we attempted to evaluate the potential of polyomavirus VLPs for the antiviral vaccine using simian virus 40 (SV40). We constructed chimeric SV40-VLPs carrying an HLA-A*02:01-restricted, cytotoxic T lymphocyte (CTL) epitope derived from influenza A virus. HLA-A*02:01-transgenic mice were then immunized with the chimeric SV40-VLPs. The chimeric SV40-VLPs effectively induced influenza-specific CTLs and heterosubtypic protection against influenza A viruses without the need of adjuvants. Because DNase I treatment of the chimeric SV40-VLPs did not disrupt CTL induction, the intrinsic adjuvant property may not result from DNA contaminants in the VLP preparation. In addition, immunization with the chimeric SV40-VLPs generated long-lasting memory CTLs. We here propose that the chimeric SV40-VLPs harboring an epitope may be a promising CTL-based vaccine platform with self-adjuvant properties. © 2013 Elsevier Inc. All rights reserved.

  12. Induction of long-term protective immune responses by influenza H5N1 virus-like particles.

    Directory of Open Access Journals (Sweden)

    Sang-Moo Kang

    Full Text Available Recurrent outbreaks of highly pathogenic H5N1 avian influenza virus pose a threat of eventually causing a pandemic. Early vaccination of the population would be the single most effective measure for the control of an emerging influenza pandemic.Influenza virus-like particles (VLPs produced in insect cell-culture substrates do not depend on the availability of fertile eggs for vaccine manufacturing. We produced VLPs containing influenza A/Viet Nam1203/04 (H5N1 hemagglutinin, neuraminidase, and matrix proteins, and investigated their preclinical immunogenicity and protective efficacy. Mice immunized intranasally with H5N1 VLPs developed high levels of H5N1 specific antibodies and were 100% protected against a high dose of homologous H5N1 virus infection at 30 weeks after immunization. Protection is likely to be correlated with humoral and cellular immunologic memory at systemic and mucosal sites as evidenced by rapid anamnestic responses to re-stimulation with viral antigen in vivo and in vitro.These results provide support for clinical evaluation of H5N1 VLP vaccination as a public health intervention to mitigate a possible pandemic of H5N1 influenza.

  13. Maize rayado fino virus virus-like particles expressed in tobacco plants: A new platform for cysteine selective bioconjugation peptide display.

    Science.gov (United States)

    Natilla, Angela; Hammond, Rosemarie W

    2011-12-01

    Maize rayado fino virus (MRFV) virus-like-particles (VLPs) produced in tobacco plants were examined for their ability to serve as a novel platform to which a variety of peptides can be covalently displayed when expressed through a Potato virus X (PVX)-based vector. To provide an anchor for chemical modifications, three Cys-MRFV-VLPs mutants were created by substituting several of the amino acids present on the shell of the wild-type MRFV-VLPs with cysteine residues. The mutant designated Cys 2-VLPs exhibited, under native conditions, cysteine thiol reactivity in bioconjugation reactions with a fluorescent dye. In addition, this Cys 2-VLPs was cross-linked by NHS-PEG4-Maleimide to 17 (F) and 8 (HN) amino acid long peptides, corresponding to neutralizing epitopes of Newcastle disease virus (NDV). The resulting Cys 2-VLPs-F and Cys 2-VLPs-HN were recognized in Western blots by antibodies to MRFV as well as to F and HN. The results demonstrated that plant-produced MRFV-VLPs have the ability to function as a novel platform for the multivalent display of surface ligands. Published by Elsevier B.V.

  14. Drosophila Nora virus capsid proteins differ from those of other picorna-like viruses.

    Science.gov (United States)

    Ekström, Jens-Ola; Habayeb, Mazen S; Srivastava, Vaibhav; Kieselbach, Thomas; Wingsle, Gunnar; Hultmark, Dan

    2011-09-01

    The recently discovered Nora virus from Drosophila melanogaster is a single-stranded RNA virus. Its published genomic sequence encodes a typical picorna-like cassette of replicative enzymes, but no capsid proteins similar to those in other picorna-like viruses. We have now done additional sequencing at the termini of the viral genome, extending it by 455 nucleotides at the 5' end, but no more coding sequence was found. The completeness of the final 12,333-nucleotide sequence was verified by the production of infectious virus from the cloned genome. To identify the capsid proteins, we purified Nora virus particles and analyzed their proteins by mass spectrometry. Our results show that the capsid is built from three major proteins, VP4A, B and C, encoded in the fourth open reading frame of the viral genome. The viral particles also contain traces of a protein from the third open reading frame, VP3. VP4A and B are not closely related to other picorna-like virus capsid proteins in sequence, but may form similar jelly roll folds. VP4C differs from the others and is predicted to have an essentially α-helical conformation. In a related virus, identified from EST database sequences from Nasonia parasitoid wasps, VP4C is encoded in a separate open reading frame, separated from VP4A and B by a frame-shift. This opens a possibility that VP4C is produced in non-equimolar quantities. Altogether, our results suggest that the Nora virus capsid has a different protein organization compared to the order Picornavirales. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Incorporation of chimeric HIV-SIV-Env and modified HIV-Env proteins into HIV pseudovirions

    International Nuclear Information System (INIS)

    Devitt, Gerard; Emerson, Vanessa; Holtkotte, Denise; Pfeiffer, Tanya; Pisch, Thorsten; Bosch, Valerie

    2007-01-01

    Low level incorporation of the viral glycoprotein (Env) into human immunodeficiency virus (HIV) particles is a major drawback for vaccine strategies against HIV/AIDS in which HIV particles are used as immunogen. Within this study, we have examined two strategies aimed at achieving higher levels of Env incorporation into non-infectious pseudovirions (PVs). First, we have generated chimeric HIV/SIV Env proteins containing the truncated C-terminal tail region of simian immunodeficiency virus (SIV)mac239-Env767 stop , which mediates strongly increased incorporation of SIV-Env into SIV particles. In a second strategy, we have employed a truncated HIV-Env protein (Env-Tr752 N750K ) which we have previously demonstrated to be incorporated into HIV virions, generated in infected T-cells, to a higher level than that of Wt-HIV-Env. Although the chimeric HIV/SIV Env proteins were expressed at the cell surface and induced increased levels of cell-cell fusion in comparison to Wt-HIV-Env, they did not exhibit increased incorporation into either HIV-PVs or SIV-PVs. Only Env-Tr752 N750K exhibited significantly higher (threefold) levels of incorporation into HIV-PVs, an improvement, which, although not dramatic, is worthwhile for the large-scale preparation of non-infectious PVs for vaccine studies aimed at inducing Env humoral responses

  16. Synthetic virus-like particles target dendritic cell lipid rafts for rapid endocytosis primarily but not exclusively by macropinocytosis.

    Directory of Open Access Journals (Sweden)

    Rajni Sharma

    Full Text Available DC employ several endocytic routes for processing antigens, driving forward adaptive immunity. Recent advances in synthetic biology have created small (20-30 nm virus-like particles based on lipopeptides containing a virus-derived coiled coil sequence coupled to synthetic B- and T-cell epitope mimetics. These self-assembling SVLP efficiently induce adaptive immunity without requirement for adjuvant. We hypothesized that the characteristics of DC interaction with SVLP would elaborate on the roles of cell membrane and intracellular compartments in the handling of a virus-like entity known for its efficacy as a vaccine. DC rapidly bind SVLP within min, co-localised with CTB and CD9, but not caveolin-1. In contrast, internalisation is a relatively slow process, delivering SVLP into the cell periphery where they are maintained for a number of hrs in association with microtubules. Although there is early association with clathrin, this is no longer seen after 10 min. Association with EEA-1(+ early endosomes is also early, but proteolytic processing appears slow, the SVLP-vesicles remaining peripheral. Association with transferrin occurs rarely, and only in the periphery, possibly signifying translocation of some SVLP for delivery to B-lymphocytes. Most SVLP co-localise with high molecular weight dextran. Uptake of both is impaired with mature DC, but there remains a residual uptake of SVLP. These results imply that DC use multiple endocytic routes for SVLP uptake, dominated by caveolin-independent, lipid raft-mediated macropinocytosis. With most SVLP-containing vesicles being retained in the periphery, not always interacting with early endosomes, this relates to slow proteolytic degradation and antigen retention by DC. The present characterization allows for a definition of how DC handle virus-like particles showing efficacious immunogenicity, elements valuable for novel vaccine design in the future.

  17. Synthetic Virus-Like Particles Target Dendritic Cell Lipid Rafts for Rapid Endocytosis Primarily but Not Exclusively by Macropinocytosis

    Science.gov (United States)

    Sharma, Rajni; Ghasparian, Arin; Robinson, John A.; McCullough, Kenneth C.

    2012-01-01

    DC employ several endocytic routes for processing antigens, driving forward adaptive immunity. Recent advances in synthetic biology have created small (20–30 nm) virus-like particles based on lipopeptides containing a virus-derived coiled coil sequence coupled to synthetic B- and T-cell epitope mimetics. These self-assembling SVLP efficiently induce adaptive immunity without requirement for adjuvant. We hypothesized that the characteristics of DC interaction with SVLP would elaborate on the roles of cell membrane and intracellular compartments in the handling of a virus-like entity known for its efficacy as a vaccine. DC rapidly bind SVLP within min, co-localised with CTB and CD9, but not caveolin-1. In contrast, internalisation is a relatively slow process, delivering SVLP into the cell periphery where they are maintained for a number of hrs in association with microtubules. Although there is early association with clathrin, this is no longer seen after 10 min. Association with EEA-1+ early endosomes is also early, but proteolytic processing appears slow, the SVLP-vesicles remaining peripheral. Association with transferrin occurs rarely, and only in the periphery, possibly signifying translocation of some SVLP for delivery to B-lymphocytes. Most SVLP co-localise with high molecular weight dextran. Uptake of both is impaired with mature DC, but there remains a residual uptake of SVLP. These results imply that DC use multiple endocytic routes for SVLP uptake, dominated by caveolin-independent, lipid raft-mediated macropinocytosis. With most SVLP-containing vesicles being retained in the periphery, not always interacting with early endosomes, this relates to slow proteolytic degradation and antigen retention by DC. The present characterization allows for a definition of how DC handle virus-like particles showing efficacious immunogenicity, elements valuable for novel vaccine design in the future. PMID:22905240

  18. Thermal Stability of RNA Phage Virus-Like Particles Displaying Foreign Peptides

    Directory of Open Access Journals (Sweden)

    Peabody David S

    2011-05-01

    Full Text Available Abstract Background To be useful for genetic display of foreign peptides a viral coat protein must tolerate peptide insertions without major disruption of subunit folding and capsid assembly. The folding of the coat protein of RNA phage MS2 does not normally tolerate insertions in its AB-loop, but an engineered single-chain dimer readily accepts them as long as they are restricted to one of its two halves. Results Here we characterize the effects of peptide insertions on the thermal stabilities of MS2 virus-like particles (VLPs displaying a variety of different peptides in one AB-loop of the coat protein single-chain dimer. These particles typically denature at temperatures around 5-10°C lower than unmodified VLPs. Even so, they are generally stable up to about 50°C. VLPs of the related RNA phage PP7 are cross-linked with intersubunit disulfide bonds and are therefore significantly more stable. An AB-loop insertion also reduces the stability of PP7 VLPs, but they only begin to denature above about 70°C. Conclusions VLPs assembled from MS2 single-chain dimer coat proteins with peptide insertions in one of their AB-loops are somewhat less stable than the wild-type particle, but still resist heating up to about 50°C. Because they possess disulfide cross-links, PP7-derived VLPs provide an alternate platform with even higher stability.

  19. Silica nanoparticles as the adjuvant for the immunisation of mice using hepatitis B core virus-like particles.

    Directory of Open Access Journals (Sweden)

    Dace Skrastina

    Full Text Available Advances in nanotechnology and nanomaterials have facilitated the development of silicon dioxide, or Silica, particles as a promising immunological adjuvant for the generation of novel prophylactic and therapeutic vaccines. In the present study, we have compared the adjuvanting potential of commercially available Silica nanoparticles (initial particles size of 10-20 nm with that of aluminium hydroxide, or Alum, as well as that of complete and incomplete Freund's adjuvants for the immunisation of BALB/c mice with virus-like particles (VLPs formed by recombinant full-length Hepatitis B virus core (HBc protein. The induction of B-cell and T-cell responses was studied after immunisation. Silica nanoparticles were able to adsorb maximally 40% of the added HBc, whereas the adsorption capacity of Alum exceeded 90% at the same VLPs/adjuvant ratio. Both Silica and Alum formed large complexes with HBc VLPs that sedimented rapidly after formulation, as detected by dynamic light scattering, spectrophotometry, and electron microscopy. Both Silica and Alum augmented the humoral response against HBc VLPs to the high anti-HBc level in the case of intraperitoneal immunisation, whereas in subcutaneous immunisation, the Silica-adjuvanted anti-HBc level even exceeded the level adjuvanted by Alum. The adjuvanting of HBc VLPs by Silica resulted in the same typical IgG2a/IgG1 ratios as in the case of the adjuvanting by Alum. The combination of Silica with monophosphoryl lipid A (MPL led to the same enhancement of the HBc-specific T-cell induction as in the case of the Alum and MPL combination. These findings demonstrate that Silica is not a weaker putative adjuvant than Alum for induction of B-cell and T-cell responses against recombinant HBc VLPs. This finding may have an essential impact on the development of the set of Silica-adjuvanted vaccines based on a long list of HBc-derived virus-like particles as the biological component.

  20. Comparison of Influenza Virus Particle Purification Using Magnetic Sulfated Cellulose Particles with an Established Centrifugation Method for Analytics.

    Science.gov (United States)

    Serve, Anja; Pieler, Michael Martin; Benndorf, Dirk; Rapp, Erdmann; Wolff, Michael Werner; Reichl, Udo

    2015-11-03

    A method for the purification of influenza virus particles using novel magnetic sulfated cellulose particles is presented and compared to an established centrifugation method for analytics. Therefore, purified influenza A virus particles from adherent and suspension MDCK host cell lines were characterized on the protein level with mass spectrometry to compare the viral and residual host cell proteins. Both methods allowed one to identify all 10 influenza A virus proteins, including low-abundance proteins like the matrix protein 2 and nonstructural protein 1, with a similar impurity level of host cell proteins. Compared to the centrifugation method, use of the novel magnetic sulfated cellulose particles reduced the influenza A virus particle purification time from 3.5 h to 30 min before mass spectrometry analysis.

  1. Bacterial superglue enables easy development of efficient virus-like particle based vaccines

    DEFF Research Database (Denmark)

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

    2016-01-01

    BACKGROUND: Virus-like particles (VLPs) represent a significant advance in the development of subunit vaccines, combining high safety and efficacy. Their particulate nature and dense repetitive subunit organization makes them ideal scaffolds for display of vaccine antigens. Traditional approaches...... for VLP-based antigen display require labor-intensive trial-and-error optimization, and often fail to generate dense antigen display. Here we utilize the split-intein (SpyTag/SpyCatcher) conjugation system to generate stable isopeptide bound antigen-VLP complexes by simply mixing of the antigen and VLP......). CONCLUSIONS: The spy-VLP system constitutes a versatile and rapid method to develop highly immunogenic VLP-based vaccines. Our data provide proof-of-concept for the technology's ability to present complex vaccine antigens to the immune system and elicit robust functional antibody responses as well...

  2. Preparation of MS2 phage-like particles and their use as potential process control viruses for detection and quantification of enteric RNA viruses in different matrices

    Directory of Open Access Journals (Sweden)

    Pavel Mikel

    2016-12-01

    Full Text Available The detection and quantification of enteric RNA viruses is based on isolation of viral RNA from the sample followed by quantitative reverse transcription polymerase chain reaction (RT-qPCR. To control the whole process of analysis and in order to guarantee the validity and reliability of results, process control viruses (PCV are used. The present article describes the process of preparation and use of such PCV– MS2 phage-like particles (MS2 PLP – in RT-qPCR detection and quantification of enteric RNA viruses. The MS2 PLP were derived from bacteriophage MS2 carrying a unique and specific de novo-constructed RNA target sequence originating from the DNA of two extinct species. The amount of prepared MS2 particles was quantified using four independent methods - UV spectrophotometry, fluorimetry, transmission electron microscopy (TEM and a specifically developed duplex RT-qPCR. To evaluate the usefulness of MS2 PLP in routine diagnostics different matrices known to harbor enteric RNA viruses (swab samples, liver tissue, serum, feces, and vegetables were artificially contaminated with specific amounts of MS2 PLP. The extraction efficiencies were calculated for each individual matrix. The prepared particles fulfill all requirements for PCV – they are very stable, non-infectious, and are genetically distinct from the target RNA viruses. Due to these properties they represent a good morphological and physiochemical model. The use of MS2 PLP as a PCV in detection and quantification of enteric RNA viruses was evaluated in different types of matrices.

  3. M2e-displaying virus-like particles with associated RNA promote T helper 1 type adaptive immunity against influenza A.

    Directory of Open Access Journals (Sweden)

    Lorena Itatí Ibañez

    Full Text Available The ectodomain of influenza A matrix protein 2 (M2e is a candidate for a universal influenza A vaccine. We used recombinant Hepatitis B core antigen to produce virus-like particles presenting M2e (M2e-VLPs. We produced the VLPs with and without entrapped nucleic acids and compared their immunogenicity and protective efficacy. Immunization of BALB/c mice with M2e-VLPs containing nucleic acids induced a stronger, Th1-biased antibody response compared to particles lacking nucleic acids. The former also induced a stronger M2e-specific CD4(+ T cell response, as determined by ELISPOT. Mice vaccinated with alum-adjuvanted M2e-VLPs containing the nucleic acid-binding domain were better protected against influenza A virus challenge than mice vaccinated with similar particles lacking this domain, as deduced from the loss in body weight following challenge with X47 (H3N2 or PR/8 virus. Challenge of mice that had been immunized with M2e-VLPs with or without nucleic acids displayed significantly lower mortality, morbidity and lung virus titers than control-immunized groups. We conclude that nucleic acids present in M2e-VLPs correlate with improved immune protection.

  4. Viruses & kidney disease: beyond HIV

    OpenAIRE

    Waldman, Meryl; Marshall, Vickie; Whitby, Denise; Kopp, Jeffrey B.

    2008-01-01

    HIV-infected patients may acquire new viral co-infections; they may also experience the reactivation or worsening of existing viral infections, including active, smoldering, or latent infections. HIV-infected patients may be predisposed to these viral infections due to immunodeficiency or to risk factors common to HIV and other viruses. A number of these affect the kidney, either by direct infection or by deposition of immune complexes. In this review we discuss the renal manifestations and t...

  5. High-throughput screening using pseudotyped lentiviral particles: a strategy for the identification of HIV-1 inhibitors in a cell-based assay.

    Science.gov (United States)

    Garcia, Jean-Michel; Gao, Anhui; He, Pei-Lan; Choi, Joyce; Tang, Wei; Bruzzone, Roberto; Schwartz, Olivier; Naya, Hugo; Nan, Fa-Jun; Li, Jia; Altmeyer, Ralf; Zuo, Jian-Ping

    2009-03-01

    Two decades after its discovery the human immunodeficiency virus (HIV) is still spreading worldwide and killing millions. There are 25 drugs formally approved for HIV currently on the market, but side effects as well as the emergence of HIV strains showing single or multiple resistances to current drug-therapy are causes for concern. Furthermore, these drugs target only 4 steps of the viral cycle, hence the urgent need for new drugs and also new targets. In order to tackle this problem, we have devised a cell-based assay using lentiviral particles to look for post-entry inhibitors of HIV-1. We report here the assay development, validation as well as confirmation of the hits using both wild-type and drug-resistant HIV-1 viruses. The screening was performed on an original library, rich in natural compounds and pure molecules from Traditional Chinese Medicine pharmacopoeia, which had never been screened for anti-HIV activity. The identified hits belong to four chemical sub-families that appear to be all non-nucleoside reverse transcriptase inhibitors (NNRTIs). Secondary tests with live viruses showed that there was good agreement with pseudotyped particles, confirming the validity of this approach for high-throughput drug screens. This assay will be a useful tool that can be easily adapted to screen for inhibitors of viral entry.

  6. Role of Mason-Pfizer Monkey Virus CA-NC Spacer Peptide-Like Domain in Assembly of Immature Particles

    Czech Academy of Sciences Publication Activity Database

    Strohalmová-Böhmová, Karolína; Spiwok, V.; Lepšík, Martin; Hadravová, Romana; Křížová, Ivana; Ulbrich, P.; Pichová, Iva; Bednárová, Lucie; Ruml, T.; Rumlová, Michaela

    2014-01-01

    Roč. 88, č. 24 (2014), s. 14148-14160 ISSN 0022-538X R&D Projects: GA ČR(CZ) GA14-15326S; GA MŠk LO1302; GA ČR GBP208/12/G016 Institutional support: RVO:61388963 Keywords : human immunodeficiency virus * HIV-1 capsid protein * murine leukemia virus Subject RIV: EE - Microbiology, Virology Impact factor: 4.439, year: 2014

  7. Generation of Recombinant Porcine Parvovirus Virus-Like Particles in Saccharomyces cerevisiae and Development of Virus-Specific Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    Paulius Lukas Tamošiūnas

    2014-01-01

    Full Text Available Porcine parvovirus (PPV is a widespread infectious virus that causes serious reproductive diseases of swine and death of piglets. The gene coding for the major capsid protein VP2 of PPV was amplified using viral nucleic acid extract from swine serum and inserted into yeast Saccharomyces cerevisiae expression plasmid. Recombinant PPV VP2 protein was efficiently expressed in yeast and purified using density gradient centrifugation. Electron microscopy analysis of purified PPV VP2 protein revealed the self-assembly of virus-like particles (VLPs. Nine monoclonal antibodies (MAbs against the recombinant PPV VP2 protein were generated. The specificity of the newly generated MAbs was proven by immunofluorescence analysis of PPV-infected cells. Indirect IgG ELISA based on the recombinant VLPs for detection of PPV-specific antibodies in swine sera was developed and evaluated. The sensitivity and specificity of the new assay were found to be 93.4% and 97.4%, respectively. In conclusion, yeast S. cerevisiae represents a promising expression system for generating recombinant PPV VP2 protein VLPs of diagnostic relevance.

  8. High-yield production of canine parvovirus virus-like particles in a baculovirus expression system.

    Science.gov (United States)

    Jin, Hongli; Xia, Xiaohong; Liu, Bing; Fu, Yu; Chen, Xianping; Wang, Huihui; Xia, Zhenqiang

    2016-03-01

    An optimized VP2 gene from the current prevalent CPV strain (new CPV-2a) in China was expressed in a baculovirus expression system. It was found that the VP2 proteins assembled into virus-like particles (VLPs) with antigenic properties similar to those of natural CPV and with an especially high hemagglutination (HA) titer (1:2(20)). Dogs intramuscularly or orally immunized with VLPs produced antibodies against CPV with >1:80 hemagglutination inhibition (HI) units for at least 3 months. The CPV VLPs could be considered for use as a vaccine against CPV or as a platform for research on chimeric VLP vaccines against other diseases.

  9. Development of a HIV-1 Virus Detection System Based on Nanotechnology

    Directory of Open Access Journals (Sweden)

    Jin-Ho Lee

    2015-04-01

    Full Text Available Development of a sensitive and selective detection system for pathogenic viral agents is essential for medical healthcare from diagnostics to therapeutics. However, conventional detection systems are time consuming, resource-intensive and tedious to perform. Hence, the demand for sensitive and selective detection system for virus are highly increasing. To attain this aim, different aspects and techniques have been applied to develop virus sensor with improved sensitivity and selectivity. Here, among those aspects and techniques, this article reviews HIV virus particle detection systems incorporated with nanotechnology to enhance the sensitivity. This review mainly focused on four different detection system including vertically configured electrical detection based on scanning tunneling microscopy (STM, electrochemical detection based on direct electron transfer in virus, optical detection system based on localized surface plasmon resonance (LSPR and surface enhanced Raman spectroscopy (SERS using plasmonic nanoparticle.

  10. Development of a HIV-1 Virus Detection System Based on Nanotechnology.

    Science.gov (United States)

    Lee, Jin-Ho; Oh, Byung-Keun; Choi, Jeong-Woo

    2015-04-27

    Development of a sensitive and selective detection system for pathogenic viral agents is essential for medical healthcare from diagnostics to therapeutics. However, conventional detection systems are time consuming, resource-intensive and tedious to perform. Hence, the demand for sensitive and selective detection system for virus are highly increasing. To attain this aim, different aspects and techniques have been applied to develop virus sensor with improved sensitivity and selectivity. Here, among those aspects and techniques, this article reviews HIV virus particle detection systems incorporated with nanotechnology to enhance the sensitivity. This review mainly focused on four different detection system including vertically configured electrical detection based on scanning tunneling microscopy (STM), electrochemical detection based on direct electron transfer in virus, optical detection system based on localized surface plasmon resonance (LSPR) and surface enhanced Raman spectroscopy (SERS) using plasmonic nanoparticle.

  11. Chimaera and its modern virus-like descendants.

    Science.gov (United States)

    Ulrich, R; Gerlich, W H; Krüger, D H

    1996-01-01

    Chimaera was a monster in ancient Greek mythology combining elements from different animal species in its body. Modern molecular biology enabled the generation of harmless but useful chimaeras consisting of elements from different nonrelated viruses. The objective is that the resulting chimaeras form highly immunogenic virus-like particles (VLPs). Such chimaeric VLPs can be used as highly efficient carriers for sequential and conformational B cell epitopes and T cell epitopes. Most VLPs are readily produced in heterologous hosts and are easy to purify. This article deals with various systems of VLPs described in this topical issue of Intervirology and makes comparisons with chimaeric replication-competent viruses, recombinant virus vectors expressing foreign proteins, and DNA vaccines.

  12. Deletions in the fifth alpha helix of HIV-1 matrix block virus release

    International Nuclear Information System (INIS)

    Sanford, Bridget; Li, Yan; Maly, Connor J.; Madson, Christian J.; Chen, Han; Zhou, You; Belshan, Michael

    2014-01-01

    The matrix (MA) protein of HIV-1 is the N-terminal component of the Gag structural protein and is critical for the early and late stages of viral replication. MA contains five α-helices (α1–α5). Deletions in the N-terminus of α5 as small as three amino acids impaired virus release. Electron microscopy of one deletion mutant (MA∆96-120) showed that its particles were tethered to the surface of cells by membranous stalks. Immunoblots indicated all mutants were processed completely, but mutants with large deletions had alternative processing intermediates. Consistent with the EM data, MA∆96-120 retained membrane association and multimerization capability. Co-expression of this mutant inhibited wild type particle release. Alanine scanning mutation in this region did not affect virus release, although the progeny virions were poorly infectious. Combined, these data demonstrate that structural ablation of the α5 of MA inhibits virus release. - Highlights: • Deletions were identified in the C-terminus of matrix that block virus release. • These deletion mutants still multimerized and associated with membranes. • TEM showed the mutant particles were tethered to the cell surface. • Amino acid mutagenesis of the region did not affect release. • The data suggests that disruption of matrix structure blocks virus release

  13. Deletions in the fifth alpha helix of HIV-1 matrix block virus release

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, Bridget; Li, Yan; Maly, Connor J.; Madson, Christian J. [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); Chen, Han [Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE (United States); Zhou, You [Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE (United States); Nebraska Center for Virology, Lincoln, NE (United States); Belshan, Michael, E-mail: michaelbelshan@creighton.edu [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); Nebraska Center for Virology, Lincoln, NE (United States)

    2014-11-15

    The matrix (MA) protein of HIV-1 is the N-terminal component of the Gag structural protein and is critical for the early and late stages of viral replication. MA contains five α-helices (α1–α5). Deletions in the N-terminus of α5 as small as three amino acids impaired virus release. Electron microscopy of one deletion mutant (MA∆96-120) showed that its particles were tethered to the surface of cells by membranous stalks. Immunoblots indicated all mutants were processed completely, but mutants with large deletions had alternative processing intermediates. Consistent with the EM data, MA∆96-120 retained membrane association and multimerization capability. Co-expression of this mutant inhibited wild type particle release. Alanine scanning mutation in this region did not affect virus release, although the progeny virions were poorly infectious. Combined, these data demonstrate that structural ablation of the α5 of MA inhibits virus release. - Highlights: • Deletions were identified in the C-terminus of matrix that block virus release. • These deletion mutants still multimerized and associated with membranes. • TEM showed the mutant particles were tethered to the cell surface. • Amino acid mutagenesis of the region did not affect release. • The data suggests that disruption of matrix structure blocks virus release.

  14. Enhanced stability of a chimeric hepatitis B core antigen virus-like-particle (HBcAg-VLP) by a C-terminal linker-hexahistidine-peptide.

    Science.gov (United States)

    Schumacher, Jens; Bacic, Tijana; Staritzbichler, René; Daneschdar, Matin; Klamp, Thorsten; Arnold, Philipp; Jägle, Sabrina; Türeci, Özlem; Markl, Jürgen; Sahin, Ugur

    2018-04-13

    Virus-like-particles (VLPs) are attractive nanoparticulate scaffolds for broad applications in material/biological sciences and medicine. Prior their functionalization, specific adaptations have to be carried out. These adjustments frequently lead to disordered particles, but the particle integrity is an essential factor for the VLP suitability. Therefore, major requirements for particle stabilization exist. The objective of this study was to evaluate novel stabilizing elements for functionalized chimeric hepatitis B virus core antigen virus-like particles (HBcAg-VLP), with beneficial characteristics for vaccine development, imaging or delivery. The effects of a carboxy-terminal polyhistidine-peptide and an intradimer disulfide-bridge on the stability of preclinically approved chimeric HBcAg-VLPs were assessed. We purified recombinant chimeric HBcAg-VLPs bearing different modified C-termini and compared their physical and chemical particle stability by quantitative protein-biochemical and biophysical techniques. We observed lower chemical resistance of T = 3- compared to T = 4-VLP (triangulation number) capsids and profound impairment of accessibility of hexahistidine-peptides in assembled VLPs. Histidines attached to the C-terminus were associated with superior mechanical and/or chemical particle stability depending on the number of histidine moieties. A molecular modeling approach based on cryo-electron microscopy and biolayer interferometry revealed the underlying structural mechanism for the strengthening of the integrity of VLPs. Interactions triggering capsid stabilization occur on a highly conserved residue on the basis of HBcAg-monomers as well as on hexahistidine-peptides of adjacent monomers. This new stabilization mechanism appears to mimic an evolutionary conserved stabilization concept for hepadnavirus core proteins. These findings establish the genetically simply transferable C-terminal polyhistidine-peptide as a general stabilizing element

  15. The prototype HIV-1 maturation inhibitor, bevirimat, binds to the CA-SP1 cleavage site in immature Gag particles

    Directory of Open Access Journals (Sweden)

    Nguyen Albert T

    2011-12-01

    Full Text Available Abstract Background Bevirimat, the prototype Human Immunodeficiency Virus type 1 (HIV-1 maturation inhibitor, is highly potent in cell culture and efficacious in HIV-1 infected patients. In contrast to inhibitors that target the active site of the viral protease, bevirimat specifically inhibits a single cleavage event, the final processing step for the Gag precursor where p25 (CA-SP1 is cleaved to p24 (CA and SP1. Results In this study, photoaffinity analogs of bevirimat and mass spectrometry were employed to map the binding site of bevirimat to Gag within immature virus-like particles. Bevirimat analogs were found to crosslink to sequences overlapping, or proximal to, the CA-SP1 cleavage site, consistent with previous biochemical data on the effect of bevirimat on Gag processing and with genetic data from resistance mutations, in a region predicted by NMR and mutational studies to have α-helical character. Unexpectedly, a second region of interaction was found within the Major Homology Region (MHR. Extensive prior genetic evidence suggests that the MHR is critical for virus assembly. Conclusions This is the first demonstration of a direct interaction between the maturation inhibitor, bevirimat, and its target, Gag. Information gained from this study sheds light on the mechanisms by which the virus develops resistance to this class of drug and may aid in the design of next-generation maturation inhibitors.

  16. The inhibition of assembly of HIV-1 virus-like particles by 3-O-(3',3'-dimethylsuccinyl betulinic acid (DSB is counteracted by Vif and requires its Zinc-binding domain

    Directory of Open Access Journals (Sweden)

    Bouaziz Serge

    2008-12-01

    Full Text Available Abstract Background DSB, the 3-O-(3',3'dimethylsuccinyl derivative of betulinic acid, blocks the last step of protease-mediated processing of HIV-1 Gag precursor (Pr55Gag, which leads to immature, noninfectious virions. When administered to Pr55Gag-expressing insect cells (Sf9, DSB inhibits the assembly and budding of membrane-enveloped virus-like particles (VLP. In order to explore the possibility that viral factors could modulate the susceptibility to DSB of the VLP assembly process, several viral proteins were coexpressed individually with Pr55Gag in DSB-treated cells, and VLP yields assayed in the extracellular medium. Results Wild-type Vif (Vifwt restored the VLP production in DSB-treated cells to levels observed in control, untreated cells. DSB-counteracting effect was also observed with Vif mutants defective in encapsidation into VLP, suggesting that packaging and anti-DSB effect were separate functions in Vif. The anti-DSB effect was abolished for VifC133S and VifS116V, two mutants which lacked the zinc binding domain (ZBD formed by the four H108C114C133H139 coordinates with a Zn atom. Electron microscopic analysis of cells coexpressing Pr55Gag and Vifwt showed that a large proportion of VLP budded into cytoplasmic vesicles and were released from Sf9 cells by exocytosis. However, in the presence of mutant VifC133S or VifS116V, most of the VLP assembled and budded at the plasma membrane, as in control cells expressing Pr55Gag alone. Conclusion The function of HIV-1 Vif protein which negated the DSB inhibition of VLP assembly was independent of its packaging capability, but depended on the integrity of ZBD. In the presence of Vifwt, but not with ZBD mutants VifC133S and VifS116V, VLP were redirected to a vesicular compartment and egressed via the exocytic pathway.

  17. Immunogenicity of plant-produced African horse sickness virus-like particles: implications for a novel vaccine.

    Science.gov (United States)

    Dennis, Susan J; Meyers, Ann E; Guthrie, Alan J; Hitzeroth, Inga I; Rybicki, Edward P

    2018-02-01

    African horse sickness (AHS) is a debilitating and often fatal viral disease affecting horses in much of Africa, caused by the dsRNA orbivirus African horse sickness virus (AHSV). Vaccination remains the single most effective weapon in combatting AHS, as there is no treatment for the disease apart from good animal husbandry. However, the only commercially available vaccine is a live-attenuated version of the virus (LAV). The threat of outbreaks of the disease outside its endemic region and the fact that the LAV is not licensed for use elsewhere in the world, have spurred attempts to develop an alternative safer, yet cost-effective recombinant vaccine. Here, we report the plant-based production of a virus-like particle (VLP) AHSV serotype five candidate vaccine by Agrobacterium tumefaciens-mediated transient expression of all four capsid proteins in Nicotiana benthamiana using the cowpea mosaic virus-based HyperTrans (CPMV-HT) and associated pEAQ plant expression vector system. The production process is fast and simple, scalable, economically viable, and most importantly, guinea pig antiserum raised against the vaccine was shown to neutralize live virus in cell-based assays. To our knowledge, this is the first report of AHSV VLPs produced in plants, which has important implications for the containment of, and fight against the spread of, this deadly disease. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  18. Chimeric SV40 virus-like particles induce specific cytotoxicity and protective immunity against influenza A virus without the need of adjuvants

    International Nuclear Information System (INIS)

    Kawano, Masaaki; Morikawa, Katsuma; Suda, Tatsuya; Ohno, Naohito; Matsushita, Sho; Akatsuka, Toshitaka; Handa, Hiroshi; Matsui, Masanori

    2014-01-01

    Virus-like particles (VLPs) are a promising vaccine platform due to the safety and efficiency. However, it is still unclear whether polyomavirus-based VLPs are useful for this purpose. Here, we attempted to evaluate the potential of polyomavirus VLPs for the antiviral vaccine using simian virus 40 (SV40). We constructed chimeric SV40-VLPs carrying an HLA-A ⁎ 02:01-restricted, cytotoxic T lymphocyte (CTL) epitope derived from influenza A virus. HLA-A ⁎ 02:01-transgenic mice were then immunized with the chimeric SV40-VLPs. The chimeric SV40-VLPs effectively induced influenza-specific CTLs and heterosubtypic protection against influenza A viruses without the need of adjuvants. Because DNase I treatment of the chimeric SV40-VLPs did not disrupt CTL induction, the intrinsic adjuvant property may not result from DNA contaminants in the VLP preparation. In addition, immunization with the chimeric SV40-VLPs generated long-lasting memory CTLs. We here propose that the chimeric SV40-VLPs harboring an epitope may be a promising CTL-based vaccine platform with self-adjuvant properties. - Highlights: • We constructed chimeric SV40-VLPs carrying an influenza virus-derived CTL epitope. • Chimeric SV40-VLPs induce influenza-specific CTLs in mice without adjuvants. • Chimeric SV40-VLPs induce heterosubtypic protection against influenza A viruses. • Chimeric SV40-VLPs induce long-lasting memory CTLs. • Chimeric SV40-VLPs is a promising vaccine platform with self-adjuvant properties

  19. Chimeric SV40 virus-like particles induce specific cytotoxicity and protective immunity against influenza A virus without the need of adjuvants

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Masaaki [Department of Allergy and Immunology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Morikawa, Katsuma [Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); Suda, Tatsuya [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Laboratory for Immunopharmacology of Microbial Products, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Ohno, Naohito [Laboratory for Immunopharmacology of Microbial Products, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Matsushita, Sho [Department of Allergy and Immunology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Allergy Center, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Akatsuka, Toshitaka [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Handa, Hiroshi, E-mail: handa.h.aa@m.titech.ac.jp [Solutions Research Laboratory, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503 (Japan); Matsui, Masanori, E-mail: mmatsui@saitama-med.ac.jp [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan)

    2014-01-05

    Virus-like particles (VLPs) are a promising vaccine platform due to the safety and efficiency. However, it is still unclear whether polyomavirus-based VLPs are useful for this purpose. Here, we attempted to evaluate the potential of polyomavirus VLPs for the antiviral vaccine using simian virus 40 (SV40). We constructed chimeric SV40-VLPs carrying an HLA-A{sup ⁎}02:01-restricted, cytotoxic T lymphocyte (CTL) epitope derived from influenza A virus. HLA-A{sup ⁎}02:01-transgenic mice were then immunized with the chimeric SV40-VLPs. The chimeric SV40-VLPs effectively induced influenza-specific CTLs and heterosubtypic protection against influenza A viruses without the need of adjuvants. Because DNase I treatment of the chimeric SV40-VLPs did not disrupt CTL induction, the intrinsic adjuvant property may not result from DNA contaminants in the VLP preparation. In addition, immunization with the chimeric SV40-VLPs generated long-lasting memory CTLs. We here propose that the chimeric SV40-VLPs harboring an epitope may be a promising CTL-based vaccine platform with self-adjuvant properties. - Highlights: • We constructed chimeric SV40-VLPs carrying an influenza virus-derived CTL epitope. • Chimeric SV40-VLPs induce influenza-specific CTLs in mice without adjuvants. • Chimeric SV40-VLPs induce heterosubtypic protection against influenza A viruses. • Chimeric SV40-VLPs induce long-lasting memory CTLs. • Chimeric SV40-VLPs is a promising vaccine platform with self-adjuvant properties.

  20. In vitro protease cleavage and computer simulations reveal the HIV-1 capsid maturation pathway

    Science.gov (United States)

    Ning, Jiying; Erdemci-Tandogan, Gonca; Yufenyuy, Ernest L.; Wagner, Jef; Himes, Benjamin A.; Zhao, Gongpu; Aiken, Christopher; Zandi, Roya; Zhang, Peijun

    2016-12-01

    HIV-1 virions assemble as immature particles containing Gag polyproteins that are processed by the viral protease into individual components, resulting in the formation of mature infectious particles. There are two competing models for the process of forming the mature HIV-1 core: the disassembly and de novo reassembly model and the non-diffusional displacive model. To study the maturation pathway, we simulate HIV-1 maturation in vitro by digesting immature particles and assembled virus-like particles with recombinant HIV-1 protease and monitor the process with biochemical assays and cryoEM structural analysis in parallel. Processing of Gag in vitro is accurate and efficient and results in both soluble capsid protein and conical or tubular capsid assemblies, seemingly converted from immature Gag particles. Computer simulations further reveal probable assembly pathways of HIV-1 capsid formation. Combining the experimental data and computer simulations, our results suggest a sequential combination of both displacive and disassembly/reassembly processes for HIV-1 maturation.

  1. Human Immunodeficiency Virus (HIV) Seropositivity In African ...

    African Journals Online (AJOL)

    A seroprevalence study of Human immunodeficiency virus (HIV) infection in new patients attending the eye clinic of LAUTECH Teaching Hospital in Osogbo, Osun State, Nigeria showed that twenty-nine patients 2.7%) were positive to HIV1. No patient was positive to HIV 2. There were 21 males (72.4%) and 8 females ...

  2. Torque Teno Virus in HIV-infected transgender in Surakarta, Indonesia

    Science.gov (United States)

    Hartono; Agung Prasetyo, Afiono; Fanani, Mohammad

    2018-05-01

    Torque Teno Virus (TTV) is a circular single-stranded DNA virus that may co-infected with human immunodeficiency virus (HIV), especially in the high-risk community e.g. the transgender performing high-riskbehavior. TTV shows an increased viremia in HIV patients and maybe influence the HIV clinical progression. Blood samples collected from transgender performing high-riskbehavior in Surakarta were tested by serological and molecular assays to detect the presence of HIV infection. The blood samples with HIV positive status were then tested by a nested polymerase chain reaction (PCR) to detect the presentation of TTV DNA. The amplified PCR products were molecularly cloned and subjected to sequence analysis. TTV DNA was detected in 40.0% HIV-positive samples. The molecular characterization revealed that the most prevalent was genogroup 3, followed by genogroup 2 and 1, respectively. TTV was detected in HIV-infected transgender performing high-riskbehavior in Surakarta with high infection rate.

  3. Robust production of virus-like particles and monoclonal antibodies with geminiviral replicon vectors in lettuce

    Science.gov (United States)

    Lai, Huafang; He, Junyun; Engle, Michael; Diamond, Michael S.; Chen, Qiang

    2011-01-01

    Summary Pharmaceutical protein production in plants has been greatly promoted by the development of viral-based vectors and transient expression systems. Tobacco and related Nicotiana species are currently the most common host plants for generation of plant-made pharmaceutical proteins (PMPs). Downstream processing of target PMPs from these plants, however, is hindered by potential technical and regulatory difficulties due to the presence of high levels of phenolics and toxic alkaloids. Here, we explored the use of lettuce, which grows quickly yet produces low levels of secondary metabolites, and viral vector-based transient expression systems to develop a robust PMP production platform. Our results showed that a geminiviral replicon system based on the bean yellow dwarf virus permits high-level expression in lettuce of virus-like particles (VLP) derived from the Norwalk virus capsid protein and therapeutic monoclonal antibodies (mAbs) against Ebola and West Nile viruses. These vaccine and therapeutic candidates can be readily purified from lettuce leaves with scalable processing methods while fully retaining functional activity. Furthermore, this study also demonstrated the feasibility of using commercially produced lettuce for high-level PMP production. This allows our production system to have access to unlimited quantities of inexpensive plant material for large-scale production. These results establish a new production platform for biological pharmaceutical agents that is effective, safe, low-cost, and amenable to large-scale manufacturing. PMID:21883868

  4. Analysis of the initiating events in HIV-1 particle assembly and genome packaging.

    Directory of Open Access Journals (Sweden)

    Sebla B Kutluay

    2010-11-01

    Full Text Available HIV-1 Gag drives a number of events during the genesis of virions and is the only viral protein required for the assembly of virus-like particles in vitro and in cells. Although a reasonable understanding of the processes that accompany the later stages of HIV-1 assembly has accrued, events that occur at the initiation of assembly are less well defined. In this regard, important uncertainties include where in the cell Gag first multimerizes and interacts with the viral RNA, and whether Gag-RNA interaction requires or induces Gag multimerization in a living cell. To address these questions, we developed assays in which protein crosslinking and RNA/protein co-immunoprecipitation were coupled with membrane flotation analyses in transfected or infected cells. We found that interaction between Gag and viral RNA occurred in the cytoplasm and was independent of the ability of Gag to localize to the plasma membrane. However, Gag:RNA binding was stabilized by the C-terminal domain (CTD of capsid (CA, which participates in Gag-Gag interactions. We also found that Gag was present as monomers and low-order multimers (e.g. dimers but did not form higher-order multimers in the cytoplasm. Rather, high-order multimers formed only at the plasma membrane and required the presence of a membrane-binding signal, but not a Gag domain (the CA-CTD that is essential for complete particle assembly. Finally, sequential RNA-immunoprecipitation assays indicated that at least a fraction of Gag molecules can form multimers on viral genomes in the cytoplasm. Taken together, our results suggest that HIV-1 particle assembly is initiated by the interaction between Gag and viral RNA in the cytoplasm and that this initial Gag-RNA encounter involves Gag monomers or low order multimers. These interactions per se do not induce or require high-order Gag multimerization in the cytoplasm. Instead, membrane interactions are necessary for higher order Gag multimerization and subsequent

  5. A Case of Respiratory Syncytial Virus Infection in an HIV-Positive Adult

    Directory of Open Access Journals (Sweden)

    Aakriti Gupta

    2012-01-01

    Full Text Available Respiratory syncytial virus (RSV is commonly known to cause an influenza-like illness. However, it can also cause more severe disease in young children and older adults comprising of organ transplant patients with immunocompromised status. Till date, only four cases of RSV infections have been reported in HIV-positive adults. We describe here a case of HIV-positive female with relatively preserved immune function who presented with RSV infection requiring ventilation and showed improvement after prompt treatment with intravenous immunoglobulin.

  6. Antiviral Activity of Gold/Copper Sulfide Core/Shell Nanoparticles against Human Norovirus Virus-Like Particles.

    Directory of Open Access Journals (Sweden)

    Jessica Jenkins Broglie

    Full Text Available Human norovirus is a leading cause of acute gastroenteritis worldwide in a plethora of residential and commercial settings, including restaurants, schools, and hospitals. Methods for easily detecting the virus and for treating and preventing infection are critical to stopping norovirus outbreaks, and inactivation via nanoparticles (NPs is a more universal and attractive alternative to other physical and chemical approaches. Using norovirus GI.1 (Norwalk virus-like particles (VLPs as a model viral system, this study characterized the antiviral activity of Au/CuS core/shell nanoparticles (NPs against GI.1 VLPs for the rapid inactivation of HuNoV. Inactivation of VLPs (GI.1 by Au/CuS NPs evaluated using an absorbance-based ELISA indicated that treatment with 0.083 μM NPs for 10 min inactivated ~50% VLPs in a 0.37 μg/ml VLP solution and 0.83 μM NPs for 10 min completely inactivated the VLPs. Increasing nanoparticle concentration and/or VLP-NP contact time significantly increased the virucidal efficacy of Au/CuS NPs. Changes to the VLP particle morphology, size, and capsid protein were characterized using dynamic light scattering, transmission electron microscopy, and Western blot analysis. The strategy reported here provides the first reported proof-of-concept Au/CuS NPs-based virucide for rapidly inactivating human norovirus.

  7. Solution Properties of Murine Leukemia Virus Gag Protein: Differences from HIV-1 Gag▿

    Science.gov (United States)

    Datta, Siddhartha A. K.; Zuo, Xiaobing; Clark, Patrick K.; Campbell, Stephen J.; Wang, Yun-Xing; Rein, Alan

    2011-01-01

    Immature retrovirus particles are assembled from the multidomain Gag protein. In these particles, the Gag proteins are arranged radially as elongated rods. We have previously characterized the properties of HIV-1 Gag in solution. In the absence of nucleic acid, HIV-1 Gag displays moderately weak interprotein interactions, existing in monomer-dimer equilibrium. Neutron scattering and hydrodynamic studies suggest that the protein is compact, and biochemical studies indicate that the two ends can approach close in three-dimensional space, implying the need for a significant conformational change during assembly. We now describe the properties of the Gag protein of Moloney murine leukemia virus (MLV), a gammaretrovirus. We found that this protein is very different from HIV-1 Gag: it has much weaker protein-protein interaction and is predominantly monomeric in solution. This has allowed us to study the protein by small-angle X-ray scattering and to build a low-resolution molecular envelope for the protein. We found that MLV Gag is extended in solution, with an axial ratio of ∼7, comparable to its dimensions in immature particles. Mutational analysis suggests that runs of prolines in its matrix and p12 domains and the highly charged stretch at the C terminus of its capsid domain all contribute to this extended conformation. These differences between MLV Gag and HIV-1 Gag and their implications for retroviral assembly are discussed. PMID:21917964

  8. Modification of a loop sequence between α-helices 6 and 7 of virus capsid (CA protein in a human immunodeficiency virus type 1 (HIV-1 derivative that has simian immunodeficiency virus (SIVmac239 vif and CA α-helices 4 and 5 loop improves replication in cynomolgus monkey cells

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    Adachi Akio

    2009-08-01

    Full Text Available Abstract Background Human immunodeficiency virus type 1 (HIV-1 productively infects only humans and chimpanzees but not cynomolgus or rhesus monkeys while simian immunodeficiency virus isolated from macaque (SIVmac readily establishes infection in those monkeys. Several HIV-1 and SIVmac chimeric viruses have been constructed in order to develop an animal model for HIV-1 infection. Construction of an HIV-1 derivative which contains sequences of a SIVmac239 loop between α-helices 4 and 5 (L4/5 of capsid protein (CA and the entire SIVmac239 vif gene was previously reported. Although this chimeric virus could grow in cynomolgus monkey cells, it did so much more slowly than did SIVmac. It was also reported that intrinsic TRIM5α restricts the post-entry step of HIV-1 replication in rhesus and cynomolgus monkey cells, and we previously demonstrated that a single amino acid in a loop between α-helices 6 and 7 (L6/7 of HIV type 2 (HIV-2 CA determines the susceptibility of HIV-2 to cynomolgus monkey TRIM5α. Results In the study presented here, we replaced L6/7 of HIV-1 CA in addition to L4/5 and vif with the corresponding segments of SIVmac. The resultant HIV-1 derivatives showed enhanced replication capability in established T cell lines as well as in CD8+ cell-depleted primary peripheral blood mononuclear cells from cynomolgus monkey. Compared with the wild type HIV-1 particles, the viral particles produced from a chimeric HIV-1 genome with those two SIVmac loops were less able to saturate the intrinsic restriction in rhesus monkey cells. Conclusion We have succeeded in making the replication of simian-tropic HIV-1 in cynomolgus monkey cells more efficient by introducing into HIV-1 the L6/7 CA loop from SIVmac. It would be of interest to determine whether HIV-1 derivatives with SIVmac CA L4/5 and L6/7 can establish infection of cynomolgus monkeys in vivo.

  9. Respiratory viruses in young South African children with acute lower respiratory infections and interactions with HIV.

    Science.gov (United States)

    Annamalay, Alicia A; Abbott, Salome; Sikazwe, Chisha; Khoo, Siew-Kim; Bizzintino, Joelene; Zhang, Guicheng; Laing, Ingrid; Chidlow, Glenys R; Smith, David W; Gern, James; Goldblatt, Jack; Lehmann, Deborah; Green, Robin J; Le Souëf, Peter N

    2016-08-01

    Human rhinovirus (RV) is the most common respiratory virus and has been associated with frequent and severe acute lower respiratory infections (ALRI). The prevalence of RV species among HIV-infected children in South Africa is unknown. To describe the prevalence of respiratory viruses, including RV species, associated with HIV status and other clinical symptoms in children less than two years of age with and without ALRI in Pretoria, South Africa. Nasopharyngeal aspirates were collected from 105 hospitalized ALRI cases and 53 non-ALRI controls less than two years of age. HIV status was determined. Common respiratory viruses were identified by PCR, and RV species and genotypes were identified by semi-nested PCR, sequencing and phylogenetic tree analyses. Respiratory viruses were more common among ALRI cases than controls (83.8% vs. 69.2%; p=0.041). RV was the most commonly identified virus in cases with pneumonia (45.6%) or bronchiolitis (52.1%), regardless of HIV status, as well as in controls (39.6%). RV-A was identified in 26.7% of cases and 15.1% of controls while RV-C was identified in 21.0% of cases and 18.9% of controls. HIV-infected children were more likely to be diagnosed with pneumonia than bronchiolitis (pinfected cases (n=15) compared with 30.6% of HIV-uninfected cases (n=85, p=0.013), and was identified more frequently in bronchiolitis than in pneumonia cases (43.8% vs. 12.3%; pinfection may be protective against RSV and bronchiolitis. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Inactivation and purification of cowpea mosaic virus-like particles displaying peptide antigens from Bacillus anthracis

    OpenAIRE

    Phelps, Jamie P.; Dang, Nghiep; Rasochova, Lada

    2007-01-01

    Chimeric cowpea mosaic virus (CPMV) particles displaying foreign peptide antigens on the particle surface are suitable for development of peptide-based vaccines. However, commonly used PEG precipitation-based purification methods are not sufficient for production of high quality vaccine candidates because they do not allow for separation of chimeric particles from cleaved contaminating species. Moreover, the purified particles remain infectious to plants. To advance the CPMV technology furthe...

  11. From Cells to Virus Particles: Quantitative Methods to Monitor RNA Packaging

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    Mireia Ferrer

    2016-08-01

    Full Text Available In cells, positive strand RNA viruses, such as Retroviridae, must selectively recognize their full-length RNA genome among abundant cellular RNAs to assemble and release particles. How viruses coordinate the intracellular trafficking of both RNA and protein components to the assembly sites of infectious particles at the cell surface remains a long-standing question. The mechanisms ensuring packaging of genomic RNA are essential for viral infectivity. Since RNA packaging impacts on several essential functions of retroviral replication such as RNA dimerization, translation and recombination events, there are many studies that require the determination of RNA packaging efficiency and/or RNA packaging ability. Studies of RNA encapsidation rely upon techniques for the identification and quantification of RNA species packaged by the virus. This review focuses on the different approaches available to monitor RNA packaging: Northern blot analysis, ribonuclease protection assay and quantitative reverse transcriptase-coupled polymerase chain reaction as well as the most recent RNA imaging and sequencing technologies. Advantages, disadvantages and limitations of these approaches will be discussed in order to help the investigator to choose the most appropriate technique. Although the review was written with the prototypic simple murine leukemia virus (MLV and complex human immunodeficiency virus type 1 (HIV-1 in mind, the techniques were described in order to benefit to a larger community.

  12. Oral Immunization with Recombinant Norwalk Virus-Like Particles Induces a Systemic and Mucosal Immune Response in Mice

    OpenAIRE

    Ball, Judith M.; Hardy, Michele E.; Atmar, Robert L.; Conner, Margaret E.; Estes, Mary K.

    1998-01-01

    Recombinant Norwalk virus-like particles (rNV VLPs) produced in insect cells were evaluated as an oral immunogen in CD1 and BALB/c mice by monitoring rNV-specific serum total and subclass immunoglobulin G (IgG) and intestinal IgA responses. Dose and kinetics of response were evaluated in the presence and absence of the mucosal adjuvant cholera toxin (CT). rNV-specific serum IgG and intestinal IgA were detected in the absence of CT, and the number of responders was not significantly different ...

  13. Detection of norovirus virus-like particles using a surface plasmon resonance-assisted fluoroimmunosensor optimized for quantum dot fluorescent labels.

    Science.gov (United States)

    Ashiba, Hiroki; Sugiyama, Yuki; Wang, Xiaomin; Shirato, Haruko; Higo-Moriguchi, Kyoko; Taniguchi, Koki; Ohki, Yoshimichi; Fujimaki, Makoto

    2017-07-15

    A highly sensitive biosensor to detect norovirus in environment is desired to prevent the spread of infection. In this study, we investigated a design of surface plasmon resonance (SPR)-assisted fluoroimmunosensor to increase its sensitivity and performed detection of norovirus virus-like particles (VLPs). A quantum dot fluorescent dye was employed because of its large Stokes shift. The sensor design was optimized for the CdSe-ZnS-based quantum dots. The optimal design was applied to a simple SPR-assisted fluoroimmunosensor that uses a sensor chip equipped with a V-shaped trench. Excitation efficiency of the quantum dots, degree of electric field enhancement by SPR, and intensity of autofluorescence of a substrate of the sensor chip were theoretically and experimentally evaluated to maximize the signal-to-noise ratio. As the result, an excitation wavelength of 390nm was selected to excite SPR on an Al film of the sensor chip. The sandwich assay of norovirus VLPs was performed using the designed sensor. Minimum detectable concentration of 0.01ng/mL, which corresponds to 100 virus-like particles included in the detection region of the V-trench, was demonstrated. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. An enhanced heterologous virus-like particle for human papillomavirus type 16 tumour immunotherapy.

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    Khairunadwa Jemon

    Full Text Available Cervical cancer is caused by high-risk, cancer-causing human papillomaviruses (HPV and is the second highest cause of cancer deaths in women globally. The majority of cervical cancers express well-characterized HPV oncogenes, which are potential targets for immunotherapeutic vaccination. Here we develop a rabbit haemorrhagic disease virus (RHDV virus-like particle (VLP-based vaccine designed for immunotherapy against HPV16 positive tumours. An RHDV-VLP, modified to contain the universal helper T cell epitope PADRE and decorated with an MHC I-restricted peptide (aa 48-57 from the HPV16 E6, was tested for its immunotherapeutic efficacy against the TC-1 HPV16 E6 and E7-expressing tumour in mice. The E6-RHDV-VLP-PADRE was administered therapeutically for the treatment of a pre-existing TC-1 tumour and was delivered with antibodies either to deplete regulatory T cells (anti-CD25 or to block T cell suppression mediated through CTLA-4. As a result, the tumour burden was reduced by around 50% and the median survival time of mice to the humane endpoint was almost doubled the compared to controls. The incorporation of PADRE into the RHDV-VLP was necessary for an E6-specific enhancement of the anti-tumour response and the co-administration of the immune modifying antibodies contributed to the overall efficacy of the immunotherapy. The E6-RHDV-VLP-PADRE shows immunotherapeutic efficacy, prolonging survival for HPV tumour-bearing mice. This was enhanced by the systemic administration of immune-modifying antibodies that are commercially available for use in humans. There is potential to further modify these particles for even greater efficacy in the path to development of an immunotherapeutic treatment for HPV precancerous and cancer stages.

  15. The HIV-1 Rev/RRE system is required for HIV-1 5' UTR cis elements to augment encapsidation of heterologous RNA into HIV-1 viral particles

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    Ma Hong

    2011-06-01

    Full Text Available Abstract Background The process of HIV-1 genomic RNA (gRNA encapsidation is governed by a number of viral encoded components, most notably the Gag protein and gRNA cis elements in the canonical packaging signal (ψ. Also implicated in encapsidation are cis determinants in the R, U5, and PBS (primer binding site from the 5' untranslated region (UTR. Although conventionally associated with nuclear export of HIV-1 RNA, there is a burgeoning role for the Rev/RRE in the encapsidation process. Pleiotropic effects exhibited by these cis and trans viral components may confound the ability to examine their independent, and combined, impact on encapsidation of RNA into HIV-1 viral particles in their innate viral context. We systematically reconstructed the HIV-1 packaging system in the context of a heterologous murine leukemia virus (MLV vector RNA to elucidate a mechanism in which the Rev/RRE system is central to achieving efficient and specific encapsidation into HIV-1 viral particles. Results We show for the first time that the Rev/RRE system can augment RNA encapsidation independent of all cis elements from the 5' UTR (R, U5, PBS, and ψ. Incorporation of all the 5' UTR cis elements did not enhance RNA encapsidation in the absence of the Rev/RRE system. In fact, we demonstrate that the Rev/RRE system is required for specific and efficient encapsidation commonly associated with the canonical packaging signal. The mechanism of Rev/RRE-mediated encapsidation is not a general phenomenon, since the combination of the Rev/RRE system and 5' UTR cis elements did not enhance encapsidation into MLV-derived viral particles. Lastly, we show that heterologous MLV RNAs conform to transduction properties commonly associated with HIV-1 viral particles, including in vivo transduction of non-dividing cells (i.e. mouse neurons; however, the cDNA forms are episomes predominantly in the 1-LTR circle form. Conclusions Premised on encapsidation of a heterologous RNA into

  16. A SNAP-tagged derivative of HIV-1--a versatile tool to study virus-cell interactions.

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    Manon Eckhardt

    Full Text Available Fluorescently labeled human immunodeficiency virus (HIV derivatives, combined with the use of advanced fluorescence microscopy techniques, allow the direct visualization of dynamic events and individual steps in the viral life cycle. HIV proteins tagged with fluorescent proteins (FPs have been successfully used for live-cell imaging analyses of HIV-cell interactions. However, FPs display limitations with respect to their physicochemical properties, and their maturation kinetics. Furthermore, several independent FP-tagged constructs have to be cloned and characterized in order to obtain spectral variations suitable for multi-color imaging setups. In contrast, the so-called SNAP-tag represents a genetically encoded non-fluorescent tag which mediates specific covalent coupling to fluorescent substrate molecules in a self-labeling reaction. Fusion of the SNAP-tag to the protein of interest allows specific labeling of the fusion protein with a variety of synthetic dyes, thereby offering enhanced flexibility for fluorescence imaging approaches.Here we describe the construction and characterization of the HIV derivative HIV(SNAP, which carries the SNAP-tag as an additional domain within the viral structural polyprotein Gag. Introduction of the tag close to the C-terminus of the matrix domain of Gag did not interfere with particle assembly, release or proteolytic virus maturation. The modified virions were infectious and could be propagated in tissue culture, albeit with reduced replication capacity. Insertion of the SNAP domain within Gag allowed specific staining of the viral polyprotein in the context of virus producing cells using a SNAP reactive dye as well as the visualization of individual virions and viral budding sites by stochastic optical reconstruction microscopy. Thus, HIV(SNAP represents a versatile tool which expands the possibilities for the analysis of HIV-cell interactions using live cell imaging and sub-diffraction fluorescence

  17. Orthoretroviral-like prototype foamy virus gag-pol expression is compatible with viral replication

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    Reh Juliane

    2011-08-01

    Full Text Available Abstract Background Foamy viruses (FVs unlike orthoretroviruses express Pol as a separate precursor protein and not as a Gag-Pol fusion protein. A unique packaging strategy, involving recognition of briding viral RNA by both Pol precursor and Gag as well as potential Gag-Pol protein interactions, ensures Pol particle encapsidation. Results Several Prototype FV (PFV Gag-Pol fusion protein constructs were generated to examine whether PFV replication is compatible with an orthoretroviral-like Pol expression. During their analysis, non-particle-associated secreted Pol precursor protein was discovered in extracellular wild type PFV particle preparations of different origin, copurifying in simple virion enrichment protocols. Different analysis methods suggest that extracellular wild type PFV particles contain predominantly mature p85PR-RT and p40IN Pol subunits. Characterization of various PFV Gag-Pol fusion constructs revealed that PFV Pol expression in an orthoretroviral manner is compatible with PFV replication as long as a proteolytic processing between Gag and Pol proteins is possible. PFV Gag-Pol translation by a HIV-1 like ribosomal frameshift signal resulted in production of replication-competent virions, although cell- and particle-associated Pol levels were reduced in comparison to wild type. In-frame fusion of PFV Gag and Pol ORFs led to increased cellular Pol levels, but particle incorporation was only marginally elevated. Unlike that reported for similar orthoretroviral constructs, a full-length in-frame PFV Gag-Pol fusion construct showed wildtype-like particle release and infectivity characteristics. In contrast, in-frame PFV Gag-Pol fusion with C-terminal Gag ORF truncations or non-removable Gag peptide addition to Pol displayed wildtype particle release, but reduced particle infectivity. PFV Gag-Pol precursor fusion proteins with inactivated protease were highly deficient in regular particle release, although coexpression of p71Gag

  18. Chikungunya virus-like particle vaccine

    NARCIS (Netherlands)

    Metz, S.W.H.

    2013-01-01

    Chikungunya virus (CHIKV) is an arthropod-borne alphavirus (family Togaviridae) and is the causative agent of chikungunya fever. This disease is characterised by the sudden onset of high fever and long-lasting arthritic disease. First identified in Tanzania in 1952,

  19. Dynamics of HIV-1 RNA Near the Plasma Membrane during Virus Assembly.

    Science.gov (United States)

    Sardo, Luca; Hatch, Steven C; Chen, Jianbo; Nikolaitchik, Olga; Burdick, Ryan C; Chen, De; Westlake, Christopher J; Lockett, Stephen; Pathak, Vinay K; Hu, Wei-Shau

    2015-11-01

    To increase our understanding of the events that lead to HIV-1 genome packaging, we examined the dynamics of viral RNA and Gag-RNA interactions near the plasma membrane by using total internal reflection fluorescence microscopy. We labeled HIV-1 RNA with a photoconvertible Eos protein via an RNA-binding protein that recognizes stem-loop sequences engineered into the viral genome. Near-UV light exposure causes an irreversible structural change in Eos and alters its emitted fluorescence from green to red. We studied the dynamics of HIV-1 RNA by photoconverting Eos near the plasma membrane, and we monitored the population of photoconverted red-Eos-labeled RNA signals over time. We found that in the absence of Gag, most of the HIV-1 RNAs stayed near the plasma membrane transiently, for a few minutes. The presence of Gag significantly increased the time that RNAs stayed near the plasma membrane: most of the RNAs were still detected after 30 min. We then quantified the proportion of HIV-1 RNAs near the plasma membrane that were packaged into assembling viral complexes. By tagging Gag with blue fluorescent protein, we observed that only a portion, ∼13 to 34%, of the HIV-1 RNAs that reached the membrane were recruited into assembling particles in an hour, and the frequency of HIV-1 RNA packaging varied with the Gag expression level. Our studies reveal the HIV-1 RNA dynamics on the plasma membrane and the efficiency of RNA recruitment and provide insights into the events leading to the generation of infectious HIV-1 virions. Nascent HIV-1 particles assemble on plasma membranes. During the assembly process, HIV-1 RNA genomes must be encapsidated into viral complexes to generate infectious particles. To gain insights into the RNA packaging and virus assembly mechanisms, we labeled and monitored the HIV-1 RNA signals near the plasma membrane. Our results showed that most of the HIV-1 RNAs stayed near the plasma membrane for only a few minutes in the absence of Gag, whereas

  20. Membrane fusion-competent virus-like proteoliposomes and proteinaceous supported bilayers made directly from cell plasma membranes.

    Science.gov (United States)

    Costello, Deirdre A; Hsia, Chih-Yun; Millet, Jean K; Porri, Teresa; Daniel, Susan

    2013-05-28

    Virus-like particles are useful materials for studying virus-host interactions in a safe manner. However, the standard production of pseudovirus based on the vesicular stomatitis virus (VSV) backbone is an intricate procedure that requires trained laboratory personnel. In this work, a new strategy for creating virus-like proteoliposomes (VLPLs) and virus-like supported bilayers (VLSBs) is presented. This strategy uses a cell blebbing technique to induce the formation of nanoscale vesicles from the plasma membrane of BHK cells expressing the hemagglutinin (HA) fusion protein of influenza X-31. These vesicles and supported bilayers contain HA and are used to carry out single particle membrane fusion events, monitored using total internal reflection fluorescence microscopy. The results of these studies show that the VLPLs and VLSBs contain HA proteins that are fully competent to carry out membrane fusion, including the formation of a fusion pore and the release of fluorophores loaded into vesicles. This new strategy for creating spherical and planar geometry virus-like membranes has many potential applications. VLPLs could be used to study fusion proteins of virulent viruses in a safe manner, or they could be used as therapeutic delivery particles to transport beneficial proteins coexpressed in the cells to a target cell. VLSBs could facilitate high throughput screening of antiviral drugs or pathogen-host cell interactions.

  1. Toll-like receptor agonist augments virus-like particle-mediated protection from Ebola virus with transient immune activation.

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    Karen A O Martins

    Full Text Available Identifying safe and effective adjuvants is critical for the advanced development of protein-based vaccines. Pattern recognition receptor (PRR agonists are increasingly being explored as potential adjuvants, but there is concern that the efficacy of these molecules may be dependent on potentially dangerous levels of non-specific immune activation. The filovirus virus-like particle (VLP vaccine protects mice, guinea pigs, and nonhuman primates from viral challenge. In this study, we explored the impact of a stabilized dsRNA mimic, polyICLC, on VLP vaccination of C57BL/6 mice and Hartley guinea pigs. We show that at dose levels as low as 100 ng, the adjuvant increased the efficacy of the vaccine in mice. Antigen-specific, polyfunctional CD4 and CD8 T cell responses and antibody responses increased significantly upon inclusion of adjuvant. To determine whether the efficacy of polyICLC correlated with systemic immune activation, we examined serum cytokine levels and cellular activation in the draining lymph node. PolyICLC administration was associated with increases in TNFα, IL6, MCP1, MIP1α, KC, and MIP1β levels in the periphery and with the activation of dendritic cells (DCs, NK cells, and B cells. However, this activation resolved within 24 to 72 hours at efficacious adjuvant dose levels. These studies are the first to examine the polyICLC-induced enhancement of antigen-specific immune responses in the context of non-specific immune activation, and they provide a framework from which to consider adjuvant dose levels.

  2. Meloxicam blocks neuroinflammation, but not depressive-like behaviors, in HIV-1 transgenic female rats.

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    Christina L Nemeth

    Full Text Available Adolescents living with human immunodeficiency virus (HIV comprise approximately 12% of the HIV-positive population worldwide. HIV-positive adolescents experience a higher rate of clinical depression, a greater risk of sexual and drug abuse behaviors, and a decreased adherence to highly active antiretroviral therapies (HAART. Using adolescent HIV-1 transgenic rats (HIV-1 tg that display related immune response alterations and pathologies, this study tested the hypothesis that developmental expression of HIV-1-related proteins induces a depressive-like phenotype that parallels a decrease in hippocampal cell proliferation and an increase in pro-inflammatory cytokine expression in the hippocampus. Consistent with this hypothesis, adolescent HIV-1 tg rats demonstrated a depressive-like behavioral phenotype, had decreased levels of cell proliferation, and exhibited elevated expression of monocyte chemotactic protein-1 (Mcp-1 in the hippocampus relative to controls. Subsequently, we tested the ability of meloxicam, a selective COX-2 inhibitor, to attenuate behavioral deficits via inflammatory mechanisms. Daily meloxicam treatments did not alter the behavioral profile despite effectively reducing hippocampal inflammatory gene expression. Together, these data support a biological basis for the co-morbid manifestation of depression in HIV-positive patients as early as in adolescence and suggest that modifications in behavior manifest independent of inflammatory activity in the hippocampus.

  3. Host apolipoprotein B messenger RNA-editing enzyme catalytic polypeptide-like 3G is an innate defensive factor and drug target against hepatitis C virus.

    Science.gov (United States)

    Peng, Zong-Gen; Zhao, Zhi-Yun; Li, Yan-Ping; Wang, Yu-Ping; Hao, Lan-Hu; Fan, Bo; Li, Yu-Huan; Wang, Yue-Ming; Shan, Yong-Qiang; Han, Yan-Xing; Zhu, Yan-Ping; Li, Jian-Rui; You, Xue-Fu; Li, Zhuo-Rong; Jiang, Jian-Dong

    2011-04-01

    Host cellular factor apolipoprotein B messenger RNA (mRNA)-editing enzyme catalytic polypeptide-like 3G (hA3G) is a cytidine deaminase that inhibits a group of viruses including human immunodeficiency virus-1 (HIV-1). In the continuation of our research on hA3G, we found that hA3G stabilizing compounds significantly inhibited hepatitis C virus (HCV) replication. Therefore, this study investigated the role of hA3G in HCV replication. Introduction of external hA3G into HCV-infected Huh7.5 human hepatocytes inhibited HCV replication; knockdown of endogenous hA3G enhanced HCV replication. Exogenous HIV-1 virion infectivity factor (Vif) decreased intracellular hA3G and therefore enhanced HCV proliferation, suggesting that the presence of Vif might be an explanation for the HIV-1/HCV coinfection often observed in HIV-1(+) individuals. Treatment of the HCV-infected Huh7.5 cells with RN-5 or IMB-26, two known hA3G stabilizing compounds, increased intracellular hA3G and accordingly inhibited HCV replication. The compounds inhibit HCV through increasing the level of hA3G incorporated into HCV particles, but not through inhibiting HCV enzymes. However, G/A hypermutation in the HCV genome were not detected, suggesting a new antiviral mechanism of hA3G in HCV, different from that in HIV-1. Stabilization of hA3G by RN-5 was safe in vivo. hA3G appears to be a cellular restrict factor against HCV and could be a potential target for drug discovery. 2011 American Association for the Study of Liver Diseases.

  4. The pathogenesis of liver disease in the setting of HIV-hepatitis B virus coinfection.

    Science.gov (United States)

    Iser, David M; Lewin, Sharon R

    2009-01-01

    There are many potential reasons for increased liver-related mortality in HIV-hepatitis B virus (HBV) coinfection compared with either infection alone. HIV infects multiple cells in the liver and might potentially alter the life cycle of HBV, although evidence to date is limited. Unique mutations in HBV have been defined in HIV-HBV-coinfected individuals and might directly alter pathogenesis. In addition, an impaired HBV-specific T-cell immune response is likely to be important. The roles of microbial translocation, immune activation and increased hepatic stellate cell activation will be important areas for future study.

  5. Effects of adjuvants on IgG subclasses elicited by virus-like Particles

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    Visciano Maria Luisa

    2012-01-01

    Full Text Available Abstract Background Virus-Like Particles (VLPs represent an efficient strategy to present and deliver conformational antigens to the immune system, inducing both arms of the adaptive immune response. Moreover, their particulate structure surrounded by cell membrane provides an adjuvanted effect to VLP-based immunizations. In the present study, the elicitation of different patterns of IgG subclasses by VLPs, administered in CpG ODN1826 or poly(I:C adjuvants, has been evaluated in an animal model. Results Adjuvanted VLPs elicited a higher titer of total specific IgG compared to VLPs alone. Furthermore, while VLPs alone induced a balanced TH2 pattern, VLPs formulated with either adjuvant elicited a TH1-biased IgG subclasses (IgG2a and IgG3, with poly(I:C more potent than CpG ODN1826. Conclusions The results confirmed that adjuvants efficiently improve antigen immunogenicity and represent a suitable strategy to skew the adaptive immune response toward the differentiation of the desired T helper subset, also using VLPs as antigen.

  6. Virus-like particles activate type I interferon pathways to facilitate post-exposure protection against Ebola virus infection.

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    Natarajan Ayithan

    Full Text Available Ebola virus (EBOV causes a severe hemorrhagic disease with high fatality. Virus-like particles (VLPs are a promising vaccine candidate against EBOV. We recently showed that VLPs protect mice from lethal EBOV infection when given before or after viral infection. To elucidate pathways through which VLPs confer post-exposure protection, we investigated the role of type I interferon (IFN signaling. We found that VLPs lead to accelerated induction of IFN stimulated genes (ISGs in liver and spleen of wild type mice, but not in Ifnar-/- mice. Accordingly, EBOV infected Ifnar-/- mice, unlike wild type mice succumbed to death even after VLP treatment. The ISGs induced in wild type mice included anti-viral proteins and negative feedback factors known to restrict viral replication and excessive inflammatory responses. Importantly, proinflammatory cytokine/chemokine expression was much higher in WT mice without VLPs than mice treated with VLPs. In EBOV infected Ifnar-/- mice, however, uninhibited viral replication and elevated proinflammatory factor expression ensued, irrespective of VLP treatment, supporting the view that type I IFN signaling helps to limit viral replication and attenuate inflammatory responses. Further analyses showed that VLP protection requires the transcription factor, IRF8 known to amplify type I IFN signaling in dendritic cells and macrophages, the probable sites of initial EBOV infection. Together, this study indicates that VLPs afford post-exposure protection by promoting expeditious initiation of type I IFN signaling in the host.

  7. Broad, Intense Anti-Human Immunodeficiency Virus (HIV) Ex Vivo CD8+ Responses in HIV Type 1-Infected Patients: Comparison with Anti-Epstein-Barr Virus Responses and Changes during Antiretroviral Therapy

    Science.gov (United States)

    Dalod, Marc; Dupuis, Marion; Deschemin, Jean-Christophe; Sicard, Didier; Salmon, Dominique; Delfraissy, Jean-Francois; Venet, Alain; Sinet, Martine; Guillet, Jean-Gerard

    1999-01-01

    The ex vivo antiviral CD8+ repertoires of 34 human immunodeficiency virus (HIV)-seropositive patients with various CD4+ T-cell counts and virus loads were analyzed by gamma interferon enzyme-linked immunospot assay, using peptides derived from HIV type 1 and Epstein-Barr virus (EBV). Most patients recognized many HIV peptides, with markedly high frequencies, in association with all the HLA class I molecules tested. We found no correlation between the intensity of anti-HIV CD8+ responses and the CD4+ counts or virus load. In contrast, the polyclonality of anti-HIV CD8+ responses was positively correlated with the CD4+ counts. The anti-EBV responses were significantly less intense than the anti-HIV responses and were positively correlated with the CD4+ counts. Longitudinal follow-up of several patients revealed the remarkable stability of the anti-HIV and anti-EBV CD8+ responses in two patients with stable CD4+ counts, while both antiviral responses decreased in two patients with obvious progression toward disease. Last, highly active antiretroviral therapy induced marked decreases in the number of anti-HIV CD8+ T cells, while the anti-EBV responses increased. These findings emphasize the magnitude of the ex vivo HIV-specific CD8+ responses at all stages of HIV infection and suggest that the CD8+ hyperlymphocytosis commonly observed in HIV infection is driven mainly by virus replication, through intense, continuous activation of HIV-specific CD8+ T cells until ultimate progression toward disease. Nevertheless, highly polyclonal anti-HIV CD8+ responses may be associated with a better clinical status. Our data also suggest that a decrease of anti-EBV CD8+ responses may occur with depletion of CD4+ T cells, but this could be restored by highly active antiretroviral treatment. PMID:10438796

  8. Characterization of self-assembled virus-like particles of human polyomavirus BK generated by recombinant baculoviruses

    International Nuclear Information System (INIS)

    Li, T.-C.; Takeda, Naokazu; Kato, Kenzo; Nilsson, Josefina; Xing Li; Haag, Lars; Cheng, R. Holland; Miyamura, Tatsuo

    2003-01-01

    The major structural protein of the human polyomavirus BK (BKV), VP1, was expressed by using recombinant baculoviruses. A large amount of protein with a molecular mass of about 42 kDa was synthesized and identified by Western blotting. The protein was detected exclusively in the nuclei by immunofluorescent analysis and it was released into culture medium. The expressed BKV VP1 protein was self-assembled into virus-like particles (BK-VLPs) with two different sizes (50 and 26 nm in diameter), which migrated into four different bands in CsCl gradient with buoyant densities of 1.29, 1.30, 1.33, and 1.35 g/cm 3 . The immunological studies on the BK-VLPs suggested that they have similar antigenicity with those of authentic BKV particles. Cryoelectron microscopy and 3D image analysis further revealed that the larger BK-VLPs were composed of 72 capsomers which all were pentamers arranged in a T = 7 surface lattice. This system provides useful information for detailed studies of viral morphogenesis and the structural basis for the antigenicity of BKV

  9. Structure determination of feline calicivirus virus-like particles in the context of a pseudo-octahedral arrangement.

    Directory of Open Access Journals (Sweden)

    Wim P Burmeister

    Full Text Available The vesivirus feline calicivirus (FCV is a positive strand RNA virus encapsidated by an icosahedral T=3 shell formed by the viral VP1 protein. Upon its expression in the insect cell - baculovirus system in the context of vaccine development, two types of virus-like particles (VLPs were formed, a majority built of 60 subunits (T=1 and a minority probably built of 180 subunits (T=3. The structure of the small particles was determined by x-ray crystallography at 0.8 nm resolution helped by cryo-electron microscopy in order to understand their formation. Cubic crystals belonged to space group P213. Their self-rotation function showed the presence of an octahedral pseudo-symmetry similar to the one described previously by Agerbandje and co-workers for human parvovirus VLPs. The crystal structure could be solved starting from the published VP1 structure in the context of the T=3 viral capsid. In contrast to viral capsids, where the capsomers are interlocked by the exchange of the N-terminal arm (NTA domain, this domain is disordered in the T=1 capsid of the VLPs. Furthermore it is prone to proteolytic cleavage. The relative orientation of P (protrusion and S (shell domains is alerted so as to fit VP1 to the smaller T=1 particle whereas the intermolecular contacts around 2-fold, 3-fold and 5-fold axes are conserved. By consequence the surface of the VLP is very similar compared to the viral capsid and suggests a similar antigenicity. The knowledge of the structure of the VLPs will help to improve their stability, in respect to a use for vaccination.

  10. Prevalence of Anaemia Among Human Immunodeficiency Virus (HIV)

    African Journals Online (AJOL)

    Background: Anaemia is the most commonly encountered haematological abnormality in human immunodeficiency virus (HIV) positive patients with estimates climbing as high as 95% depending on clinical settings. The twin effects of HIV infection and anaemia in pregnancy is associated with adverse maternal and ...

  11. Long-term protective immunity from an influenza virus-like particle vaccine administered with a microneedle patch.

    Science.gov (United States)

    Quan, Fu-Shi; Kim, Yeu-Chun; Song, Jae-Min; Hwang, Hye Suk; Compans, Richard W; Prausnitz, Mark R; Kang, Sang-Moo

    2013-09-01

    Skin vaccination with influenza virus-like particles (VLPs) using microneedles has been shown to induce protection similar to or better than that induced by intramuscular immunization. In this study, we examined the long-term protective efficacy of influenza (H1N1 A/PR/8/34) VLPs after skin vaccination using microneedle patches coated with the vaccine. Microneedle vaccination of mice in the skin induced 100% protection against lethal challenge infection with influenza A/PR/8/34 virus 14 months after a single vaccine dose. Influenza virus-specific total IgG response and hemagglutination inhibition (HAI) titers were maintained at high levels for over 1 year after microneedle vaccination. Microneedle vaccination also induced substantial levels of lung IgG and IgA antibody responses, and antibody-secreting plasma cells from spleen and bone marrow, as well as conferring effective control of lung viral loads, resulting in complete protection 14 months after vaccination. These strong and long-lasting immune responses were enabled in part by stabilization of the vaccine by formulation with trehalose during microneedle patch fabrication. Administration of the stabilized vaccine using microneedles was especially effective at enabling strong recall responses measured 4 days after lethal virus challenge, including increased HAI and antibody-secreting cells in the spleen and reduced viral titer and inflammatory response in the lung. The results in this study indicate that skin vaccination with VLP vaccine using a microneedle patch provides long-term protection against influenza in mice.

  12. Inhibition of HIV Virus by Neutralizing Vhh Attached to Dual Functional Liposomes Encapsulating Dapivirine.

    Science.gov (United States)

    Wang, Scarlet Xiaoyan; Michiels, Johan; Ariën, Kevin K; New, Roger; Vanham, Guido; Roitt, Ivan

    2016-12-01

    Although highly active antiretroviral therapy (HAART) has greatly improved the life expectancy of HIV/AIDS patients, the treatment is not curative. It is a global challenge which fosters an urgent need to develop an effective drug or neutralizing antibody delivery approach for the prevention and treatment of this disease. Due to the low density of envelope spikes with restricted mobility present on the surface of HIV virus, which limit the antibody potency and allow virus mutation and escape from the immune system, it is important for a neutralizing antibody to form bivalent or multivalent bonds with the virus. Liposome constructs could fulfil this need due to the flexible mobility of the membrane with its attached antibodies and the capacity for drug encapsulation. In this study, we evaluated the neutralization activity of a range of liposome formulations in different sizes coated with anti-gp120 llama antibody fragments (Vhhs) conjugated via either non-covalent metal chelation or a covalent linkage. The non-covalent construct demonstrated identical binding affinity to HIV-1 envelope glycoprotein gp120 and neutralizing ability for HIV virus as free Vhh. Although covalently linked Vhh showed significant binding affinity to gp120, it unexpectedly had a lower neutralization potency. This may be due to the comparability in size of the viral and liposome particles restricting the number which can be bound to the liposome surface so involving only a fraction of the antibodies, whereas non-covalently attached antibodies dissociate from the surface after acting with gp120 and free the remainder to bind further viruses. Covalently conjugated Vhh might also trigger the cellular uptake of a liposome-virion complex. To explore the possible ability of the antibody-coated liposomes to have a further function, we encapsulated the hydrophobic antiviral drug dapivirine into both of the non-covalently and covalently conjugated liposome formulations, both of which revealed high

  13. Inhibition of HIV Virus by Neutralizing Vhh Attached to Dual Functional Liposomes Encapsulating Dapivirine

    Science.gov (United States)

    Wang, Scarlet Xiaoyan; Michiels, Johan; Ariën, Kevin K.; New, Roger; Vanham, Guido; Roitt, Ivan

    2016-07-01

    Although highly active antiretroviral therapy (HAART) has greatly improved the life expectancy of HIV/AIDS patients, the treatment is not curative. It is a global challenge which fosters an urgent need to develop an effective drug or neutralizing antibody delivery approach for the prevention and treatment of this disease. Due to the low density of envelope spikes with restricted mobility present on the surface of HIV virus, which limit the antibody potency and allow virus mutation and escape from the immune system, it is important for a neutralizing antibody to form bivalent or multivalent bonds with the virus. Liposome constructs could fulfil this need due to the flexible mobility of the membrane with its attached antibodies and the capacity for drug encapsulation. In this study, we evaluated the neutralization activity of a range of liposome formulations in different sizes coated with anti-gp120 llama antibody fragments (Vhhs) conjugated via either non-covalent metal chelation or a covalent linkage. The non-covalent construct demonstrated identical binding affinity to HIV-1 envelope glycoprotein gp120 and neutralizing ability for HIV virus as free Vhh. Although covalently linked Vhh showed significant binding affinity to gp120, it unexpectedly had a lower neutralization potency. This may be due to the comparability in size of the viral and liposome particles restricting the number which can be bound to the liposome surface so involving only a fraction of the antibodies, whereas non-covalently attached antibodies dissociate from the surface after acting with gp120 and free the remainder to bind further viruses. Covalently conjugated Vhh might also trigger the cellular uptake of a liposome-virion complex. To explore the possible ability of the antibody-coated liposomes to have a further function, we encapsulated the hydrophobic antiviral drug dapivirine into both of the non-covalently and covalently conjugated liposome formulations, both of which revealed high

  14. The anti-HIV-1 effect of scutellarin

    International Nuclear Information System (INIS)

    Zhang Gaohong; Wang Qian; Chen Jijun; Zhang Xuemei; Tam, S.-C.; Zheng Yongtang

    2005-01-01

    Scutellarin was purified from the plant Erigeron breviscapus (Vant.) Hand.-Mazz. The activity against 3 strains of human immunodeficiency virus (HIV) was determined in vitro in this study. These were laboratory-derived virus (HIV-1 IIIB ), drug-resistant virus (HIV-1 74V ), and low-passage clinical isolated virus (HIV-1 KM018 ). From syncytia inhibition study, the EC 50 of scutellarin against HIV-1 IIIB direct infection in C8166 cells was 26 μM with a therapeutic index of 36. When the mode of infection changed from acute infection to cell-to-cell infection, this compound became even more potent and the EC 50 reduced to 15 μM. This suggested that cell fusion might be affected by this compound. By comparing the inhibitory effects on p24 antigen, scutellarin was also found to be active against HIV-1 74V (EC 50 253 μM) and HIV-1 KM018 (EC 50 136 μM) infection with significant difference in potency. The mechanism of its action was also explored in this study. At a concentration of 433 μM, scutellarin inhibited 48% of the cell free recombinant HIV-1 RT activity. It also caused 82% inhibition of HIV-1 particle attachment and 45% inhibition of fusion at the concentrations of 54 μM. In summary, scutellarin was found to inhibit several strains of HIV-1 replication with different potencies. It appeared to inhibit HIV-1 RT activity, HIV-1 particle attachment and cell fusion. These are essential activities for viral transmission and replication

  15. Prevalence of human immunodeficiency virus (HIV) infection among ...

    African Journals Online (AJOL)

    AJB SERVER

    2007-02-05

    Feb 5, 2007 ... ... virus (HIV) was disco- vered in 1983 (two years after the diseases AIDS was ... de this lipid bilayer is a matrix (MA) protein (p17). Below the matrix is ... conformational changes in the viral envelope to permit virus-cell fusion.

  16. Virus-Like Particles of Chimeric Recombinant Porcine Circovirus Type 2 as Antigen Vehicle Carrying Foreign Epitopes

    Directory of Open Access Journals (Sweden)

    Huawei Zhang

    2014-12-01

    Full Text Available Virus-like particles (VLPs of chimeric porcine circovirus type 2 (PCV2 were generated by replacing the nuclear localization signal (NLS; at 1–39 aa of PCV2 capsid protein (Cap with classical swine fever virus (CSFV T-cell epitope (1446–1460 aa, CSFV B-cell epitope (693–716 aa and CSFV T-cell epitope conjugated with B-cell epitope. The recombinant proteins were expressed using the baculovirus expression system and detected by immunoblotting and indirect immunofluorescence assay. The abilities to form PCV2 VLPs were confirmed by transmission electron microscopy. Immunogenicities of the three recombinant proteins were evaluated in mice. Our Results indicated that Cap protein NLS deletion or substitution with CSFV epitopes did not affect the VLPs assembly. Three chimeric Cap proteins could form VLPs and induce efficient humoral and cellular immunity against PCV2 and CSFV in mice. Results show that PCV2 VLPs can be used as an efficient antigen carrier for delivery of foreign epitopes, and a potential novel vaccine.

  17. The Oncolytic Virus MG1 Targets and Eliminates Cells Latently Infected With HIV-1: Implications for an HIV Cure.

    Science.gov (United States)

    Ranganath, Nischal; Sandstrom, Teslin S; Burke Schinkel, Stephanie C; Côté, Sandra C; Angel, Jonathan B

    2018-02-14

    Cells latently infected with human immunodeficiency virus (HIV) evade immune- and drug-mediated clearance. These cells harbor intracellular signaling defects, including impairment of the antiviral type I interferon response. Such defects have also been observed in several cancers and have been exploited for the development of therapeutic oncolytic viruses, including the recombinant Maraba virus (MG1). We therefore hypothesized that MG1 would infect and eliminate cells latently infected with HIV-1, while sparing healthy uninfected cells. Preferential infection and elimination by MG1 was first demonstrated in cell lines latently infected with HIV-1. Following this, a reduction in HIV-1 DNA and inducible HIV-1 replication was observed following MG1 infection of latently infected, resting CD4+ T cells generated using an in vitro model of latency. Last, MG1 infection resulted in a reduction in HIV-1 DNA and inducible HIV-1 replication in memory CD4+ T cells isolated from effectively treated, HIV-1-infected individuals. Our results therefore highlight a novel approach to eliminate the latent HIV-1 reservoir. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  18. Co-immunization with virus-like particle and DNA vaccines induces protection against respiratory syncytial virus infection and bronchiolitis

    Science.gov (United States)

    Hwang, Hye Suk; Kwon, Young-Man; Lee, Jong Seok; Yoo, Si-Eun; Lee, Yu-Na; Ko, Eun-Ju; Kim, Min-Chul; Cho, Min-Kyoung; Lee, Young-Tae; Jung, Yu-Jin; Lee, Ji-Yun; Li, Jian Dong; Kang, Sang-Moo

    2014-01-01

    This study demonstrates that immunization with non-replicating virus-like particle (FFG VLP) containing RSV F and G glycoproteins together with RSV F DNA induced T helper type 1 antibody responses to RSV F similar to live RSV infection. Upon RSV challenge 21 weeks after immunization, FFG VLP vaccination induced protection against RSV infection as shown by clearance of lung viral loads, and the absence of eosinophil infiltrates, and did not cause lung pathology. In contrast, formalin-inactivated RSV (FI-RSV) vaccination showed significant pulmonary eosinophilia, severe mucus production, and extensive histopathology resulting in a hallmark of pulmonary pathology. Substantial lung pathology was also observed in mice with RSV re-infections. High levels of systemic and local inflammatory cytokine-secreting cells were induced in mice with FI-RSV but not with FFG VLP immunization after RSV challenge. Therefore, the results provide evidence that recombinant RSV FFG VLP vaccine can confer long-term protection against RSV without causing lung pathology. PMID:25110201

  19. Duck hepatitis A virus structural proteins expressed in insect cells self-assemble into virus-like particles with strong immunogenicity in ducklings.

    Science.gov (United States)

    Wang, Anping; Gu, Lingling; Wu, Shuang; Zhu, Shanyuan

    2018-02-01

    Duck hepatitis A virus (DHAV), a non-enveloped ssRNA virus, can cause a highly contagious disease in young ducklings. The three capsid proteins of VP0, VP1 and VP3 are translated within a single large open reading frame (ORF) and hydrolyzed by protease 3CD. However, little is known on whether the recombinant viral structural proteins (VPs) expressed in insect cells could spontaneously assemble into virus-like particles (VLPs) and whether these VLPs could induce protective immunity in young ducklings. To address these issues, the structural polyprotein precursor gene P1 and the protease gene 3CD were amplified by PCR, and the recombinant proteins were expressed in insect cells using a baculovirus expression system for the characterization of their structures and immunogenicity. The recombinant proteins expressed in Sf9 cells were detected by indirect immunofluorescence assay and Western blot analysis. Electron microscopy showed that the recombinant proteins spontaneously assembled into VLPs in insect cells. Western blot analysis of the purified VLPs revealed that the VLPs were composed with the three structural proteins. In addition, vaccination with the VLPs induced high humoral immune response and provided strong protection. Therefore, our findings may provide a framework for development of new vaccines for the prevention of duck viral hepatitis. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Development of Lentivirus-Based Reference Materials for Ebola Virus Nucleic Acid Amplification Technology-Based Assays.

    Science.gov (United States)

    Mattiuzzo, Giada; Ashall, James; Doris, Kathryn S; MacLellan-Gibson, Kirsty; Nicolson, Carolyn; Wilkinson, Dianna E; Harvey, Ruth; Almond, Neil; Anderson, Robert; Efstathiou, Stacey; Minor, Philip D; Page, Mark

    2015-01-01

    The 2013-present Ebola virus outbreak in Western Africa has prompted the production of many diagnostic assays, mostly based on nucleic acid amplification technologies (NAT). The calibration and performance assessment of established assays and those under evaluation requires reference materials that can be used in parallel with the clinical sample to standardise or control for every step of the procedure, from extraction to the final qualitative/quantitative result. We have developed safe and stable Ebola virus RNA reference materials by encapsidating anti sense viral RNA into HIV-1-like particles. The lentiviral particles are replication-deficient and non-infectious due to the lack of HIV-1 genes and Envelope protein. Ebola virus genes were subcloned for encapsidation into two lentiviral preparations, one containing NP-VP35-GP and the other VP40 and L RNA. Each reference material was formulated as a high-titre standard for use as a calibrator for secondary or internal standards, and a 10,000-fold lower titre preparation to serve as an in-run control. The preparations have been freeze-dried to maximise stability. These HIV-Ebola virus RNA reference materials were suitable for use with in-house and commercial quantitative RT-PCR assays and with digital RT-PCR. The HIV-Ebola virus RNA reference materials are stable at up to 37°C for two weeks, allowing the shipment of the material worldwide at ambient temperature. These results support further evaluation of the HIV-Ebola virus RNA reference materials as part of an International collaborative study for the establishment of the 1st International Standard for Ebola virus RNA.

  1. Development of Lentivirus-Based Reference Materials for Ebola Virus Nucleic Acid Amplification Technology-Based Assays.

    Directory of Open Access Journals (Sweden)

    Giada Mattiuzzo

    Full Text Available The 2013-present Ebola virus outbreak in Western Africa has prompted the production of many diagnostic assays, mostly based on nucleic acid amplification technologies (NAT. The calibration and performance assessment of established assays and those under evaluation requires reference materials that can be used in parallel with the clinical sample to standardise or control for every step of the procedure, from extraction to the final qualitative/quantitative result. We have developed safe and stable Ebola virus RNA reference materials by encapsidating anti sense viral RNA into HIV-1-like particles. The lentiviral particles are replication-deficient and non-infectious due to the lack of HIV-1 genes and Envelope protein. Ebola virus genes were subcloned for encapsidation into two lentiviral preparations, one containing NP-VP35-GP and the other VP40 and L RNA. Each reference material was formulated as a high-titre standard for use as a calibrator for secondary or internal standards, and a 10,000-fold lower titre preparation to serve as an in-run control. The preparations have been freeze-dried to maximise stability. These HIV-Ebola virus RNA reference materials were suitable for use with in-house and commercial quantitative RT-PCR assays and with digital RT-PCR. The HIV-Ebola virus RNA reference materials are stable at up to 37°C for two weeks, allowing the shipment of the material worldwide at ambient temperature. These results support further evaluation of the HIV-Ebola virus RNA reference materials as part of an International collaborative study for the establishment of the 1st International Standard for Ebola virus RNA.

  2. Canine parvovirus VP2 protein expressed in silkworm pupae self-assembles into virus-like particles with high immunogenicity.

    Directory of Open Access Journals (Sweden)

    Hao Feng

    Full Text Available The VP2 structural protein of parvovirus can produce virus-like particles (VLPs by a self-assembly process in vitro, making VLPs attractive vaccine candidates. In this study, the VP2 protein of canine parvovirus (CPV was expressed using a baculovirus expression system and assembled into parvovirus-like particles in insect cells and pupae. Electron micrographs of VLPs showed that they were very similar in size and morphology when compared to the wild-type parvovirus. The immunogenicity of the VLPs was investigated in mice and dogs. Mice immunized intramuscularly with purified VLPs, in the absence of an adjuvant, elicited CD4(+ and CD8(+ T cell responses and were able to elicit a neutralizing antibody response against CPV, while the oral administration of raw homogenates containing VLPs to the dogs resulted in a systemic immune response and long-lasting immunity. These results demonstrate that the CPV-VLPs stimulate both cellular and humoral immune responses, and so CPV-VLPs may be a promising candidate vaccine for the prevention of CPV-associated disease.

  3. Canine parvovirus VP2 protein expressed in silkworm pupae self-assembles into virus-like particles with high immunogenicity.

    Science.gov (United States)

    Feng, Hao; Hu, Gui-qiu; Wang, Hua-lei; Liang, Meng; Liang, Hongru; Guo, He; Zhao, Pingsen; Yang, Yu-jiao; Zheng, Xue-xing; Zhang, Zhi-fang; Zhao, Yong-kun; Gao, Yu-wei; Yang, Song-tao; Xia, Xian-zhu

    2014-01-01

    The VP2 structural protein of parvovirus can produce virus-like particles (VLPs) by a self-assembly process in vitro, making VLPs attractive vaccine candidates. In this study, the VP2 protein of canine parvovirus (CPV) was expressed using a baculovirus expression system and assembled into parvovirus-like particles in insect cells and pupae. Electron micrographs of VLPs showed that they were very similar in size and morphology when compared to the wild-type parvovirus. The immunogenicity of the VLPs was investigated in mice and dogs. Mice immunized intramuscularly with purified VLPs, in the absence of an adjuvant, elicited CD4(+) and CD8(+) T cell responses and were able to elicit a neutralizing antibody response against CPV, while the oral administration of raw homogenates containing VLPs to the dogs resulted in a systemic immune response and long-lasting immunity. These results demonstrate that the CPV-VLPs stimulate both cellular and humoral immune responses, and so CPV-VLPs may be a promising candidate vaccine for the prevention of CPV-associated disease.

  4. Hepatitis C virus infection in HIV-infected patients.

    Science.gov (United States)

    Sulkowski, Mark S

    2007-10-01

    The hepatitis C virus (HCV) is a spherical enveloped RNA virus of the Flaviviridae family, classified within the Hepacivirus genus. Since its discovery in 1989, HCV has been recognized as a major cause of chronic hepatitis and hepatic fibrosis that progresses in some patients to cirrhosis and hepatocellular carcinoma. In the United States, approximately 4 million people have been infected with HCV, and 10,000 HCVrelated deaths occur each year. Due to shared routes of transmission, HCV and HIV co-infection are common, affecting approximately one third of all HIV-infected persons in the United States. In addition, HIV co-infection is associated with higher HCV RNA viral load and a more rapid progression of HCV-related liver disease, leading to an increased risk of cirrhosis. HCV infection may also impact the course and management of HIV disease, particularly by increasing the risk of antiretroviral drug-induced hepatotoxicity. Thus, chronic HCV infection acts as an opportunistic disease in HIV-infected persons because the incidence of infection is increased and the natural history of HCV infection is accelerated in co-infected persons. Strategies to prevent primary HCV infection and to modify the progression of HCV-related liver disease are urgently needed among HIV/HCV co-infected individuals.

  5. Molecular characterization of viruses associated with gastrointestinal infection in HIV-positive patients

    Directory of Open Access Journals (Sweden)

    Raquel C Silva

    Full Text Available BACKGROUND: Diarrhea is a major cause of morbidity and mortality among HIV-infected patients worldwide. OBJECTIVE: We sought to determine the frequency of viral gastrointestinal infections among Brazilian HIV-infected patients with diarrhea. METHODS: A collection of 90 fecal specimens from HIV-infected individuals with diarrhea, previously tested for the presence of bacteria and parasite was analyzed by polymerase chain reaction and sequence analysis for the presence of enteric viruses such as astrovirus, norovirus, rotavirus groups A, B and C, adenovirus, herpes simplex virus, Epstein-Barr virus, cytomegalovirus, and human bocavirus. RESULTS: Twenty patients (22.2%; n = 90 were infected with parasites (11 single infections and nine coinfected with virus. Enteropathogenic bacteria were not found. Virus infections were detected in 28.9% (26/90 of the specimens. Cytomegalovirus was the most common virus detected (24.4%; 22/90. Coinfections with viruses and/or parasite were observed in 10 (11.1% samples. CONCLUSION: Gastrointestinal virus infections were more frequent than parasitic or bacterial infections in this patient population.

  6. Goose parvovirus structural proteins expressed by recombinant baculoviruses self-assemble into virus-like particles with strong immunogenicity in goose

    International Nuclear Information System (INIS)

    Ju, Huanyu; Wei, Na; Wang, Qian; Wang, Chunyuan; Jing, Zhiqiang; Guo, Lu; Liu, Dapeng; Gao, Mingchun; Ma, Bo; Wang, Junwei

    2011-01-01

    Highlights: → All three capsid proteins can be expressed in insect cells in baculovirus expression system. → All three recombinant proteins were spontaneously self-assemble into virus-like particles whose size and appearance were similar to those of native purified GPV virions. → The immunogenicity of GPV-VLPs was better than commercial inactivated vaccine and attenuated vaccine. -- Abstract: Goose parvovirus (GPV), a small non-enveloped ssDNA virus, can cause Derzsy's disease, and three capsid proteins of VP1, VP2, and VP3 are encoded by an overlapping nucleotide sequence. However, little is known on whether recombinant viral proteins (VPs) could spontaneously assemble into virus-like particles (VLPs) in insect cells and whether these VLPs could retain their immunoreactivity and immunogenicity in susceptible geese. To address these issues, genes for these GPV VPs were amplified by PCR, and the recombinant VPs proteins were expressed in insect cells using a baculovirus expression system for the characterization of their structures, immunoreactivity, and immunogenicity. The rVP1, rVP2, and rVP3 expressed in Sf9 cells were detected by anti-GPV sera, anti-VP3 sera, and anti-His antibodies, respectively. Electron microscopy revealed that these rVPs spontaneously assembled into VLPs in insect cells, similar to that of the purified wild-type GPV virions. In addition, vaccination with individual types of VLPs, particularly with the rVP2-VLPs, induced higher titers of antibodies and neutralized different strains of GPVs in primary goose and duck embryo fibroblast cells in vitro. These data indicated that these VLPs retained immunoreactivity and had strong immunogenicity in susceptible geese. Therefore, our findings may provide a framework for development of new vaccines for the prevention of Derzsy's disease and vehicles for the delivery of drugs.

  7. Goose parvovirus structural proteins expressed by recombinant baculoviruses self-assemble into virus-like particles with strong immunogenicity in goose

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Huanyu; Wei, Na; Wang, Qian; Wang, Chunyuan; Jing, Zhiqiang; Guo, Lu; Liu, Dapeng; Gao, Mingchun; Ma, Bo [College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030 (China); Wang, Junwei, E-mail: jwwang@neau.edu.cn [College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030 (China)

    2011-05-27

    Highlights: {yields} All three capsid proteins can be expressed in insect cells in baculovirus expression system. {yields} All three recombinant proteins were spontaneously self-assemble into virus-like particles whose size and appearance were similar to those of native purified GPV virions. {yields} The immunogenicity of GPV-VLPs was better than commercial inactivated vaccine and attenuated vaccine. -- Abstract: Goose parvovirus (GPV), a small non-enveloped ssDNA virus, can cause Derzsy's disease, and three capsid proteins of VP1, VP2, and VP3 are encoded by an overlapping nucleotide sequence. However, little is known on whether recombinant viral proteins (VPs) could spontaneously assemble into virus-like particles (VLPs) in insect cells and whether these VLPs could retain their immunoreactivity and immunogenicity in susceptible geese. To address these issues, genes for these GPV VPs were amplified by PCR, and the recombinant VPs proteins were expressed in insect cells using a baculovirus expression system for the characterization of their structures, immunoreactivity, and immunogenicity. The rVP1, rVP2, and rVP3 expressed in Sf9 cells were detected by anti-GPV sera, anti-VP3 sera, and anti-His antibodies, respectively. Electron microscopy revealed that these rVPs spontaneously assembled into VLPs in insect cells, similar to that of the purified wild-type GPV virions. In addition, vaccination with individual types of VLPs, particularly with the rVP2-VLPs, induced higher titers of antibodies and neutralized different strains of GPVs in primary goose and duck embryo fibroblast cells in vitro. These data indicated that these VLPs retained immunoreactivity and had strong immunogenicity in susceptible geese. Therefore, our findings may provide a framework for development of new vaccines for the prevention of Derzsy's disease and vehicles for the delivery of drugs.

  8. Binding of Human GII.4 Norovirus Virus-Like Particles to Carbohydrates of Romaine Lettuce Leaf Cell Wall Materials

    Science.gov (United States)

    Esseili, Malak A.

    2012-01-01

    Norovirus (NoV) genogroup II genotype 4 (GII.4) strains are the dominant cause of the majority of food-borne outbreaks, including those that involve leafy greens, such as lettuce. Since human NoVs use carbohydrates of histo-blood group antigens as receptors/coreceptors, we examined the role of carbohydrates in the attachment of NoV to lettuce leaves by using virus-like particles (VLPs) of a human NoV/GII.4 strain. Immunofluorescence analysis showed that the VLPs attached to the leaf surface, especially to cut edges, stomata, and along minor veins. Binding was quantified using enzyme-linked immunosorbent assay (ELISA) performed on cell wall materials (CWM) from innermost younger leaves and outermost lamina of older leaves. The binding to CWM of older leaves was significantly (P lettuce CWM by utilizing multiple carbohydrate moieties. This binding may enhance virus persistence on the leaf surface and prevent effective decontamination. PMID:22138991

  9. Application of virus-like particles (VLP) to NMR characterization of viral membrane protein interactions

    Energy Technology Data Exchange (ETDEWEB)

    Antanasijevic, Aleksandar; Kingsley, Carolyn [University of Illinois at Chicago, Department of Biochemistry and Molecular Genetics (United States); Basu, Arnab; Bowlin, Terry L. [Microbiotix Inc. (United States); Rong, Lijun [University of Illinois at Chicago, Department of Microbiology and Immunology (United States); Caffrey, Michael, E-mail: caffrey@uic.edu [University of Illinois at Chicago, Department of Biochemistry and Molecular Genetics (United States)

    2016-03-15

    The membrane proteins of viruses play critical roles in the virus life cycle and are attractive targets for therapeutic intervention. Virus-like particles (VLP) present the possibility to study the biochemical and biophysical properties of viral membrane proteins in their native environment. Specifically, the VLP constructs contain the entire protein sequence and are comprised of native membrane components including lipids, cholesterol, carbohydrates and cellular proteins. In this study we prepare VLP containing full-length hemagglutinin (HA) or neuraminidase (NA) from influenza and characterize their interactions with small molecule inhibitors. Using HA-VLP, we first show that VLP samples prepared using the standard sucrose gradient purification scheme contain significant amounts of serum proteins, which exhibit high potential for non-specific interactions, thereby complicating NMR studies of ligand-target interactions. We then show that the serum contaminants may be largely removed with the addition of a gel filtration chromatography step. Next, using HA-VLP we demonstrate that WaterLOGSY NMR is significantly more sensitive than Saturation Transfer Difference (STD) NMR for the study of ligand interactions with membrane bound targets. In addition, we compare the ligand orientation to HA embedded in VLP with that of recombinant HA by STD NMR. In a subsequent step, using NA-VLP we characterize the kinetic and binding properties of substrate analogs and inhibitors of NA, including study of the H274Y-NA mutant, which leads to wide spread resistance to current influenza antivirals. In summary, our work suggests that VLP have high potential to become standard tools in biochemical and biophysical studies of viral membrane proteins, particularly when VLP are highly purified and combined with control VLP containing native membrane proteins.

  10. Characterizing Enterovirus 71 and Coxsackievirus A16 virus-like particles production in insect cells.

    Science.gov (United States)

    Somasundaram, Balaji; Chang, Cindy; Fan, Yuan Y; Lim, Pei-Yin; Cardosa, Jane; Lua, Linda

    2016-02-15

    Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) are two viruses commonly responsible for hand, foot and mouth disease (HFMD) in children. The lack of prophylactic or therapeutic measures against HFMD is a major public health concern. Insect cell-based EV71 and CVA16 virus-like particles (VLPs) are promising vaccine candidates against HFMD and are currently under development. In this paper, the influence of insect cell line, incubation temperature, and serial passaging effect and stability of budded virus (BV) stocks on EV71 and CVA16 VLP production was investigated. Enhanced EV71 and CVA16 VLP production was observed in Sf9 cells compared to High Five™ cells. Lowering the incubation temperature from the standard 27°C to 21°C increased the production of both VLPs in Sf9 cells. Serial passaging of CVA16 BV stocks in cell culture had a detrimental effect on the productivity of the structural proteins and the effect was observed with only 5 passages of BV stocks. A 2.7× higher production yield was achieved with EV71 compared to CVA16. High-resolution asymmetric flow field-flow fractionation couple with multi-angle light scattering (AF4-MALS) was used for the first time to characterize EV71 and CVA16 VLPs, displaying an average root mean square radius of 15±1nm and 15.3±5.8 nm respectively. This study highlights the need for different approaches in the design of production process to develop a bivalent EV71 and CVA16 vaccine. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Sero-prevalence of Human Immunodeficiency Virus (HIV) and ...

    African Journals Online (AJOL)

    Three hundred and seven (307) healthy blood donors aged 18 – 55 years were used to determine the sero-prevalence of Human Immunodeficiency Virus (HIV) and Hepatitis B virus (HBV) in Yola, Nigeria. The association between donors' age, occupation and marital status and the prevalence of the infections among blood ...

  12. Molecular characterization of Torque teno virus and SEN virus co-infection with HIV in patients from Southern Iran

    Directory of Open Access Journals (Sweden)

    Aliyar Pirouzi

    2014-06-01

    Full Text Available Introduction Torque teno virus (TTV and SEN virus are circular single-stranded DNA viruses that cause blood-borne infections. The SEN virus (SEN-V was originally detected in the serum of an injection drug user infected with human immunodeficiency virus (HIV. Recently TTV was discovered as a potential causative agent of non-A-E hepatitis. The aim of this study was to investigate the prevalence of the SEN-V-D/H and TTV in HIV patients and healthy blood donors in Iran. Methods One hundred and fifty HIV patients with a mean age of 50.46 ± 18.46 years and 150 healthy blood donors with a mean age of 48.16 ± 13.73 years were included in this study. TTV and SEN-V were detected by the PCR and were quantitatively assayed by competitive PCR (nested and semi-nested PCR. Restriction fragment length polymorphisms (RFLPs were used to determine the heterogeneity of TTV. Results TTV and SEN-V were detected 96 (64% and 84 (56% of 150 HIV patients respectively. These rates were 34% (n=51 and 37.33% (n=56 in healthy blood donors (significant, p<0.05. PCR detected SEN-V/TTV DNA from 32 of the healthy blood donors (21.33%, while 65 (43.33% of HIV patients were positive for SEN-V/TTV DNA. Of 150 HIV patients, 32.66% and 23.33% were positive for SEN-V-H and SEN-V-D, respectively and 18.66% (n=28 were co-infected with SEN-V-D/H. Conclusions The prevalence of SEN-VD/H and TTV is higher in HIV patients than in healthy blood donors in Southern Iran. Our results suggest that TTV and SEN-V might play a role in the development of liver disease in patients with immunodeficiency diseases.

  13. HIV-1 neutralizing antibodies induced by native-like envelope trimers

    NARCIS (Netherlands)

    Sanders, Rogier W.; van Gils, Marit J.; Derking, Ronald; Sok, Devin; Ketas, Thomas J.; Burger, Judith A.; Ozorowski, Gabriel; Cupo, Albert; Simonich, Cassandra; Goo, Leslie; Arendt, Heather; Kim, Helen J.; Lee, Jeong Hyun; Pugach, Pavel; Williams, Melissa; Debnath, Gargi; Moldt, Brian; van Breemen, Mariëlle J.; Isik, Gözde; Medina-Ramírez, Max; Back, Jaap Willem; Koff, Wayne C.; Julien, Jean-Philippe; Rakasz, Eva G.; Seaman, Michael S.; Guttman, Miklos; Lee, Kelly K.; Klasse, Per Johan; Labranche, Celia; Schief, William R.; Wilson, Ian A.; Overbaugh, Julie; Burton, Dennis R.; Ward, Andrew B.; Montefiori, David C.; Dean, Hansi; Moore, John P.

    2015-01-01

    A challenge for HIV-1 immunogen design is the difficulty of inducing neutralizing antibodies (NAbs) against neutralization-resistant (tier 2) viruses that dominate human transmissions. We show that a soluble recombinant HIV-1 envelope glycoprotein trimer that adopts a native conformation, BG505

  14. Surfactant Protein D modulates HIV infection of both T-cells and dendritic cells.

    Directory of Open Access Journals (Sweden)

    Jens Madsen

    Full Text Available Surfactant Protein D (SP-D is an oligomerized C-type lectin molecule with immunomodulatory properties and involvement in lung surfactant homeostasis in the respiratory tract. SP-D binds to the enveloped viruses, influenza A virus and respiratory syncytial virus and inhibits their replication in vitro and in vivo. SP-D has been shown to bind to HIV via the HIV envelope protein gp120 and inhibit infectivity in vitro. Here we show that SP-D binds to different strains of HIV (BaL and IIIB and the binding occurs at both pH 7.4 and 5.0 resembling physiological relevant pH values found in the body and the female urogenital tract, respectively. The binding of SP-D to HIV particles and gp120 was inhibited by the presence of several hexoses with mannose found to be the strongest inhibitor. Competition studies showed that soluble CD4 and CVN did not interfere with the interaction between SP-D and gp120. However, soluble recombinant DC-SIGN was shown to inhibit the binding between SP-D and gp120. SP-D agglutinated HIV and gp120 in a calcium dependent manner. SP-D inhibited the infectivity of HIV strains at both pH values of 7.4 and 5.0 in a concentration dependent manner. The inhibition of the infectivity was abolished by the presence of mannose. SP-D enhanced the binding of HIV to immature monocyte derived dendritic cells (iMDDCs and was also found to enhance HIV capture and transfer to the T-cell like line PM1. These results suggest that SP-D can bind to and inhibit direct infection of T-cells by HIV but also enhance the transfer of infectious HIV particles from DCs to T-cells in vivo.

  15. Population immunity to measles virus and the effect of HIV-1 infection after a mass measles vaccination campaign in Lusaka, Zambia: a cross-sectional survey.

    Science.gov (United States)

    Lowther, Sara A; Curriero, Frank C; Kalish, Brian T; Shields, Timothy M; Monze, Mwaka; Moss, William J

    2009-03-21

    Measles control efforts are hindered by challenges in sustaining high vaccination coverage, waning immunity in HIV-1-infected children, and clustering of susceptible individuals. Our aim was to assess population immunity to measles virus after a mass vaccination campaign in a region with high HIV prevalence. 3 years after a measles supplemental immunisation activity (SIA), we undertook a cross-sectional survey in Lusaka, Zambia. Households were randomly selected from a satellite image. Children aged 9 months to 5 years from selected households were eligible for enrolment. A questionnaire was administered to the children's caregivers to obtain information about measles vaccination history and history of measles. Oral fluid samples were obtained from children and tested for antibodies to measles virus and HIV-1 by EIA. 1015 children from 668 residences provided adequate specimens. 853 (84%) children had a history of measles vaccination according to either caregiver report or immunisation card. 679 children (67%) had antibodies to measles virus, and 64 (6%) children had antibodies to HIV-1. Children with antibodies to HIV-1 were as likely to have no history of measles vaccination as those without antibodies to HIV-1 (odds ratio [OR] 1.17, 95% CI 0.57-2.41). Children without measles antibodies were more likely to have never received measles vaccine than those with antibodies (adjusted OR 2.50, 1.69-3.71). In vaccinated children, 33 (61%) of 54 children with antibodies to HIV-1 also had antibodies to measles virus, compared with 568 (71%) of 796 children without antibodies to HIV-1 (p=0.1). 3 years after an SIA, population immunity to measles was insufficient to interrupt measles virus transmission. The use of oral fluid and satellite images for sampling are potential methods to assess population immunity and the timing of SIAs.

  16. Recombinant norovirus-specific scFv inhibit virus-like particle binding to cellular ligands

    Directory of Open Access Journals (Sweden)

    Hardy Michele E

    2008-01-01

    Full Text Available Abstract Background Noroviruses cause epidemic outbreaks of gastrointestinal illness in all age-groups. The rapid onset and ease of person-to-person transmission suggest that inhibitors of the initial steps of virus binding to susceptible cells have value in limiting spread and outbreak persistence. We previously generated a monoclonal antibody (mAb 54.6 that blocks binding of recombinant norovirus-like particles (VLP to Caco-2 intestinal cells and inhibits VLP-mediated hemagglutination. In this study, we engineered the antigen binding domains of mAb 54.6 into a single chain variable fragment (scFv and tested whether these scFv could function as cell binding inhibitors, similar to the parent mAb. Results The scFv54.6 construct was engineered to encode the light (VL and heavy (VH variable domains of mAb 54.6 separated by a flexible peptide linker, and this recombinant protein was expressed in Pichia pastoris. Purified scFv54.6 recognized native VLPs by immunoblot, inhibited VLP-mediated hemagglutination, and blocked VLP binding to H carbohydrate antigen expressed on the surface of a CHO cell line stably transfected to express α 1,2-fucosyltransferase. Conclusion scFv54.6 retained the functional properties of the parent mAb with respect to inhibiting norovirus particle interactions with cells. With further engineering into a form deliverable to the gut mucosa, norovirus neutralizing antibodies represent a prophylactic strategy that would be valuable in outbreak settings.

  17. In vitro assembly into virus-like particles is an intrinsic quality of Pichia pastoris derived HCV core protein

    International Nuclear Information System (INIS)

    Acosta-Rivero, Nelson; Rodriguez, Armando; Musacchio, Alexis; Falcon, Viviana; Suarez, Viana M.; Martinez, Gillian; Guerra, Ivis; Paz-Lago, Dalila; Morera, Yanelys; Rosa, Maria C. de la; Morales-Grillo, Juan; Duenas-Carrera, Santiago

    2004-01-01

    Different variants of hepatitis C virus core protein (HCcAg) have proved to self-assemble in vitro into virus-like particles (VLPs). However, difficulties in obtaining purified mature HCcAg have limited these studies. In this study, a high degree of monomeric HCcAg purification was accomplished using chromatographic procedures under denaturing conditions. Size exclusion chromatography and sucrose density gradient centrifugation of renatured HCcAg (in the absence of structured RNA) under reducing conditions suggested that it assembled into empty capsids. The electron microscopy analysis of renatured HCcAg showed the presence of spherical VLPs with irregular shapes and an average diameter of 35 nm. Data indicated that HCcAg monomers assembled in vitro into VLPs in the absence of structured RNA, suggesting that recombinant HCcAg used in this work contains all the information necessary for the assembly process. However, they also suggest that some cellular factors might be required for the proper in vitro assembly of capsids

  18. Increased Hepatitis E Virus Seroprevalence Correlates with Lower CD4+ Cell Counts in HIV-Infected Persons in Argentina.

    Directory of Open Access Journals (Sweden)

    José D Debes

    Full Text Available Hepatitis E virus (HEV is a single-stranded RNA virus that can cause hepatitis in an epidemic fashion. HEV usually causes asymptomatic or limited acute infections in immunocompetent individuals, whereas in immunosuppressed individuals such as transplant recipients, HEV can cause chronic infections. The risks and outcomes of HEV co-infection in patients infected with human immunodeficiency virus (HIV are poorly characterized. We used a third generation immunoassay to measure serum IgG antibodies specific for HEV in 204 HIV-infected individuals from Argentina and a control group of 433 HIV-negative individuals. We found 15 of 204 (7.3%, 95%CI 3.74-10.96% individuals in the HIV-positive group to have positive HEV IgG levels suggestive of previous infection, compared to 19 of 433 (4.4%, 95% CI 2.5-6.3% individuals in the HIV-negative control group (p = 0.12. Among HIV-positive individuals, those with HEV seropositivity had lower CD4 counts compared to those that were HEV seronegative (average CD4 count of 234 vs 422 mm3, p = 0.01, indicating that patients with lower CD4 counts were more likely to be HEV IgG positive. Moreover, HEV seropositivity in patients with CD4 counts 200 mm3 (p = 0.012. We found a positive PCR result for HEV in one individual. Our study found that increased seroprevalence of HEV IgG correlated with lower CD4 counts in HIV-infected patients in Argentina.

  19. Three-Year Durability of Immune Responses Induced by HIV-DNA and HIV-Modified Vaccinia Virus Ankara and Effect of a Late HIV-Modified Vaccinia Virus Ankara Boost in Tanzanian Volunteers.

    Science.gov (United States)

    Joachim, Agricola; Munseri, Patricia J; Nilsson, Charlotta; Bakari, Muhammad; Aboud, Said; Lyamuya, Eligius F; Tecleab, Teghesti; Liakina, Valentina; Scarlatti, Gabriella; Robb, Merlin L; Earl, Patricia L; Moss, Bernard; Wahren, Britta; Mhalu, Fred; Ferrari, Guido; Sandstrom, Eric; Biberfeld, Gunnel

    2017-08-01

    We explored the duration of immune responses and the effect of a late third HIV-modified vaccinia virus Ankara (MVA) boost in HIV-DNA primed and HIV-MVA boosted Tanzanian volunteers. Twenty volunteers who had previously received three HIV-DNA and two HIV-MVA immunizations were given a third HIV-MVA immunization 3 years after the second HIV-MVA boost. At the time of the third HIV-MVA, 90% of the vaccinees had antibodies to HIV-1 subtype C gp140 (median titer 200) and 85% to subtype B gp160 (median titer 100). The majority of vaccinees had detectable antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies, 70% against CRF01_AE virus-infected cells (median titer 239) and 84% against CRF01_AE gp120-coated cells (median titer 499). A high proportion (74%) of vaccinees had IFN-γ ELISpot responses, 63% to Gag and 42% to Env, 3 years after the second HIV-MVA boost. After the third HIV-MVA, there was an increase in Env-binding antibodies and ADCC-mediating antibodies relative to the response seen at the time of the third HIV-MVA vaccination, p < .0001 and p < .05, respectively. The frequency of IFN-γ ELISpot responses increased to 95% against Gag or Env and 90% to both Gag and Env, p = .064 and p = .002, respectively. In conclusion, the HIV-DNA prime/HIV-MVA boost regimen elicited potent antibody and cellular immune responses with remarkable durability, and a third HIV-MVA immunization significantly boosted both antibody and cellular immune responses relative to the levels detected at the time of the third HIV-MVA, but not to higher levels than after the second HIV-MVA.

  20. Fluorescent protein-tagged Vpr dissociates from HIV-1 core after viral fusion and rapidly enters the cell nucleus.

    Science.gov (United States)

    Desai, Tanay M; Marin, Mariana; Sood, Chetan; Shi, Jiong; Nawaz, Fatima; Aiken, Christopher; Melikyan, Gregory B

    2015-10-29

    HIV-1 Vpr is recruited into virions during assembly and appears to remain associated with the viral core after the reverse transcription and uncoating steps of entry. This feature has prompted the use of fluorescently labeled Vpr to visualize viral particles and to follow trafficking of post-fusion HIV-1 cores in the cytoplasm. Here, we tracked single pseudovirus entry and fusion and observed that fluorescently tagged Vpr gradually dissociates from post-fusion viral cores over the course of several minutes and accumulates in the nucleus. Kinetics measurements showed that fluorescent Vpr released from the cores very rapidly entered the cell nucleus. More than 10,000 Vpr molecules can be delivered into the cell nucleus within 45 min of infection by HIV-1 particles pseudotyped with the avian sarcoma and leukosis virus envelope glycoprotein. The fraction of Vpr from cell-bound viruses that accumulated in the nucleus was proportional to the extent of virus-cell fusion and was fully blocked by viral fusion inhibitors. Entry of virus-derived Vpr into the nucleus occurred independently of envelope glycoproteins or target cells. Fluorescence correlation spectroscopy revealed two forms of nuclear Vpr-monomers and very large complexes, likely involving host factors. The kinetics of viral Vpr entering the nucleus after fusion was not affected by point mutations in the capsid protein that alter the stability of the viral core. The independence of Vpr shedding of capsid stability and its relatively rapid dissociation from post-fusion cores suggest that this process may precede capsid uncoating, which appears to occur on a slower time scale. Our results thus demonstrate that a bulk of fluorescently labeled Vpr incorporated into HIV-1 particles is released shortly after fusion. Future studies will address the question whether the quick and efficient nuclear delivery of Vpr derived from incoming viruses can regulate subsequent steps of HIV-1 infection.

  1. Human immunodeficiency virus (HIV) infection in tuberculosis ...

    African Journals Online (AJOL)

    Human immunodeficiency virus (HIV) infection in tuberculosis patients in Addis ... METHODS: A cross-sectional survey whereby blood sample was collected ... of co-infection appeared to have increased compared to previous studies, 6.6%, ...

  2. Spatial Localization of the Ebola Virus Glycoprotein Mucin-Like Domain Determined by Cryo-Electron Tomography

    OpenAIRE

    Tran, Erin E. H.; Simmons, James A.; Bartesaghi, Alberto; Shoemaker, Charles J.; Nelson, Elizabeth; White, Judith M.; Subramaniam, Sriram

    2014-01-01

    The Ebola virus glycoprotein mucin-like domain (MLD) is implicated in Ebola virus cell entry and immune evasion. Using cryo-electron tomography of Ebola virus-like particles, we determined a three-dimensional structure for the full-length glycoprotein in a near-native state and compared it to that of a glycoprotein lacking the MLD. Our results, which show that the MLD is located at the apex and the sides of each glycoprotein monomer, provide a structural template for analysis of MLD function.

  3. Identifying potential survival strategies of HIV-1 through virus-host protein interaction networks

    Directory of Open Access Journals (Sweden)

    Boucher Charles AB

    2010-07-01

    Full Text Available Abstract Background The National Institute of Allergy and Infectious Diseases has launched the HIV-1 Human Protein Interaction Database in an effort to catalogue all published interactions between HIV-1 and human proteins. In order to systematically investigate these interactions functionally and dynamically, we have constructed an HIV-1 human protein interaction network. This network was analyzed for important proteins and processes that are specific for the HIV life-cycle. In order to expose viral strategies, network motif analysis was carried out showing reoccurring patterns in virus-host dynamics. Results Our analyses show that human proteins interacting with HIV form a densely connected and central sub-network within the total human protein interaction network. The evaluation of this sub-network for connectivity and centrality resulted in a set of proteins essential for the HIV life-cycle. Remarkably, we were able to associate proteins involved in RNA polymerase II transcription with hubs and proteasome formation with bottlenecks. Inferred network motifs show significant over-representation of positive and negative feedback patterns between virus and host. Strikingly, such patterns have never been reported in combined virus-host systems. Conclusions HIV infection results in a reprioritization of cellular processes reflected by an increase in the relative importance of transcriptional machinery and proteasome formation. We conclude that during the evolution of HIV, some patterns of interaction have been selected for resulting in a system where virus proteins preferably interact with central human proteins for direct control and with proteasomal proteins for indirect control over the cellular processes. Finally, the patterns described by network motifs illustrate how virus and host interact with one another.

  4. The role of influenza, RSV and other common respiratory viruses in severe acute respiratory infections and influenza-like illness in a population with a high HIV sero-prevalence, South Africa 2012-2015.

    Science.gov (United States)

    Pretorius, Marthi A; Tempia, Stefano; Walaza, Sibongile; Cohen, Adam L; Moyes, Jocelyn; Variava, Ebrahim; Dawood, Halima; Seleka, Mpho; Hellferscee, Orienka; Treurnicht, Florette; Cohen, Cheryl; Venter, Marietjie

    2016-02-01

    Viruses detected in patients with acute respiratory infections may be the cause of illness or asymptomatic shedding. To estimate the attributable fraction (AF) and the detection rate attributable to illness for each of the different respiratory viruses We compared the prevalence of 10 common respiratory viruses (influenza A and B viruses, parainfluenza virus 1-3; respiratory syncytial virus (RSV); adenovirus, rhinovirus, human metapneumovirus (hMPV) and enterovirus) in both HIV positive and negative patients hospitalized with severe acute respiratory illness (SARI), outpatients with influenza-like illness (ILI), and control subjects who did not report any febrile, respiratory or gastrointestinal illness during 2012-2015 in South Africa. We enrolled 1959 SARI, 3784 ILI and 1793 controls with a HIV sero-prevalence of 26%, 30% and 43%, respectively. Influenza virus (AF: 86.3%; 95%CI: 77.7-91.6%), hMPV (AF: 85.6%; 95%CI: 72.0-92.6%), and RSV (AF: 83.7%; 95%CI: 77.5-88.2%) infections were associated with severe disease., while rhinovirus (AF: 46.9%; 95%CI: 37.6-56.5%) and adenovirus (AF: 36.4%; 95%CI: 20.6-49.0%) were only moderately associated. Influenza, RSV and hMPV can be considered pathogens if detected in ILI and SARI while rhinovirus and adenovirus were commonly identified in controls suggesting that they may cause only a proportion of clinical disease observed in positive patients. Nonetheless, they may be important contributors to disease. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Comparison of Newly Assembled Full Length HIV-1 Integrase With Prototype Foamy Virus Integrase: Structure-Function Prospective.

    Science.gov (United States)

    Dayer, Mohammad Reza

    2016-05-01

    Drug design against human immunodeficiency virus type 1 (HIV-1) integrase through its mechanistic study is of great interest in the area in biological research. The main obstacle in this area is the absence of the full-length crystal structure for HIV-1 integrase to be used as a model. A complete structure, similar to HIV-1 of a prototype foamy virus integrase in complex with DNA, including all conservative residues, is available and has been extensively used in recent investigations. The aim of this study was to determine whether the above model is precisely representative of HIV-1 integrase. This would critically determine the success of any designed drug using the model in deactivation of integrase and AIDS treatment. Primarily, a new structure for HIV-1 was constructed, using a crystal structure of prototype foamy virus as the starting structure. The constructed structure of HIV-1 integrase was simultaneously simulated with a prototype foamy virus integrase on a separate occasion. Our results indicate that the HIV-1 system behaves differently from the prototype foamy virus in terms of folding, hydration, hydrophobicity of binding site and stability. Based on our findings, we can conclude that HIV-1 integrase is vastly different from the prototype foamy virus integrase and does not resemble it, and the modeling output of the prototype foamy virus simulations could not be simply generalized to HIV-1 integrase. Therefore, our HIV-1 model seems to be more representative and more useful for future research.

  6. Silicified virus-like nanoparticles in an extreme thermal environment: implications for the preservation of viruses in the geological record.

    Science.gov (United States)

    Peng, X; Xu, H; Jones, B; Chen, S; Zhou, H

    2013-11-01

    Biofilms that grow around Gumingquan hot spring (T = 71 °C, pH = 9.2) in the Rehai geothermal area, Tengchong, China, are formed of various cyanobacteria, Firmicutes, Aquificae, Thermodesulfobacteria, Desulfurococcales, and Thermoproteales. Silicified virus-like nanoparticles, 40-200 nm in diameter, are common inside the microbial cells and the extracellular polymeric substances around the cells. These nanoparticles, which are formed of a core encased by a silica cortex, are morphologically akin to known viruses and directly comparable to silicified virus-like particles that were produced in biofilms cultured in the laboratory. The information obtained from examination of the natural and laboratory-produced samples suggests that viruses can be preserved by silicification, especially while they are still encased in their host cells. These results expand our views of virus-host mineral interaction in extreme thermal environments and imply that viruses can be potentially preserved and identified in the geological record. © 2013 John Wiley & Sons Ltd.

  7. Rab3a-Bound CD63 Is Degraded and Rab3a-Free CD63 Is Incorporated into HIV-1 Particles

    Directory of Open Access Journals (Sweden)

    Yoshinao Kubo

    2017-08-01

    Full Text Available CD63, a member of the tetraspanin family, is involved in virion production by human immunodeficiency virus type 1 (HIV-1, but its mechanism is unknown. In this study, we showed that a small GTP-binding protein, Rab3a, interacts with CD63. When Rab3a was exogenously expressed, the amounts of CD63 decreased in cells. The Rab3a-mediated reduction of CD63 was suppressed by lysosomal and proteasomal inhibitors. The amount of CD63 was increased by reducing the endogenous Rab3a level using a specific shRNA. These results indicate that Rab3a binds to CD63 to induce the degradation of CD63. Rab3a is thought to be involved in exocytosis, but we found that another function of Rab3a affects the fate of CD63 in lysosomes. CD63 interacted with Rab3a and was incorporated into HIV-1 particles. However, Rab3a was not detected in HIV-1 virions, thereby indicating that Rab3a-free CD63, but not Rab3a-bound CD63, is incorporated into HIV-1 particles. Overexpression or silencing of Rab3a moderately reduced HIV-1 virion formation. Overexpression of Rab3a decreased CD63 levels, but did not affect the incorporation of CD63 into HIV-1 particles. This study showed that Rab3a binds to CD63 to induce the degradation of CD63, and only Rab3a-free CD63 is incorporated into HIV-1 particles.

  8. 78 FR 67175 - Proposed Collection; 60-Day Comment Request: Incident HIV/Hepatitis B Virus Infections in South...

    Science.gov (United States)

    2013-11-08

    ... Comment Request: Incident HIV/ Hepatitis B Virus Infections in South African Blood Donors: Behavioral Risk... Collection: Incident HIV/Hepatitis B virus (HBV) infections in South African blood donors: Behavioral risk... (either antibody or antigen detection tests) to screen blood donors for HIV and Hepatitis-B Virus (HBV...

  9. Structure of the immature HIV-1 capsid in intact virus particles at 8.8 angstrom resolution

    Czech Academy of Sciences Publication Activity Database

    Schur, F. K. M.; Hagen, W. J. H.; Rumlová, Michaela; Ruml, T.; Müller, B.; Kräusslich, H. G.; Briggs, J. A. G.

    2015-01-01

    Roč. 517, č. 7535 (2015), s. 505-508 ISSN 0028-0836 R&D Projects: GA ČR(CZ) GA14-15326S Institutional support: RVO:61388963 Keywords : retrovirus * HIV * M-PMV * capsid protein * CA * assembly * immature particles Subject RIV: CE - Biochemistry Impact factor: 38.138, year: 2015

  10. Immunogenicity of virus-like particles containing modified goose parvovirus VP2 protein.

    Science.gov (United States)

    Chen, Zongyan; Li, Chuanfeng; Zhu, Yingqi; Wang, Binbin; Meng, Chunchun; Liu, Guangqing

    2012-10-01

    The major capsid protein VP2 of goose parvovirus (GPV) expressed using a baculovirus expression system (BES) assembles into virus-like particles (VLPs). To optimize VP2 gene expression in Sf9 cells, we converted wild-type VP2 (VP2) codons into codons that are more common in insect genes. This change greatly increased VP2 protein production in Sf9 cells. The protein generated from the codon-optimized VP2 (optVP2) was detected by immunoblotting and an indirect immunofluorescence assay (IFA). Transmission electron microscopy analysis revealed the formation of VLPs. These findings indicate that optVP2 yielded stable and high-quality VLPs. Immunogenicity assays revealed that the VLPs are highly immunogenic, elicit a high level of neutralizing antibodies and provide protection against lethal challenge. The antibody levels appeared to be directly related to the number of GP-Ag-positive hepatocytes. The variation trends for GP-Ag-positive hepatocytes were similar in the vaccine groups. In comparison with the control group, the optVP2 VLPs groups exhibited obviously better responses. These data indicate that the VLPs retained immunoreactivity and had strong immunogenicity in susceptible geese. Thus, GPV optVP2 appears to be a good candidate for the vaccination of goslings. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. A single intranasal administration of virus-like particle vaccine induces an efficient protection for mice against human respiratory syncytial virus.

    Science.gov (United States)

    Jiao, Yue-Ying; Fu, Yuan-Hui; Yan, Yi-Fei; Hua, Ying; Ma, Yao; Zhang, Xiu-Juan; Song, Jing-Dong; Peng, Xiang-Lei; Huang, Jiaqiang; Hong, Tao; He, Jin-Sheng

    2017-08-01

    Human respiratory syncytial virus (RSV) is an important pediatric pathogen causing acute viral respiratory disease in infants and young children. However, no licensed vaccines are currently available. Virus-like particles (VLPs) may bring new hope to producing RSV VLP vaccine with high immunogenicity and safety. Here, we constructed the recombinants of matrix protein (M) and fusion glycoprotein (F) of RSV, respectively into a replication-deficient first-generation adenoviral vector (FGAd), which were used to co-infect Vero cells to assemble RSV VLPs successfully. The resulting VLPs showed similar immunoreactivity and function to RSV virion in vitro. Moreover, Th1 polarized response, and effective mucosal virus-neutralizing antibody and CD8 + T-cell responses were induced by a single intranasal (i.n.) administration of RSV VLPs rather than intramuscular (i.m.) inoculation, although the comparable RSV F-specific serum IgG and long-lasting RSV-specific neutralizing antibody were detected in the mice immunized by both routes. Upon RSV challenge, VLP-immunized mice showed increased viral clearance but decreased signs of enhanced lung pathology and fewer eosinophils compared to mice immunized with formalin-inactivated RSV (FI-RSV). In addition, a single i.n. RSV VLP vaccine has the capability to induce RSV-specific long-lasting neutralizing antibody responses observable up to 15 months. Our results demonstrate that the long-term and memory immune responses in mice against RSV were induced by a single i.n. administration of RSV VLP vaccine, suggesting a successful approach of RSV VLPs as an effective and safe mucosal vaccine against RSV infection, and an applicable and qualified platform of FGAd-infected Vero cells for VLP production. Copyright © 2017. Published by Elsevier B.V.

  12. Identification of human microRNA-like sequences embedded within the protein-encoding genes of the human immunodeficiency virus.

    Directory of Open Access Journals (Sweden)

    Bryan Holland

    Full Text Available BACKGROUND: MicroRNAs (miRNAs are highly conserved, short (18-22 nts, non-coding RNA molecules that regulate gene expression by binding to the 3' untranslated regions (3'UTRs of mRNAs. While numerous cellular microRNAs have been associated with the progression of various diseases including cancer, miRNAs associated with retroviruses have not been well characterized. Herein we report identification of microRNA-like sequences in coding regions of several HIV-1 genomes. RESULTS: Based on our earlier proteomics and bioinformatics studies, we have identified 8 cellular miRNAs that are predicted to bind to the mRNAs of multiple proteins that are dysregulated during HIV-infection of CD4+ T-cells in vitro. In silico analysis of the full length and mature sequences of these 8 miRNAs and comparisons with all the genomic and subgenomic sequences of HIV-1 strains in global databases revealed that the first 18/18 sequences of the mature hsa-miR-195 sequence (including the short seed sequence, matched perfectly (100%, or with one nucleotide mismatch, within the envelope (env genes of five HIV-1 genomes from Africa. In addition, we have identified 4 other miRNA-like sequences (hsa-miR-30d, hsa-miR-30e, hsa-miR-374a and hsa-miR-424 within the env and the gag-pol encoding regions of several HIV-1 strains, albeit with reduced homology. Mapping of the miRNA-homologues of env within HIV-1 genomes localized these sequence to the functionally significant variable regions of the env glycoprotein gp120 designated V1, V2, V4 and V5. CONCLUSIONS: We conclude that microRNA-like sequences are embedded within the protein-encoding regions of several HIV-1 genomes. Given that the V1 to V5 regions of HIV-1 envelopes contain specific, well-characterized domains that are critical for immune responses, virus neutralization and disease progression, we propose that the newly discovered miRNA-like sequences within the HIV-1 genomes may have evolved to self-regulate survival of the

  13. Identifying SARS-CoV membrane protein amino acid residues linked to virus-like particle assembly.

    Directory of Open Access Journals (Sweden)

    Ying-Tzu Tseng

    Full Text Available Severe acute respiratory syndrome coronavirus (SARS-CoV membrane (M proteins are capable of self-assembly and release in the form of membrane-enveloped vesicles, and of forming virus-like particles (VLPs when coexpressed with SARS-CoV nucleocapsid (N protein. According to previous deletion analyses, M self-assembly involves multiple M sequence regions. To identify important M amino acid residues for VLP assembly, we coexpressed N with multiple M mutants containing substitution mutations at the amino-terminal ectodomain, carboxyl-terminal endodomain, or transmembrane segments. Our results indicate that a dileucine motif in the endodomain tail (218LL219 is required for efficient N packaging into VLPs. Results from cross-linking VLP analyses suggest that the cysteine residues 63, 85 and 158 are not in close proximity to the M dimer interface. We noted a significant reduction in M secretion due to serine replacement for C158, but not for C63 or C85. Further analysis suggests that C158 is involved in M-N interaction. In addition to mutations of the highly conserved 107-SWWSFNPE-114 motif, substitutions at codons W19, W57, P58, W91, Y94 or F95 all resulted in significantly reduced VLP yields, largely due to defective M secretion. VLP production was not significantly affected by a tryptophan replacement of Y94 or F95 or a phenylalanine replacement of W19, W57 or W91. Combined, these results indicate the involvement of specific M amino acids during SARS-CoV virus assembly, and suggest that aromatic residue retention at specific positions is critical for M function in terms of directing virus assembly.

  14. Mortality in siblings of patients coinfected with HIV and hepatitis C virus

    DEFF Research Database (Denmark)

    Hansen, Ann-Brit Eg; Gerstoft, Jan; Kronborg, Gitte

    2007-01-01

    BACKGROUND: Coinfection with hepatitis C virus (HCV) is a poor prognostic factor for human immunodeficiency virus (HIV)-infected patients. We examined whether the increased mortality in these patients is partly explained by a familial excess risk of death. METHODS: Danish HIV-infected patients who...... had had at least 1 HCV test were included (n=3531). In addition, 336,652 population control subjects matched for sex, age, and residency were identified from the Danish Civil Registration System. For both HIV-infected patients and population control subjects, we identified all siblings born after 1951......, with dates of death or emigration. Siblings of HIV-infected patients were classified according to the patients' HCV serostatus. Survival after age 20 years was compared among the groups of siblings. RESULTS: We identified 437 siblings of HIV/HCV-coinfected patients, 1856 siblings of HIV-monoinfected patients...

  15. The influence of ligand charge and length on the assembly of Brome mosaic virus derived virus-like particles with magnetic core

    Science.gov (United States)

    Mieloch, Adam A.; Krecisz, Monika; Rybka, Jakub D.; Strugała, Aleksander; Krupiński, Michał; Urbanowicz, Anna; Kozak, Maciej; Skalski, Bohdan; Figlerowicz, Marek; Giersig, Michael

    2018-03-01

    Virus-like particles (VLPs) have sparked a great interest in the field of nanobiotechnology and nanomedicine. The introduction of superparamagnetic nanoparticles (SPIONs) as a core, provides potential use of VLPs in the hyperthermia therapy, MRI contrast agents and magnetically-powered delivery agents. Magnetite NPs also provide a significant improvement in terms of VLPs stability. Moreover employing viral structural proteins as self-assembling units has opened a new paths for targeted therapy, drug delivery systems, vaccines design, and many more. In many cases, the self-assembly of a virus strongly depends on electrostatic interactions between positively charged groups of the capsid proteins and negatively charged nucleic acid. This phenomenon imposes the negative net charge as a key requirement for the core nanoparticle. In our experiments, Brome mosaic virus (BMV) capsid proteins isolated from infected plants Hordeum vulgare were used. Superparamagnetic iron oxide nanoparticles (Fe3O4) with 15 nm in diameter were synthesized by thermal decomposition and functionalized with COOH-PEG-PL polymer or dihexadecylphosphate (DHP) in order to provide water solubility and negative charge required for the assembly. Nanoparticles were characterized by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Zeta Potential, Fourier Transformed Infrared Spectroscopy (FTIR) and Superconducting Quantum Interference Device (SQUID) magnetometry. TEM and DLS study were conducted to verify VLPs creation. This study demonstrates that the increase of negative surface charge is not a sufficient factor determining successful assembly. Additional steric interactions provided by longer ligands are crucial for the assembly of BMV SPION VLPs and may enhance the colloidal stability.

  16. The influence of ligand charge and length on the assembly of Brome mosaic virus derived virus-like particles with magnetic core

    Directory of Open Access Journals (Sweden)

    Adam A. Mieloch

    2018-03-01

    Full Text Available Virus-like particles (VLPs have sparked a great interest in the field of nanobiotechnology and nanomedicine. The introduction of superparamagnetic nanoparticles (SPIONs as a core, provides potential use of VLPs in the hyperthermia therapy, MRI contrast agents and magnetically-powered delivery agents. Magnetite NPs also provide a significant improvement in terms of VLPs stability. Moreover employing viral structural proteins as self-assembling units has opened a new paths for targeted therapy, drug delivery systems, vaccines design, and many more. In many cases, the self-assembly of a virus strongly depends on electrostatic interactions between positively charged groups of the capsid proteins and negatively charged nucleic acid. This phenomenon imposes the negative net charge as a key requirement for the core nanoparticle. In our experiments, Brome mosaic virus (BMV capsid proteins isolated from infected plants Hordeum vulgare were used. Superparamagnetic iron oxide nanoparticles (Fe3O4 with 15 nm in diameter were synthesized by thermal decomposition and functionalized with COOH-PEG-PL polymer or dihexadecylphosphate (DHP in order to provide water solubility and negative charge required for the assembly. Nanoparticles were characterized by Transmission Electron Microscopy (TEM, Dynamic Light Scattering (DLS, Zeta Potential, Fourier Transformed Infrared Spectroscopy (FTIR and Superconducting Quantum Interference Device (SQUID magnetometry. TEM and DLS study were conducted to verify VLPs creation. This study demonstrates that the increase of negative surface charge is not a sufficient factor determining successful assembly. Additional steric interactions provided by longer ligands are crucial for the assembly of BMV SPION VLPs and may enhance the colloidal stability.

  17. Mechanisms for Cell-to-Cell Transmission of HIV-1

    Science.gov (United States)

    Bracq, Lucie; Xie, Maorong; Benichou, Serge; Bouchet, Jérôme

    2018-01-01

    While HIV-1 infection of target cells with cell-free viral particles has been largely documented, intercellular transmission through direct cell-to-cell contact may be a predominant mode of propagation in host. To spread, HIV-1 infects cells of the immune system and takes advantage of their specific particularities and functions. Subversion of intercellular communication allows to improve HIV-1 replication through a multiplicity of intercellular structures and membrane protrusions, like tunneling nanotubes, filopodia, or lamellipodia-like structures involved in the formation of the virological synapse. Other features of immune cells, like the immunological synapse or the phagocytosis of infected cells are hijacked by HIV-1 and used as gateways to infect target cells. Finally, HIV-1 reuses its fusogenic capacity to provoke fusion between infected donor cells and target cells, and to form infected syncytia with high capacity of viral production and improved capacities of motility or survival. All these modes of cell-to-cell transfer are now considered as viral mechanisms to escape immune system and antiretroviral therapies, and could be involved in the establishment of persistent virus reservoirs in different host tissues. PMID:29515578

  18. Cryo-electron microscopy and single molecule fluorescent microscopy detect CD4 receptor induced HIV size expansion prior to cell entry

    International Nuclear Information System (INIS)

    Pham, Son; Tabarin, Thibault; Garvey, Megan; Pade, Corinna; Rossy, Jérémie; Monaghan, Paul; Hyatt, Alex; Böcking, Till; Leis, Andrew; Gaus, Katharina; Mak, Johnson

    2015-01-01

    Viruses are often thought to have static structure, and they only remodel after the viruses have entered target cells. Here, we detected a size expansion of virus particles prior to viral entry using cryo-electron microscopy (cryo-EM) and single molecule fluorescence imaging. HIV expanded both under cell-free conditions with soluble receptor CD4 (sCD4) targeting the CD4 binding site on the HIV-1 envelope protein (Env) and when HIV binds to receptor on cellular membrane. We have shown that the HIV Env is needed to facilitate receptor induced virus size expansions, showing that the ‘lynchpin’ for size expansion is highly specific. We demonstrate that the size expansion required maturation of HIV and an internal capsid core with wild type stability, suggesting that different HIV compartments are linked and are involved in remodelling. Our work reveals a previously unknown event in HIV entry, and we propose that this pre-entry priming process enables HIV particles to facilitate the subsequent steps in infection. - Highlights: • Cell free viruses are able to receive external trigger that leads to apparent size expansion. • Virus envelope and CD4 receptor engagement is the lynchpin of virus size expansion. • Internal capsid organisation can influence receptor mediated virus size expansion. • Pre-existing virus-associated lipid membrane in cell free virus can accommodate the receptor mediated virus size expansion.

  19. Cryo-electron microscopy and single molecule fluorescent microscopy detect CD4 receptor induced HIV size expansion prior to cell entry

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Son [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Tabarin, Thibault [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Garvey, Megan; Pade, Corinna [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Rossy, Jérémie [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Monaghan, Paul; Hyatt, Alex [CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Böcking, Till [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Leis, Andrew [CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Gaus, Katharina, E-mail: k.gaus@unsw.edu.au [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Mak, Johnson, E-mail: j.mak@deakin.edu.au [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia)

    2015-12-15

    Viruses are often thought to have static structure, and they only remodel after the viruses have entered target cells. Here, we detected a size expansion of virus particles prior to viral entry using cryo-electron microscopy (cryo-EM) and single molecule fluorescence imaging. HIV expanded both under cell-free conditions with soluble receptor CD4 (sCD4) targeting the CD4 binding site on the HIV-1 envelope protein (Env) and when HIV binds to receptor on cellular membrane. We have shown that the HIV Env is needed to facilitate receptor induced virus size expansions, showing that the ‘lynchpin’ for size expansion is highly specific. We demonstrate that the size expansion required maturation of HIV and an internal capsid core with wild type stability, suggesting that different HIV compartments are linked and are involved in remodelling. Our work reveals a previously unknown event in HIV entry, and we propose that this pre-entry priming process enables HIV particles to facilitate the subsequent steps in infection. - Highlights: • Cell free viruses are able to receive external trigger that leads to apparent size expansion. • Virus envelope and CD4 receptor engagement is the lynchpin of virus size expansion. • Internal capsid organisation can influence receptor mediated virus size expansion. • Pre-existing virus-associated lipid membrane in cell free virus can accommodate the receptor mediated virus size expansion.

  20. [Construction and immunogenicity of recombinant porcine parvovirus-like particles with somatostatin].

    Science.gov (United States)

    Zhang, Xuehua; Zheng, Qisheng; Chen, Jin; Xue, Gang; Hou, Hongyan; Hou, Jibo

    2010-08-01

    In order to obtain a virus-like particle vaccine both for porcine parvovirus (PPV) prevention and growth-promotion, VP2 gene of PPV NJ-a strain was amplified with PCR, and four copies of synthetic somatostatin gene were fused to the N-terminal of VP2 gene. The fused gene was cloned into pFast-HT A to construct the recombinant plasmid pFast-SS4-VP2, then the pFast-SS4-VP2 was transformed into DH10Bac competent cells and recombined with shuttle vector Bacmid, followed by identification with blue-white screening and PCR analysis for three cycles, and the positive recombinant was named as rBacmid-SS4-VP2. The positive Sf-9 cells were transfected with rBacmid-SS4-VP2 by Lipofectamine to produce recombinant baculovirus. When the cytopathic effect (CPE) was obvious, the transfected Sf-9 cell was harvested, and the positive recombinant virus was named as rBac-SS4-VP2. The insertion for the target gene into baculovirus genome was confirmed with PCR. SDS-PAGE and Western blotting revealed that the calculated protein of approximately 68 kDa was in the expressed in the insect cells. The Sf-9 cells infected with rBac-SS4-VP2 were stained positive against PPV antibody using the indirect immunofluorescence assay (IFA). Moreover, the virus particle self-assembly was observed under electron microscopy. 90 four-week-old mice were immunized by the recombinant protein coupled with different adjuvants alhydrogel, IMS and oil. VP2-specific ELISA antibodies, PPV-specific neutralizing antibody, somatostatin antibody and growth hormone levels were examined to evaluate the immunogenicity of this virus like particle. Results indicated that mice groups immunized rSS4-VP2 protein with alhydrogel and IMS developed similar humoral immune response comparing with inactived PPV vaccine. Mice group immunized with rSS4-VP2 generated higher level of SS antibody and growth hormone comparing with negative control, mice receiving rSS4-VP2 with alhydrogel developed the highest antibody titre than all

  1. Spatial localization of the Ebola virus glycoprotein mucin-like domain determined by cryo-electron tomography.

    Science.gov (United States)

    Tran, Erin E H; Simmons, James A; Bartesaghi, Alberto; Shoemaker, Charles J; Nelson, Elizabeth; White, Judith M; Subramaniam, Sriram

    2014-09-01

    The Ebola virus glycoprotein mucin-like domain (MLD) is implicated in Ebola virus cell entry and immune evasion. Using cryo-electron tomography of Ebola virus-like particles, we determined a three-dimensional structure for the full-length glycoprotein in a near-native state and compared it to that of a glycoprotein lacking the MLD. Our results, which show that the MLD is located at the apex and the sides of each glycoprotein monomer, provide a structural template for analysis of MLD function. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  2. Neutralization epitopes on HIV pseudotyped with HTLV-I: Conservation of carbohydrate Epitopes

    DEFF Research Database (Denmark)

    Sørensen, A M; Nielsen, C; Arendrup, M

    1994-01-01

    One mechanism for expanding the cellular tropism of human immunodeficiency virus (HIV) in vitro is through formation of phenotypically mixed particles (pseudotypes) with human T lymphotropic virus type I (HTLV-I). In this study we found that pseudotypes allow penetration of HIV particles into CD4......-negative cells, previously nonsusceptible to HIV infection. The infection of CD4-negative cells with pseudotypes could be blocked with anti-HTLV-I serum but failed to be significantly inhibited with anti-HIV serum or a V3-neutralizing anti-gp120 monoclonal antibody. This may represent a possibility...... by cell-free pseudotypes in CD4-negative cells. We suggest that although viral cofactors might expand the tropism of HIV in vivo, HIV and HTLV-I seem to induce common carbohydrate neutralization epitopes....

  3. Neutralization epitopes on HIV pseudotyped with HTLV-I: conservation of carbohydrate epitopes

    DEFF Research Database (Denmark)

    Sørensen, A M; Nielsen, C; Arendrup, M

    1994-01-01

    One mechanism for expanding the cellular tropism of human immunodeficiency virus (HIV) in vitro is through formation of phenotypically mixed particles (pseudotypes) with human T lymphotropic virus type I (HTLV-I). In this study we found that pseudotypes allow penetration of HIV particles into CD4......-negative cells, previously nonsusceptible to HIV infection. The infection of CD4-negative cells with pseudotypes could be blocked with anti-HTLV-I serum but failed to be significantly inhibited with anti-HIV serum or a V3-neutralizing anti-gp120 monoclonal antibody. This may represent a possibility...... by cell-free pseudotypes in CD4-negative cells. We suggest that although viral cofactors might expand the tropism of HIV in vivo, HIV and HTLV-I seem to induce common carbohydrate neutralization epitopes....

  4. A novel H6N1 virus-like particle vaccine induces long-lasting cross-clade antibody immunity against human and avian H6N1 viruses.

    Science.gov (United States)

    Yang, Ji-Rong; Chen, Chih-Yuan; Kuo, Chuan-Yi; Cheng, Chieh-Yu; Lee, Min-Shiuh; Cheng, Ming-Chu; Yang, Yu-Chih; Wu, Chia-Ying; Wu, Ho-Sheng; Liu, Ming-Tsan; Hsiao, Pei-Wen

    2016-02-01

    Avian influenza A(H6N1) virus is one of the most common viruses isolated from migrating birds and domestic poultry in many countries. The first and only known case of human infection by H6N1 virus in the world was reported in Taiwan in 2013. This led to concern that H6N1 virus may cause a threat to public health. In this study, we engineered a recombinant H6N1 virus-like particle (VLP) and investigated its vaccine effectiveness compared to the traditional egg-based whole inactivated virus (WIV) vaccine. The H6N1-VLPs exhibited similar morphology and functional characteristics to influenza viruses. Prime-boost intramuscular immunization in mice with unadjuvanted H6N1-VLPs were highly immunogenic and induced long-lasting antibody immunity. The functional activity of the VLP-elicited IgG antibodies was proved by in vitro seroprotective hemagglutination inhibition and microneutralization titers against the homologous human H6N1 virus, as well as in vivo viral challenge analyses which showed H6N1-VLP immunization significantly reduced viral load in the lung, and protected against human H6N1 virus infection. Of particular note, the H6N1-VLPs but not the H6N1-WIVs were able to confer cross-reactive humoral immunity; antibodies induced by H6N1-VLP vaccine robustly inhibited the hemagglutination activities and in vitro replication of distantly-related heterologous avian H6N1 viruses. Furthermore, the H6N1-VLPs were found to elicit significantly greater anti-HA2 antibody responses in immunized mice than H6N1-WIVs. Collectively, we demonstrated for the first time a novel H6N1-VLP vaccine that effectively provides broadly protective immunity against both human and avian H6N1 viruses. These results, which uncover the underlying mechanisms for induction of wide-range immunity against influenza viruses, may be useful for future influenza vaccine development. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein

    OpenAIRE

    Theo Luiz Ferraz de Souza; Sheila Maria Barbosa de Lima; Vanessa L. de Azevedo Braga; David S. Peabody; Davis Fernandes Ferreira; M. Lucia Bianconi; Andre Marco de Oliveira Gomes; Jerson Lima Silva; Andréa Cheble de Oliveira

    2016-01-01

    Background Hepatitis C virus (HCV) core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124) is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs) in vitro. The specific...

  6. Studies towards the potential of poliovirus as a vector for the expression of HPV 16 virus-like-particles.

    Science.gov (United States)

    van Kuppeveld, Frank J M; de Jong, Arjan; Dijkman, Henri B P M; Andino, Raul; Melchers, Willem J G

    2002-11-15

    Development of human cervical carcinomas is associated with infection by certain human papillomavirus (HPV) types. Thus, protection against HPV infection through vaccination may prevent development of cervical cancer. The purpose of this study was to investigate the possibility of using a poliovirus recombinant vector to induce immunity against HPV. A poliovirus recombinant was constructed which contained the complete coding sequence of the HPV 16 major capsid protein L1, between the P1 and P2 region of the poliovirus polyprotein. A replication-competent virus was obtained after transfection of the recombinant RNA into tissue culture cells. Electron microscopically examination of cells infected with the poliovirus-HPV L1 recombinant indicated that HPV 16 L1 self-assembles into virus-like particles. To investigate the immunological response in vivo, susceptible transgenic mice carrying the poliovirus receptor were infected with the recombinant poliovirus. In all mice a modest but consistent immune response against HPV 16 was observed. Based on these results, the potential for picornavirus-derived vectors in vaccine development against HPV infection is discussed.

  7. Hepatitis B, C and Human Immunodeficiency Virus (HIV) Co ...

    African Journals Online (AJOL)

    TNHJOURNALPH

    BACKGROUND. Nigeria which has one of the world's highest burden of children living with. Sickle cell anaemia is also endemic for hepatitis B, C and the Human immunodeficiency virus (HIV). This study set out to determine the prevalence of. Hepatitis B surface antigen (HBsAg), antibodies to Hepatitis C Virus (HCV) and.

  8. An optimized formulation of a thermostable spray dried virus-like particles vaccine against human papillomavirus

    Science.gov (United States)

    Saboo, Sugandha; Tumban, Ebenezer; Peabody, Julianne; Wafula, Denis; Peabody, David S.; Chackerian, Bryce; Muttil, Pavan

    2016-01-01

    Existing vaccines against human papillomavirus (HPV) require continuous cold-chain storage. Previously, we developed a bacteriophage virus-like particle (VLP) based vaccine for Human Papillomavirus (HPV) infection, which elicits broadly neutralizing antibodies against diverse HPV types. Here, we formulated these VLPs into a thermostable dry powder using a multi-component excipient system and by optimizing the spray drying parameters using a half-factorial design approach. Dry powder VLPs were stable after spray drying and after long-term storage at elevated temperatures. Immunization of mice with a single dose of reconstituted dry powder VLPs that were stored at 37°C for more than a year elicited high anti-L2 IgG antibody titers. Spray dried thermostable, broadly protective L2 bacteriophage VLPs vaccine could be accessible to remote regions of the world (where ~84% of cervical cancer patients reside) by eliminating the cold-chain requirement during transportation and storage. PMID:27019231

  9. Frequent hepatitis B virus rebound among HIV-hepatitis B virus-coinfected patients following antiretroviral therapy interruption

    DEFF Research Database (Denmark)

    Dore, Gregory J; Soriano, Vicente; Rockstroh, Jürgen

    2010-01-01

    .0002), nondetectable HBV DNA at baseline (P = 0.007), and black race (P = 0.03). Time to ART reinitiation was shorter (7.5, 15.6, and 17.8 months; P hepatitis C virus-positive and non-HBV/hepatitis...... C virus participants in the drug conservation arm. No hepatic decompensation events occurred among HBV-positive participants in either arm. CONCLUSION: HBV DNA rebound following ART interruption is common and may be associated with accelerated immune deficiency in HIV-HBV-coinfected patients.......BACKGROUND: The impact of antiretroviral therapy (ART) interruption in HIV-hepatitis B virus (HBV)-coinfected patients was examined in the Strategic Management of AntiRetroviral Therapy (SMART) study. METHODS: Plasma HBV DNA was measured in all hepatitis B surface antigen-positive (HBV...

  10. Early low-titer neutralizing antibodies impede HIV-1 replication and select for virus escape.

    Directory of Open Access Journals (Sweden)

    Katharine J Bar

    Full Text Available Single genome sequencing of early HIV-1 genomes provides a sensitive, dynamic assessment of virus evolution and insight into the earliest anti-viral immune responses in vivo. By using this approach, together with deep sequencing, site-directed mutagenesis, antibody adsorptions and virus-entry assays, we found evidence in three subjects of neutralizing antibody (Nab responses as early as 2 weeks post-seroconversion, with Nab titers as low as 1∶20 to 1∶50 (IC(50 selecting for virus escape. In each of the subjects, Nabs targeted different regions of the HIV-1 envelope (Env in a strain-specific, conformationally sensitive manner. In subject CH40, virus escape was first mediated by mutations in the V1 region of the Env, followed by V3. HIV-1 specific monoclonal antibodies from this subject mapped to an immunodominant region at the base of V3 and exhibited neutralizing patterns indistinguishable from polyclonal antibody responses, indicating V1-V3 interactions within the Env trimer. In subject CH77, escape mutations mapped to the V2 region of Env, several of which selected for alterations of glycosylation. And in subject CH58, escape mutations mapped to the Env outer domain. In all three subjects, initial Nab recognition was followed by sequential rounds of virus escape and Nab elicitation, with Nab escape variants exhibiting variable costs to replication fitness. Although delayed in comparison with autologous CD8 T-cell responses, our findings show that Nabs appear earlier in HIV-1 infection than previously recognized, target diverse sites on HIV-1 Env, and impede virus replication at surprisingly low titers. The unexpected in vivo sensitivity of early transmitted/founder virus to Nabs raises the possibility that similarly low concentrations of vaccine-induced Nabs could impair virus acquisition in natural HIV-1 transmission, where the risk of infection is low and the number of viruses responsible for transmission and productive clinical

  11. Unpolarized release of vaccinia virus and HIV antigen by colchicine treatment enhances intranasal HIV antigen expression and mucosal humoral responses.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available The induction of a strong mucosal immune response is essential to building successful HIV vaccines. Highly attenuated recombinant HIV vaccinia virus can be administered mucosally, but even high doses of immunization have been found unable to induce strong mucosal antibody responses. In order to solve this problem, we studied the interactions of recombinant HIV vaccinia virus Tiantan strain (rVTT-gagpol in mucosal epithelial cells (specifically Caco-2 cell layers and in BALB/c mice. We evaluated the impact of this virus on HIV antigen delivery and specific immune responses. The results demonstrated that rVTT-gagpol was able to infect Caco-2 cell layers and both the nasal and lung epithelia in BALB/c mice. The progeny viruses and expressed p24 were released mainly from apical surfaces. In BALB/c mice, the infection was limited to the respiratory system and was not observed in the blood. This showed that polarized distribution limited antigen delivery into the whole body and thus limited immune response. To see if this could be improved upon, we stimulated unpolarized budding of the virus and HIV antigens by treating both Caco-2 cells and BALB/c mice with colchicine. We found that, in BALB/c mice, the degree of infection and antigen expression in the epithelia went up. As a result, specific immune responses increased correspondingly. Together, these data suggest that polarized budding limits antigen delivery and immune responses, but unpolarized distribution can increase antigen expression and delivery and thus enhance specific immune responses. This conclusion can be used to optimize mucosal HIV vaccine strategies.

  12. Engineering and Characterization of a Fluorescent Native-Like HIV-1 Envelope Glycoprotein Trimer

    Directory of Open Access Journals (Sweden)

    Kwinten Sliepen

    2015-10-01

    Full Text Available Generation of a stable, soluble mimic of the HIV-1 envelope glycoprotein (Env trimer on the virion surface has been considered an important first step for developing a successful HIV-1 vaccine. Recently, a soluble native-like Env trimer (BG505 SOSIP.664 has been described. This protein has facilitated major advances in the HIV-1 vaccine field, since it was the first Env immunogen that induced consistent neutralizing antibodies against a neutralization-resistant (tier 2 virus. Moreover, BG505 SOSIP.664 enabled elucidation of the atomic resolution structure of the Env trimer and facilitated the isolation and characterization of new broadly neutralizing antibodies against HIV-1. Here, we designed and characterized the BG505 SOSIP.664 trimer fused to fluorescent superfolder GFP (sfGFP, a GFP variant that allows efficient folding (BG505 SOSIP.664-sfGFP. Despite the presence of the sfGFP, the Env protein largely retained its morphology, antigenicity, glycan composition, and thermostability. In addition, we show that BG505 SOSIP.664-sfGFP can be used for fluorescence-based assays, such as flow cytometry.

  13. Surgical excision for recurrent herpes simplex virus 2 (HSV-2) anogenital infection in a patient with human immunodeficiency virus (HIV).

    Science.gov (United States)

    Arinze, Folasade; Shaver, Aaron; Raffanti, Stephen

    2017-10-01

    Recurrent anogenital herpes simplex virus infections are common in patients with human immunodeficiency virus (HIV), of whom approximately 5% develop resistance to acyclovir. We present a case of a 49-year-old man with HIV who had an 8-year history of recurrent left inguinal herpes simplex virus type 2 ulcerations. He initially responded to oral acyclovir, but developed resistance to acyclovir and eventually foscarnet. The lesion progressed to a large hypertrophic mass that required surgical excision, which led to resolution without recurrences. Our case highlights the importance of surgical excision as a treatment option in refractory herpes simplex virus anogenital infections.

  14. Vaccine efficacy against malaria by the combination of porcine parvovirus-like particles and vaccinia virus vectors expressing CS of Plasmodium.

    Science.gov (United States)

    Rodríguez, Dolores; González-Aseguinolaza, Gloria; Rodríguez, Juan R; Vijayan, Aneesh; Gherardi, Magdalena; Rueda, Paloma; Casal, J Ignacio; Esteban, Mariano

    2012-01-01

    With the aim to develop an efficient and cost-effective approach to control malaria, we have generated porcine parvovirus-like particles (PPV-VLPs) carrying the CD8(+) T cell epitope (SYVPSAEQI) of the circumsporozoite (CS) protein from Plasmodium yoelii fused to the PPV VP2 capsid protein (PPV-PYCS), and tested in prime/boost protocols with poxvirus vectors for efficacy in a rodent malaria model. As a proof-of concept, we have characterized the anti-CS CD8(+) T cell response elicited by these hybrid PPV-VLPs in BALB/c mice after immunizations with the protein PPV-PYCS administered alone or in combination with recombinant vaccinia virus (VACV) vectors from the Western Reserve (WR) and modified virus Ankara (MVA) strains expressing the entire P. yoelii CS protein. The results of different immunization protocols showed that the combination of PPV-PYCS prime/poxvirus boost was highly immunogenic, inducing specific CD8+ T cell responses to CS resulting in 95% reduction in liver stage parasites two days following sporozoite challenge. In contrast, neither the administration of PPV-PYCS alone nor the immunization with the vectors given in the order poxvirus/VLPs was as effective. The immune profile induced by VLPs/MVA boost was associated with polyfunctional and effector memory CD8+ T cell responses. These findings highlight the use of recombinant parvovirus PPV-PYCS particles as priming agents and poxvirus vectors, like MVA, as booster to enhance specific CD8+ T cell responses to Plasmodium antigens and to control infection. These observations are relevant in the design of T cell-inducing vaccines against malaria.

  15. The virus-like particles of a braconid endoparasitoid wasp, Meteorus pulchricornis, inhibit hemocyte spreading in its noctuid host, Pseudaletia separata.

    Science.gov (United States)

    Suzuki, M; Miura, K; Tanaka, T

    2008-06-01

    We previously reported that the virus-like particles of Meteorus pulchricornis (MpVLPs) are capable of inducing apoptosis by around 6h in the hemocytes of the host, Pseudaletia separata [Suzuki, M., Tanaka, T., 2006. Virus-like particles in venom of Meteorus pulchricornis induce host hemocyte apoptosis. Journal of Insect Physiology 52, 602-611], thereby protecting the oviposited egg. In the present study, we focused on analyses of the earlier events caused by the MpVLPs upon the host immune response, namely their effects on hemocyte spreading. After recognition and attachment on foreign substance, the granulocytes and plasmatocytes assemble focal complexes and focal adhesions and spread by protruding filopodia/lamellipodia. The well-spread, cultured hemocytes were subjected to MpVLPs exposure, and the morphological changes were observed. The granulocytes lost the focal complexes/adhesions visualized as phosphotyrosine clusters and retracted the filopodia/lamellipodia within 30min after exposure, while the plasmatocytes exhibited similar but distinct responses. The two hemocyte species prepared from either parasitized or MpVLP-injected hosts lost the ability to form both filopodia/lamellipodia and phosphotyrosine clusters. A caspase inhibitor, Z-VAD-FMK, did not affect these MpVLP-induced morphological changes, indicating that these earlier changes found in the hemocytes precede apoptosis. The present study together with our previous data has established that the attenuation of host immune defense by the MpVLPs comprises at least two temporally distinguishable phases: immediate and early inhibition of hemocyte spreading and the eventual induction of hemocyte apoptosis.

  16. Influenza A virus does not encode a tetherin antagonist with Vpu-like activity and induces IFN-dependent tetherin expression in infected cells.

    Directory of Open Access Journals (Sweden)

    Michael Winkler

    Full Text Available The interferon-induced host cell factor tetherin inhibits release of human immunodeficiency virus (HIV from the plasma membrane of infected cells and is counteracted by the HIV-1 protein Vpu. Influenza A virus (FLUAV also buds from the plasma membrane and is not inhibited by tetherin. Here, we investigated if FLUAV encodes a functional equivalent of Vpu for tetherin antagonism. We found that expression of the FLUAV protein NS1, which antagonizes the interferon (IFN response, did not block the tetherin-mediated restriction of HIV release, which was rescued by Vpu. Similarly, tetherin-mediated inhibition of HIV release was not rescued by FLUAV infection. In contrast, FLUAV infection induced tetherin expression on target cells in an IFN-dependent manner. These results suggest that FLUAV escapes the antiviral effects of tetherin without encoding a tetherin antagonist with Vpu-like activity.

  17. Analysis of Select Herpes Simplex Virus 1 (HSV-1) Proteins for Restriction of Human Immunodeficiency Virus Type 1 (HIV-1): HSV-1 gM Protein Potently Restricts HIV-1 by Preventing Intracellular Transport and Processing of Env gp160.

    Science.gov (United States)

    Polpitiya Arachchige, Sachith; Henke, Wyatt; Pramanik, Ankita; Kalamvoki, Maria; Stephens, Edward B

    2018-01-15

    Virus-encoded proteins that impair or shut down specific host cell functions during replication can be used as probes to identify potential proteins/pathways used in the replication of viruses from other families. We screened nine proteins from herpes simplex virus 1 (HSV-1) for the ability to enhance or restrict human immunodeficiency virus type 1 (HIV-1) replication. We show that several HSV-1 proteins (glycoprotein M [gM], US3, and UL24) potently restricted the replication of HIV-1. Unlike UL24 and US3, which reduced viral protein synthesis, we observed that gM restriction of HIV-1 occurred through interference with the processing and transport of gp160, resulting in a significantly reduced level of mature gp120/gp41 released from cells. Finally, we show that an HSV-1 gM mutant lacking the majority of the C-terminal domain (HA-gM[Δ345-473]) restricted neither gp160 processing nor the release of infectious virus. These studies identify proteins from heterologous viruses that can restrict viruses through novel pathways. IMPORTANCE HIV-1 infection of humans results in AIDS, characterized by the loss of CD4 + T cells and increased susceptibility to opportunistic infections. Both HIV-1 and HSV-1 can infect astrocytes and microglia of the central nervous system (CNS). Thus, the identification of HSV-1 proteins that directly restrict HIV-1 or interfere with pathways required for HIV-1 replication could lead to novel antiretroviral strategies. The results of this study show that select viral proteins from HSV-1 can potently restrict HIV-1. Further, our results indicate that the gM protein of HSV-1 restricts HIV-1 through a novel pathway by interfering with the processing of gp160 and its incorporation into virus maturing from the cell. Copyright © 2018 American Society for Microbiology.

  18. Tunnel current through virus particles between columnar structures in mesoporous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Vashpanov, Yuriy; Jung, Jae-Il; Dal Kwack, Kae [Electrical Engineering and Computer Science Division of Hanyang Institute of Technology, Hanyang University, 17 Haengdang-dong, Seongdong-gu, 133-791 Seoul (Korea, Republic of)

    2011-07-15

    Earlier we reported on a tunnel charge transport mechanism in mesoporous silicon with columnar structures under adsorption of plant nematode-transmitted polyhedral (NEPO) viruses at room temperature. Additional experiments are performed in this paper to establish that this observed tunnel current is connected to a conduction path through virus particles. The plant NEPO viruses have an orbicular shape with a diameter of around 25-30 nm. This size is matched well to the porous size distribution in manufactured samples. The tunnel charge transport in semiconductor structures was not observed on loading protein macromolecules of smaller sizes. A physical mechanism of the observed phenomena can be interpreted to be the result of a shunting effect through virus particles between the two closely located columnar silicon structures. This effect is likely to result from double points at virus adsorption under the condition of matching of pore and virus sizes. The magnitudes of the tunnel barrier heights depend on the type of loaded plant viruses. The investigated columnar structures of mesoporous silicon can be used for research on the electrical properties of different viruses with corresponding sizes in the range of 20-30 nm. The existence of a tunnel current between columnar structures in mesoporous silicon under virus adsorption can be used as a simple method for their detection in the environment. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Ebola Virus RNA in Semen from an HIV-Positive Survivor of Ebola.

    Science.gov (United States)

    Purpura, Lawrence J; Rogers, Emerson; Baller, April; White, Stephen; Soka, Moses; Choi, Mary J; Mahmoud, Nuha; Wasunna, Christine; Massaquoi, Moses; Kollie, Jomah; Dweh, Straker; Bemah, Philip; Ladele, Victor; Kpaka, Jonathan; Jawara, Mary; Mugisha, Margaret; Subah, Onyekachi; Faikai, Mylene; Bailey, Jeff A; Rollin, Pierre; Marston, Barbara; Nyenswah, Tolbert; Gasasira, Alex; Knust, Barbara; Nichol, Stuart; Williams, Desmond

    2017-04-01

    Ebola virus is known to persist in semen of male survivors of Ebola virus disease (EVD). However, maximum duration of, or risk factors for, virus persistence are unknown. We report an EVD survivor with preexisting HIV infection, whose semen was positive for Ebola virus RNA 565 days after recovery from EVD.

  20. Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

    International Nuclear Information System (INIS)

    Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique; Licona-Limón, Ileana; Huerta, Leonor

    2017-01-01

    Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4"+ T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. - Highlights: • Jurkat T cells expressing the HIV-1 envelope fuse with THP-1 monocytes. • Heterokaryons display a dominant myeloid phenotype and monocyte function. • Heterokaryons exhibit activation features in the absence of activation agents. • Activation is not due to cell-cell interaction but requires cell-cell fusion. • The

  1. Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique; Licona-Limón, Ileana; Huerta, Leonor, E-mail: leonorhh@biomedicas.unam.mx

    2017-03-01

    Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4{sup +} T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. - Highlights: • Jurkat T cells expressing the HIV-1 envelope fuse with THP-1 monocytes. • Heterokaryons display a dominant myeloid phenotype and monocyte function. • Heterokaryons exhibit activation features in the absence of activation agents. • Activation is not due to cell-cell interaction but requires cell-cell fusion. • The

  2. Evaluation of the stability of enterovirus 71 virus-like particle.

    Science.gov (United States)

    Lin, Shih-Yeh; Chung, Yao-Chi; Chiu, Hsin-Yi; Chi, Wei-Kuang; Chiang, Bor-Luen; Hu, Yu-Chen

    2014-03-01

    Enterovirus 71 (EV71) is responsible for the outbreaks of hand-foot-and-mouth disease that caused significant mortality in children, but no vaccine is available yet. EV71 virus-like particle (VLP) is the empty capsid consisting of viral structural proteins but can elicit potent immune responses, rendering VLP a promising EV71 vaccine candidate. To evaluate whether VLP remains stable after long-term storage, which is crucial for advancing the VLP vaccine to the clinical setting, we evaluated the effects of NaCl concentration, buffers and temperatures on the VLP stability. We first validated the use of dynamic light scattering (DLS) for measuring the hydrodynamic diameter (≈30-35 nm) of VLP, which was close to the VLP diameter (≈25-27 nm) as measured by transmission electron microscopy (TEM). Using these techniques, we found that EV71 VLP remained stable for 5 months in sodium phosphate (NaPi) buffers with various NaCl concentrations. EV71 VLP also remained morphologically stable in NaPi, citrate and TE(+) buffers for 5 months, yet the enzyme-linked immunosorbent assay (ELISA) revealed that the VLP stored in citrate and TE(+) buffers partially lost the immunogenicity after 5 months. In contrast, the VLP stored in the NaPi buffer at 4°C remained stable macroscopically and microscopically for 5 months, as judged from the DLS, TEM and ELISA. The VLP stored at 25°C and 37°C also retained stability for 1 month, which would obviate the need of a cold chain during the shipping. These data altogether proved the stability of EV71 VLP and suggested that the VLP is amenable to bioprocessing and storage. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. A virus-like particle based bivalent vaccine confers dual protection against enterovirus 71 and coxsackievirus A16 infections in mice.

    Science.gov (United States)

    Ku, Zhiqiang; Liu, Qingwei; Ye, Xiaohua; Cai, Yicun; Wang, Xiaoli; Shi, Jinping; Li, Dapeng; Jin, Xia; An, Wenqi; Huang, Zhong

    2014-07-23

    Enterovirus 71(EV71) and coxsackievirus A16 (CA16) are responsible for hand, foot and mouth disease which has been prevalent in Asia-Pacific regions, causing significant morbidity and mortality in young children. Co-circulation of and co-infection by both viruses underscores the importance and urgency of developing vaccines against both viruses simultaneously. Here we report the immunogenicity and protective efficacy of a bivalent combination vaccine comprised of EV71 and CA16 virus-like particles (VLPs). We show that monovalent EV71- or CA16-VLPs-elicited serum antibodies exhibited potent neutralization effect on the homotypic virus but little or no effect on the heterotypic one, whereas the antisera against the bivalent vaccine formulation were able to efficiently neutralize both EV71 and CA16, indicating there is no immunological interference between the two antigens with respect to their ability to induce virus-specific neutralizing antibodies. Passive immunization with monovalent VLP vaccines protected mice against a homotypic virus challenge but not heterotypic infection. Surprisingly, antibody-dependent enhancement (ADE) of disease was observed in mice passively transferred with mono-specific anti-CA16 VLP sera and subsequently challenged with EV71. In contrast, the bivalent VLP vaccine conferred full protection against lethal challenge by either EV71 or CA16, thus eliminating the potential of ADE. Taken together, our results demonstrate for the first time that the bivalent VLP approach represents a safe and efficacious vaccine strategy for both EV71 and CA16. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Hepatitis B Virus Vaccination in HIV-1-Infected Young Adults: A Tool to Reduce the Size of HIV-1 Reservoirs?

    Science.gov (United States)

    Bekele, Yonas; Graham, Rebecka Lantto; Soeria-Atmadja, Sandra; Nasi, Aikaterini; Zazzi, Maurizio; Vicenti, Ilaria; Naver, Lars; Nilsson, Anna; Chiodi, Francesca

    2017-01-01

    During anti-retroviral therapy (ART) HIV-1 persists in cellular reservoirs, mostly represented by CD4+ memory T cells. Several approaches are currently being undertaken to develop a cure for HIV-1 infection through elimination (or reduction) of these reservoirs. Few studies have so far been conducted to assess the possibility of reducing the size of HIV-1 reservoirs through vaccination in virologically controlled HIV-1-infected children. We recently conducted a vaccination study with a combined hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccine in 22 HIV-1-infected children. We assessed the size of the virus reservoir, measured as total HIV-1 DNA copies in blood cells, pre- and postvaccination. In addition, we investigated by immunostaining whether the frequencies of CD4+ and CD8+ T cells and parameters of immune activation and proliferation on these cells were modulated by vaccination. At 1 month from the last vaccination dose, we found that 20 out of 22 children mounted a serological response to HBV; a majority of children had antibodies against HAV at baseline. The number of HIV-1 DNA copies in blood at 1 month postvaccination was reduced in comparison to baseline although this reduction was not statistically significant. A significant reduction of HIV-1 DNA copies in blood following vaccination was found in 12 children. The frequencies of CD4+ (naïve, effector memory) and CD8+ (central memory) T-cell subpopulations changed following vaccinations and a reduction in the activation and proliferation pattern of these cells was also noticed. Multivariate linear regression analysis revealed that the frequency of CD8+ effector memory T cells prior to vaccination was strongly predictive of the reduction of HIV-1 DNA copies in blood following vaccination of the 22 HIV-1-infected children. The results of this study suggest a beneficial effect of vaccination to reduce the size of virus reservoir in HIV-1-infected children receiving ART. A reduced frequency of

  5. Hepatitis B Virus Vaccination in HIV-1-Infected Young Adults: A Tool to Reduce the Size of HIV-1 Reservoirs?

    Directory of Open Access Journals (Sweden)

    Yonas Bekele

    2018-01-01

    Full Text Available During anti-retroviral therapy (ART HIV-1 persists in cellular reservoirs, mostly represented by CD4+ memory T cells. Several approaches are currently being undertaken to develop a cure for HIV-1 infection through elimination (or reduction of these reservoirs. Few studies have so far been conducted to assess the possibility of reducing the size of HIV-1 reservoirs through vaccination in virologically controlled HIV-1-infected children. We recently conducted a vaccination study with a combined hepatitis A virus (HAV and hepatitis B virus (HBV vaccine in 22 HIV-1-infected children. We assessed the size of the virus reservoir, measured as total HIV-1 DNA copies in blood cells, pre- and postvaccination. In addition, we investigated by immunostaining whether the frequencies of CD4+ and CD8+ T cells and parameters of immune activation and proliferation on these cells were modulated by vaccination. At 1 month from the last vaccination dose, we found that 20 out of 22 children mounted a serological response to HBV; a majority of children had antibodies against HAV at baseline. The number of HIV-1 DNA copies in blood at 1 month postvaccination was reduced in comparison to baseline although this reduction was not statistically significant. A significant reduction of HIV-1 DNA copies in blood following vaccination was found in 12 children. The frequencies of CD4+ (naïve, effector memory and CD8+ (central memory T-cell subpopulations changed following vaccinations and a reduction in the activation and proliferation pattern of these cells was also noticed. Multivariate linear regression analysis revealed that the frequency of CD8+ effector memory T cells prior to vaccination was strongly predictive of the reduction of HIV-1 DNA copies in blood following vaccination of the 22 HIV-1-infected children. The results of this study suggest a beneficial effect of vaccination to reduce the size of virus reservoir in HIV-1-infected children receiving ART. A reduced

  6. Hepatitis B Virus Vaccination in HIV-1-Infected Young Adults: A Tool to Reduce the Size of HIV-1 Reservoirs?

    Science.gov (United States)

    Bekele, Yonas; Graham, Rebecka Lantto; Soeria-Atmadja, Sandra; Nasi, Aikaterini; Zazzi, Maurizio; Vicenti, Ilaria; Naver, Lars; Nilsson, Anna; Chiodi, Francesca

    2018-01-01

    During anti-retroviral therapy (ART) HIV-1 persists in cellular reservoirs, mostly represented by CD4+ memory T cells. Several approaches are currently being undertaken to develop a cure for HIV-1 infection through elimination (or reduction) of these reservoirs. Few studies have so far been conducted to assess the possibility of reducing the size of HIV-1 reservoirs through vaccination in virologically controlled HIV-1-infected children. We recently conducted a vaccination study with a combined hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccine in 22 HIV-1-infected children. We assessed the size of the virus reservoir, measured as total HIV-1 DNA copies in blood cells, pre- and postvaccination. In addition, we investigated by immunostaining whether the frequencies of CD4+ and CD8+ T cells and parameters of immune activation and proliferation on these cells were modulated by vaccination. At 1 month from the last vaccination dose, we found that 20 out of 22 children mounted a serological response to HBV; a majority of children had antibodies against HAV at baseline. The number of HIV-1 DNA copies in blood at 1 month postvaccination was reduced in comparison to baseline although this reduction was not statistically significant. A significant reduction of HIV-1 DNA copies in blood following vaccination was found in 12 children. The frequencies of CD4+ (naïve, effector memory) and CD8+ (central memory) T-cell subpopulations changed following vaccinations and a reduction in the activation and proliferation pattern of these cells was also noticed. Multivariate linear regression analysis revealed that the frequency of CD8+ effector memory T cells prior to vaccination was strongly predictive of the reduction of HIV-1 DNA copies in blood following vaccination of the 22 HIV-1-infected children. The results of this study suggest a beneficial effect of vaccination to reduce the size of virus reservoir in HIV-1-infected children receiving ART. A reduced frequency of

  7. Moderate restriction of macrophage-tropic human immunodeficiency virus type 1 by SAMHD1 in monocyte-derived macrophages.

    Science.gov (United States)

    Taya, Kahoru; Nakayama, Emi E; Shioda, Tatsuo

    2014-01-01

    Macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains are able to grow to high titers in human monocyte-derived macrophages. However, it was recently reported that cellular protein SAMHD1 restricts HIV-1 replication in human cells of the myeloid lineage, including monocyte-derived macrophages. Here we show that degradation of SAMHD1 in monocyte-derived macrophages was associated with moderately enhanced growth of the macrophage-tropic HIV-1 strain. SAMHD1 degradation was induced by treating target macrophages with vesicular stomatitis virus glycoprotein-pseudotyped human immunodeficiency virus type 2 (HIV-2) particles containing viral protein X. For undifferentiated monocytes, HIV-2 particle treatment allowed undifferentiated monocytes to be fully permissive for productive infection by the macrophage-tropic HIV-1 strain. In contrast, untreated monocytes were totally resistant to HIV-1 replication. These results indicated that SAMHD1 moderately restricts even a macrophage-tropic HIV-1 strain in monocyte-derived macrophages, whereas the protein potently restricts HIV-1 replication in undifferentiated monocytes.

  8. Tandem fusion of hepatitis B core antigen allows assembly of virus-like particles in bacteria and plants with enhanced capacity to accommodate foreign proteins.

    Directory of Open Access Journals (Sweden)

    Hadrien Peyret

    Full Text Available The core protein of the hepatitis B virus, HBcAg, assembles into highly immunogenic virus-like particles (HBc VLPs when expressed in a variety of heterologous systems. Specifically, the major insertion region (MIR on the HBcAg protein allows the insertion of foreign sequences, which are then exposed on the tips of surface spike structures on the outside of the assembled particle. Here, we present a novel strategy which aids the display of whole proteins on the surface of HBc particles. This strategy, named tandem core, is based on the production of the HBcAg dimer as a single polypeptide chain by tandem fusion of two HBcAg open reading frames. This allows the insertion of large heterologous sequences in only one of the two MIRs in each spike, without compromising VLP formation. We present the use of tandem core technology in both plant and bacterial expression systems. The results show that tandem core particles can be produced with unmodified MIRs, or with one MIR in each tandem dimer modified to contain the entire sequence of GFP or of a camelid nanobody. Both inserted proteins are correctly folded and the nanobody fused to the surface of the tandem core particle (which we name tandibody retains the ability to bind to its cognate antigen. This technology paves the way for the display of natively folded proteins on the surface of HBc particles either through direct fusion or through non-covalent attachment via a nanobody.

  9. Introducing a frameshift mutation to the POL sequence of HIV-1 provirus and evaluation of the immunogenic characteristics of the mutated virions (RINNL4-3).

    Science.gov (United States)

    Zabihollahi, Rezvan; Sadat, Seyed Mehdi; Vahabpour, Rouhollah; Salehi, Mansoor; Azadmanesh, Kayhan; Siadat, Seyed Davar; Saraji, Ali Reza Azizi; Pouriavali, Mohamamd Hassan; Momen, Seyed Bahman; Aghasadeghi, Mohamad Reza

    2012-01-01

    Inactivation of the reverse transcriptase (RT) and integrase (IN) enzymes can abolish the replication of the human immunodeficiency virus (HIV) and, thus, its infectivity. Here, inactivated HIV particles convenient for designing virus-like particle (VLP) based vaccines have been produced. Inactivated HIV-provirus was created by introducing a frame shift mutation. HIV provirus DNA was cut in the pol region by Age I restriction enzyme, followed by filling of sticky ends using the Klenow fragment before ligation. The resulting plasmid was named as pRINNL4-3. HEK-293T cells were used as producer, after being transfected with the modified plasmid. Viral particle production and biological activity were assayed by virus capsid protein (p24) quantification and syncytium formation in MT2 cells, respectively. The immunogenicity of the RINNL4-3 virions was investigated in a mouse model. The mutation was expected to inactivate the virus RT and IN enzymes. The results showed that the VLPs were assembled, as measured by the p24 load of the culture supernatant, and contained functional envelope proteins (Env) as monitored by the syncytium formation. However, these VLPs had no ability to infect target MT2 cells, as well as their VSVG (vesicular stomatitis virus-glycoprotein) pseudotyped counterparts infected HEK-293T cells. A high level of antibody response was observed in immunized mice. Since RINNL4-3 virions are replication incompetent, they are convenient for production and use in biomedical studies. Also, RINNL4-3 is a candidate for a vaccine development due to it contains envelope and structural virus proteins which are crucial for triggering neutralizing antibodies and the cellular immune response.

  10. Epidemiology of hepatitis C virus in HIV-infected patients

    DEFF Research Database (Denmark)

    Peters, Lars; Klein, Marina B

    2015-01-01

    PURPOSE OF REVIEW: This review will give an update on the prevalence of HIV/hepatitis C virus (HCV) coinfection, and describe recent trends in all-cause and cause-specific mortality. The focus is mainly on patients followed in clinics in high-income countries and their heterogeneity in terms...... of risk factors and clinical outcomes. RECENT FINDINGS: In countries that have introduced comprehensive preventive strategies for injection drug users, the prevalence of HIV/HCV coinfection has declined. Compared with HIV monoinfected patients, the mortality among HCV-coinfected patients remains markedly...

  11. Prevalence of HIV infection in seronegative high-risk individuals examined by virus isolation and PCR

    DEFF Research Database (Denmark)

    Nielsen, C; Teglbjærg, Lars Stubbe; Pedersen, C

    1991-01-01

    HIV seronegative individuals with high-risk behavior were tested for HIV infection by sensitive virus isolation techniques using T4 lymphocytes and monocyte/macrophages, and by detection of proviral DNA using PCR with three different sets of nested primers. No evidence of HIV infection was found...... among the 31 seronegative high-risk subjects, either by virus isolation of by PCR (97.5% confidence limits, 0-11). Our results indicate that ongoing HIV infection in seronegative persons at high risk of infection is a rare event....

  12. Antibody Persistence in Adults Two Years after Vaccination with an H1N1 2009 Pandemic Influenza Virus-Like Particle Vaccine.

    Directory of Open Access Journals (Sweden)

    Nuriban Valero-Pacheco

    Full Text Available The influenza virus is a human pathogen that causes epidemics every year, as well as potential pandemic outbreaks, as occurred in 2009. Vaccination has proven to be sufficient in the prevention and containment of viral spreading. In addition to the current egg-based vaccines, new and promising vaccine platforms, such as cell culture-derived vaccines that include virus-like particles (VLPs, have been developed. VLPs have been shown to be both safe and immunogenic against influenza infections. Although antibody persistence has been studied in traditional egg-based influenza vaccines, studies on antibody response durations induced by VLP influenza vaccines in humans are scarce. Here, we show that subjects vaccinated with an insect cell-derived VLP vaccine, in the midst of the 2009 H1N1 influenza pandemic outbreak in Mexico City, showed antibody persistence up to 24 months post-vaccination. Additionally, we found that subjects that reported being revaccinated with a subsequent inactivated influenza virus vaccine showed higher antibody titres to the pandemic influenza virus than those who were not revaccinated. These findings provide insights into the duration of the antibody responses elicited by an insect cell-derived pandemic influenza VLP vaccine and the possible effects of subsequent influenza vaccination on antibody persistence induced by this VLP vaccine in humans.

  13. The allosteric HIV-1 integrase inhibitor BI-D affects virion maturation but does not influence packaging of a functional RNA genome.

    Directory of Open Access Journals (Sweden)

    Nikki van Bel

    Full Text Available The viral integrase (IN is an essential protein for HIV-1 replication. IN inserts the viral dsDNA into the host chromosome, thereby aided by the cellular co-factor LEDGF/p75. Recently a new class of integrase inhibitors was described: allosteric IN inhibitors (ALLINIs. Although designed to interfere with the IN-LEDGF/p75 interaction to block HIV DNA integration during the early phase of HIV-1 replication, the major impact was surprisingly found on the process of virus maturation during the late phase, causing a reverse transcription defect upon infection of target cells. Virus particles produced in the presence of an ALLINI are misformed with the ribonucleoprotein located outside the virus core. Virus assembly and maturation are highly orchestrated and regulated processes in which several viral proteins and RNA molecules closely interact. It is therefore of interest to study whether ALLINIs have unpredicted pleiotropic effects on these RNA-related processes. We confirm that the ALLINI BI-D inhibits virus replication and that the produced virus is non-infectious. Furthermore, we show that the wild-type level of HIV-1 genomic RNA is packaged in virions and these genomes are in a dimeric state. The tRNAlys3 primer for reverse transcription was properly placed on this genomic RNA and could be extended ex vivo. In addition, the packaged reverse transcriptase enzyme was fully active when extracted from virions. As the RNA and enzyme components for reverse transcription are properly present in virions produced in the presence of BI-D, the inhibition of reverse transcription is likely to reflect the mislocalization of the components in the aberrant virus particle.

  14. The allosteric HIV-1 integrase inhibitor BI-D affects virion maturation but does not influence packaging of a functional RNA genome.

    Science.gov (United States)

    van Bel, Nikki; van der Velden, Yme; Bonnard, Damien; Le Rouzic, Erwann; Das, Atze T; Benarous, Richard; Berkhout, Ben

    2014-01-01

    The viral integrase (IN) is an essential protein for HIV-1 replication. IN inserts the viral dsDNA into the host chromosome, thereby aided by the cellular co-factor LEDGF/p75. Recently a new class of integrase inhibitors was described: allosteric IN inhibitors (ALLINIs). Although designed to interfere with the IN-LEDGF/p75 interaction to block HIV DNA integration during the early phase of HIV-1 replication, the major impact was surprisingly found on the process of virus maturation during the late phase, causing a reverse transcription defect upon infection of target cells. Virus particles produced in the presence of an ALLINI are misformed with the ribonucleoprotein located outside the virus core. Virus assembly and maturation are highly orchestrated and regulated processes in which several viral proteins and RNA molecules closely interact. It is therefore of interest to study whether ALLINIs have unpredicted pleiotropic effects on these RNA-related processes. We confirm that the ALLINI BI-D inhibits virus replication and that the produced virus is non-infectious. Furthermore, we show that the wild-type level of HIV-1 genomic RNA is packaged in virions and these genomes are in a dimeric state. The tRNAlys3 primer for reverse transcription was properly placed on this genomic RNA and could be extended ex vivo. In addition, the packaged reverse transcriptase enzyme was fully active when extracted from virions. As the RNA and enzyme components for reverse transcription are properly present in virions produced in the presence of BI-D, the inhibition of reverse transcription is likely to reflect the mislocalization of the components in the aberrant virus particle.

  15. High prevalence of HIV-1 CRF01_AE viruses among female commercial sex workers residing in Surabaya, Indonesia.

    Science.gov (United States)

    Kotaki, Tomohiro; Khairunisa, Siti Qamariyah; Sukartiningrum, Septhia Dwi; Arfijanto, M Vitanata; Utsumi, Takako; Normalina, Irine; Handajani, Retno; Widiyanti, Prihartini; Rusli, Musofa; Rahayu, Retno Pudji; Lusida, Maria Inge; Hayashi, Yoshitake; Nasronudin; Kameoka, Masanori

    2013-01-01

    Human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) cause serious health problems and have an impact on the Indonesian economy. In addition, the rapid epidemic growth of HIV is continuing in Indonesia. Commercial sex plays a significant role in the spread of HIV; therefore, in order to reveal the current HIV prevalence rate among commercial sex workers (CSWs), we conducted an epidemiological study on HIV infection among CSWs residing in Surabaya, the capital of East Java province of Indonesia with large communities of CSWs. The prevalence of HIV infection among 200 CSWs was studied. In addition, the subtype of HIV type 1 (HIV-1) and the prevalence of other blood-borne viruses, hepatitis B virus (HBV), hepatitis C virus (HCV) and GB virus C (GBV-C), were studied. The prevalence rates of HIV, hepatitis B core antibody, hepatitis B surface antigen, anti-HCV antibodies and anti-GBV-C antibodies were 11%, 64%, 4%, 0.5% and 0% among CSWs involved in this study, respectively. HIV-1 CRF01_AE viral gene fragments were detected in most HIV-positive samples. In addition, most CSWs showed low awareness of sexually transmitted diseases and had unprotected sex with their clients. The HIV prevalence rate among CSWs was significantly higher than that among the general population in Indonesia (0.2-0.4%). In addition, CSWs were at a high risk of exposure to HBV, although chronic HBV infection was less frequently established. Our results suggest the necessity of efficient prevention programs for HIV and other blood-borne viral infections among CSWs in Surabaya, Indonesia.

  16. Vaccine efficacy against malaria by the combination of porcine parvovirus-like particles and vaccinia virus vectors expressing CS of Plasmodium.

    Directory of Open Access Journals (Sweden)

    Dolores Rodríguez

    Full Text Available With the aim to develop an efficient and cost-effective approach to control malaria, we have generated porcine parvovirus-like particles (PPV-VLPs carrying the CD8(+ T cell epitope (SYVPSAEQI of the circumsporozoite (CS protein from Plasmodium yoelii fused to the PPV VP2 capsid protein (PPV-PYCS, and tested in prime/boost protocols with poxvirus vectors for efficacy in a rodent malaria model. As a proof-of concept, we have characterized the anti-CS CD8(+ T cell response elicited by these hybrid PPV-VLPs in BALB/c mice after immunizations with the protein PPV-PYCS administered alone or in combination with recombinant vaccinia virus (VACV vectors from the Western Reserve (WR and modified virus Ankara (MVA strains expressing the entire P. yoelii CS protein. The results of different immunization protocols showed that the combination of PPV-PYCS prime/poxvirus boost was highly immunogenic, inducing specific CD8+ T cell responses to CS resulting in 95% reduction in liver stage parasites two days following sporozoite challenge. In contrast, neither the administration of PPV-PYCS alone nor the immunization with the vectors given in the order poxvirus/VLPs was as effective. The immune profile induced by VLPs/MVA boost was associated with polyfunctional and effector memory CD8+ T cell responses. These findings highlight the use of recombinant parvovirus PPV-PYCS particles as priming agents and poxvirus vectors, like MVA, as booster to enhance specific CD8+ T cell responses to Plasmodium antigens and to control infection. These observations are relevant in the design of T cell-inducing vaccines against malaria.

  17. Novel chimeric foot-and-mouth disease virus-like particles harboring serotype O VP1 protect guinea pigs against challenge.

    Science.gov (United States)

    Li, Haitao; Li, Zhiyong; Xie, Yinli; Qin, Xiaodong; Qi, Xingcai; Sun, Peng; Bai, Xingwen; Ma, Youji; Zhang, Zhidong

    2016-02-01

    Foot-and-mouth disease is a highly contagious, acute viral disease of cloven-hoofed animal species causing severe economic losses worldwide. Among the seven serotypes of foot-and-mouth disease virus (FMDV), serotype O is predominant, but its viral capsid is more acid sensitive than other serotypes, making it more difficult to produce empty serotype O VLPs in the low pH insect hemolymph. Therefore, a novel chimeric virus-like particle (VLP)-based candidate vaccine for serotype O FMDV was developed and characterized in the present study. The chimeric VLPs were composed of antigenic VP1 from serotype O and segments of viral capsid proteins from serotype Asia1. These VLPs elicited significantly higher FMDV-specific antibody levels in immunized mice than did the inactivated vaccine. Furthermore, the chimeric VLPs protected guinea pigs from FMDV challenge with an efficacy similar to that of the inactivated vaccine. These results suggest that chimeric VLPs have the potential for use in vaccines against serotype O FMDV infection. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Virus detection and quantification using electrical parameters

    Science.gov (United States)

    Ahmad, Mahmoud Al; Mustafa, Farah; Ali, Lizna M.; Rizvi, Tahir A.

    2014-10-01

    Here we identify and quantitate two similar viruses, human and feline immunodeficiency viruses (HIV and FIV), suspended in a liquid medium without labeling, using a semiconductor technique. The virus count was estimated by calculating the impurities inside a defined volume by observing the change in electrical parameters. Empirically, the virus count was similar to the absolute value of the ratio of the change of the virus suspension dopant concentration relative to the mock dopant over the change in virus suspension Debye volume relative to mock Debye volume. The virus type was identified by constructing a concentration-mobility relationship which is unique for each kind of virus, allowing for a fast (within minutes) and label-free virus quantification and identification. For validation, the HIV and FIV virus preparations were further quantified by a biochemical technique and the results obtained by both approaches corroborated well. We further demonstrate that the electrical technique could be applied to accurately measure and characterize silica nanoparticles that resemble the virus particles in size. Based on these results, we anticipate our present approach to be a starting point towards establishing the foundation for label-free electrical-based identification and quantification of an unlimited number of viruses and other nano-sized particles.

  19. Expression and characterization of human group C rotavirus virus-like particles in insect cells

    International Nuclear Information System (INIS)

    Clark, Kristina B.; Lin, S.-C.; Humphrey, Charles; Foytich, Kimberly; Esona, Mathew; Wang Yuhuan; Liu, Merry; Jiang Baoming

    2009-01-01

    Group C rotavirus (GpC RV) is a causative agent of acute gastroenteritis in children and adults. We expressed the three major capsid proteins VP2, VP6 and VP7 of human GpC RV in baculovirus and demonstrated the self-assembly of VP2/6/7 or VP6/7 virus-like particles (VLPs) in insect cells. We examined a number of parameters, including the kinetics of protein synthesis in different cell lines and media, to optimize the most favorable conditions for the synthesis of recombinant viral proteins and the production of VLPs in Sf9 cells. Hyperimmune serum to VP2/6/7 and VP6/7 VLPs recognized individual recombinant proteins of human GpC RV by Western blot analysis. This serum also showed specific reactivities with the corresponding GpC VLPs but not GpA RV by using immune electron microscopy (IEM) and enzyme immunoassay (EIA). The ability to produce an unlimited amount of GpC RV antigen and the availability of high quality antibody will allow us to develop sensitive and specific diagnostic assays to better determine the epidemiology and disease burden of GpC RV in humans.

  20. Multifaceted counter-APOBEC3G mechanisms employed by HIV-1 Vif.

    Science.gov (United States)

    Britan-Rosich, Elena; Nowarski, Roni; Kotler, Moshe

    2011-07-29

    In the absence of human immunodeficiency virus type 1 (HIV-1) Vif protein, the host antiviral deaminase apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G (A3G) restricts the production of infectious HIV-1 by deamination of dC residues in the negative single-stranded DNA produced by reverse transcription. The Vif protein averts the lethal threat of deamination by precluding the packaging of A3G into assembling virions by mediating proteasomal degradation of A3G. In spite of this robust Vif activity, residual A3G molecules that escape degradation and incorporate into newly assembled virions are potentially deleterious to the virus. We hypothesized that virion-associated Vif inhibits A3G enzymatic activity and therefore prevents lethal mutagenesis of the newly synthesized viral DNA. Here, we show that (i) Vif-proficient HIV-1 particles released from H9 cells contain A3G with lower specific activity compared with Δvif-virus-associated A3G, (ii) encapsidated HIV-1 Vif inhibits the deamination activity of recombinant A3G, and (iii) purified HIV-1 Vif protein and the Vif-derived peptide Vif25-39 inhibit A3G activity in vitro at nanomolar concentrations in an uncompetitive manner. Our results manifest the potentiality of Vif to control the deamination threat in virions or in the pre-integration complexes following entry to target cells. Hence, virion-associated Vif could serve as a last line of defense, protecting the virus against A3G antiviral activity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Timing of the HIV-1 subtype C epidemic in Ethiopia based on early virus strains and subsequent virus diversification

    NARCIS (Netherlands)

    Abebe, A.; Lukashov, V. V.; Pollakis, G.; Kliphuis, A.; Fontanet, A. L.; Goudsmit, J.; Rinke de Wit, T. F.

    2001-01-01

    OBJECTIVE: To trace the introduction of HIV-1 subtype C into Ethiopia based on virus diversification during the epidemic. DESIGN: A set of 474 serum samples obtained in Ethiopia in 1982-1985 was tested for HIV-1. HIV-1 env gp120 V3 and gag or pol regions were sequenced and analysed together with

  2. Evidence for a Euro-American origin of human immunodeficiency virus (HIV).

    Science.gov (United States)

    Katner, H P; Pankey, G A

    1987-10-01

    Recent reports of the nonspecificity of the enzyme-linked immunosorbent assay (ELISA) test in African populations, significant genomic differences between simian T-cell lymphotropic virus and human immunodeficiency virus (HIV), and the early appearance of clinical acquired immunodeficiency syndroME (AIDS) in the US and Europe are powerful arguments against the assumption that AIDS originated in Africa. The authors postulate that HIV infection has been endemic in the Euro-American population at least since the beginning of the 20th century and that sociocultural changes led to the introduction of the virus into Africa. A search of the literature reveals 28 cases of disseminated Kaposi's sarcoma in the pre-epidemic 1902-66 period. In none of these cases are notations made on intravenous drug abuse, homosexuality, or other risk factors for AIDS. The majority of cases involved men, however. It is pointed out that, in a population where the incidence of a virus such as HIV is low, the number of sexual partners is limited, and intravenous drug abuse is nonexistent, an infection with as long a latency period as HIV may not only be expressed sporadically, but would probably not be recognized as a transmissible infection. On the other hand, the significant changes in these social factors that occurred as a result of the sexual revolution of the late 1960s and early 1970s would be expected to increase the spread of infection and clinical disease so that recognition would be achieved. During the past decade, there have been marked increases in the number of sexually transmitted infections in the homosexual male population. The efficiency of anal intercourse as a mode of transmission probably accounts for the fact that HIV infection first expressed itself in this population.

  3. Surfactant protein D binds to human immunodeficiency virus (HIV) envelope protein gp120 and inhibits HIV replication

    DEFF Research Database (Denmark)

    Meschi, Joseph; Crouch, Erika C; Skolnik, Paul

    2005-01-01

    The envelope protein (gp120) of human immunodeficiency virus (HIV) contains highly conserved mannosylated oligosaccharides. These glycoconjugates contribute to resistance to antibody neutralization, and binding to cell surface lectins on macrophages and dendritic cells. Mannose-binding lectin (MBL......) binds to gp120 and plays a role in defence against the virus. In this study it is demonstrated that surfactant protein D (SP-D) binds to gp120 and inhibits HIV infectivity at significantly lower concentrations than MBL. The binding of SP-D was mediated by its calcium-dependent carbohydrate......-binding activity and was dependent on glycosylation of gp120. Native dodecameric SP-D bound to HIV gp120 more strongly than native trimeric SP-D. Since one common polymorphic form of SP-D is predominantly expressed as trimers and associated with lower blood levels, these individuals may have less effective innate...

  4. Natural HIV-1 NEF accelerates virus replication in primary human lymphocytes

    NARCIS (Netherlands)

    de Ronde, A.; Klaver, B.; Keulen, W.; Smit, L.; Goudsmit, J.

    1992-01-01

    HIV-1 NEF genes were isolated directly from peripheral blood lymphocyte DNA of two HIV-1-infected individuals and cloned into an HXB-2-infectious molecular clone. The effect of NEF on virus production in T-cell lines and primary human lymphocytes was studied. Naturally occurring NEF accelerates

  5. High prevalence of HIV-1 CRF01_AE viruses among female commercial sex workers residing in Surabaya, Indonesia.

    Directory of Open Access Journals (Sweden)

    Tomohiro Kotaki

    Full Text Available Human immunodeficiency virus (HIV infection and acquired immune deficiency syndrome (AIDS cause serious health problems and have an impact on the Indonesian economy. In addition, the rapid epidemic growth of HIV is continuing in Indonesia. Commercial sex plays a significant role in the spread of HIV; therefore, in order to reveal the current HIV prevalence rate among commercial sex workers (CSWs, we conducted an epidemiological study on HIV infection among CSWs residing in Surabaya, the capital of East Java province of Indonesia with large communities of CSWs.The prevalence of HIV infection among 200 CSWs was studied. In addition, the subtype of HIV type 1 (HIV-1 and the prevalence of other blood-borne viruses, hepatitis B virus (HBV, hepatitis C virus (HCV and GB virus C (GBV-C, were studied. The prevalence rates of HIV, hepatitis B core antibody, hepatitis B surface antigen, anti-HCV antibodies and anti-GBV-C antibodies were 11%, 64%, 4%, 0.5% and 0% among CSWs involved in this study, respectively. HIV-1 CRF01_AE viral gene fragments were detected in most HIV-positive samples. In addition, most CSWs showed low awareness of sexually transmitted diseases and had unprotected sex with their clients.The HIV prevalence rate among CSWs was significantly higher than that among the general population in Indonesia (0.2-0.4%. In addition, CSWs were at a high risk of exposure to HBV, although chronic HBV infection was less frequently established. Our results suggest the necessity of efficient prevention programs for HIV and other blood-borne viral infections among CSWs in Surabaya, Indonesia.

  6. Ruxolitinib and Tofacitinib Are Potent and Selective Inhibitors of HIV-1 Replication and Virus Reactivation In Vitro

    Science.gov (United States)

    Gavegnano, Christina; Detorio, Mervi; Montero, Catherine; Bosque, Alberto; Planelles, Vicente

    2014-01-01

    The JAK-STAT pathway is activated in both macrophages and lymphocytes upon human immunodeficiency virus type 1 (HIV-1) infection and thus represents an attractive cellular target to achieve HIV suppression and reduced inflammation, which may impact virus sanctuaries. Ruxolitinib and tofacitinib are JAK1/2 inhibitors that are FDA approved for rheumatoid arthritis and myelofibrosis, respectively, but their therapeutic application for treatment of HIV infection was unexplored. Both drugs demonstrated submicromolar inhibition of infection with HIV-1, HIV-2, and a simian-human immunodeficiency virus, RT-SHIV, across primary human or rhesus macaque lymphocytes and macrophages, with no apparent significant cytotoxicity at 2 to 3 logs above the median effective antiviral concentration. Combination of tofacitinib and ruxolitinib increased the efficacy by 53- to 161-fold versus that observed for monotherapy, respectively, and each drug applied alone to primary human lymphocytes displayed similar efficacy against HIV-1 containing various polymerase substitutions. Both drugs inhibited virus replication in lymphocytes stimulated with phytohemagglutinin (PHA) plus interleukin-2 (IL-2), but not PHA alone, and inhibited reactivation of latent HIV-1 at low-micromolar concentrations across the J-Lat T cell latency model and in primary human central memory lymphocytes. Thus, targeted inhibition of JAK provided a selective, potent, and novel mechanism to inhibit HIV-1 replication in lymphocytes and macrophages, replication of drug-resistant HIV-1, and reactivation of latent HIV-1 and has the potential to reset the immunologic milieu in HIV-infected individuals. PMID:24419350

  7. Atypical presentations of genital herpes simplex virus in HIV-1 and HIV-2 effectively treated by imiquimod.

    Science.gov (United States)

    McKendry, Anna; Narayana, Srinivasulu; Browne, Rita

    2015-05-01

    Atypical presentations of genital herpes simplex virus have been described in HIV. We report two cases with hypertrophic presentations which were effectively treated with imiquimod, one of which is the first reported case occurring in a patient with HIV-2. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  8. Canine distemper virus matrix protein influences particle infectivity, particle composition, and envelope distribution in polarized epithelial cells and modulates virulence.

    Science.gov (United States)

    Dietzel, Erik; Anderson, Danielle E; Castan, Alexandre; von Messling, Veronika; Maisner, Andrea

    2011-07-01

    In paramyxoviruses, the matrix (M) protein mediates the interaction between the envelope and internal proteins during particle assembly and egress. In measles virus (MeV), M mutations, such as those found in subacute sclerosing panencephalitis (SSPE) strains, and differences in vaccine and wild-type M proteins can affect the strength of interaction with the envelope glycoproteins, assembly efficiency, and spread. However, the contribution of the M protein to the replication and pathogenesis of the closely related canine distemper virus (CDV) has not been characterized. To this end this, we generated a recombinant wild-type CDV carrying a vaccine strain M protein. The recombinant virus retained the parental growth phenotype in VerodogSLAMtag cells, but displayed an increased particle-to-infectivity ratio very similar to that of the vaccine strain, likely due to inefficient H protein incorporation. Even though infectious virus was released only from the apical surface, consistent with the release polarity of the wild-type CDV strain, envelope protein distribution in polarized epithelial cells reproduced the bipolar pattern seen in vaccine strain-infected cells. Most notably, the chimeric virus was completely attenuated in ferrets and caused only a mild and transient leukopenia, indicating that the differences in particle infectivity and envelope protein sorting mediated by the vaccine M protein contribute importantly to vaccine strain attenuation.

  9. Seroprevalence of hiv and hepatitis viruses in directed blood donors ...

    African Journals Online (AJOL)

    Aims: To determine the seroprevalence of HIV and Hepatitis B viruses in directed blood donors in Nguru and also to see if there is co-infection of these viruses in this category of donor population. Method: This is a prospective study carried out at the blood bank of the Federal Medical Centre Nguru, Yobe State between ...

  10. Awareness of Human Immunodeficiency Virus (HIV) infection among ...

    African Journals Online (AJOL)

    Objective: To determine the level of awareness of Human Immunodeficiency Virus (HIV) infection among antenatal clients in Nnewi Nigeria. Subjects and Methods: A cross sectional descriptive study of six hundred consecutive antenatal clients attending the Nnamdi Azikiwe University Teaching Hospital and five private ...

  11. Inhibition of human immunodeficiency virus type 1 (HIV-1) nuclear import via Vpr-Importin α interactions as a novel HIV-1 therapy

    International Nuclear Information System (INIS)

    Suzuki, Tatsunori; Yamamoto, Norio; Nonaka, Mizuho; Hashimoto, Yoshie; Matsuda, Go; Takeshima, Shin-nosuke; Matsuyama, Megumi; Igarashi, Tatsuhiko; Miura, Tomoyuki; Tanaka, Rie; Kato, Shingo; Aida, Yoko

    2009-01-01

    The development of multidrug-resistant viruses compromises the efficacy of anti-human immunodeficiency virus (HIV) therapy and limits treatment options. Therefore, new targets that can be used to develop novel antiviral agents need to be identified. One such target is the interaction between Vpr, one of the accessory gene products of HIV-1 and Importin α, which is crucial, not only for the nuclear import of Vpr, but also for HIV-1 replication in macrophages. We have identified a potential parent compound, hematoxylin, which suppresses Vpr-Importin α interaction, thereby inhibiting HIV-1 replication in a Vpr-dependent manner. Analysis by real-time PCR demonstrated that hematoxylin specifically inhibited nuclear import step of pre-integration complex. Thus, hematoxylin is a new anti-HIV-1 inhibitor that targets the nuclear import of HIV-1 via the Vpr-Importin α interaction, suggesting that a specific inhibitor of the interaction between viral protein and the cellular factor may provide a new strategy for HIV-1 therapy.

  12. Research on human immunodeficiency virus (HIV) in Malawi: the ...

    African Journals Online (AJOL)

    Research on human immunodeficiency virus (HIV) in Malawi: the Johns Hopkins University- Ministry of Health (JHU-MOH) project. TE Taha, JK Canner, AM Wangel, JD Chiphangwi, NG Liomba, PG Miotti, GA Dallabetta, AJ Saah ...

  13. Complete Genome Sequence of the Largest Known Flavi-Like Virus, Diaphorina citri flavi-like virus, a Novel Virus of the Asian Citrus Psyllid, Diaphorina citri

    OpenAIRE

    Matsumura, Emilyn E.; Nerva, Luca; Nigg, Jared C.; Falk, Bryce W.; Nouri, Shahideh

    2016-01-01

    A novel flavi-like virus tentatively named Diaphorina citri flavi-like virus (DcFLV) was identified in field populations of Diaphorina citri through small RNA and transcriptome sequencing followed by reverse transcription (RT)-PCR. We report here the complete nucleotide sequence and genome organization of DcFLV, the largest flavi-like virus identified to date.

  14. A case of lupus-like glomerulonephritis in an HIV patient with nephrotic range proteinuria, purpura, and elevated IgA level.

    Science.gov (United States)

    Yang, Jihyun; Seo, Min Young; Kim, Ki Tae; Lee, Jun Yong; Kim, Sun-Chul; Kim, Myung-Gyu; Jo, Sang-Kyung; Cho, Won-Yong; Kim, Hyoung-Kyu; Won, Nam Hee; Cha, Ran-Hui; Cho, Eunjung

    2014-01-01

    Human immunodeficiency virus (HIV) infection is growing medical concern worldwide. There are many types of glomerulonephritis which are associated with HIV infection. We report a case of a 53-year-old Korean man with an HIV infection, who was developed nephritic range proteinuria and purpura with elevated IgA level rasing a possibility of Henoch-Schölein Purpura (H-S purpura). However, renal biopsy showed "lupus-like feature" glomerulonephritis without clinical or serologic evidence of systemic lupus erythematosus. Although baseline renal function was maintained without further need for maintenance dialysis following anti-retroviral therapy (ART) and steroid, patient died from uncontrolled gastrointestinal bleeding.

  15. Hepatitis B virus treatment in HIV-infected patients.

    Science.gov (United States)

    Thio, Chloe L

    Hepatitis B virus (HBV) infection is common in HIV-infected persons and is associated with increased risk of liver-related morbidity and mortality. Agents available to treat HBV infection in coinfected patients include lamivudine, entecavir, emtricitabine, adefovir, peginterferon alfa, and the recently approved telbivudine. Treatment decisions should take into account a number of factors, including antiretroviral therapy status, HBV genotype, prior experience of lamivudine, and the need to avoid drug resistance in both HIV- and HBV-infected persons. This article summarizes a presentation on treatment and management of HBV infection in HIV-infected patients made by Chloe L. Thio, MD, at the 9th Annual Ryan White CARE Act Update in Washington, DC. The original presentation is available as a Webcast at www.iasusa.org.

  16. An unusual case of primary human immunodeficiency virus infection presenting as mononucleosis-like syndrome and acute aseptic meningoencephalitis. Report of a case and review of the literature

    Directory of Open Access Journals (Sweden)

    Marcelo Corti

    2014-01-01

    Full Text Available Clinical presentation of primary human immunodeficiency virus (HIV infection includes a wide spectrum of manifestations from asymptomatic infection to a symptomatic and severe illness. Central nervous system involvement should be always considered as a severe clinical form of primary HIV infection. Physicians should be aware to the broad clinical spectrum of primary HIV infection. We report a case of a female with diagnosis of mononucleosis-like syndrome and acute aseptic meningoencephalitis during primary HIV infection.

  17. Human immunodeficiency virus (HIV) seropositivity and hepatitis B ...

    African Journals Online (AJOL)

    Method: A total of 130 donors comprising 120 commercial donors and 10 voluntary donors were tested for antibodies to human immunodeficiency virus and hepatitis B surface antigen in Benin city using Immunocomb HIV - 1 and 2 Biospot kit and Quimica Clinica Aplicada direct latex agglutination method respectively.

  18. Human immunodeficiency virus-associated disruption of mucosal barriers and its role in HIV transmission and pathogenesis of HIV/AIDS disease

    Science.gov (United States)

    Tugizov, Sharof

    2016-01-01

    Abstract Oral, intestinal and genital mucosal epithelia have a barrier function to prevent paracellular penetration by viral, bacterial and other pathogens, including human immunodeficiency virus (HIV). HIV can overcome these barriers by disrupting the tight and adherens junctions of mucosal epithelia. HIV-associated disruption of epithelial junctions may also facilitate paracellular penetration and dissemination of other viral pathogens. This review focuses on possible molecular mechanisms of HIV-associated disruption of mucosal epithelial junctions and its role in HIV transmission and pathogenesis of HIV and acquired immune deficiency syndrome (AIDS). PMID:27583187

  19. Molecular epidemiology of co-infection with hepatitis B virus and human immunodeficiency virus (HIV) among adult patients in Harare, Zimbabwe.

    Science.gov (United States)

    Baudi, Ian; Iijima, Sayuki; Chin'ombe, Nyasha; Mtapuri-Zinyowera, Sekesai; Murakami, Shuko; Isogawa, Masanori; Hachiya, Atsuko; Iwatani, Yasumasa; Tanaka, Yasuhito

    2017-02-01

    The objective of this study was to determine the prevalence of co-infection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) and the genetic characteristics of both viruses among pre-HIV-treatment patients in Harare, Zimbabwe. This cross-sectional survey involved 176 remnant plasma samples collected from consenting HIV patients (median age 35 [18-74]) between June and September 2014. HBV seromarkers were determined by high-sensitivity chemiluminescence assays. Molecular evolutionary analyses were conducted on the basal core promoter/precore (BCP/PC) and S regions of HBV, as well as part of the HIV pol region. Of the 176 participants (65.7% female), 19 (10.8%) were positive for HBsAg (median 0.033 IU/ml (IQR 0.01-415). The HBsAg incidence was higher in men than women (P = 0.009). HBsAg-positive subjects had lower median CD4 counts (P = 0.016). HBV DNA was detectable in 12 HBsAg-positive samples (median 3.36 log cp/ml (2.86-4.51), seven being amplified and sequenced. All isolates were subgenotype A1 without HBV drug resistance mutations but each had at least one BCP/PC mutation. PreS deletion mutants and small S antigen variants M133I/T and D144G were identified. Of the 164 HIV isolates successfully genotyped, 163 (99.4%) were HIV-1 subtype C and only one was HIV-1 subtype F1. Sixteen (9.8%) had at least one drug resistance mutation, predominantly non-nucleoside reverse transcriptase inhibitor-related mutations, observed mostly among female participants. This study shows that co-infection with HBV is present among HIV patients enrolling into HIV care in Zimbabwe, suggesting that HBV screening and monitoring programmes be strengthened in this context. J. Med. Virol. 89:257-266, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Co-evolution of a broadly neutralizing HIV-1 antibody and founder virus

    Science.gov (United States)

    Liao, Hua-Xin; Lynch, Rebecca; Zhou, Tongqing; Gao, Feng; Alam, S. Munir; Boyd, Scott D.; Fire, Andrew Z.; Roskin, Krishna M.; Schramm, Chaim A.; Zhang, Zhenhai; Zhu, Jiang; Shapiro, Lawrence; Mullikin, James C.; Gnanakaran, S.; Hraber, Peter; Wiehe, Kevin; Kelsoe, Garnett; Yang, Guang; Xia, Shi-Mao; Montefiori, David C.; Parks, Robert; Lloyd, Krissey E.; Scearce, Richard M.; Soderberg, Kelly A.; Cohen, Myron; Kaminga, Gift; Louder, Mark K.; Tran, Lillan M.; Chen, Yue; Cai, Fangping; Chen, Sheri; Moquin, Stephanie; Du, Xiulian; Joyce, Gordon M.; Srivatsan, Sanjay; Zhang, Baoshan; Zheng, Anqi; Shaw, George M.; Hahn, Beatrice H.; Kepler, Thomas B.; Korber, Bette T.M.; Kwong, Peter D.; Mascola, John R.; Haynes, Barton F.

    2013-01-01

    Current HIV-1 vaccines elicit strain-specific neutralizing antibodies. However, cross-reactive neutralizing antibodies arise in ~20% of HIV-1-infected individuals, and details of their generation could provide a roadmap for effective vaccination. Here we report the isolation, evolution and structure of a broadly neutralizing antibody from an African donor followed from time of infection. The mature antibody, CH103, neutralized ~55% of HIV-1 isolates, and its co-crystal structure with gp120 revealed a novel loop-based mechanism of CD4-binding site recognition. Virus and antibody gene sequencing revealed concomitant virus evolution and antibody maturation. Notably, the CH103-lineage unmutated common ancestor avidly bound the transmitted/founder HIV-1 envelope glycoprotein, and evolution of antibody neutralization breadth was preceded by extensive viral diversification in and near the CH103 epitope. These data elucidate the viral and antibody evolution leading to induction of a lineage of HIV-1 broadly neutralizing antibodies and provide insights into strategies to elicit similar antibodies via vaccination. PMID:23552890

  1. Analysis of the solvent accessibility of cysteine residues on Maize rayado fino virus virus-like particles produced in Nicotiana benthamiana plants and cross-linking of peptides to VLPs.

    Science.gov (United States)

    Natilla, Angela; Hammond, Rosemarie W

    2013-02-14

    Mimicking and exploiting virus properties and physicochemical and physical characteristics holds promise to provide solutions to some of the world's most pressing challenges. The sheer range and types of viruses coupled with their intriguing properties potentially give endless opportunities for applications in virus-based technologies. Viruses have the ability to self- assemble into particles with discrete shape and size, specificity of symmetry, polyvalence, and stable properties under a wide range of temperature and pH conditions. Not surprisingly, with such a remarkable range of properties, viruses are proposed for use in biomaterials, vaccines, electronic materials, chemical tools, and molecular electronic containers. In order to utilize viruses in nanotechnology, they must be modified from their natural forms to impart new functions. This challenging process can be performed through several mechanisms including genetic modification of the viral genome and chemically attaching foreign or desired molecules to the virus particle reactive groups. The ability to modify a virus primarily depends upon the physiochemical and physical properties of the virus. In addition, the genetic or physiochemical modifications need to be performed without adversely affecting the virus native structure and virus function. Maize rayado fino virus (MRFV) coat proteins self-assemble in Escherichia coli producing stable and empty VLPs that are stabilized by protein-protein interactions and that can be used in virus-based technologies applications. VLPs produced in tobacco plants were examined as a scaffold on which a variety of peptides can be covalently displayed. Here, we describe the steps to 1) determine which of the solvent-accessible cysteines in a virus capsid are available for modification, and 2) bioconjugate peptides to the modified capsids. By using native or mutationally-inserted amino acid residues and standard coupling technologies, a wide variety of materials have been

  2. NMR structure of the myristylated feline immunodeficiency virus matrix protein.

    Science.gov (United States)

    Brown, Lola A; Cox, Cassiah; Baptiste, Janae; Summers, Holly; Button, Ryan; Bahlow, Kennedy; Spurrier, Vaughn; Kyser, Jenna; Luttge, Benjamin G; Kuo, Lillian; Freed, Eric O; Summers, Michael F

    2015-04-30

    Membrane targeting by the Gag proteins of the human immunodeficiency viruses (HIV types-1 and -2) is mediated by Gag's N-terminally myristylated matrix (MA) domain and is dependent on cellular phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]. To determine if other lentiviruses employ a similar membrane targeting mechanism, we initiated studies of the feline immunodeficiency virus (FIV), a widespread feline pathogen with potential utility for development of human therapeutics. Bacterial co-translational myristylation was facilitated by mutation of two amino acids near the amino-terminus of the protein (Q5A/G6S; myrMAQ5A/G6S). These substitutions did not affect virus assembly or release from transfected cells. NMR studies revealed that the myristyl group is buried within a hydrophobic pocket in a manner that is structurally similar to that observed for the myristylated HIV-1 protein. Comparisons with a recent crystal structure of the unmyristylated FIV protein [myr(-)MA] indicate that only small changes in helix orientation are required to accommodate the sequestered myr group. Depletion of PI(4,5)P2 from the plasma membrane of FIV-infected CRFK cells inhibited production of FIV particles, indicating that, like HIV, FIV hijacks the PI(4,5)P2 cellular signaling system to direct intracellular Gag trafficking during virus assembly.

  3. NMR Structure of the Myristylated Feline Immunodeficiency Virus Matrix Protein

    Directory of Open Access Journals (Sweden)

    Lola A. Brown

    2015-04-01

    Full Text Available Membrane targeting by the Gag proteins of the human immunodeficiency viruses (HIV types-1 and -2 is mediated by Gag’s N-terminally myristylated matrix (MA domain and is dependent on cellular phosphatidylinositol-4,5-bisphosphate [PI(4,5P2]. To determine if other lentiviruses employ a similar membrane targeting mechanism, we initiated studies of the feline immunodeficiency virus (FIV, a widespread feline pathogen with potential utility for development of human therapeutics. Bacterial co-translational myristylation was facilitated by mutation of two amino acids near the amino-terminus of the protein (Q5A/G6S; myrMAQ5A/G6S. These substitutions did not affect virus assembly or release from transfected cells. NMR studies revealed that the myristyl group is buried within a hydrophobic pocket in a manner that is structurally similar to that observed for the myristylated HIV-1 protein. Comparisons with a recent crystal structure of the unmyristylated FIV protein [myr(-MA] indicate that only small changes in helix orientation are required to accommodate the sequestered myr group. Depletion of PI(4,5P2 from the plasma membrane of FIV-infected CRFK cells inhibited production of FIV particles, indicating that, like HIV, FIV hijacks the PI(4,5P2 cellular signaling system to direct intracellular Gag trafficking during virus assembly.

  4. Complete Genome Sequence of the Largest Known Flavi-Like Virus, Diaphorina citri flavi-like virus, a Novel Virus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Matsumura, Emilyn E; Nerva, Luca; Nigg, Jared C; Falk, Bryce W; Nouri, Shahideh

    2016-09-08

    A novel flavi-like virus tentatively named Diaphorina citri flavi-like virus (DcFLV) was identified in field populations of Diaphorina citri through small RNA and transcriptome sequencing followed by reverse transcription (RT)-PCR. We report here the complete nucleotide sequence and genome organization of DcFLV, the largest flavi-like virus identified to date. Copyright © 2016 Matsumura et al.

  5. Epidemiology and pathogesis of human immunodifiency virus(HIV ...

    African Journals Online (AJOL)

    Epidemiology and pathogesis of human immunodifiency virus(HIV) related heart disease: A review. MU Sani, BN Okeahialam. Abstract. No Abstract. Nigerian Journal of Medicine Vol. 14(3) 2005: 255-260. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African ...

  6. Management of human immunodeficiency virus (HIV) infection in ...

    African Journals Online (AJOL)

    Management of human immunodeficiency virus (HIV) infection in adults in resource-limited countries: Challenges and prospects in Nigeria. AG Habib. Abstract. No Abstract. Annals of Ibadan Postgraduate Medicine Vol. 3 (1) 2005: pp. 26-32. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL ...

  7. Murine Leukemia Virus (MLV)-based Coronavirus Spike-pseudotyped Particle Production and Infection

    Science.gov (United States)

    Millet, Jean Kaoru; Whittaker, Gary R.

    2016-01-01

    Viral pseudotyped particles (pp) are enveloped virus particles, typically derived from retroviruses or rhabdoviruses, that harbor heterologous envelope glycoproteins on their surface and a genome lacking essential genes. These synthetic viral particles are safer surrogates of native viruses and acquire the tropism and host entry pathway characteristics governed by the heterologous envelope glycoprotein used. They have proven to be very useful tools used in research with many applications, such as enabling the study of entry pathways of enveloped viruses and to generate effective gene-delivery vectors. The basis for their generation lies in the capacity of some viruses, such as murine leukemia virus (MLV), to incorporate envelope glycoproteins of other viruses into a pseudotyped virus particle. These can be engineered to contain reporter genes such as luciferase, enabling quantification of virus entry events upon pseudotyped particle infection with susceptible cells. Here, we detail a protocol enabling generation of MLV-based pseudotyped particles, using the Middle East respiratory syndrome coronavirus (MERS-CoV) spike (S) as an example of a heterologous envelope glycoprotein to be incorporated. We also describe how these particles are used to infect susceptible cells and to perform a quantitative infectivity readout by a luciferase assay. PMID:28018942

  8. Mutations in the alpha-helical region of the amino terminus of the Maize rayado fino virus capsid protein and CP:RNA ratios affect virus-like particle encapsidation of RNAs.

    Science.gov (United States)

    Natilla, Angela; Murphy, Charles; Hammond, Rosemarie W

    2015-01-22

    Viral-based nanoplatforms rely on balancing the delicate array of virus properties to optimally achieve encapsidation of foreign materials with various potential objectives. We investigated the use of Maize rayado fino virus (MRFV)-virus-like particles (VLPs) as a multifunctional nanoplatform and their potential application as protein cages. MRFV-VLPs are composed of two serologically related, carboxy co-terminal coat proteins (CP1 and CP2) which are capable of self-assembling in Nicotiana benthamiana plants into 30nm particles with T=3 symmetry. The N-terminus of CP1 was targeted for genetic modification to exploit the driving forces for VLP assembly, packaging and retention of RNA in vivo and in vitro. The N-terminus of MRFV-CP1 contains a peptide sequence of 37 amino acids which has been predicted to have an alpha-helical structure, is rich in hydrophobic amino acids, facilitates CP-RNA interactions, and is not required for self-assembly. Amino acid substitutions were introduced in the 37 amino acid N-terminus by site-directed mutagenesis and the mutant VLPs produced in plants by a Potato virus X (PVX)-based vector were tested for particle stability and RNA encapsidation. All mutant CPs resulted in production of VLPs which encapsidated non-viral RNAs, including PVX genomic and subgenomic (sg) RNAs, 18S rRNA and cellular and viral mRNAs. In addition, MRFV-VLPs encapsidated GFP mRNA when was expressed in plant cells from the pGD vector. These results suggest that RNA packaging in MRFV-VLPs is predominantly driven by electrostatic interactions between the N-terminal 37 amino acid extension of CP1 and RNA, and that the overall species concentration of RNA in the cellular pool may determine the abundance and species of the RNAs packaged into the VLPs. Furthermore, RNA encapsidation is not required for VLPs stability, VLPs formed from MRFV-CP1 were stable at temperatures up to 70°C, and can be disassembled into CP monomers, which can then reassemble in vitro into

  9. Development and evaluation of a competitive ELISA using a monoclonal antibody for antibody detection after goose parvovirus virus-like particles (VLPs) and vaccine immunization in goose sera.

    Science.gov (United States)

    Wang, Qian; Ju, Huanyu; Li, Yanwei; Jing, Zhiqiang; Guo, Lu; Zhao, Yu; Ma, Bo; Gao, Mingchun; Zhang, Wenlong; Wang, Junwei

    2014-12-01

    An assay protocol based on a monoclonal antibody-based competitive enzyme-linked immunosorbent assay (MAb-based C-ELISA) for detecting antibodies against goose parvovirus (GPV) and its virus-like particles (VLPs) is described. The assay was developed using baculovirus-expressed recombinant VP2 virus-like particles (rVP2-VLPs) as antigens and a monoclonal antibody against GPV as the competitive antibody. Of the four anti-GPV MAbs that were screened, MAb 1G3 was selected as it was blocked by the GPV positive serum. Based on the distribution of percent inhibition (PI) of the known negative sera (n=225), a cut-off value was set at 36% inhibition. Using this cut-off value, the sensitivity of the assay was 93.3% and the specificity was 95.8%, as compared with the gold standard (virus neutralization assay). The rVP2-VLPs did not react with anti-sera to other goose pathogens, indicating that it is specific for the recognization of goose parvovirus antibodies. The assay was then validated with serum samples from goslings vaccinated with several VLPs (rVP1-VLPs, rVP2-VLPs, rVP3-VLPs, and rCGV-VLPs) and other vaccines (inactivated and attenuated). The C-ELISA described in this study is a sensitive and specific diagnostic test and should have wide applications for the sero-diagnosis and immunologic surveillance of GPV. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Interaction between Ebola Virus Glycoprotein and Host Toll-Like Receptor 4 Leads to Induction of Proinflammatory Cytokines and SOCS1 ▿ †

    OpenAIRE

    Okumura, Atsushi; Pitha, Paula M.; Yoshimura, Akihiko; Harty, Ronald N.

    2009-01-01

    Ebola virus initially targets monocytes and macrophages, which can lead to the release of proinflammatory cytokines and chemokines. These inflammatory cytokines are thought to contribute to the development of circulatory shock seen in fatal Ebola virus infections. Here we report that host Toll-like receptor 4 (TLR4) is a sensor for Ebola virus glycoprotein (GP) on virus-like particles (VLPs) and that resultant TLR4 signaling pathways lead to the production of proinflammatory cytokines and sup...

  11. Frequency of Hepatitis B Virus, Hepatitis C Virus and HIV Infections in Cannabis and Opioid Addicts

    Directory of Open Access Journals (Sweden)

    Nuran KARABULUT

    2017-04-01

    Full Text Available Objective: There are very few data about the epidemiology of hepatitis B virus (HBV, hepatitis C virus (HCV and HIV infections in drug addicts in Turkey, whereas several countries have a developed surveillance systems to monitor the spread of HBV, HCV and HIV infections in drug users. In this study, HBV, HCV and HIV prevalence in cannabis and opioid addicts were investigated. Materials and Methods: Hepatitis B surface antigen (HBsAg, anti-HBs, anti-HCV and anti-HIV tests were analyzed by enzyme-linked immunosorbent assay. The cannabis and opioid metabolites in urine samples of drug addicts were analyzed by cloned enzyme donor immunoassay. Results: This retrospective study was conducted on 276 individuals with a mean age of 28.89±10.49 years. HBsAg, anti-HBs and anti-HCV prevalence in drug addicts was found to be 4%, 52.3% and 7.9%, respectively. In all the drug addicts, anti-HIV test was negative. Whereas the rate of HBsAg among cannabis users (8.8% was higher than opioid (4.1% and both cannabis and opioid users (1.4%, the difference was not statistically significant. Although anti-HCV positivity among cannabis users was not detected, 6.4% of opioid users and 15.9% of both cannabis and opioid users were anti-HCV positive (p=0.009. Conclusion: This study showed that HCV infection among especially opioid users and both cannabis and opioid users was a problem. Understanding of local status in HBV, HCV and HIV infections is crucial for developing prevention and geographical strategies for these infections.

  12. Plant-derived chimeric virus particles for the diagnosis of primary Sjögren syndrome

    Directory of Open Access Journals (Sweden)

    Elisa eTinazzi

    2015-12-01

    Full Text Available Plants are ideal for the production of protein-based nanomaterials because they synthesize and assemble complex multimeric proteins that cannot be expressed efficiently using other platforms. Plant viruses can be thought of as self-replicating proteinaceous nanomaterials generally stable and easily produced in high titers. We used Potato virus X (PVX chimeric virus particles (CVPs and Cowpea mosaic virus (CPMV empty virus-like particles (eVLPs to display a linear peptide (lipo derived from human lipocalin , which is immunodominant in Sjögren’s syndrome (SjS and is thus recognized by autoantibodies in SjS patient serum. These virus-derived nanoparticles (VNPs were thus used to develop a diagnostic assay for SjS based on a direct enzyme linked immunosorbent assay (ELISA format. We found that PVX-lipo formulations were more sensitive than the chemically synthesized immunodominant peptide and equally specific when used to distinguish between healthy individuals and SjS patients. Our novel assay therefore allows the diagnosis of SjS using a simple, low-invasive serum test, contrasting with the invasive labial biopsy required for current tests. Our results demonstrate that nanomaterials based on plant viruses can be used as diagnostic reagents for SjS, and could also be developed for the diagnosis of other diseases.

  13. Human immunodeficiency virus type 1 (HIV-1 reservoirs: mechanisms of latency and therapeutic strategies = Reservorios del virus de inmunodeficiencia humana tipo 1 (VIH-1: mecanismos de latencia y estrategias terapéuticas

    Directory of Open Access Journals (Sweden)

    Arcia Anaya, Eliuth David

    2014-07-01

    Full Text Available The human immunodeficiency virus type 1 can establish a latent infection in different kind of cells, which constitute the cellular reservoirs for the virus and allow its maintenance in the body indefinitely, even in patients with antiretroviral treatment. The main reservoirs of the HIV-1 are resting CD4+ T cells, although cells like monocytes/macrophages, dendritic cells, and other cells like hematopoietic stem cells and mast cells may be reservoirs of the virus. There are different mechanisms that contribute to the establishment and maintenance of latency in those cells, and include transcriptional interference, low availability of transcription factors, chromatin condensation, some microRNA that block viral translation, and so on. The knowledge of these mechanisms is crucial for the development of new drugs that may eliminate the virus from the body and lead to a cure.

  14. Nucleocapsid promotes localization of HIV-1 gag to uropods that participate in virological synapses between T cells.

    Science.gov (United States)

    Llewellyn, G Nicholas; Hogue, Ian B; Grover, Jonathan R; Ono, Akira

    2010-10-28

    T cells adopt a polarized morphology in lymphoid organs, where cell-to-cell transmission of HIV-1 is likely frequent. However, despite the importance of understanding virus spread in vivo, little is known about the HIV-1 life cycle, particularly its late phase, in polarized T cells. Polarized T cells form two ends, the leading edge at the front and a protrusion called a uropod at the rear. Using multiple uropod markers, we observed that HIV-1 Gag localizes to the uropod in polarized T cells. Infected T cells formed contacts with uninfected target T cells preferentially via HIV-1 Gag-containing uropods compared to leading edges that lack plasma-membrane-associated Gag. Cell contacts enriched in Gag and CD4, which define the virological synapse (VS), are also enriched in uropod markers. These results indicate that Gag-laden uropods participate in the formation and/or structure of the VS, which likely plays a key role in cell-to-cell transmission of HIV-1. Consistent with this notion, a myosin light chain kinase inhibitor, which disrupts uropods, reduced virus particle transfer from infected T cells to target T cells. Mechanistically, we observed that Gag copatches with antibody-crosslinked uropod markers even in non-polarized cells, suggesting an association of Gag with uropod-specific microdomains that carry Gag to uropods. Finally, we determined that localization of Gag to the uropod depends on higher-order clustering driven by its NC domain. Taken together, these results support a model in which NC-dependent Gag accumulation to uropods establishes a preformed platform that later constitutes T-cell-T-cell contacts at which HIV-1 virus transfer occurs.

  15. Nucleocapsid promotes localization of HIV-1 gag to uropods that participate in virological synapses between T cells.

    Directory of Open Access Journals (Sweden)

    G Nicholas Llewellyn

    2010-10-01

    Full Text Available T cells adopt a polarized morphology in lymphoid organs, where cell-to-cell transmission of HIV-1 is likely frequent. However, despite the importance of understanding virus spread in vivo, little is known about the HIV-1 life cycle, particularly its late phase, in polarized T cells. Polarized T cells form two ends, the leading edge at the front and a protrusion called a uropod at the rear. Using multiple uropod markers, we observed that HIV-1 Gag localizes to the uropod in polarized T cells. Infected T cells formed contacts with uninfected target T cells preferentially via HIV-1 Gag-containing uropods compared to leading edges that lack plasma-membrane-associated Gag. Cell contacts enriched in Gag and CD4, which define the virological synapse (VS, are also enriched in uropod markers. These results indicate that Gag-laden uropods participate in the formation and/or structure of the VS, which likely plays a key role in cell-to-cell transmission of HIV-1. Consistent with this notion, a myosin light chain kinase inhibitor, which disrupts uropods, reduced virus particle transfer from infected T cells to target T cells. Mechanistically, we observed that Gag copatches with antibody-crosslinked uropod markers even in non-polarized cells, suggesting an association of Gag with uropod-specific microdomains that carry Gag to uropods. Finally, we determined that localization of Gag to the uropod depends on higher-order clustering driven by its NC domain. Taken together, these results support a model in which NC-dependent Gag accumulation to uropods establishes a preformed platform that later constitutes T-cell-T-cell contacts at which HIV-1 virus transfer occurs.

  16. Generation and Characterization of HIV-1 Transmitted and Founder Virus Consensus Sequence from Intravenous Drug Users in Xinjiang, China.

    Science.gov (United States)

    Li, Fan; Ma, Liying; Feng, Yi; Hu, Jing; Ni, Na; Ruan, Yuhua; Shao, Yiming

    2017-06-01

    HIV-1 transmission in intravenous drug users (IDUs) has been characterized by high genetic multiplicity and suggests a greater challenge for HIV-1 infection blocking. We investigated a total of 749 sequences of full-length gp160 gene obtained by single genome sequencing (SGS) from 22 HIV-1 early infected IDUs in Xinjiang province, northwest China, and generated a transmitted and founder virus (T/F virus) consensus sequence (IDU.CON). The T/F virus was classified as subtype CRF07_BC and predicted to be CCR5-tropic virus. The variable region (V1, V2, and V4 loop) of IDU.CON showed length variation compared with the heterosexual T/F virus consensus sequence (HSX.CON) and homosexual T/F virus consensus sequence (MSM.CON). A total of 26 N-linked glycosylation sites were discovered in the IDU.CON sequence, which is less than that of MSM.CON and HSX.CON. Characterization of T/F virus from IDUs highlights the genetic make-up and complexity of virus near the moment of transmission or in early infection preceding systemic dissemination and is important toward the development of an effective HIV-1 preventive methods, including vaccines.

  17. Highly conserved serine residue 40 in HIV-1 p6 regulates capsid processing and virus core assembly

    Directory of Open Access Journals (Sweden)

    Solbak Sara MØ

    2011-02-01

    Full Text Available Abstract Background The HIV-1 p6 Gag protein regulates the final abscission step of nascent virions from the cell membrane by the action of two late assembly (L- domains. Although p6 is located within one of the most polymorphic regions of the HIV-1 gag gene, the 52 amino acid peptide binds at least to two cellular budding factors (Tsg101 and ALIX, is a substrate for phosphorylation, ubiquitination, and sumoylation, and mediates the incorporation of the HIV-1 accessory protein Vpr into viral particles. As expected, known functional domains mostly overlap with several conserved residues in p6. In this study, we investigated the importance of the highly conserved serine residue at position 40, which until now has not been assigned to any known function of p6. Results Consistently with previous data, we found that mutation of Ser-40 has no effect on ALIX mediated rescue of HIV-1 L-domain mutants. However, the only feasible S40F mutation that preserves the overlapping pol open reading frame (ORF reduces virus replication in T-cell lines and in human lymphocyte tissue cultivated ex vivo. Most intriguingly, L-domain mediated virus release is not dependent on the integrity of Ser-40. However, the S40F mutation significantly reduces the specific infectivity of released virions. Further, it was observed that mutation of Ser-40 selectively interferes with the cleavage between capsid (CA and the spacer peptide SP1 in Gag, without affecting cleavage of other Gag products. This deficiency in processing of CA, in consequence, led to an irregular morphology of the virus core and the formation of an electron dense extra core structure. Moreover, the defects induced by the S40F mutation in p6 can be rescued by the A1V mutation in SP1 that generally enhances processing of the CA-SP1 cleavage site. Conclusions Overall, these data support a so far unrecognized function of p6 mediated by Ser-40 that occurs independently of the L-domain function, but selectively

  18. Quantitative live-cell imaging of human immunodeficiency virus (HIV-1) assembly.

    Science.gov (United States)

    Baumgärtel, Viola; Müller, Barbara; Lamb, Don C

    2012-05-01

    Advances in fluorescence methodologies make it possible to investigate biological systems in unprecedented detail. Over the last few years, quantitative live-cell imaging has increasingly been used to study the dynamic interactions of viruses with cells and is expected to become even more indispensable in the future. Here, we describe different fluorescence labeling strategies that have been used to label HIV-1 for live cell imaging and the fluorescence based methods used to visualize individual aspects of virus-cell interactions. This review presents an overview of experimental methods and recent experiments that have employed quantitative microscopy in order to elucidate the dynamics of late stages in the HIV-1 replication cycle. This includes cytosolic interactions of the main structural protein, Gag, with itself and the viral RNA genome, the recruitment of Gag and RNA to the plasma membrane, virion assembly at the membrane and the recruitment of cellular proteins involved in HIV-1 release to the nascent budding site.

  19. Immunological changes in human immunodeficiency virus (HIV)-infected individuals during HIV-specific protease inhibitor treatment

    DEFF Research Database (Denmark)

    Ullum, H; Katzenstein, T; Aladdin, H

    1999-01-01

    The present study examines the influence of effective anti-retroviral treatment on immune function, evaluated by a broad array of immunological tests. We followed 12 individuals infected with human immunodeficiency virus (HIV) for 6 months after initiation of combination anti-retroviral treatment...

  20. Endophilins interact with Moloney murine leukemia virus Gag and modulate virion production

    Directory of Open Access Journals (Sweden)

    De Camilli Pietro

    2003-12-01

    Full Text Available Abstract Background The retroviral Gag protein is the central player in the process of virion assembly at the plasma membrane, and is sufficient to induce the formation and release of virus-like particles. Recent evidence suggests that Gag may co-opt the host cell's endocytic machinery to facilitate retroviral assembly and release. Results A search for novel partners interacting with the Gag protein of the Moloney murine leukemia virus (Mo-MuLV via the yeast two-hybrid protein-protein interaction assay resulted in the identification of endophilin 2, a component of the machinery involved in clathrin-mediated endocytosis. We demonstrate that endophilin interacts with the matrix or MA domain of the Gag protein of Mo-MuLV, but not of human immunodeficiency virus, HIV. Both exogenously expressed and endogenous endophilin are incorporated into Mo-MuLV viral particles. Titration experiments suggest that the binding sites for inclusion of endophilin into viral particles are limited and saturable. Knock-down of endophilin with small interfering RNA (siRNA had no effect on virion production, but overexpression of endophilin and, to a lesser extent, of several fragments of the protein, result in inhibition of Mo-MuLV virion production, but not of HIV virion production. Conclusions This study shows that endophilins interact with Mo-MuLV Gag and affect virion production. The findings imply that endophilin is another component of the large complex that is hijacked by retroviruses to promote virion production.

  1. GB Virus C (GBV-C Infection in Hepatitis C Virus (HCV Seropositive Women with or at Risk for HIV Infection.

    Directory of Open Access Journals (Sweden)

    Jason T Blackard

    Full Text Available GB virus C (GBV-C may have a beneficial impact on HIV disease progression; however, the epidemiologic characteristics of this virus are not well characterized. Behavioral factors and gender may lead to differential rates of GBV-C infection; yet, studies have rarely addressed GBV-C infections in women or racial/ethnic minorities. Therefore, we evaluated GBV-C RNA prevalence and genotype distribution in a large prospective study of high-risk women in the US.438 hepatitis C virus (HCV seropositive women, including 306 HIV-infected and 132 HIV-uninfected women, from the HIV Epidemiologic Research Study were evaluated for GBV-C RNA. 347 (79.2% women were GBV-C RNA negative, while 91 (20.8% were GBV-C RNA positive. GBV-C positive women were younger than GBV-C negative women. Among 306 HIV-infected women, 70 (22.9% women were HIV/GBV-C co-infected. Among HIV-infected women, the only significant difference between GBV-negative and GBV-positive women was age (mean 38.4 vs. 35.1 years; p<0.001. Median baseline CD4 cell counts and plasma HIV RNA levels were similar. The GBV-C genotypes were 1 (n = 31; 44.3%, 2 (n = 36; 51.4%, and 3 (n = 3; 4.3%. The distribution of GBV-C genotypes in co-infected women differed significantly by race/ethnicity. However, median CD4 cell counts and log10 HIV RNA levels did not differ by GBV-C genotype. GBV-C incidence was 2.7% over a median follow-up of 2.9 (IQR: 1.5, 4.9 years, while GBV-C clearance was 35.7% over a median follow-up of 2.44 (1.4, 3.5 years. 4 women switched genotypes.Age, injection drug use, a history of sex for money or drugs, and number of recent male sex partners were associated with GBV-C infection among all women in this analysis. However, CD4 cell count and HIV viral load of HIV/HCV/GBV-C co-infected women were not different although race was associated with GBV-C genotype.

  2. Conditional live virus as a novel approach towards a safe live attenuated HIV vaccine

    NARCIS (Netherlands)

    Das, Atze T.; Zhou, Xue; Vink, Monique; Klaver, Bep; Berkhout, Ben

    2002-01-01

    To control the worldwide spread of HIV, a safe and effective prophylactic vaccine is urgently needed. Studies with the simian immunodeficiency virus demonstrated that a live attenuated virus can be effective as a vaccine, but serious concerns about the safety of such a vaccine virus have arisen. We

  3. Incorporation of membrane-anchored flagellin or Escherichia coli heat-labile enterotoxin B subunit enhances the immunogenicity of rabies virus-like particles in mice and dogs

    Directory of Open Access Journals (Sweden)

    Yinglin eQi

    2015-03-01

    Full Text Available Rabies remains an important worldwide public health threat, so safe, effective and affordable vaccines are still being sought. Virus-like particle (VLP-based vaccines targeting various viral pathogens have been successfully produced, licensed and commercialized. Here, we designed and constructed two chimeric rabies virus-like particles (cRVLPs containing rabies virus (RABV glycoprotein (G, matrix (M protein, and membrane-anchored flagellin (EVLP-F or Escherichia coli heat-labile enterotoxin B subunit (EVLP-L as molecular adjuvants to enhance the immune response against rabies. The immunogenicity and potential of cRVLPs as novel rabies vaccine were evaluated by intramuscular vaccination in mouse and dog models. Mouse studies demonstrated that both EVLP-F and EVLP-L induced faster and larger virus-neutralizing antibodies (VNA responses and elicited greater numbers of CD4+ and CD8+ T cells secreting IFN-γ or IL-4 compared with a standard rabies VLP (sRVLP containing only G and M. Moreover, cRVLPs recruited and/or activated more B cells and dendritic cells in inguinal lymph nodes. EVLP-F induced a strong, specific IgG2a response but not an IgG1 response, suggesting the activation of Th1 class immunity; in contrast, Th2 class immunity was observed with EVLP-L. The significantly enhanced humoral and cellular immune responses induced by cRVLPs provided complete protection against lethal challenge with RABV. Most importantly, dogs vaccinated with EVLP-F or EVLP-L exhibited increased VNA titers in sera and enhanced IFN-γ and IL-4 secretion from peripheral blood mononuclear cells. Taken together, these results illustrate that when incorporated into sRVLP, membrane-anchored flagellin and LTB possess strong adjuvant activity. EVLP-F and EVLP-L induce significantly enhanced RABV-specific humoral and cellular immune responses in both mouse and dog. Therefore, these cRVLPs may be developed as safe and more efficacious rabies vaccine candidate for animals.

  4. Hepatitis C virus and HIV co-infection among pregnant women in Rwanda.

    Science.gov (United States)

    Mutagoma, Mwumvaneza; Balisanga, Helene; Sebuhoro, Dieudonné; Mbituyumuremyi, Aimable; Remera, Eric; Malamba, Samuel S; Riedel, David J; Nsanzimana, Sabin

    2017-02-22

    Hepatitis C virus (HCV) infection is a pandemic causing disease; more than 185 million people are infected worldwide. An HCV antibody (Ab) prevalence of 6.0% was estimated in Central African countries. The study aimed at providing HCV prevalence estimates among pregnant women in Rwanda. HCV surveillance through antibody screening test among pregnant women attending antenatal clinics was performed in 30 HIV sentinel surveillance sites in Rwanda. Among 12,903 pregnant women tested at antenatal clinics, 335 (2.6% [95% Confidence Interval 2.32-2.87]) tested positive for HCV Ab. The prevalence of HCV Ab in women aged 25-49 years was 2.8% compared to 2.4% in women aged 15-24 years (aOR = 1.3; [1.05-1.59]); This proportion was 2.7% [2.37-2.94] in pregnant women in engaged in non-salaried employment compared to 1.2% [0.24-2.14] in those engaged in salaried employment (aOR = 3.2; [1.60-6.58]). The proportion of HCV Ab-positive co-infected with HIV was estimated at 3.9% (13 cases). Women in urban residence were more likely to be associated with HCV-infection (OR = 1.3; 95%CI [1.0-1.6]) compared to those living in rural setting. HCV is a public health problem in pregnant women in Rwanda. Few pregnant women were co-infected with HCV and HIV. Living in urban setting was more likely to associate pregnant women with HCV infection.

  5. Combined virus-like particle and fusion protein-encoding DNA vaccination of cotton rats induces protection against respiratory syncytial virus without causing vaccine-enhanced disease

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Hye Suk; Lee, Young-Tae; Kim, Ki-Hye; Park, Soojin; Kwon, Young-Man; Lee, Youri; Ko, Eun-Ju; Jung, Yu-Jin [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); Lee, Jong Seok [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); National Institute of Biological Resources, Incheon (Korea, Republic of); Kim, Yu-Jin [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); Lee, Yu-Na; Kim, Min-Chul [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); Animal and Plant Quarantine Agency, Gyeonggi-do, Gimcheon, Gyeongsangbukdo (Korea, Republic of); Cho, Minkyoung [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States); Kang, Sang-Moo, E-mail: skang24@gsu.edu [Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences and Department of Biology, Georgia State University, Atlanta, GA (United States)

    2016-07-15

    A safe and effective vaccine against respiratory syncytial virus (RSV) should confer protection without causing vaccine-enhanced disease. Here, using a cotton rat model, we investigated the protective efficacy and safety of an RSV combination vaccine composed of F-encoding plasmid DNA and virus-like particles containing RSV fusion (F) and attachment (G) glycoproteins (FFG-VLP). Cotton rats with FFG-VLP vaccination controlled lung viral replication below the detection limit, and effectively induced neutralizing activity and antibody-secreting cell responses. In comparison with formalin inactivated RSV (FI-RSV) causing severe RSV disease after challenge, FFG-VLP vaccination did not cause weight loss, airway hyper-responsiveness, IL-4 cytokines, histopathology, and infiltrates of proinflammatory cells such as eosinophils. FFG-VLP was even more effective in preventing RSV-induced pulmonary inflammation than live RSV infections. This study provides evidence that FFG-VLP can be developed into a safe and effective RSV vaccine candidate. - Highlights: • Combined RSV FFG VLP vaccine is effective in inducing F specific responses. • FFG VLP vaccine confers RSV neutralizing activity and viral control in cotton rats. • Cotton rats with RSV FFG VLP vaccination do not show vaccine-enhanced disease. • Cotton rats with FFG VLP vaccine induce F specific antibody secreting cell responses. • Cotton rats with FFG VLP do not induce lung cellular infiltrates and Th2 cytokine.

  6. A Rapid Screen for Host-Encoded miRNAs with Inhibitory Effects against Ebola Virus Using a Transcription- and Replication-Competent Virus-Like Particle System

    Directory of Open Access Journals (Sweden)

    Zhongyi Wang

    2018-05-01

    Full Text Available MicroRNAs (miRNAs may become efficient antiviral agents against the Ebola virus (EBOV targeting viral genomic RNAs or transcripts. We previously conducted a genome-wide search for differentially expressed miRNAs during viral replication and transcription. In this study, we established a rapid screen for miRNAs with inhibitory effects against EBOV using a tetracistronic transcription- and replication-competent virus-like particle (trVLP system. This system uses a minigenome comprising an EBOV leader region, luciferase reporter, VP40, GP, VP24, EBOV trailer region, and three noncoding regions from the EBOV genome and can be used to model the life cycle of EBOV under biosafety level (BSL 2 conditions. Informatic analysis was performed to select up-regulated miRNAs targeting the coding regions of the minigenome with the highest binding energy to perform inhibitory effect screening. Among these miRNAs, miR-150-3p had the most significant inhibitory effect. Reverse transcription polymerase chain reaction (RT-PCR, Western blot, and double fluorescence reporter experiments demonstrated that miR-150-3p inhibited the reproduction of trVLPs via the regulation of GP and VP40 expression by directly targeting the coding regions of GP and VP40. This novel, rapid, and convenient screening method will efficiently facilitate the exploration of miRNAs against EBOV under BSL-2 conditions.

  7. Combined virus-like particle and fusion protein-encoding DNA vaccination of cotton rats induces protection against respiratory syncytial virus without causing vaccine-enhanced disease

    International Nuclear Information System (INIS)

    Hwang, Hye Suk; Lee, Young-Tae; Kim, Ki-Hye; Park, Soojin; Kwon, Young-Man; Lee, Youri; Ko, Eun-Ju; Jung, Yu-Jin; Lee, Jong Seok; Kim, Yu-Jin; Lee, Yu-Na; Kim, Min-Chul; Cho, Minkyoung; Kang, Sang-Moo

    2016-01-01

    A safe and effective vaccine against respiratory syncytial virus (RSV) should confer protection without causing vaccine-enhanced disease. Here, using a cotton rat model, we investigated the protective efficacy and safety of an RSV combination vaccine composed of F-encoding plasmid DNA and virus-like particles containing RSV fusion (F) and attachment (G) glycoproteins (FFG-VLP). Cotton rats with FFG-VLP vaccination controlled lung viral replication below the detection limit, and effectively induced neutralizing activity and antibody-secreting cell responses. In comparison with formalin inactivated RSV (FI-RSV) causing severe RSV disease after challenge, FFG-VLP vaccination did not cause weight loss, airway hyper-responsiveness, IL-4 cytokines, histopathology, and infiltrates of proinflammatory cells such as eosinophils. FFG-VLP was even more effective in preventing RSV-induced pulmonary inflammation than live RSV infections. This study provides evidence that FFG-VLP can be developed into a safe and effective RSV vaccine candidate. - Highlights: • Combined RSV FFG VLP vaccine is effective in inducing F specific responses. • FFG VLP vaccine confers RSV neutralizing activity and viral control in cotton rats. • Cotton rats with RSV FFG VLP vaccination do not show vaccine-enhanced disease. • Cotton rats with FFG VLP vaccine induce F specific antibody secreting cell responses. • Cotton rats with FFG VLP do not induce lung cellular infiltrates and Th2 cytokine.

  8. Burden of Respiratory Syncytial Virus Infection in South African Human Immunodeficiency Virus (HIV)-Infected and HIV-Uninfected Pregnant and Postpartum Women: A Longitudinal Cohort Study.

    Science.gov (United States)

    Madhi, Shabir A; Cutland, Clare L; Downs, Sarah; Jones, Stephanie; van Niekerk, Nadia; Simoes, Eric A F; Nunes, Marta C

    2018-05-17

    Limited data exist on the burden of respiratory syncytial virus (RSV) illness among pregnant women, to determine their potential benefit from RSV vaccination. We evaluated the incidence of RSV illness from midpregnancy until 24 weeks postpartum in human immunodeficiency virus (HIV)-uninfected and HIV-infected women and their infants. Mother-infant dyads were enrolled in maternal influenza vaccine efficacy trials. These included 1060 and 1056 HIV-uninfected pregnant women in 2011 and 2012, respectively, 194 HIV-infected pregnant women in 2011, and their infants. Upper respiratory tract samples obtained at illness visits were tested for RSV. The incidence (per 1000 person-months) of RSV illness (n = 43 overall) among HIV-uninfected women was lower in 2011 (1.2; 95% confidence interval [CI], .6-2.2) than in 2012 (4.0; 95% CI, 2.8-5.6). The incidence of RSV illness (n = 5) in HIV-infected women was 3.4 (95% CI, 1.4-8.1). Maternal RSV infection was associated with respiratory symptoms including cough (72.1%), rhinorrhea (39.5%), sore throat (37.2%), and headache (42%), but fever was absent. RSV infection during pregnancy was not associated with adverse pregnancy outcomes. Postpartum, RSV infection in mothers (n = 27) was associated with concurrent infection among 51.9% of their infants and, conversely, 29.8% of mothers investigated within 7 days of their infants having an RSV illness also tested positive for RSV. RSV infection is associated with respiratory illness during pregnancy and postpartum. Vaccination of pregnant women against RSV could benefit the mother, albeit primarily against nonfebrile illness, and her infant. NCT01306669 and NCT01306682.

  9. Self-assembly of virus-like particles of porcine circovirus type 2 capsid protein expressed from Escherichia coli

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    Cai Xuepeng

    2010-07-01

    Full Text Available Abstract Background Porcine circovirus 2 (PCV2 is a serious problem to the swine industry and can lead to significant negative impacts on profitability of pork production. Syndrome associated with PCV2 is known as porcine circovirus closely associated with post-weaning multisystemic wasting syndrome (PMWS. The capsid (Cap protein of PCV2 is a major candidate antigen for development of recombinant vaccine and serological diagnostic method. The recombinant Cap protein has the ability to self-assemble into virus-like particles (VLPs in vitro, it is particularly opportunity to develop the PV2 VLPs vaccine in Escherichia coli,(E.coli , because where the cost of the vaccine must be weighed against the value of the vaccinated pig, when it was to extend use the VLPs vaccine of PCV2. Results In this report, a highly soluble Cap-tag protein expressed in E.coli was constructed with a p-SMK expression vector with a fusion tag of small ubiquitin-like modifiers (SUMO. The recombinant Cap was purified using Ni2+ affinity resins, whereas the tag was used to remove the SUMO protease. Simultaneously, the whole native Cap protein was able to self-assemble into VLPs in vitro when viewed under an electron microscope. The Cap-like particles had a size and shape that resembled the authentic Cap. The result could also be applied in the large-scale production of VLPs of PCV2 and could be used as a diagnostic antigen or a potential VLP vaccine against PCV2 infection in pigs. Conclusion we have, for the first time, utilized the SUMO fusion motif to successfully express the entire authentic Cap protein of PCV2 in E. coli. After the cleavage of the fusion motif, the nCap protein has the ability to self-assemble into VLPs, which can be used as as a potential vaccine to protect pigs from PCV2-infection.

  10. Self-assembly of virus-like particles of porcine circovirus type 2 capsid protein expressed from Escherichia coli

    Science.gov (United States)

    2010-01-01

    Background Porcine circovirus 2 (PCV2) is a serious problem to the swine industry and can lead to significant negative impacts on profitability of pork production. Syndrome associated with PCV2 is known as porcine circovirus closely associated with post-weaning multisystemic wasting syndrome (PMWS). The capsid (Cap) protein of PCV2 is a major candidate antigen for development of recombinant vaccine and serological diagnostic method. The recombinant Cap protein has the ability to self-assemble into virus-like particles (VLPs) in vitro, it is particularly opportunity to develop the PV2 VLPs vaccine in Escherichia coli,(E.coli ), because where the cost of the vaccine must be weighed against the value of the vaccinated pig, when it was to extend use the VLPs vaccine of PCV2. Results In this report, a highly soluble Cap-tag protein expressed in E.coli was constructed with a p-SMK expression vector with a fusion tag of small ubiquitin-like modifiers (SUMO). The recombinant Cap was purified using Ni2+ affinity resins, whereas the tag was used to remove the SUMO protease. Simultaneously, the whole native Cap protein was able to self-assemble into VLPs in vitro when viewed under an electron microscope. The Cap-like particles had a size and shape that resembled the authentic Cap. The result could also be applied in the large-scale production of VLPs of PCV2 and could be used as a diagnostic antigen or a potential VLP vaccine against PCV2 infection in pigs. Conclusion we have, for the first time, utilized the SUMO fusion motif to successfully express the entire authentic Cap protein of PCV2 in E. coli. After the cleavage of the fusion motif, the nCap protein has the ability to self-assemble into VLPs, which can be used as as a potential vaccine to protect pigs from PCV2-infection. PMID:20646322

  11. Enhanced Trapping of HIV-1 by Human Cervicovaginal Mucus Is Associated with Lactobacillus crispatus-Dominant Microbiota

    Science.gov (United States)

    Nunn, Kenetta L.; Wang, Ying-Ying; Harit, Dimple; Humphrys, Michael S.; Ma, Bing; Cone, Richard; Ravel, Jacques

    2015-01-01

    ABSTRACT Cervicovaginal mucus (CVM) can provide a barrier that precludes HIV and other sexually transmitted virions from reaching target cells in the vaginal epithelium, thereby preventing or reducing infections. However, the barrier properties of CVM differ from woman to woman, and the causes of these variations are not yet well understood. Using high-resolution particle tracking of fluorescent HIV-1 pseudoviruses, we found that neither pH nor Nugent scores nor total lactic acid levels correlated significantly with virus trapping in unmodified CVM from diverse donors. Surprisingly, HIV-1 was generally trapped in CVM with relatively high concentrations of d-lactic acid and a Lactobacillus crispatus-dominant microbiota. In contrast, a substantial fraction of HIV-1 virions diffused rapidly through CVM with low concentrations of d-lactic acid that had a Lactobacillus iners-dominant microbiota or significant amounts of Gardnerella vaginalis, a bacterium associated with bacterial vaginosis. Our results demonstrate that the vaginal microbiota, including specific species of Lactobacillus, can alter the diffusional barrier properties of CVM against HIV and likely other sexually transmitted viruses and that these microbiota-associated changes may account in part for the elevated risks of HIV acquisition linked to bacterial vaginosis or intermediate vaginal microbiota. PMID:26443453

  12. Multiple Restrictions of Human Immunodeficiency Virus Type 1 in Feline Cells▿

    Science.gov (United States)

    Münk, Carsten; Zielonka, Jörg; Constabel, Hannelore; Kloke, Björn-Philipp; Rengstl, Benjamin; Battenberg, Marion; Bonci, Francesca; Pistello, Mauro; Löchelt, Martin; Cichutek, Klaus

    2007-01-01

    The productive replication of human immunodeficiency virus type 1 (HIV-1) occurs exclusively in defined cells of human or chimpanzee origin, explaining why heterologous animal models for HIV replication, pathogenesis, vaccination, and therapy are not available. This lack of an animal model for HIV-1 studies prompted us to examine the susceptibility of feline cells in order to evaluate the cat (Felis catus) as an animal model for studying HIV-1. Here, we report that feline cell lines harbor multiple restrictions with respect to HIV-1 replication. The feline CD4 receptor does not permit virus infection. Feline T-cell lines MYA-1 and FeT-1C showed postentry restrictions resulting in low HIV-1 luciferase reporter activity and low expression of viral Gag-Pol proteins when pseudotyped vectors were used. Feline fibroblastic CrFK and KE-R cells, expressing human CD4 and CCR5, were very permissive for viral entry and HIV-long terminal repeat-driven expression but failed to support spreading infection. KE-R cells displayed a profound block with respect to release of HIV-1 particles. In contrast, CrFK cells allowed very efficient particle production; however, the CrFK cell-derived HIV-1 particles had low specific infectivity. We subsequently identified feline apolipoprotein B-editing catalytic polypeptide 3 (feAPOBEC3) proteins as active inhibitors of HIV-1 particle infectivity. CrFK cells express at least three different APOBEC3s: APOBEC3C, APOBEC3H, and APOBEC3CH. While the feAPOBEC3C did not significantly inhibit HIV-1, the feAPOBEC3H and feAPOBEC3CH induced G to A hypermutations of the viral cDNA and reduced the infectivity ∼10- to ∼40-fold. PMID:17459941

  13. Genital herpes simplex virus type 2 infection in humanized HIV-transgenic mice triggers HIV shedding and is associated with greater neurological disease.

    Science.gov (United States)

    Nixon, Briana; Fakioglu, Esra; Stefanidou, Martha; Wang, Yanhua; Dutta, Monica; Goldstein, Harris; Herold, Betsy C

    2014-02-15

    Epidemiological studies consistently demonstrate synergy between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1). Higher HIV-1 loads are observed in coinfected individuals, and conversely, HIV-1 is associated with more-severe herpetic disease. A small animal model of coinfection would facilitate identification of the biological mechanisms underlying this synergy and provide the opportunity to evaluate interventions. Mice transgenic for HIV-1 provirus and human cyclin T1 under the control of a CD4 promoter (JR-CSF/hu-cycT1) were intravaginally infected with HSV-2 and evaluated for disease progression, HIV shedding, and mucosal immune responses. HSV-2 infection resulted in higher vaginal HIV loads and genital tissue expression of HIV RNA, compared with HSV-uninfected JR-CSF/hu-cycT1 mice. There was an increase in genital tract inflammatory cells, cytokines, chemokines, and interferons in response to HSV-2, although the kinetics of the response were delayed in HIV-transgenic, compared with control mice. Moreover, the JR-CSF/hu-cycT1 mice exhibited earlier and more-severe neurological disease. The latter was associated with downregulation of secretory leukocyte protease inhibitor expression in neuronal tissue, a molecule with antiinflammatory, antiviral, and neuroprotective properties. JR-CSF/hu-cycT1 mice provide a valuable model to study HIV/HSV-2 coinfection and identify potential mechanisms by which HSV-2 facilitates HIV-1 transmission and HIV modulates HSV-2-mediated disease.

  14. Susceptibility to virus-cell fusion at the plasma membrane is reduced through expression of HIV gp41 cytoplasmic domains

    International Nuclear Information System (INIS)

    Malinowsky, Katharina; Luksza, Julia; Dittmar, Matthias T.

    2008-01-01

    The cytoplasmic tail of the HIV transmembrane protein plays an important role in viral infection. In this study we analyzed the role of retroviral cytoplasmic tails in modulating the cytoskeleton and interfering with virus-cell fusion. HeLaP4 cells expressing different HIV cytoplasmic tail constructs showed reduced acetylated tubulin levels whereas the cytoplasmic tail of MLV did not alter microtubule stability indicating a unique function for the lentiviral cytoplasmic tail. The effect on tubulin is mediated through the membrane proximal region of the HIV cytoplasmic tail and was independent of membrane localization. Site-directed mutagenesis identified three motifs in the HIV-2 cytoplasmic tail required to effect the reduction in acetylated tubulin. Both the YxxΦ domain and amino acids 21 to 45 of the HIV-2 cytoplasmic tail need to be present to change the level of acetylated tubulin in transfected cells. T-cells stably expressing one HIV-2 cytoplasmic tail derived construct showed also a reduction in acetylated tubulin thus confirming the importance of this effect not only for HeLaP4 and 293T cells. Challenge experiments using transiently transfected HeLaP4 cells and T cells stably expressing an HIV cytoplasmic tail construct revealed both reduced virus-cell fusion and replication of HIV-1 NL4.3 compared to control cells. In the virus-cell fusion assay only virions pseudotyped with either HIV or MLV envelopes showed reduced fusion efficiency, whereas VSV-G pseudotyped virions where not affected by the expression of HIV derived cytoplasmic tail constructs, indicating that fusion at the plasma but not endosomal membrane is affected. Overexpression of human histone-deacetylase 6 (HDAC6) and constitutively active RhoA resulted in a reduction of acetylated tubulin and reduced virus-cell fusion as significant as that observed following expression of HIV cytoplasmic tail constructs. Inhibition of HDAC6 showed a strong increase in acetylated tubulin and increase of

  15. Impacts of HIV infection and long-term use of antiretroviral therapy on the prevalence of oral human papilloma virus type 16.

    Science.gov (United States)

    Amornthatree, Korntip; Sriplung, Hutcha; Mitarnun, Winyou; Nittayananta, Wipawee

    2012-04-01

    The objectives of this study were to determine (i) the prevalence and the copy numbers of oral human papilloma virus type 16 (HPV-16) in HIV-infected patients compared with non-HIV controls, and (ii) the effects of antiretroviral therapy (ART) and its duration on the virus. A cross-sectional study was carried out in HIV-infected patients with and without ART and in non-HIV controls. Saliva samples were collected, and the DNA extracted from those samples was used as a template to detect HPV-16 E6 and E7 by quantitative polymerase chain reaction. Student's t-test and ANOVA test were performed to determine the prevalence rates among groups. Forty-nine HIV-infected patients: 37 on ART (age range, 23-54 years; mean, 37 years), 12 not on ART (age range, 20-40 years; mean, 31 years), and 20 non-HIV controls (age range, 19-53 years; mean, 31 years) were enrolled. The prevalence of oral HPV-16 infection and the copy numbers of the virus were significantly higher in HIV-infected patients than in non-HIV controls when using E6 assay (geometric mean = 10696 vs. 563 copies/10(5) cells, P prevalence of oral HPV-16 infection and the copy numbers of the virus (P = 0.567). We conclude that the prevalence of oral HPV-16 infection and the copy numbers of the virus are increased by HIV infection. Neither the use of ART nor its duration significantly affected the virus. © 2011 John Wiley & Sons A/S.

  16. Epidemiology of respiratory syncytial virus-associated acute lower respiratory tract infection hospitalizations among HIV-infected and HIV-uninfected South African children, 2010-2011.

    Science.gov (United States)

    Moyes, Jocelyn; Cohen, Cheryl; Pretorius, Marthi; Groome, Michelle; von Gottberg, Anne; Wolter, Nicole; Walaza, Sibongile; Haffejee, Sumayya; Chhagan, Meera; Naby, Fathima; Cohen, Adam L; Tempia, Stefano; Kahn, Kathleen; Dawood, Halima; Venter, Marietjie; Madhi, Shabir A

    2013-12-15

    There are limited data on respiratory syncytial virus (RSV) infection among children in settings with a high prevalence of human immunodeficiency virus (HIV). We studied the epidemiology of RSV-associated acute lower respiratory tract infection (ALRTI) hospitalizations among HIV-infected and HIV-uninfected children in South Africa. Children aged infection among HIV-infected and uninfected children were examined. The relative risk of hospitalization in HIV-infected and HIV-uninfected children was calculated in 1 site with population denominators. Of 4489 participants, 4293 (96%) were tested for RSV, of whom 1157 (27%) tested positive. With adjustment for age, HIV-infected children had a 3-5-fold increased risk of hospitalization with RSV-associated ALRTI (2010 relative risk, 5.6; [95% confidence interval (CI), 4.5-6.4]; 2011 relative risk, 3.1 [95% CI, 2.6-3.6]). On multivariable analysis, HIV-infected children with RSV-associated ALRTI had higher odds of death (adjusted odds ratio. 31.1; 95% CI, 5.4-179.8) and hospitalization for >5 days (adjusted odds ratio, 4.0; 95% CI, 1.5-10.6) than HIV-uninfected children. HIV-infected children have a higher risk of hospitalization with RSV-associated ALRTI and a poorer outcome than HIV-uninfected children. These children should be targeted for interventions aimed at preventing severe RSV disease.

  17. HIV and hepatitis C virus infections among hanka injection drug users in central Ukraine: a cross-sectional survey

    Directory of Open Access Journals (Sweden)

    Slobodyanyuk Pavel

    2009-08-01

    Full Text Available Abstract Background Ukraine has experienced an increase in injection drug use since the 1990s. An increase in HIV and hepatitis C virus infections has followed, but not measures of prevalence and risk factors. The purposes of this study are to estimate the prevalence of HIV, HCV, and co-infection among injection drug users (IDUs in central Ukraine and to describe risk factors for HIV and HCV. Methods A sample of 315 IDUs was recruited using snowball sampling for a structured risk interview and HIV/HCV testing (81.9% male, 42% single, average age 28.9 years [range = 18 to 55]. Results HIV and HCV antibodies were detected in 14.0% and 73.0%, respectively, and 12.1% were seropositive for both infections. The most commonly used drug was hanka, home-made from poppy straw and often mixed with other substances including dimedrol, diazepines, and hypnotics. The average period of injecting was 8.5 years; 62.5% reported past-year sharing needles or injection equipment, and 8.0% shared with a known HIV-positive person. More than half (51.1% reported multiple sexual partners, 12.9% buying or selling sex, and 10.5% exchanging sex and drugs in the past year. Those who shared with HIV positive partners were 3.4 times more likely to be HIV positive than those who did not. Those who front- or back-loaded were 4 times more likely to be HCV positive than those who did not. Conclusion Harm reduction, addiction treatment and HIV prevention programs should address risk factors to stop further spread of both HIV and HCV among IDUs and to the general population in central Ukraine.

  18. HIV and hepatitis C virus infections among hanka injection drug users in central Ukraine: a cross-sectional survey.

    Science.gov (United States)

    Dumchev, Kostyantyn V; Soldyshev, Ruslan; Qian, Han-Zhu; Zezyulin, Olexandr O; Chandler, Susan D; Slobodyanyuk, Pavel; Moroz, Larisa; Schumacher, Joseph E

    2009-08-23

    Ukraine has experienced an increase in injection drug use since the 1990s. An increase in HIV and hepatitis C virus infections has followed, but not measures of prevalence and risk factors. The purposes of this study are to estimate the prevalence of HIV, HCV, and co-infection among injection drug users (IDUs) in central Ukraine and to describe risk factors for HIV and HCV. A sample of 315 IDUs was recruited using snowball sampling for a structured risk interview and HIV/HCV testing (81.9% male, 42% single, average age 28.9 years [range = 18 to 55]). HIV and HCV antibodies were detected in 14.0% and 73.0%, respectively, and 12.1% were seropositive for both infections. The most commonly used drug was hanka, home-made from poppy straw and often mixed with other substances including dimedrol, diazepines, and hypnotics. The average period of injecting was 8.5 years; 62.5% reported past-year sharing needles or injection equipment, and 8.0% shared with a known HIV-positive person. More than half (51.1%) reported multiple sexual partners, 12.9% buying or selling sex, and 10.5% exchanging sex and drugs in the past year. Those who shared with HIV positive partners were 3.4 times more likely to be HIV positive than those who did not. Those who front- or back-loaded were 4 times more likely to be HCV positive than those who did not. Harm reduction, addiction treatment and HIV prevention programs should address risk factors to stop further spread of both HIV and HCV among IDUs and to the general population in central Ukraine.

  19. Timing of initiation of antiretroviral therapy in human immunodeficiency virus (HIV)--associated tuberculous meningitis

    NARCIS (Netherlands)

    Török, M. Estee; Yen, Nguyen Thi Bich; Chau, Tran Thi Hong; Mai, Nguyen Thi Hoang; Phu, Nguyen Hoan; Mai, Pham Phuong; Dung, Nguyen Thi; Chau, Nguyen Van Vinh; Bang, Nguyen Duc; Tien, Nguyen Anh; Minh, N. H.; Hien, Nguyen Quang; Thai, Phan Vuong Khac; Dong, Doan The; Anh, Do Thi Tuong; Thoa, Nguyen Thi Cam; Hai, Nguyen Ngoc; Lan, Nguyen Ngoc; Lan, Nguyen Thi Ngoc; Quy, Hoang Thi; Dung, Nguyen Huy; Hien, Tran Tinh; Chinh, Nguyen Tran; Simmons, Cameron Paul; de Jong, Menno; Wolbers, Marcel; Farrar, Jeremy James

    2011-01-01

    The optimal time to initiate antiretroviral therapy (ART) in human immunodeficiency virus (HIV)-associated tuberculous meningitis is unknown. We conducted a randomized, double-blind, placebo-controlled trial of immediate versus deferred ART in patients with HIV-associated tuberculous meningitis to

  20. Inhibitory effects of (-)-epigallocatechin gallate on the life cycle of human immunodeficiency virus type 1 (HIV-1).

    Science.gov (United States)

    Yamaguchi, Koushi; Honda, Mitsuo; Ikigai, Hajime; Hara, Yukihiko; Shimamura, Tadakatsu

    2002-01-01

    Epigallocatechin gallate (EGCg), the major tea catechin, is known as a potent anti-bacterial agent. In addition, anti-tumor promoting, anti-inflammatory, anti-oxidative and antiviral activities have been reported. In the present study, we investigated possible anti-human immunodeficiency virus type-1 (HIV-1) activity of EGCg and its mechanisms of action in the viral life cycle. EGCg impinges on each step of the HIV life cycle. Thus, destruction of the viral particles, viral attachment to cells, post-adsorption entry into cells, reverse transcription (RT), viral production from chronically-infected cells, and the level of expression of viral mRNA, were analyzed using T-lymphoid (H9) and monocytoid (THP-1) cell systems, and antiviral protease activity was measured using a cell-free assay. Inhibitory effects of EGCg on specific binding of the virions to the cellular surfaces and changes in the steady state viral regulation (mRNA expression) due to EGCg were not observed. However, EGCg had a destructive effect on the viral particles, and post-adsorption entry and RT in acutely infected monocytoid cells were significantly inhibited at concentrations of EGCg greater than 1 microM, and protease kinetics were suppressed at a concentration higher than 10 microM in the cell-free study. Viral production by THP-1 cells chronically-infected with HIV-1 was also inhibited in a dose-dependent manner and the inhibitory effect was enhanced by liposome modification of EGCg. As expected, increased viral mRNA production was observed in lipopolysaccharide (LPS)-activated chronically HIV-1-infected cells. This production was significantly inhibited by EGCg treatment of THP-1 cells. In contrast, production of HIV-1 viral mRNA in unstimulated or LPS-stimulated T-lymphoid cells (H9) was not inhibited by EGCg. Anti-HIV viral activity of EGCg may thus result from an interaction with several steps in the HIV-1 life cycle.

  1. Current treatment of HIV/hepatitis B virus coinfection.

    Science.gov (United States)

    Iser, David M; Sasadeusz, Joseph J

    2008-05-01

    Coinfection with HIV and hepatitis B virus (HBV) has become a significant global health problem. Liver disease is now one of the leading causes of morbidity and mortality in individuals with HIV, particularly those with viral hepatitis. There are a number of agents available with dual activity against HIV and HBV, and effective treatment depends on understanding the potential advantages and pitfalls in using these agents. There are a number of unresolved issues in the management of HIV/HBV coinfection. These include the role of liver biopsy, the significance of normal aminotransferase levels, serum HBV DNA threshold for treatment, treatment end-points, and the treatment of HBV when HIV does not yet require treatment. Treatment of HBV should be considered in individuals with HIV/HBV coinfection with evidence of significant fibrosis (>/=F2), or with elevated serum HBV DNA levels (>2000 IU/mL). Sustained suppression of serum HBV DNA to below the level of detection by the most sensitive available assay should be the goal of therapy, and, at present, treatment of HBV in HIV/HBV coinfection is lifelong. If antiretroviral therapy is required, then two agents with anti-HBV activity should be incorporated into the regimen. If antiretroviral therapy is not required, then the options are pegylated interferon, adefovir or the early introduction of antiretroviral therapy. Close monitoring is necessary to detect treatment failure or hepatic flares, such as immune reconstitution disease. Further studies of newer anti-HBV agents in individuals HIV/HBV coinfection may advance treatment of this important condition.

  2. Virus Particle Detection by Convolutional Neural Network in Transmission Electron Microscopy Images.

    Science.gov (United States)

    Ito, Eisuke; Sato, Takaaki; Sano, Daisuke; Utagawa, Etsuko; Kato, Tsuyoshi

    2018-06-01

    A new computational method for the detection of virus particles in transmission electron microscopy (TEM) images is presented. Our approach is to use a convolutional neural network that transforms a TEM image to a probabilistic map that indicates where virus particles exist in the image. Our proposed approach automatically and simultaneously learns both discriminative features and classifier for virus particle detection by machine learning, in contrast to existing methods that are based on handcrafted features that yield many false positives and require several postprocessing steps. The detection performance of the proposed method was assessed against a dataset of TEM images containing feline calicivirus particles and compared with several existing detection methods, and the state-of-the-art performance of the developed method for detecting virus was demonstrated. Since our method is based on supervised learning that requires both the input images and their corresponding annotations, it is basically used for detection of already-known viruses. However, the method is highly flexible, and the convolutional networks can adapt themselves to any virus particles by learning automatically from an annotated dataset.

  3. Natural resistance to HIV infection: The Vif-APOBEC interaction.

    Science.gov (United States)

    Malim, Michael H

    2006-11-01

    Members of the APOBEC family of cellular polynucleotide cytidine deaminases (e.g., APOBEC3G) are potent inhibitors of HIV infection. Wild type viral infections are largely spared from APOBEC function through the action of the viral Vif protein. In Vif's absence, inhibitory APOBEC proteins are encapsidated by budding virus particles leading to excessive cytidine (C) to uridine (U) hypermutation of negative sense reverse transcripts in newly infected cells. This registers as guanosine (G) to adenosine (A) mutations in plus stranded cDNA. Because the functions of Vif and APOBEC proteins oppose each other, it is likely that fluctuations in the Vif/APOBEC balance can influence the natural history of HIV infection. Experimental support for this notion would further justify and stimulate drug discovery initiatives in this area.

  4. Human Immunodeficiency Virus Type 1 Nef protein modulates the lipid composition of virions and host cell membrane microdomains

    Directory of Open Access Journals (Sweden)

    Geyer Matthias

    2007-10-01

    Full Text Available Abstract Background The Nef protein of Human Immunodeficiency Viruses optimizes viral spread in the infected host by manipulating cellular transport and signal transduction machineries. Nef also boosts the infectivity of HIV particles by an unknown mechanism. Recent studies suggested a correlation between the association of Nef with lipid raft microdomains and its positive effects on virion infectivity. Furthermore, the lipidome analysis of HIV-1 particles revealed a marked enrichment of classical raft lipids and thus identified HIV-1 virions as an example for naturally occurring membrane microdomains. Since Nef modulates the protein composition and function of membrane microdomains we tested here if Nef also has the propensity to alter microdomain lipid composition. Results Quantitative mass spectrometric lipidome analysis of highly purified HIV-1 particles revealed that the presence of Nef during virus production from T lymphocytes enforced their raft character via a significant reduction of polyunsaturated phosphatidylcholine species and a specific enrichment of sphingomyelin. In contrast, Nef did not significantly affect virion levels of phosphoglycerolipids or cholesterol. The observed alterations in virion lipid composition were insufficient to mediate Nef's effect on particle infectivity and Nef augmented virion infectivity independently of whether virus entry was targeted to or excluded from membrane microdomains. However, altered lipid compositions similar to those observed in virions were also detected in detergent-resistant membrane preparations of virus producing cells. Conclusion Nef alters not only the proteome but also the lipid composition of host cell microdomains. This novel activity represents a previously unrecognized mechanism by which Nef could manipulate HIV-1 target cells to facilitate virus propagation in vivo.

  5. Virus-like particles vaccine containing Clonorchis sinensis tegumental protein induces partial protection against Clonorchis sinensis infection.

    Science.gov (United States)

    Lee, Dong-Hun; Kim, Ah-Ra; Lee, Su-Hwa; Quan, Fu-Shi

    2017-12-29

    Human clonorchiasis, caused by the infection of Clonorchis sinensis, is one of the major health problems in Southeast Asia. However, vaccine efficacy against C. sinensis infection remains largely unknown. In this study, for the first time, we generated virus-like particles (VLPs) vaccine containing the C. sinensis tegumental protein 22.3 kDa (CsTP 22.3) and the influenza matrix protein (M1) as a core protein, and investigated the vaccine efficacy in Sprague-Dawley rats. Intranasal immunization of VLPs vaccine induced C. sinensis-specific IgG, IgG2a and IgG2c in the sera and IgA responses in the feces and intestines. Notably, upon challenge infection with C. sinensis metacercariae, significantly lower adult worm loads (70.2%) were measured in the liver of rats immunized with VLPs, compared to those of naïve rats. Furthermore, VLPs immunization induced antibody secreting cells (ASC) responses and CD4+/CD8+ T cell responses in the spleen. Our results indicated that VLPs vaccine containing C. sinensis CsTP 22.3 kDa provided partial protection against C. sisnensis infection. Thus, VLPs could be a potential vaccine candidate against C. sinensis.

  6. Seroprevalence of hepatitis B virus and hepatitis C virus co-infection among people living with HIV/AIDS visiting antiretroviral therapy centres in Nepal: a first nationally representative study.

    Science.gov (United States)

    Ionita, G; Malviya, A; Rajbhandari, R; Schluter, W William; Sharma, G; Kakchapati, S; Rijal, S; Dixit, S

    2017-07-01

    To assess the prevalence of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) co-infections among people living with HIV (PLHIV) in Nepal. A sample of 677 PLHIV representing key affected populations (KAP) in Nepal, who were undergoing antiretroviral (ART) therapy in ART clinics around the country, were voluntarily enrolled in the study. Rapid kit-based testing followed by ELISA for validation was performed, focusing on HBV surface antigen (HBsAg) and antibodies against HCV (anti-HCV). A multivariate logistic regression model was used to identify factors associated with HBV and HCV co-infection. HCV and HBV co-infection among the 677 PLHIV was found to be 19% (95% confidence interval (CI) 16.6-22.7%) and 4.4% (95% CI 3.1-6.6%), respectively. The Eastern Region had the highest percentage of HCV infection (48%). The age group with the highest rates of co-infection was 30-39 years (58% and 70%, respectively, for HCV and HBV co-infection). After adjusting for confounding, males were more likely to have HBV co-infection than females (adjusted odds ratio (AOR) 4.61, 95% CI 1.42-14.98). Similarly, PLHIV who were male (AOR 5.7, 95% CI 2.06-15.98), had a secondary level of education (AOR 3.04, 95% CI 1.06-8.70), or who were drug users (AOR 28.7, 95% CI 14.9-55.22) were significantly more likely to have HCV co-infection. This first ever national assessment of HIV, HBV, and HCV co-infection performed among PLHIV in Nepal demonstrates that HCV and HBV infections are a health threat to this population and that interventions are required to mitigate the effects of co-infection and to prevent further morbidity and mortality. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  7. Canine parvovirus-like particles, a novel nanomaterial for tumor targeting

    Directory of Open Access Journals (Sweden)

    Destito Giuseppe

    2006-02-01

    Full Text Available Abstract Specific targeting of tumor cells is an important goal for the design of nanotherapeutics for the treatment of cancer. Recently, viruses have been explored as nano-containers for specific targeting applications, however these systems typically require modification of the virus surface using chemical or genetic means to achieve tumor-specific delivery. Interestingly, there exists a subset of viruses with natural affinity for receptors on tumor cells that could be exploited for nanotechnology applications. For example, the canine parvovirus (CPV utilizes transferrin receptors (TfRs for binding and cell entry into canine as well as human cells. TfRs are over-expressed by a variety of tumor cells and are widely being investigated for tumor-targeted drug delivery. We explored whether the natural tropism of CPV to TfRs could be harnessed for targeting tumor cells. Towards this goal, CPV virus-like particles (VLPs produced by expression of the CPV-VP2 capsid protein in a baculovirus expression system were examined for attachment of small molecules and delivery to tumor cells. Structural modeling suggested that six lysines per VP2 subunit are presumably addressable for bioconjugation on the CPV capsid exterior. Between 45 and 100 of the possible 360 lysines/particle could be routinely derivatized with dye molecules depending on the conjugation conditions. Dye conjugation also demonstrated that the CPV-VLPs could withstand conditions for chemical modification on lysines. Attachment of fluorescent dyes neither impaired binding to the TfRs nor affected internalization of the 26 nm-sized VLPs into several human tumor cell lines. CPV-VLPs therefore exhibit highly favorable characteristics for development as a novel nanomaterial for tumor targeting.

  8. Neutralizing antibodies induced by recombinant virus-like particles of enterovirus 71 genotype C4 inhibit infection at pre- and post-attachment steps.

    Directory of Open Access Journals (Sweden)

    Zhiqiang Ku

    Full Text Available BACKGROUND: Enterovirus 71 (EV71 is a major causative agent of hand, foot and mouth disease, which has been prevalent in Asia-Pacific regions, causing significant morbidity and mortality in young children. Antibodies elicited by experimental EV71 vaccines could neutralize infection in vitro and passively protect animal models from lethal challenge, indicating that neutralizing antibodies play an essential role in protection. However, how neutralizing antibodies inhibit infection in vitro remains unclear. METHODS/FINDINGS: In the present study, we explored the mechanisms of neutralization by antibodies against EV71 virus-like particles (VLPs. Recombinant VLPs of EV71 genotype C4 were produced in insect cells using baculovirus vectors. Immunization with the VLPs elicited a high-titer, EV71-specific antibody response in mice. Anti-VLP mouse sera potently neutralized EV71 infection in vitro. The neutralizing antibodies in the anti-VLP mouse sera were found to target mainly an extremely conserved epitope (FGEHKQEKDLEYGAC located at the GH loop of the VP1 protein. The neutralizing anti-VLP antisera were able to inhibit virus binding to target cells efficiently. In addition, post-attachment treatment of virus-bound cells with the anti-VLP antisera also neutralized virus infection, although the antibody concentration required was higher than that of the pre-attachment treatment. CONCLUSIONS: Collectively, our findings represent a valuable addition to the understanding of mechanisms of EV71 neutralization and have strong implications for EV71 vaccine development.

  9. Research On Human Immunodeficiency Virus (HIV) In Malawi: The ...

    African Journals Online (AJOL)

    The Johns Hopkins University- Ministry of Health OHU-MOH) Project ... HIV infection among low ... in Africa were infected with the virus; these women gave ... information and medical, repro(l1K;Y~ ;~d pregnancy ... white blood cell differentials were done with a ... Malawi are at increased risk during the postnatal period.

  10. Localization and force analysis at the single virus particle level using atomic force microscopy

    International Nuclear Information System (INIS)

    Liu, Chih-Hao; Horng, Jim-Tong; Chang, Jeng-Shian; Hsieh, Chung-Fan; Tseng, You-Chen; Lin, Shiming

    2012-01-01

    Highlights: ► Localization of single virus particle. ► Force measurements. ► Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

  11. Preventing HIV infection without targeting the virus: how reducing HIV target cells at the genital tract is a new approach to HIV prevention.

    Science.gov (United States)

    Lajoie, Julie; Mwangi, Lucy; Fowke, Keith R

    2017-09-12

    For over three decades, HIV infection has had a tremendous impact on the lives of individuals and public health. Microbicides and vaccines studies have shown that immune activation at the genital tract is a risk factor for HIV infection. Furthermore, lower level of immune activation, or what we call immune quiescence, has been associated with a lower risk of HIV acquisition. This unique phenotype is observed in highly-exposed seronegative individuals from different populations including female sex workers from the Pumwani cohort in Nairobi, Kenya. Here, we review the link between immune activation and susceptibility to HIV infection. We also describe a new concept in prevention where, instead of targeting the virus, we modulate the host immune system to resist HIV infection. Mimicking the immune quiescence phenotype might become a new strategy in the toolbox of biomedical methods to prevent HIV infection. Clinical trial registration on clinicaltrial.gov: #NCT02079077.

  12. Predictors of human immunodeficiency virus (HIV) infection in primary care: a systematic review protocol.

    Science.gov (United States)

    Rumbwere Dube, Benhildah N; Marshall, Tom P; Ryan, Ronan P

    2016-09-20

    Antiretroviral therapies for human immunodeficiency virus are more effective if infected individuals are diagnosed early, before they have irreversible immunologic damage. A large proportion of patients that are diagnosed with HIV, in United Kingdom, would have seen a general practitioner (GP) within the previous year. Determining the demographic and clinical characteristics of HIV-infected patients prior to diagnosis of HIV may be useful in identifying patients likely to be HIV positive in primary care. This could help inform a strategy of early HIV testing in primary care. This systematic review aims to identify characteristics of HIV-infected adults prior to diagnosis that could be used in a prediction model for early detection of HIV in primary care. The systematic review will search for literature, mainly observational (cohort and case-control) studies, with human participants aged 18 years and over. The exposures are demographic, socio-economic or clinical risk factors or characteristics associated with HIV infection. The comparison group will be patients with no risk factors or no comparison group. The outcome is laboratory-confirmed HIV/AIDS infection. Evidence will be identified from electronic searches of online databases of EMBASE, MEDLINE, The Cochrane Library and grey literature search engines of Open Grey, Web of Science Conference Proceedings Citation Index and examination of reference lists from selected studies (reference searching). Two reviewers will be involved in quality assessment and data extraction of the review. A data extraction form will be developed to collate data from selected studies. A checklist for quality assessment will be adapted from the Scottish Intercollegiate Guidelines Network (SIGN). This systematic review will identify and consolidate existing scientific evidence on characteristics of HIV infected individuals that could be used to inform decision-making in prognostic model development. PROSPERO CRD42016042427.

  13. Identification of full-length transmitted/founder viruses and their progeny in primary HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette [Los Alamos National Laboratory; Hraber, Peter [Los Alamos National Laboratory; Giorgi, Elena [Los Alamos National Laboratory; Bhattacharya, T [Los Alamos National Laboratory

    2009-01-01

    Identification of transmitted/founder virus genomes and their progeny by is a novel strategy for probing the molecular basis of HIV-1 transmission and for evaluating the genetic imprint of viral and host factors that act to constrain or facilitate virus replication. Here, we show in a cohort of twelve acutely infected subjects (9 clade B; 3 clade C), that complete genomic sequences of transmitted/founder viruses could be inferred using single genome amplification of plasma viral RNA, direct amplicon sequencing, and a model of random virus evolution. This allowed for the precise identification, chemical synthesis, molecular cloning, and biological analysis of those viruses actually responsible for productive clinical infection and for a comprehensive mapping of sequential viral genomes and proteomes for mutations that are necessary or incidental to the establishment of HIV-1 persistence. Transmitted/founder viruses were CD4 and CCR5 tropic, replicated preferentially in activated primary T-Iymphocytes but not monocyte-derived macrophages, and were effectively shielded from most heterologous or broadly neutralizing antibodies. By 3 months of infection, the evolving viral quasispecies in three subjects showed mutational fixation at only 2-5 discreet genomic loci. By 6-12 months, mutational fixation was evident at 18-27 genomic loci. Some, but not all, of these mutations were attributable to virus escape from cytotoxic Tlymphocytes or neutralizing antibodies, suggesting that other viral or host factors may influence early HIV -1 fitness.

  14. HIV Structural Database

    Science.gov (United States)

    SRD 102 HIV Structural Database (Web, free access)   The HIV Protease Structural Database is an archive of experimentally determined 3-D structures of Human Immunodeficiency Virus 1 (HIV-1), Human Immunodeficiency Virus 2 (HIV-2) and Simian Immunodeficiency Virus (SIV) Proteases and their complexes with inhibitors or products of substrate cleavage.

  15. Porcine parvovirus capsid protein expressed in Escherichia coli self-assembles into virus-like particles with high immunogenicity in mice and guinea pigs.

    Science.gov (United States)

    Ji, Pengchao; Liu, Yunchao; Chen, Yumei; Wang, Aiping; Jiang, Dawei; Zhao, Baolei; Wang, Jvcai; Chai, Shujun; Zhou, Enmin; Zhang, Gaiping

    2017-03-01

    Porcine parvovirus (PPV) is a causative agent of reproductive failure in pregnant sows. Classical inactivated vaccine is extensively used to control PPV infection, but problems concerning safety, such as incomplete inactivation may occur. In this study, a novel subunit vaccine against PPV based on virus-like particles (VLPs) formed from the complete PPV VP2 protein expressed in a prokaryotic system with co-expressed chaperones is reported. The VLPs have a similar size, shape, and hemagglutination property to the PPV. Immunization with these VLPs stimulated the neutralization antibody and hemagglutination inhibition (HI) antibody responses in mice and guinea pigs. The lymphocyte proliferation response and cytokine secretion was also induced in immunized guinea pigs comparable to those immunized with PPV inactivated vaccine. In addition, immunization with VLPs also significantly reduced the PPV content in the spleen of guinea pigs 14 days after the challenge with intact virus. These studies suggest that PPV VLPs created as described here could be a potential candidate for vaccine development. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Proteomic analysis of purified coronavirus infectious bronchitis virus particles

    Directory of Open Access Journals (Sweden)

    Shu Dingming

    2010-06-01

    Full Text Available Abstract Background Infectious bronchitis virus (IBV is the coronavirus of domestic chickens causing major economic losses to the poultry industry. Because of the complexity of the IBV life cycle and the small number of viral structural proteins, important virus-host relationships likely remain to be discovered. Toward this goal, we performed two-dimensional gel electrophoresis fractionation coupled to mass spectrometry identification approaches to perform a comprehensive proteomic analysis of purified IBV particles. Results Apart from the virus-encoded structural proteins, we detected 60 host proteins in the purified virions which can be grouped into several functional categories including intracellular trafficking proteins (20%, molecular chaperone (18%, macromolcular biosynthesis proteins (17%, cytoskeletal proteins (15%, signal transport proteins (15%, protein degradation (8%, chromosome associated proteins (2%, ribosomal proteins (2%, and other function proteins (3%. Interestingly, 21 of the total host proteins have not been reported to be present in virions of other virus families, such as major vault protein, TENP protein, ovalbumin, and scavenger receptor protein. Following identification of the host proteins by proteomic methods, the presence of 4 proteins in the purified IBV preparation was verified by western blotting and immunogold labeling detection. Conclusions The results present the first standard proteomic profile of IBV and may facilitate the understanding of the pathogenic mechanisms.

  17. Risky sexual behaviour and human immunodeficiency virus (HIV ...

    African Journals Online (AJOL)

    2018-01-26

    Jan 26, 2018 ... However, an HIV-positive healthcare workforce is less equipped to ... four partners were 4–12 times more likely to become infected with HIV and women reporting ..... with sexual violence, understanding psychological barriers.

  18. Disassembly and reassembly of human papillomavirus virus-like particles produces more virion-like antibody reactivity

    Directory of Open Access Journals (Sweden)

    Zhao Qinjian

    2012-02-01

    Full Text Available Abstract Background Human papillomavirus (HPV vaccines based on major capsid protein L1 are licensed in over 100 countries to prevent HPV infections. The yeast-derived recombinant quadrivalent HPV L1 vaccine, GARDASIL(R, has played an important role in reducing cancer and genital warts since its introduction in 2006. The L1 proteins self-assemble into virus-like particles (VLPs. Results VLPs were subjected to post-purification disassembly and reassembly (D/R treatment during bioprocessing to improve VLP immunoreactivity and stability. The post-D/R HPV16 VLPs and their complex with H16.V5 neutralizing antibody Fab fragments were visualized by cryo electron microscopy, showing VLPs densely decorated with antibody. Along with structural improvements, post-D/R VLPs showed markedly higher antigenicity to conformational and neutralizing monoclonal antibodies (mAbs H16.V5, H16.E70 and H263.A2, whereas binding to mAbs recognizing linear epitopes (H16.J4, H16.O7, and H16.H5 was greatly reduced. Strikingly, post-D/R VLPs showed no detectable binding to H16.H5, indicating that the H16.H5 epitope is not accessible in fully assembled VLPs. An atomic homology model of the entire HPV16 VLP was generated based on previously determined high-resolution structures of bovine papillomavirus and HPV16 L1 pentameric capsomeres. Conclusions D/R treatment of HPV16 L1 VLPs produces more homogeneous VLPs with more virion-like antibody reactivity. These effects can be attributed to a combination of more complete and regular assembly of the VLPs, better folding of L1, reduced non-specific disulfide-mediated aggregation and increased stability of the VLPs. Markedly different antigenicity of HPV16 VLPs was observed upon D/R treatment with a panel of monoclonal antibodies targeting neutralization sensitive epitopes. Multiple epitope-specific assays with a panel of mAbs with different properties and epitopes are required to gain a better understanding of the immunochemical

  19. Modeling and simulation of anion-exchange membrane chromatography for purification of Sf9 insect cell-derived virus-like particles.

    Science.gov (United States)

    Ladd Effio, Christopher; Hahn, Tobias; Seiler, Julia; Oelmeier, Stefan A; Asen, Iris; Silberer, Christine; Villain, Louis; Hubbuch, Jürgen

    2016-01-15

    Recombinant protein-based virus-like particles (VLPs) are steadily gaining in importance as innovative vaccines against cancer and infectious diseases. Multiple VLPs are currently evaluated in clinical phases requiring a straightforward and rational process design. To date, there is no generic platform process available for the purification of VLPs. In order to accelerate and simplify VLP downstream processing, there is a demand for novel development approaches, technologies, and purification tools. Membrane adsorbers have been identified as promising stationary phases for the processing of bionanoparticles due to their large pore sizes. In this work, we present the potential of two strategies for designing VLP processes following the basic tenet of 'quality by design': High-throughput experimentation and process modeling of an anion-exchange membrane capture step. Automated membrane screenings allowed the identification of optimal VLP binding conditions yielding a dynamic binding capacity of 5.7 mg/mL for human B19 parvovirus-like particles derived from Spodoptera frugiperda Sf9 insect cells. A mechanistic approach was implemented for radial ion-exchange membrane chromatography using the lumped-rate model and stoichiometric displacement model for the in silico optimization of a VLP capture step. For the first time, process modeling enabled the in silico design of a selective, robust and scalable process with minimal experimental effort for a complex VLP feedstock. The optimized anion-exchange membrane chromatography process resulted in a protein purity of 81.5%, a DNA clearance of 99.2%, and a VLP recovery of 59%. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Human pegivirus (HPgV) infection in Ghanaians co-infected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV).

    Science.gov (United States)

    N'Guessan, Kombo F; Boyce, Ceejay; Kwara, Awewura; Archampong, Timothy N A; Lartey, Margaret; Sagoe, Kwamena W; Kenu, Ernest; Obo-Akwa, Adjoa; Blackard, Jason T

    2018-03-17

    Human pegivirus (HPgV) is a positive single-stranded RNA virus in the Flaviviridae family. Phylogenetic analysis reveals the presence of multiple HPgV genotypes with distinct geographic locations. HPgV is of interest because of its potential beneficial impact on HIV disease progression. Despite this, the effects of HPgV in the context of other viral infections, such as hepatitis B virus (HBV), are poorly understood, and data from resource-limited settings are scarce. Therefore, we conducted a cross-sectional analysis of HPgV in HIV/HBV co-infected patients in Ghana. Sera from 100 HIV/HBV co-infected individuals were evaluated for HPgV RNA, and the genotype determined by sequencing the 5' untranslated region. HPgV RNA was detected in 27 samples (27%). Of these, 26 were genotyped successfully with 23 belonging to HPgV genotype 1 and 3 belonging to HPgV genotype 2. The presence of HPgV RNA had no statistically significant impact on CD4 cell count or HBV DNA titers in the HIV/HBV co-infected patients. However, there was a trend towards decreased HBV DNA levels in HPgV RNA-positive patients with CD4 cell count HBV disease among HIV/HBV co-infected patients was minimal. However, decreased HBV DNA levels in HPgV RNA-positive patients with low CD4 cell counts highlight the need for prospective studies of HPgV in HIV and hepatitis co-infected patients, especially in those with advanced HIV disease, to study further the effects of HPgV on liver disease.

  1. [Construction of RNA-containing virus-like nanoparticles expression vector with cysteine residues on surface and fluorescent decoration].

    Science.gov (United States)

    Cheng, Yang-Jian; Liang, Ji-Xuan; Li, Qing-Ge

    2005-08-01

    Site-directed mutagenesis was performed at the codon 15 of the MS2 bacteriophage coat protein gene,which had been cloned to the virus-like particles expression vector containing non-self RNA fragment. The produced expression vector,termed pARSC, was transformed to E. coli DH5alpha. The positive clones were selected and proliferated. The harvested cells were treated with sonication and the supernatant was then subjected to linear sucrose density gradients centrifugation (15% to 60%) at 32000 r/min for 4 h at 4 degrees C. The virus-like particles, VLP-Cy, were collected at 35% sucrose density. The particles were examined by transmission electron microscopy and the spherical viral particles of approximately 27 nm in diameter were found. The thiolated VLP-Cy was then chemically modified with fluorescein -5'-maleimide. The covalent fluorescent labeling was confirmed by absorption analysis, SDS-PAGE and MALDI-TOF mass spectroscopy. This is the first report of preparation of RNA-containing natural fluorescent nanoparticles. The study highlight the versatility of MS2 bacteriophage capsids as building blocks for functional nanomaterials construction for a variety of application purposes.

  2. Effect of hepatitis C virus on the central nervous system of HIV-infected individuals

    Directory of Open Access Journals (Sweden)

    Forton D

    2012-11-01

    Full Text Available Markus Gess, Daniel FortonDepartment of Gastroenterology and Hepatology, St George’s University of London, London, UKAbstract: Infection with the human immunodeficiency virus (HIV is associated with a spectrum of neuropsychiatric manifestations ranging from asymptomatic cognitive impairment, detectable only by sensitive neurocognitive tests, to overt HIV-associated dementia. Highly active antiretroviral therapy has led to significant reductions in the incidence of severe HIV-associated dementia. However, the overall prevalence of milder HIV-associated cognitive disorders appears to be increasing as HIV-infected subjects live longer in the era of combined antiretroviral treatments. Chronic hepatitis C virus (HCV infection is also associated with neuropsychological symptoms and impaired cognitive performance in some patients, and recent evidence suggests that these central nervous system (CNS symptoms may be caused by HCV entry into the brain via endothelial infection. Similarly to the neuropathological processes in HIV infection, microglial activation in HCV infected subjects may underlie the CNS metabolic abnormalities and impaired cognitive performance that have been described in studies of HCV-infected cohorts. A significant proportion of HIV-infected subjects are coinfected with HCV, but the impact and clinical importance of coinfection on cognitive function has only been addressed in a small number of research studies. There is some evidence that coinfection may adversely affect neurocognitive function; however, studies published thus far are limited by a number of confounding factors and small sample sizes. This article aims to review the current evidence examining neurocognitive function in HIV- and HCV-monoinfection and further critically discusses previous studies that have explored the impact of coinfection with HCV on CNS function of HIV-infected cohorts. It is clear that, as the population of HIV-infected individuals ages and

  3. Localization and force analysis at the single virus particle level using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chih-Hao [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Horng, Jim-Tong [Department of Biochemistry, Chang Gung University, 259 Wen-Hwa First Road, Kweishan, Taoyuan 333, Taiwan (China); Chang, Jeng-Shian [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Hsieh, Chung-Fan [Graduate Institute of Biomedical Sciences, Chang Gung University, Kweishan, Taoyuan 333, Taiwan (China); Tseng, You-Chen [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Lin, Shiming, E-mail: til@ntu.edu.tw [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Center for Optoelectronic Biomedicine, College of Medicine, Nation Taiwan University, 1-1 Jen-Ai Road, Taipei 10051, Taiwan (China)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Localization of single virus particle. Black-Right-Pointing-Pointer Force measurements. Black-Right-Pointing-Pointer Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

  4. Recovery of infective virus particles in ion-exchange and hydrophobic interaction monolith chromatography is influenced by particle charge and total-to-infective particle ratio.

    Science.gov (United States)

    Sviben, Dora; Forcic, Dubravko; Ivancic-Jelecki, Jelena; Halassy, Beata; Brgles, Marija

    2017-06-01

    Viral particles are used in medical applications as vaccines or gene therapy vectors. In order to obtain product of high purity, potency and safety for medical use purification of virus particles is a prerequisite, and chromatography is gaining increased attention to meet this aim. Here, we report on the use of ion-exchange and hydrophobic interaction chromatography on monolithic columns for purification of mumps virus (MuV) and measles virus (MeV). Efficiency of the process was monitored by quantification of infective virus particles (by 50% cell culture infective dose assay) and total virus particles, and monitoring of their size (by Nanoparticle Tracking Analysis). Ion-exchange chromatography was shown to be inefficient for MuV and best results for MeV were obtained on QA column with recovery around 17%. Purification of MuV and MeV by hydrophobic interaction chromatography resulted in recoveries around 60%. Results showed that columns with small channels (d=1.4μm) are not suitable for MuV and MeV, although their size is below 400nm, whereas columns with large channels (6μm) showed to be efficient and recoveries independent on the flow rate up to 10mL/min. Heterogeneity of the virus suspension and its interday variability mostly regarding total-to-infective particle ratio was observed. Interestingly, a trend in recovery depending on the day of the harvest was also observed for both viruses, and it correlated with the total-to-infective particle ratio, indicating influence of the virus sample composition on the chromatography results. Copyright © 2017. Published by Elsevier B.V.

  5. Tight regulation of the Epstein-Barr virus setpoint: interindividual differences in Epstein-Barr virus DNA load are conserved after HIV infection

    NARCIS (Netherlands)

    Piriou, Erwan; van Dort, Karel; Otto, Sigrid; van Oers, Marinus H. J.; van Baarle, Debbie

    2008-01-01

    Healthy individuals carry a constant number of Epstein-Barr virus-infected B cells in the peripheral blood over time. Here, we show that interindividual differences in Epstein-Barr virus DNA levels are maintained after HIV infection, providing evidence for the existence of an individual Epstein-Barr

  6. Pichia pastoris-expressed dengue 2 envelope forms virus-like particles without pre-membrane protein and induces high titer neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Shailendra Mani

    Full Text Available Dengue is a mosquito-borne viral disease with a global prevalence. It is caused by four closely-related dengue viruses (DENVs 1-4. A dengue vaccine that can protect against all four viruses is an unmet public health need. Live attenuated vaccine development efforts have encountered unexpected interactions between the vaccine viruses, raising safety concerns. This has emphasized the need to explore non-replicating dengue vaccine options. Virus-like particles (VLPs which can elicit robust immunity in the absence of infection offer potential promise for the development of non-replicating dengue vaccine alternatives. We have used the methylotrophic yeast Pichia pastoris to develop DENV envelope (E protein-based VLPs. We designed a synthetic codon-optimized gene, encoding the N-terminal 395 amino acid residues of the DENV-2 E protein. It also included 5' pre-membrane-derived signal peptide-encoding sequences to ensure proper translational processing, and 3' 6× His tag-encoding sequences to facilitate purification of the expressed protein. This gene was integrated into the genome of P. pastoris host and expressed under the alcohol oxidase 1 promoter by methanol induction. Recombinant DENV-2 protein, which was present in the insoluble membrane fraction, was extracted and purified using Ni(2+-affinity chromatography under denaturing conditions. Amino terminal sequencing and detection of glycosylation indicated that DENV-2 E had undergone proper post-translational processing. Electron microscopy revealed the presence of discrete VLPs in the purified protein preparation after dialysis. The E protein present in these VLPs was recognized by two different conformation-sensitive monoclonal antibodies. Low doses of DENV-2 E VLPs formulated in alum were immunogenic in inbred and outbred mice eliciting virus neutralizing titers >1,1200 in flow cytometry based assays and protected AG129 mice against lethal challenge (p<0.05. The formation of immunogenic DENV-2 E

  7. In Vitro Assembly of Virus-Like Particles of a Gammaretrovirus, the Murine Leukemia Virus XMRV

    Czech Academy of Sciences Publication Activity Database

    Hadravová, Romana; de Marco, A.; Ulbrich, P.; Štokrová, Jitka; Doležal, Michal; Pichová, Iva; Ruml, T.; Briggs, J. A. G.; Rumlová, Michaela

    2012-01-01

    Roč. 86, č. 3 (2012), s. 1297-1306 ISSN 0022-538X R&D Projects: GA ČR GA204/09/1388; GA MŠk 1M0508 Grant - others:GA MŠk(CZ) 1M0520 Program:1M Institutional research plan: CEZ:AV0Z40550506 Keywords : human-immunodeficiency-virus * Rous sarcoma virus * chronic-fatigue-syndrome * Pfizer monkey virus * N-terminal domain Subject RIV: CE - Biochemistry Impact factor: 5.076, year: 2012

  8. Viral Outbreak in Corals Associated with an In Situ Bleaching Event: Atypical Herpes-Like Viruses and a New Megavirus Infecting Symbiodinium

    Science.gov (United States)

    Correa, Adrienne M. S.; Ainsworth, Tracy D.; Rosales, Stephanie M.; Thurber, Andrew R.; Butler, Christopher R.; Vega Thurber, Rebecca L.

    2016-01-01

    Previous studies of coral viruses have employed either microscopy or metagenomics, but few have attempted to comprehensively link the presence of a virus-like particle (VLP) to a genomic sequence. We conducted transmission electron microscopy imaging and virome analysis in tandem to characterize the most conspicuous viral types found within the dominant Pacific reef-building coral genus Acropora. Collections for this study inadvertently captured what we interpret as a natural outbreak of viral infection driven by aerial exposure of the reef flat coincident with heavy rainfall and concomitant mass bleaching. All experimental corals in this study had high titers of viral particles. Three of the dominant VLPs identified were observed in all tissue layers and budding out from the epidermis, including viruses that were ∼70, ∼120, and ∼150 nm in diameter; these VLPs all contained electron dense cores. These morphological traits are reminiscent of retroviruses, herpesviruses, and nucleocytoplasmic large DNA viruses (NCLDVs), respectively. Some 300–500 nm megavirus-like VLPs also were observed within and associated with dinoflagellate algal endosymbiont (Symbiodinium) cells. Abundant sequence similarities to a gammaretrovirus, herpesviruses, and members of the NCLDVs, based on a virome generated from five Acropora aspera colonies, corroborated these morphology-based identifications. Additionally sequence similarities to two diagnostic genes, a MutS and (based on re-annotation of sequences from another study) a DNA polymerase B gene, most closely resembled Pyramimonas orientalis virus, demonstrating the association of a cosmopolitan megavirus with Symbiodinium. We also identified several other virus-like particles in host tissues, along with sequences phylogenetically similar to circoviruses, phages, and filamentous viruses. This study suggests that viral outbreaks may be a common but previously undocumented component of natural bleaching events, particularly

  9. Epidemiology of infections with intestinal parasites and human immunodeficiency virus (HIV) among sugar-estate residents in Ethiopia

    NARCIS (Netherlands)

    Fontanet, A. L.; Sahlu, T.; Rinke de Wit, T.; Messele, T.; Masho, W.; Woldemichael, T.; Yeneneh, H.; Coutinho, R. A.

    2000-01-01

    Intestinal parasitic infections could play an important role in the progression of infection with human immunodeficiency virus (HIV), by further disturbing the immune system whilst it is already engaged in the fight against HIV. HIV and intestinal parasitic infections were investigated in 1239,

  10. Progesterone protects normative anxiety-like responding among ovariectomized female mice that conditionally express the HIV-1 regulatory protein, Tat, in the CNS.

    Science.gov (United States)

    Paris, Jason J; Fenwick, Jason; McLaughlin, Jay P

    2014-05-01

    Increased anxiety is co-morbid with human immunodeficiency virus (HIV) infection. Actions of the neurotoxic HIV-1 regulatory protein, Tat, may contribute to affective dysfunction. We hypothesized that Tat expression would increase anxiety-like behavior of female GT-tg bigenic mice that express HIV-1 Tat protein in the brain in a doxycycline-dependent manner. Furthermore, given reports that HIV-induced anxiety may occur at lower rates among women, and that the neurotoxic effects of Tat are ameliorated by sex steroids in vitro, we hypothesized that 17β-estradiol and/or progesterone would ameliorate Tat-induced anxiety-like effects. Among naturally-cycling proestrous and diestrous mice, Tat-induction via 7days of doxycycline treatment significantly increased anxiety-like responding in an open field, elevated plus maze and a marble-burying task, compared to treatment with saline. Proestrous mice demonstrated less anxiety-like behavior than diestrous mice in the open field and elevated plus maze, but these effects did not significantly interact with Tat-induction. Among ovariectomized mice, doxycycline-induced Tat protein significantly increased anxiety-like behavior in an elevated plus maze and a marble burying task compared to saline-treated mice, but not an open field (where anxiety-like responding was already maximal). Co-administration of progesterone (4mg/kg), but not 17β-estradiol (0.09mg/kg), with doxycycline significantly ameliorated anxiety-like responding in the elevated plus maze and marble burying tasks. When administered together, 17β-estradiol partially antagonized the protective effects of progesterone on Tat-induced anxiety-like behavior. These findings support evidence of steroid-protection over HIV-1 proteins, and extend them by demonstrating the protective capacity of progesterone on Tat-induced anxiety-like behavior of ovariectomized female mice. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Undetectable hepatitis C virus RNA during syphilis infection in two HIV/HCV-co-infected patients

    DEFF Research Database (Denmark)

    Salado-Rasmussen, Kirsten; Knudsen, Andreas; Krarup, Henrik Bygum

    2014-01-01

    BACKGROUND: Treponema pallidum, the causative agent of syphilis, elicits a vigorous immune response in the infected host. This study sought to describe the impact of syphilis infection on hepatitis C virus (HCV) RNA levels in patients with HIV and chronic HCV infection. METHODS: Patients......-α), interferon gamma (IFN-γ), and IFN-γ-inducible protein 10 kDa (IP-10). RESULTS: Undetectable HCV RNA at the time of early latent syphilis infection was observed in 2 patients with HIV and chronic HCV infection. After treatment of the syphilis infection, HCV RNA levels increased again in patient 1, whereas...... patient 2 initiated HCV therapy and remained HCV RNA-negative. Available plasma samples obtained before and after the episode with undetectable HCV RNA were phylogenetically identical, making the possibility of spontaneous clearance and HCV reinfection less likely. The IL-10, TNF-α, and IP-10 levels...

  12. Chimeric polyomavirus-derived virus-like particles: the immunogenicity of an inserted peptide applied without adjuvant to mice depends on its insertion site and its flanking linker sequence

    OpenAIRE

    Lawatscheck, R.; Aleksaite, E.; Schenk, J.A.; Micheel, B.; Jandrig, B.; Holland, G.; Sasnauskas, K.; Gedvilaite, A.; Ulrich, R.G.

    2007-01-01

    We inserted the sequence of the carcinoembryonic antigen-derived T cell epitope CAP-1-6D (CEA) into different positions of the hamster polyomavirus major capsid protein VP1. Independently from additional flanking linkers, yeast-expressed VP1 proteins harboring the CEA insertion between VP1 amino acid residues 80 and 89 (site 1) or 288 and 295 (site 4) or simultaneously at both positions assembled to chimeric virus-like particles (VLPs). BALB/c mice immunized with adjuvant-free VLPs developed ...

  13. Species-specific activity of SIV Nef and HIV-1 Vpu in overcoming restriction by tetherin/BST2.

    Directory of Open Access Journals (Sweden)

    Bin Jia

    2009-05-01

    Full Text Available Tetherin, also known as BST2, CD317 or HM1.24, was recently identified as an interferon-inducible host-cell factor that interferes with the detachment of virus particles from infected cells. HIV-1 overcomes this restriction by expressing an accessory protein, Vpu, which counteracts tetherin. Since lentiviruses of the SIV(smm/mac/HIV-2 lineage do not have a vpu gene, this activity has likely been assumed by other viral gene products. We found that deletion of the SIV(mac239 nef gene significantly impaired virus release in cells expressing rhesus macaque tetherin. Virus release could be restored by expressing Nef in trans. However, Nef was unable to facilitate virus release in the presence of human tetherin. Conversely, Vpu enhanced virus release in the presence of human tetherin, but not in the presence of rhesus tetherin. In accordance with the species-specificity of Nef in mediating virus release, SIV Nef downregulated cell-surface expression of rhesus tetherin, but did not downregulate human tetherin. The specificity of SIV Nef for rhesus tetherin mapped to four amino acids in the cytoplasmic domain of the molecule that are missing from human tetherin, whereas the specificity of Vpu for human tetherin mapped to amino acid differences in the transmembrane domain. Nef alleles of SIV(smm, HIV-2 and HIV-1 were also able to rescue virus release in the presence of both rhesus macaque and sooty mangabey tetherin, but were generally ineffective against human tetherin. Thus, the ability of Nef to antagonize tetherin from these Old World primates appears to be conserved among the primate lentiviruses. These results identify Nef as the viral gene product of SIV that opposes restriction by tetherin in rhesus macaques and sooty mangabeys, and reveal species-specificity in the activities of both Nef and Vpu in overcoming tetherin in their respective hosts.

  14. Clustering patterns of cytotoxic T-lymphocyte epitopes in human immunodeficiency virus type 1 (HIV-1) proteins reveal imprints of immune evasion on HIV-1 global variation

    DEFF Research Database (Denmark)

    Yusim, K.; Kesmir, Can; Gaschen, B.

    2002-01-01

    The human cytotoxic T-lymphocyte (CTL) response to human immunodeficiency virus type 1 (HIV-1) has been intensely studied, and hundreds of CTL epitopes have been experimentally defined, published, and compiled in the HIV Molecular Immunology Database. Maps of CTL epitopes on HIV-1 protein sequenc...

  15. HIV-related symptoms and patient clusters among Chileans living with HIV.

    Science.gov (United States)

    Araya, A X; Norr, K F; Pérez, C M; Levy, J A; Park, C G; Kim, M J

    2013-01-01

    Identifying both Human immunodeficiency virus (HIV)-related and co-morbid symptoms experienced by people living with HIV (PLWH) who are receiving antiretroviral therapy (ART) treatment is a major challenge for healthcare providers globally. Yet, little research to date has examined the symptoms of illness experienced by PLWH including patients living in Central and South American. To address this gap, this study was designed to identify symptoms of HIV by socio-demographic and/or clinical characteristics among Chilean patients living with the virus. A convenience sample of 209 Chilean PLWH was recruited from an outpatient clinic in Santiago, Chile. A structured interview was used to elicit socio-demographic information and HIV symptoms status. Additional clinical information was obtained through a review of the participants' medical records. Results show that patients' most commonly reported HIV-related symptoms were fear/worries (66%), anxiety (52%), gas/bloating (50%), and thirst (50%). Multivariate analysis revealed a positive association between the number of reported HIV-related symptoms and number of years living with HIV. Having completed college was negatively associated with number of symptoms. Latent class analysis indicated that PLWH in the sample who had completed college were two times more likely to experience a mild intensity of HIV-related symptoms than their lesser educated counterparts. Similarly, logistic regression revealed that college-educated PLWH were twice as likely to be classified in the subgroup reporting mild intensity of symptoms than those who lacked a college degree. Overall, the study's results reveal that many Chilean PLWH, even those with high CD4 counts and low or undetectable viral loads, are not symptom free. The findings point to the need for clinicians to tailor a plan of care for individuals living with HIV that is based on their symptomatology.

  16. Viral Causes of Lymphoma: The History of Epstein-Barr Virus and Human T-Lymphotropic Virus 1.

    Science.gov (United States)

    Esau, Daniel

    2017-01-01

    In 1964, Epstein, Barr, and Achong published a report outlining their discovery of viral particles in lymphoblasts isolated from a patient with Burkitt lymphoma. The Epstein-Barr virus (EBV) was the first human cancer virus to be described, and its discovery paved the way for further investigations into the oncogenic potential of viruses. In the decades following the discovery of EBV, multinational research efforts led to the discovery of further viral causes of various human cancers. Lymphomas are perhaps the cancer type that is most closely associated with oncogenic viruses: infection with EBV, human T-lymphotropic virus 1 (HTLV-1), human immunodeficiency virus (HIV), Kaposi sarcoma-associated herpesvirus/human herpesvirus 8, and hepatitis C virus have all been associated with lymphomagenesis. Lymphomas have also played an important role in the history of oncoviruses, as both the first human oncovirus (EBV) and the first human retrovirus (HTLV-1) were discovered through isolates taken from patients with unique lymphoma syndromes. The history of the discovery of these 2 key oncoviruses is presented here, and their impact on further medical research, using the specific example of HIV research, is briefly discussed.

  17. Viral Causes of Lymphoma: The History of Epstein-Barr Virus and Human T-Lymphotropic Virus 1

    Directory of Open Access Journals (Sweden)

    Daniel Esau

    2017-09-01

    Full Text Available In 1964, Epstein, Barr, and Achong published a report outlining their discovery of viral particles in lymphoblasts isolated from a patient with Burkitt lymphoma. The Epstein-Barr virus (EBV was the first human cancer virus to be described, and its discovery paved the way for further investigations into the oncogenic potential of viruses. In the decades following the discovery of EBV, multinational research efforts led to the discovery of further viral causes of various human cancers. Lymphomas are perhaps the cancer type that is most closely associated with oncogenic viruses: infection with EBV, human T-lymphotropic virus 1 (HTLV-1, human immunodeficiency virus (HIV, Kaposi sarcoma-associated herpesvirus/human herpesvirus 8, and hepatitis C virus have all been associated with lymphomagenesis. Lymphomas have also played an important role in the history of oncoviruses, as both the first human oncovirus (EBV and the first human retrovirus (HTLV-1 were discovered through isolates taken from patients with unique lymphoma syndromes. The history of the discovery of these 2 key oncoviruses is presented here, and their impact on further medical research, using the specific example of HIV research, is briefly discussed.

  18. [The true story and advantages of the famous Hepatitis B virus core particles: Outlook 2016].

    Science.gov (United States)

    Pumpens, P; Grens, E

    2016-01-01

    This review article is a continuation of the paper "Hepatitis B core particles as a universal display model: a structure-function basis for development" written by Pumpens P. and Grens E., ordered by Professor Lev Kisselev and published in FEBS Letters, 1999, 442, 1-6. The past 17 years have strengthened the paper's finding that the human hepatitis B virus core protein, along with other Hepadnaviridae family member core proteins, is a mysterious, multifunctional protein. The core gene of the Hepadnaviridae genome encodes five partially collinear proteins. The most important of these is the HBV core protein p21, or HBc. It can self-assemble by forming viral HBc particles, but also plays a crucial role in the regulation of viral replication. Since 1986, the HBc protein has been one of the first and the most successful tools of the virus-like particle (VLP) technology. Later, the woodchuck hepatitis virus core protein (WHc) was also used as a VLP carrier. The Hepadnaviridae core proteins remain favourite VLP candidates for the knowledge-based design of future vaccines, gene therapy vectors, specifically targeted nanocontainers, and other modern nanotechnological tools for prospective medical use.

  19. Coinfection with Hepatitis B and C Viruses among HIV Positive ...

    African Journals Online (AJOL)

    Background: Hepatitis B and C viruses coinfection in HIV positive pregnant women is a common public health problem and recognized worldwide. The consequences of this problem in our poor resource setting with the risk of mother to child transmission is obvious with increased morbidity and mortality in our environment.

  20. HIV-1 phylogenetic analysis shows HIV-1 transits through the meninges to brain and peripheral tissues.

    Science.gov (United States)

    Lamers, Susanna L; Gray, Rebecca R; Salemi, Marco; Huysentruyt, Leanne C; McGrath, Michael S

    2011-01-01

    Brain infection by the human immunodeficiency virus type 1 (HIV-1) has been investigated in many reports with a variety of conclusions concerning the time of entry and degree of viral compartmentalization. To address these diverse findings, we sequenced HIV-1 gp120 clones from a wide range of brain, peripheral and meningeal tissues from five patients who died from several HIV-1 associated disease pathologies. High-resolution phylogenetic analysis confirmed previous studies that showed a significant degree of compartmentalization in brain and peripheral tissue subpopulations. Some intermixing between the HIV-1 subpopulations was evident, especially in patients that died from pathologies other than HIV-associated dementia. Interestingly, the major tissue harboring virus from both the brain and peripheral tissues was the meninges. These results show that (1) HIV-1 is clearly capable of migrating out of the brain, (2) the meninges are the most likely primary transport tissues, and (3) infected brain macrophages comprise an important HIV reservoir during highly active antiretroviral therapy. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Reduced incorporation of the influenza B virus BM2 protein in virus particles decreases infectivity

    International Nuclear Information System (INIS)

    Jackson, David; Zuercher, Thomas; Barclay, Wendy

    2004-01-01

    BM2 is the fourth integral membrane protein encoded by the influenza B virus genome. It is synthesized late in infection and transported to the plasma membrane from where it is subsequently incorporated into progeny virus particles. It has recently been reported that BM2 has ion channel activity and may be the functional homologue of the influenza A virus M2 protein acting as an ion channel involved in viral entry. Using a reverse genetic approach it was not possible to recover virus which lacked BM2. A recombinant influenza B virus was generated in which the BM2 AUG initiation codon was mutated to GUG. This decreased the efficiency of translation of BM2 protein such that progeny virions contained only 1/8 the amount of BM2 seen in wild-type virus. The reduction in BM2 incorporation resulted in a reduction in infectivity although there was no concomitant decrease in the numbers of virions released from the infected cells. These data imply that the incorporation of sufficient BM2 protein into influenza B virions is required for infectivity of the virus particles

  2. Gene therapy for human glioblastoma using neurotropic JC virus-like particles as a gene delivery vector.

    Science.gov (United States)

    Chao, Chun-Nun; Yang, Yu-Hsuan; Wu, Mu-Sheng; Chou, Ming-Chieh; Fang, Chiung-Yao; Lin, Mien-Chun; Tai, Chien-Kuo; Shen, Cheng-Huang; Chen, Pei-Lain; Chang, Deching; Wang, Meilin

    2018-02-02

    Glioblastoma multiforme (GBM), the most common malignant brain tumor, has a short period of survival even with recent multimodality treatment. The neurotropic JC polyomavirus (JCPyV) infects glial cells and oligodendrocytes and causes fatal progressive multifocal leukoencephalopathy in patients with AIDS. In this study, a possible gene therapy strategy for GBM using JCPyV virus-like particles (VLPs) as a gene delivery vector was investigated. We found that JCPyV VLPs were able to deliver the GFP reporter gene into tumor cells (U87-MG) for expression. In an orthotopic xenograft model, nude mice implanted with U87 cells expressing the near-infrared fluorescent protein and then treated by intratumoral injection of JCPyV VLPs carrying the thymidine kinase suicide gene, combined with ganciclovir administration, exhibited significantly prolonged survival and less tumor fluorescence during the experiment compared with controls. Furthermore, JCPyV VLPs were able to protect and deliver a suicide gene to distal subcutaneously implanted U87 cells in nude mice via blood circulation and inhibit tumor growth. These findings show that metastatic brain tumors can be targeted by JCPyV VLPs carrying a therapeutic gene, thus demonstrating the potential of JCPyV VLPs to serve as a gene therapy vector for the far highly treatment-refractory GBM.

  3. epidemiology of hepatitis b and hepatitis c virus infections among hiv

    African Journals Online (AJOL)

    boaz

    Hepatitis B and hepatitis C virus infection are common in Nigeria; where they are a major cause of both acute and chronic .... for HIV counseling and testing on a daily basis. .... The Genetic and Molecular ... Among Patients with Hemophilia in.

  4. 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.

  5. Infection with Hepatitis C Virus among HIV-Infected Pregnant Women in Thailand

    Directory of Open Access Journals (Sweden)

    Denise J. Jamieson

    2008-01-01

    Full Text Available Objective. The purpose of this study was to describe the epidemiology of coinfection with hepatitis C virus (HCV and HIV among a cohort of pregnant Thai women. Methods. Samples from 1771 pregnant women enrolled in three vertical transmission of HIV studies in Bangkok, Thailand, were tested for HCV. Results. Among HIV-infected pregnant women, HCV seroprevelance was 3.8% and the active HCV infection rate was 3.0%. Among HIV-uninfected pregnant women, 0.3% were HCV-infected. Intravenous drug use by the woman was the factor most strongly associated with HCV seropositivity. Among 48 infants tested for HCV who were born to HIV/HCV coinfected women, two infants were HCV infected for an HCV transmission rate of 4.2% (95% 0.51–14.25%. Conclusions. HCV seroprevalence and perinatal transmission rates were low among this Thai cohort of HIV-infected pregnant women.

  6. Contraception in the Context of HIV/AIDS: A Review | Agboghoroma ...

    African Journals Online (AJOL)

    HIV-positive women, like their uninfected counterparts, may desire to plan pregnancies, limit their families, or avoid pregnancy. The effective use of contraception by HIV-positive clients can contribute significantly to reduction in both sexual and vertical transmission of the virus. HIV-positive clients can use most of the ...

  7. 76 FR 58517 - Public Health Service Guideline for Reducing Transmission of Human Immunodeficiency Virus (HIV...

    Science.gov (United States)

    2011-09-21

    ...-2011-0011] Public Health Service Guideline for Reducing Transmission of Human Immunodeficiency Virus... public comment on the draft Public Health Service Guideline for Reducing Transmission of Human..., Attn: Public Health Service Guideline for Reducing Transmission of Human Immunodeficiency Virus (HIV...

  8. Increased incidence of cancer observed in HIV/hepatitis C virus-coinfected patients versus HIV-monoinfected.

    Science.gov (United States)

    Meijide, Héctor; Pértega, Sonia; Rodríguez-Osorio, Iria; Castro-Iglesias, Ángeles; Baliñas, Josefa; Rodríguez-Martínez, Guillermo; Mena, Álvaro; Poveda, Eva

    2017-05-15

    Cancer is a growing problem in persons living with HIV infection (PLWH) and hepatitis C virus (HCV) coinfection could play an additional role in carcinogenesis. Herein, all cancers in an HIV-mono and HIV/HCV-coinfected cohort were evaluated and compared to identify any differences between these two populations. A retrospective cohort study was conducted including all cancers in PLWH between 1993 and 2014. Cancers were classified in two groups: AIDS-defining cancer (ADC) and non-AIDS-defining cancer (NADC). Cancer incidence rates were calculated and compared with that observed in the Spanish general population (GLOBOCAN, 2012), computing the standardized incidence ratios (SIRs). A competing risk approach was used to estimate the probability of cancer after HIV diagnosis. Cumulative incidence in HIV-monoinfected and HIV/HCV-coinfected patients was also compared using multivariable analysis. A total of 185 patients (117 HIV-monoinfected and 68 HIV/HCV) developed cancer in the 26 580 patient-years cohort, with an incidence rate of 696 cancers per 100 000 person-years, higher than in the general population (SIR = 3.8). The incidence rate of NADC in HIV/HCV-coinfected patients was 415.0 (SIR = 3.4), significantly higher than in monoinfected (377.3; SIR = 1.8). After adjustments, HIV/HCV-coinfected patients had a higher cumulative incidence of NADC than HIV-monoinfected (adjusted hazard ratio = 1.80), even when excluding hepatocellular carcinomas (adjusted hazard ratio = 1.26). PLWH have a higher incidence of NADC than the general population and HCV-coinfection is associated with a higher incidence of NADC. These data justify the need for prevention strategies in these two populations and the importance of eradicating HCV.

  9. Evolving T-cell vaccine strategies for HIV, the virus with a thousand faces

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette [Los Alamos National Laboratory

    2009-01-01

    HIV's rapid global spread and the human suffering it has left in its wake have made AIDS a global heath priority for the 25 years since its discovery. Yet its capacity to rapidly evolve has made combating this virus a tremendous challenge. The obstacles to creating an effective HIV vaccine are formidable, but there are advances in the field on many fronts, in terms of novel vectors, adjuvants, and antigen design strategies. SIV live attenuated vaccine models are able to confer protection against heterologous challenge, and this continues to provide opportunities to explore the biological underpinnings of a protective effect (9). More indirect, but equally important, is new understanding regarding the biology of acute infection (43), the role of immune response in long-term non-progression (6,62, 81), and defining characteristics of broadly neutralizing antibodies (4). In this review we will focus on summarizing strategies directed towards a single issue, that of contending with HIV variation in terms of designing aT-cell vaccine. The strategies that prove most effective in this area can ultimately be combined with the best strategies under development in other areas, with the hope of ultimately converging on a viable vaccine candidate. Only two large HIV vaccine efficacy trials have been completed and both have failed to prevent infection or confer a benefit to infected individual (23,34), but there is ample reason to continue our efforts. A historic breakthrough came in 1996, when it was realized that although the virus could escape from a single antiretroviral (ARV) therapy, it could be thwarted by a combination of medications that simultaneously targeted different parts of the virus (HAART) (38). This revelation came after 15 years of research, thought, and clinical testing; to enable that vital progress the research and clinical communities had to first define and understand, then develop a strategy to counter, the remarkable evolutionary potential of the

  10. Current antiviral drugs and their analysis in biological materials - Part II: Antivirals against hepatitis and HIV viruses.

    Science.gov (United States)

    Nováková, Lucie; Pavlík, Jakub; Chrenková, Lucia; Martinec, Ondřej; Červený, Lukáš

    2018-01-05

    This review is a Part II of the series aiming to provide comprehensive overview of currently used antiviral drugs and to show modern approaches to their analysis. While in the Part I antivirals against herpes viruses and antivirals against respiratory viruses were addressed, this part concerns antivirals against hepatitis viruses (B and C) and human immunodeficiency virus (HIV). Many novel antivirals against hepatitis C virus (HCV) and HIV have been introduced into the clinical practice over the last decade. The recent broadening portfolio of these groups of antivirals is reflected in increasing number of developed analytical methods required to meet the needs of clinical terrain. Part II summarizes the mechanisms of action of antivirals against hepatitis B virus (HBV), HCV, and HIV, their use in clinical practice, and analytical methods for individual classes. It also provides expert opinion on state of art in the field of bioanalysis of these drugs. Analytical methods reflect novelty of these chemical structures and use by far the most current approaches, such as simple and high-throughput sample preparation and fast separation, often by means of UHPLC-MS/MS. Proper method validation based on requirements of bioanalytical guidelines is an inherent part of the developed methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. A comparative study of human T-cell lymphotropic virus-associated myelopathy in HIV-positive and HIV-negative patients in KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Hoosain F. Paruk

    2017-12-01

    Full Text Available Background: KwaZulu-Natal is an endemic area for HIV and human T-cell lymphotropic virus (HTLV infection. The main neurological manifestation of HTLV is HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP. The effect of HIV co-infection in patients with HAM/TSP is not well documented. Aims: To determine the prevalence of HIV seropositivity in patients with HAM/TSP and compare the clinical, laboratory and radiological features of patients mono-infected with HTLV and those dually infected with HTLV and HIV. Methods: Adult patients referred to the Neurology Department at Inkosi Albert Luthuli Central Hospital in KwaZulu-Natal, South Africa, for the period 01 January 2004 to 31 December 2015 with a positive HTLV serology were identified from the National Health Laboratory Service database. A retrospective chart review was conducted to identify all patients who had a diagnosis of HAM/TSP and to record their HIV status. Clinical, laboratory and radiological data were compared for HIV-positive and HIV-negative patients. Results: A total of 52 patients with HAM/TSP were identified. HIV results were available in 44 patients of whom 23 (52% patients were HIV co-infected. Patients who were HIV-positive had a younger age of presentation compared to HIV-negative patients (median: 31 vs 50 years, p = 0.002. HIV-positive patients had a median duration of symptoms at presentation of 12 months compared to 16 months for HIV-negative patients, but the difference did not reach statistical significance (p = 0.082. The CD4 cell counts of HIV-positive patients were well preserved with a median count of 781 cells/µL. Conclusions: HIV co-infection is commonly seen in the setting of HAM/TSP in KwaZulu-Natal. An interaction between the viruses may accelerate the development of HAM/TSP, leading to a younger age of presentation. Co-infection may have treatment implications because of CD4 counts being preserved in these patients.

  12. Reconstructing an icosahedral virus from single-particle diffraction experiments

    Science.gov (United States)

    Saldin, D. K.; Poon, H.-C.; Schwander, P.; Uddin, M.; Schmidt, M.

    2011-08-01

    The first experimental data from single-particle scattering experiments from free electron lasers (FELs) are now becoming available. The first such experiments are being performed on relatively large objects such as viruses, which produce relatively low-resolution, low-noise diffraction patterns in so-called ``diffract-and-destroy'' experiments. We describe a very simple test on the angular correlations of measured diffraction data to determine if the scattering is from an icosahedral particle. If this is confirmed, the efficient algorithm proposed can then combine diffraction data from multiple shots of particles in random unknown orientations to generate a full 3D image of the icosahedral particle. We demonstrate this with a simulation for the satellite tobacco necrosis virus (STNV), the atomic coordinates of whose asymmetric unit is given in Protein Data Bank entry 2BUK.

  13. Quality control assessment of human immunodeficiency virus type 2 (HIV-2) viral load quantification assays: results from an international collaboration on HIV-2 infection in 2006

    NARCIS (Netherlands)

    Damond, Florence; Benard, Antoine; Ruelle, Jean; Alabi, Abraham; Kupfer, Bernd; Gomes, Perpetua; Rodes, Berta; Albert, Jan; Böni, Jürg; Garson, Jeremy; Ferns, Bridget; Matheron, Sophie; Chene, Geneviève; Brun-Vezinet, Françoise; Goubau, Patrick; Campa, Pauline; Descamps, Diane; Simon, François; Taieb, Audrey; Autran, Brigitte; Cotten, Matt; Jaye, Assan; Peterson, Kevin; Rowland-Jones, Sarah; Rockstroh, Jürgen; Schwarze-Zander, Carolynne; de Wolf, Frank; van Sighem, Ard; Reiss, Peter; van der Loeff, Maarten Schim; Schutten, Martin; Camacho, Ricardo; Mansinho, Kamal; Antunes, Francisco; Luis, Franca; Valadas, Emilia; Toro, Carlos; Soriano, Vicente; Gyllensten, Katarina; Sonnerborg, Anders; Yilmaz, Aylin; Gisslén, Magnus; Calmy, Alexandra; Rickenbach, Martin; Pillay, Deenan; Tosswill, Jennifer; Anderson, Jane; Chadwick, David

    2008-01-01

    Human immunodeficiency virus type 2 (HIV-2) RNA quantification assays used in nine laboratories of the ACHI(E)V(2E) (A Collaboration on HIV-2 Infection) study group were evaluated. In a blinded experimental design, laboratories quantified three series of aliquots of an HIV-2 subtype A strain, each

  14. Gender inequality and domestic violence: implications for human immunodeficiency virus (HIV) prevention

    OpenAIRE

    Kaye, Dan K

    2004-01-01

    Domestic violence and human immunodeficiency virus (HIV) infection are problems of great public health worldwide, especially sub-Saharan Africa and much of the developing countries. This is due to their far reaching social, economic and public health consequences. The two problems have gender inequality and gender power imbalances as the driving force behind the “epidemics”. HIV infection is mainly acquired through heterosexual relations, which themselves are greatly influenced by socio-cultu...

  15. The oral microbiome in human immunodeficiency virus (HIV)-positive individuals.

    Science.gov (United States)

    Kistler, James O; Arirachakaran, Pratanporn; Poovorawan, Yong; Dahlén, Gunnar; Wade, William G

    2015-09-01

    Human immunodeficiency virus (HIV) infection is associated with a range of oral conditions, and increased numbers of disease-associated microbial species have previously been found in HIV-positive subjects. The aim of this study was to use next-generation sequencing to compare the composition of the oral microbiome in HIV-positive and -negative individuals. Plaque and saliva were collected from 37 HIV-positive individuals and 37 HIV-negative individuals, and their bacterial composition determined by pyrosequencing of partial 16S rRNA genes. A total of 855,222 sequences were analysed. The number of species-level operational taxonomic units (OTUs) detected was significantly lower in the saliva of HIV-positive individuals (mean = 303.3) than in that of HIV-negative individuals (mean = 365.5) (P PCoA) based on community membership (Jaccard index) and structure (Yue and Clayton measure of dissimilarity) showed significant separation of plaque and saliva samples [analysis of molecular variance (AMOVA), P PCoA plots did not show any clear separation based on HIV status. However, AMOVA indicated that there was a significant difference in the community membership of saliva between HIV-positive and -negative groups (P = 0.001). Linear discriminant analysis effect size revealed an OTU identified as Haemophilus parainfluenzae to be significantly associated with HIV-positive individuals, whilst Streptococcus mitis/HOT473 was most significantly associated with HIV-negative individuals. In conclusion, this study has confirmed that the microbial composition of saliva and plaque is different. The oral microbiomes of HIV-positive and -negative individuals were found to be similar overall, although there were minor but significant differences in the composition of the salivary microbiota of the two groups.

  16. HIV positive patient with GBS-like syndrome.

    Science.gov (United States)

    Shepherd, Samantha J; Black, Heather; Thomson, Emma C; Gunson, Rory N

    2017-08-01

    Introduction. Guillain-Barré Syndrome (GBS) is an acute demyelinating polyneuropathy which can occur post-infection. Criteria of diagnosis of GBS include areflexia with progressive bilateral weakness in arms and legs. GBS can lead to severe respiratory and cardiac complications. The fatality rate can be up to 5 % in patients, depending on the severity of the symptoms. HIV can cause a range of neurological disorders including, on rare occasions, GBS. GBS can occur at any stage of HIV infection, highlighting the complexity of diagnosis of GBS within HIV patients. Case presentation. A 57 year old female with lumbar back pain radiating to the legs, poor mobility and tiredness, with reports of a viral-like illness four days previously, was initially diagnosed with a lower respiratory tract infection and discharged. Seventeen days later the patient was readmitted to hospital with progressive lower and upper limb weakness, areflexia and sensory loss. She was diagnosed with GBS and was unexpectedly discovered to be HIV-positive. HIV avidity was low indicating a recently acquired HIV infection. The patient was treated with intravenous immunoglobulin for five days for the GBS and commenced antriretrovirals for HIV. The patient was discharge from hospital 53 days after admission with walking aids and regular physiotherapy follow-up. . This case highlighted the need for all clinicians to be aware that patients with symptoms of GBS, regardless of clinical history should be offered an HIV test. GBS can be the first sign a patient is HIV-positive.

  17. A stochastic spatial model of HIV dynamics with an asymmetric battle between the virus and the immune system

    International Nuclear Information System (INIS)

    Lin Hai; Shuai, J W

    2010-01-01

    A stochastic spatial model based on the Monte Carlo approach is developed to study the dynamics of human immunodeficiency virus (HIV) infection. We aim to propose a more detailed and realistic simulation frame by incorporating many important features of HIV dynamics, which include infections, replications and mutations of viruses, antigen recognitions, activations and proliferations of lymphocytes, and diffusions, encounters and interactions of virions and lymphocytes. Our model successfully reproduces the three-phase pattern observed in HIV infection, and the simulation results for the time distribution from infection to AIDS onset are also in good agreement with the clinical data. The interactions of viruses and the immune system in all the three phases are investigated. We assess the relative importance of various immune system components in the acute phase. The dynamics of how the two important factors, namely the viral diversity and the asymmetric battle between HIV and the immune system, result in AIDS are investigated in detail with the model.

  18. Prevalence of hepatitis C and B virus among patients infected with HIV: a cross-sectional analysis of a large HIV care programme in Myanmar.

    Science.gov (United States)

    Zaw, Sai Ko Ko; Tun, Sai Thein Than; Thida, Aye; Aung, Thet Ko; Maung, Win; Shwe, Myint; Aye, Mar Mar; Clevenbergh, Phillipe

    2013-07-01

    Co-infection with the hepatitis C virus (HCV) and/or hepatitis B virus (HBV) influences the morbidity and mortality of patients with HIV. A cross sectional analysis was of 11,032 HIV-infected patients enrolled in the Integrated HIV Care Program from May 2005 to April 2012 and Epi-info 3.5 was used to determine the serological prevalence of chronic hepatitis B and hepatitis C. The mean ± standard deviation age of patients was 36 ± 8.4 years (adult cohort) and 7 ± 3 years (paediatric cohort). The sero prevalence of hepatitis B surface antigen, hepatitis C (anti HCV antibodies) and triple infection are 8.7%, 5.3% and 0.35%, respectively. Men who have sex with men are at the highest risk of being co-infected with hepatitis B while intravenous drug users are at the highest risk of being co-infected with hepatitis C. It is important to screen for hepatitis B and C in HIV infected people in order to provide quality care for HIV patients with co-infection.

  19. HIV antibodies for treatment of HIV infection.

    Science.gov (United States)

    Margolis, David M; Koup, Richard A; Ferrari, Guido

    2017-01-01

    The bar is high to improve on current combination antiretroviral therapy (ART), now highly effective, safe, and simple. However, antibodies that bind the HIV envelope are able to uniquely target the virus as it seeks to enter new target cells, or as it is expressed from previously infected cells. Furthermore, the use of antibodies against HIV as a therapeutic may offer advantages. Antibodies can have long half-lives, and are being considered as partners for long-acting antiretrovirals for use in therapy or prevention of HIV infection. Early studies in animal models and in clinical trials suggest that such antibodies can have antiviral activity but, as with small-molecule antiretrovirals, the issues of viral escape and resistance will have to be addressed. Most promising, however, are the unique properties of anti-HIV antibodies: the potential ability to opsonize viral particles, to direct antibody-dependent cellular cytotoxicity (ADCC) against actively infected cells, and ultimately the ability to direct the clearance of HIV-infected cells by effector cells of the immune system. These distinctive activities suggest that HIV antibodies and their derivatives may play an important role in the next frontier of HIV therapeutics, the effort to develop treatments that could lead to an HIV cure. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  20. Nucleocapsid-like structures of Ebola virus reconstructed using electron tomography

    International Nuclear Information System (INIS)

    Noda, T.; Aoyama, K.; Sagara, H.; Kida, H.; Kawaoka, Y.

    2005-01-01

    Electron tomography (ET) is a new technique for high resolution, three-dimensional (3D) reconstruction of pleiomocphic mac. n)molecular complexes, such as virus components. By employing this technique, we resolved the 3D structure of Ebola virus nucleocapsid-like (NC-like) structures in the cytoplasm of cells expressing NP, VP24, and VP35: the minimum components required to form these NC-like structures. Reconstruction of these tubular NC-like structures of Ebola virus showed them to be composed of left-handed helices spaced at short intervals, which is structurally consistent with other non-segmented negative-strand RNA viruses

  1. Synthesis and evaluation of antiviral activities of novel sonochemical silver nanorods against HIV and HSV viruses

    Directory of Open Access Journals (Sweden)

    Mazyar Etemadzade

    2016-11-01

    Full Text Available Objective: To evaluate the effect of novel sonochemical silver nanorods on HIV and herpes simplex virus type 1 (HSV-1 viruses in human cervical cancer HeLa cells. Methods: The formation of silver nanorods conjugated with sodium 2-mercaptoethane sulfonate (Ag-MES was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and thermal gravimetric analysis. The antiviral activity of this Ag-MES was examined against HIV and HSV-1 virus replication. Results: The characterizations of Ag-MES and physiochemical structure were determined by scanning electron microscopy, Fourier transform infrared spectroscopy and thermal gravimetric analysis. Approximately entire viral replication was inhibited by Ag-MES at 10 µmol/mL concentration. About 90% of HSV virions failed to replicate in the present of this concentration of nanorods. However, HIV showed more sensitivity to Ag-MES than HSV-1. Conclusions: According to the obtained data, the synthesized sonochemical silver nanorod in this study is a promising candidate for further drug discovery investigation.

  2. Human immunodeficiency virus type-1 (HIV-1) genetic diversity and ...

    African Journals Online (AJOL)

    The presence of human immunodeficiency virus (HIV) type-1 diversity has an impact on vaccine efficacy and drug resistance. It is important to know the circulating genetic variants and associated drug-resistance mutations in the context of scale up of antiretroviral therapy (ART) in Nigeria. The objective of this study was to ...

  3. Goose parvovirus structural proteins expressed by recombinant baculoviruses self-assemble into virus-like particles with strong immunogenicity in goose.

    Science.gov (United States)

    Ju, Huanyu; Wei, Na; Wang, Qian; Wang, Chunyuan; Jing, Zhiqiang; Guo, Lu; Liu, Dapeng; Gao, Mingchun; Ma, Bo; Wang, Junwei

    2011-05-27

    Goose parvovirus (GPV), a small non-enveloped ssDNA virus, can cause Derzsy's disease, and three capsid proteins of VP1, VP2, and VP3 are encoded by an overlapping nucleotide sequence. However, little is known on whether recombinant viral proteins (VPs) could spontaneously assemble into virus-like particles (VLPs) in insect cells and whether these VLPs could retain their immunoreactivity and immunogenicity in susceptible geese. To address these issues, genes for these GPV VPs were amplified by PCR, and the recombinant VPs proteins were expressed in insect cells using a baculovirus expression system for the characterization of their structures, immunoreactivity, and immunogenicity. The rVP1, rVP2, and rVP3 expressed in Sf9 cells were detected by anti-GPV sera, anti-VP3 sera, and anti-His antibodies, respectively. Electron microscopy revealed that these rVPs spontaneously assembled into VLPs in insect cells, similar to that of the purified wild-type GPV virions. In addition, vaccination with individual types of VLPs, particularly with the rVP2-VLPs, induced higher titers of antibodies and neutralized different strains of GPVs in primary goose and duck embryo fibroblast cells in vitro. These data indicated that these VLPs retained immunoreactivity and had strong immunogenicity in susceptible geese. Therefore, our findings may provide a framework for development of new vaccines for the prevention of Derzsy's disease and vehicles for the delivery of drugs. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Epstein-Barr virus and human immunodeficiency virus serological responses and viral burdens in HIV-infected patients treated with HAART

    Science.gov (United States)

    O'Sullivan, Cathal E.; Peng, RongSheng; Cole, Kelly Stefano; Montelaro, Ronald C.; Sturgeon, Timothy; Jenson, Hal B.; Ling, Paul D.; Butel, J. S. (Principal Investigator)

    2002-01-01

    Epstein-Barr virus (EBV) associated non-Hodgkin lymphoma is recognized as a complication of human immunodeficiency virus (HIV) infection. Little is known regarding the influence of highly active antiretroviral therapy (HAART) on the biology of EBV in this population. To characterize the EBV- and HIV-specific serological responses together with EBV DNA levels in a cohort of HIV-infected adults treated with HAART, a study was conducted to compare EBV and HIV serologies and EBV DNA copy number (DNAemia) over a 12-month period after the commencement of HAART. All patients were seropositive for EBV at baseline. Approximately 50% of patients had detectable EBV DNA at baseline, and 27/30 had detectable EBV DNA at some point over the follow-up period of 1 year. Changes in EBV DNA copy number over time for any individual were unpredictable. Significant increases in the levels of Epstein-Barr nuclear antigen (EBNA) and Epstein-Barr early antigen (EA) antibodies were demonstrated in the 17 patients who had a good response to HAART. Of 29 patients with paired samples tested, four-fold or greater increases in titers were detected for EA in 12/29 (41%), for EBNA in 7/29 (24%), for VCA-IgG in 4/29 (14%); four-fold decreases in titers were detected in 2/29 (7%) for EA and 12/29 (41%) for EBNA. A significant decline in the titer of anti-HIV antibodies was also demonstrated. It was concluded that patients with advanced HIV infection who respond to HAART have an increase in their EBV specific antibodies and a decrease in their HIV-specific antibodies. For the cohort overall, there was a transient increase in EBV DNA levels that had declined by 12 months. Copyright 2002 Wiley-Liss, Inc.

  5. Virus-Like Particle Vaccination Protects Nonhuman Primates from Lethal Aerosol Exposure with Marburgvirus (VLP Vaccination Protects Macaques against Aerosol Challenges

    Directory of Open Access Journals (Sweden)

    John M. Dye

    2016-04-01

    Full Text Available Marburg virus (MARV was the first filovirus to be identified following an outbreak of viral hemorrhagic fever disease in Marburg, Germany in 1967. Due to several factors inherent to filoviruses, they are considered a potential bioweapon that could be disseminated via an aerosol route. Previous studies demonstrated that MARV virus-like particles (VLPs containing the glycoprotein (GP, matrix protein VP40 and nucleoprotein (NP generated using a baculovirus/insect cell expression system could protect macaques from subcutaneous (SQ challenge with multiple species of marburgviruses. In the current study, the protective efficacy of the MARV VLPs in conjunction with two different adjuvants: QS-21, a saponin derivative, and poly I:C against homologous aerosol challenge was assessed in cynomolgus macaques. Antibody responses against the GP antigen were equivalent in all groups receiving MARV VLPs irrespective of the adjuvant; adjuvant only-vaccinated macaques did not demonstrate appreciable antibody responses. All macaques were subsequently challenged with lethal doses of MARV via aerosol or SQ as a positive control. All MARV VLP-vaccinated macaques survived either aerosol or SQ challenge while animals administered adjuvant only exhibited clinical signs and lesions consistent with MARV disease and were euthanized after meeting the predetermined criteria. Therefore, MARV VLPs induce IgG antibodies recognizing MARV GP and VP40 and protect cynomolgus macaques from an otherwise lethal aerosol exposure with MARV.

  6. A Lagrangian particle model to predict the airborne spread of foot-and-mouth disease virus

    Science.gov (United States)

    Mayer, D.; Reiczigel, J.; Rubel, F.

    Airborne spread of bioaerosols in the boundary layer over a complex terrain is simulated using a Lagrangian particle model, and applied to modelling the airborne spread of foot-and-mouth disease (FMD) virus. Two case studies are made with study domains located in a hilly region in the northwest of the Styrian capital Graz, the second largest town in Austria. Mountainous terrain as well as inhomogeneous and time varying meteorological conditions prevent from application of so far used Gaussian dispersion models, while the proposed model can handle these realistically. In the model, trajectories of several thousands of particles are computed and the distribution of virus concentration near the ground is calculated. This allows to assess risk of infection areas with respect to animal species of interest, such as cattle, swine or sheep. Meteorological input data like wind field and other variables necessary to compute turbulence were taken from the new pre-operational version of the non-hydrostatic numerical weather prediction model LMK ( Lokal-Modell-Kürzestfrist) running at the German weather service DWD ( Deutscher Wetterdienst). The LMK model provides meteorological parameters with a spatial resolution of about 2.8 km. To account for the spatial resolution of 400 m used by the Lagrangian particle model, the initial wind field is interpolated upon the finer grid by a mass consistent interpolation method. Case studies depict a significant influence of local wind systems on the spread of virus. Higher virus concentrations at the upwind side of the hills and marginal concentrations in the lee are well observable, as well as canalization effects by valleys. The study demonstrates that the Lagrangian particle model is an appropriate tool for risk assessment of airborne spread of virus by taking into account the realistic orographic and meteorological conditions.

  7. The prevalence of hepatitis B virus infection markers and socio-demographic risk factors in HIV-infected patients in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Saulo Martins

    2014-10-01

    Full Text Available Introduction Hepatitis B virus (HBV and human immunodeficiency virus (HIV infections are two of the world's most important infectious diseases. Our objective was to determine the hepatitis B surface antigen (HBsAg and hepatitis B core antibody (anti-HBc prevalences among adult HIV-infected patients and identify the associations between socio-demographic variables and these HBV infection markers. Methods This study was performed from October 2012 to March 2013. Three hundred HIV-seropositive patients were monitored by the Clinical Analysis Laboratory of Professor Polydoro Ernani de São Thiago University Hospital, Santa Catarina, Brazil. The blood tests included HBsAg, anti-HBc immunoglobulin M (IgM and total anti-HBc. Patients reported their HIV viral loads and CD4+ T-cell counts using a questionnaire designed to collect sociodemographic data. Results The mean patient age was 44.6 years, the mean CD4 T-cell count was 525/mm3, the mean time since beginning antiretroviral therapy was 7.6 years, and the mean time since HIV diagnosis was 9.6 years. The overall prevalences of HBsAg and total anti-HBc were 2.3% and 29.3%, respectively. Among the individuals analyzed, 0.3% were positive for HBsAg, 27.3% were positive for total anti-HBc, and 2.0% were positive either for HBsAg or total anti-HBc and were classified as chronically HBV-infected. Furthermore, 70.3% of the patients were classified as never having been infected. Male gender, age >40 years and Caucasian ethnicity were associated with an anti-HBc positive test. Conclusions The results showed an intermediate prevalence of HBsAg among the studied patients. Moreover, the associations between the anti-HBc marker and socio-demographic factors suggest a need for HBV immunization among these HIV-positive individuals, who are likely to have HIV/HBV coinfection.

  8. On the Role of the SP1 Domain in HIV-1 Particle Assembly: a Molecular Switch?▿

    Science.gov (United States)

    Datta, Siddhartha A. K.; Temeselew, Lakew G.; Crist, Rachael M.; Soheilian, Ferri; Kamata, Anne; Mirro, Jane; Harvin, Demetria; Nagashima, Kunio; Cachau, Raul E.; Rein, Alan

    2011-01-01

    Expression of a retroviral protein, Gag, in mammalian cells is sufficient for assembly of immature virus-like particles (VLPs). VLP assembly is mediated largely by interactions between the capsid (CA) domains of Gag molecules but is facilitated by binding of the nucleocapsid (NC) domain to nucleic acid. We have investigated the role of SP1, a spacer between CA and NC in HIV-1 Gag, in VLP assembly. Mutational analysis showed that even subtle changes in the first 4 residues of SP1 destroy the ability of Gag to assemble correctly, frequently leading to formation of tubes or other misassembled structures rather than proper VLPs. We also studied the conformation of the CA-SP1 junction region in solution, using both molecular dynamics simulations and circular dichroism. Consonant with nuclear magnetic resonance (NMR) studies from other laboratories, we found that SP1 is nearly unstructured in aqueous solution but undergoes a concerted change to an α-helical conformation when the polarity of the environment is reduced by addition of dimethyl sulfoxide (DMSO), trifluoroethanol, or ethanol. Remarkably, such a coil-to-helix transition is also recapitulated in an aqueous medium at high peptide concentrations. The exquisite sensitivity of SP1 to mutational changes and its ability to undergo a concentration-dependent structural transition raise the possibility that SP1 could act as a molecular switch to prime HIV-1 Gag for VLP assembly. We suggest that changes in the local environment of SP1 when Gag oligomerizes on nucleic acid might trigger this switch. PMID:21325421

  9. Hepatitis E virus co-infection in HIV-infected patients in Foggia and Naples in southern Italy.

    Science.gov (United States)

    Scotto, Gaetano; Grisorio, Benvenuto; Filippini, Pietro; Ferrara, Sergio; Massa, Salvatore; Bulla, Fabio; Martini, Salvatore; Filippini, Alberico; Tartaglia, Alessandra; Lo Muzio, Lorenzo; Fazio, Vincenzina

    2015-01-01

    Hepatitis E virus (HEV) infection represents an emerging infection in developed countries and is thought to be a zoonotic infection. It has recently been described as a new causative agent of acute and chronic hepatitis in immunosuppressed subjects, including HIV-infected patients. The aim of this study was to assess the sero-virological prevalence of HEV in HIV patients and in the general population as control group. A prospective and observational cohort study was carried out in two hospitals in southern Italy. The seroprevalence of HEV was determined in a cohort of 959 subjects, 509 (53%) of whom were HIV-positive patients and 450 were from the general population. Serum samples were tested for anti-HEV antibodies; repeatedly positive results were confirmed by a Western blot assay. In positive patients HEV RNA and genotypes were also determined. A total of 46 (4.8%) of the 959 serum samples examined were reactive to anti-HEV Ig and confirmed by Western blotting. The prevalence of HEV antibodies (IgG and/or IgM) was 2.7% in the control group and 6.7% in HIV-infected patients. Anti-HEV IgM was found in 6/46 (13.0%) of the anti-HEV Ig-positive serum samples, in 5/34 HIV patients and in 1/12 of the general population. No HIV-infected patient presented chronic hepatitis with HEV infection alone. This study indicates a higher circulation of HEV in HIV-infected patients, whereas a low prevalence of HEV antibodies in the general Italian population was shown. Chronic hepatitis with HEV alone was absent, while it was present in subjects with HIV-HEV, co-infected with hepatitis B virus (HBV) and/or hepatitis C virus (HCV).

  10. Is a Pacific Coexistence Between Virus and Host the Unexploited Path That May Lead to an HIV Functional Cure?

    Directory of Open Access Journals (Sweden)

    Jonathan Fior

    2013-02-01

    Full Text Available The SupT1 cell line supports optimal HIV-1 replication, and prolonged in vitro replication in SupT1 cells renders the virus significantly less virulent. This raises the question of whether the infusion of SupT1 cells could be used as a cell-based therapy to induce a pacific coexistence between the HIV virus and its human host. In a recent study, I investigated this potential therapeutic strategy in vitro. The results suggested that this approach should be further explored in HIV-susceptible animal models. Such studies may lead to the development of a functional cure for HIV infection.

  11. Chronic Hepatitis B and C Virus Infection and Risk for Non-Hodgkin Lymphoma in HIV-Infected Patients

    DEFF Research Database (Denmark)

    Wang, Qing; De Luca, Andrea; Smith, Colette

    2017-01-01

    Background: Non-Hodgkin lymphoma (NHL) is the most common AIDS-defining condition in the era of antiretroviral therapy (ART). Whether chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection promote NHL in HIV-infected patients is unclear. Objective: To investigate whether chronic HBV...... and HCV infection are associated with increased incidence of NHL in HIV-infected patients. Design: Cohort study. Setting: 18 of 33 cohorts from the Collaboration of Observational HIV Epidemiological Research Europe (COHERE). Patients: HIV-infected patients with information on HBV surface antigen...... measurements and detectable HCV RNA, or a positive HCV antibody test result if HCV RNA measurements were not available. Measurements: Time-dependent Cox models to assess risk for NHL in treatment-naive patients and those initiating ART, with inverse probability weighting to control for informative censoring...

  12. The Measles Virus Receptor SLAMF1 Can Mediate Particle Endocytosis.

    Science.gov (United States)

    Gonçalves-Carneiro, Daniel; McKeating, Jane A; Bailey, Dalan

    2017-04-01

    The signaling lymphocyte activation molecule F1 (SLAMF1) is both a microbial sensor and entry receptor for measles virus (MeV). Herein, we describe a new role for SLAMF1 to mediate MeV endocytosis that is in contrast with the alternative, and generally accepted, model that MeV genome enters cells only after fusion at the cell surface. We demonstrated that MeV engagement of SLAMF1 induces dramatic but transient morphological changes, most prominently in the formation of membrane blebs, which were shown to colocalize with incoming viral particles, and rearrangement of the actin cytoskeleton in infected cells. MeV infection was dependent on these dynamic cytoskeletal changes as well as fluid uptake through a macropinocytosis-like pathway as chemical inhibition of these processes inhibited entry. Moreover, we identified a role for the RhoA-ROCK-myosin II signaling axis in this MeV internalization process, highlighting a novel role for this recently characterized pathway in virus entry. Our study shows that MeV can hijack a microbial sensor normally involved in bacterial phagocytosis to drive endocytosis using a complex pathway that shares features with canonical viral macropinocytosis, phagocytosis, and mechanotransduction. This uptake pathway is specific to SLAMF1-positive cells and occurs within 60 min of viral attachment. Measles virus remains a significant cause of mortality in human populations, and this research sheds new light on the very first steps of infection of this important pathogen. IMPORTANCE Measles is a significant disease in humans and is estimated to have killed over 200 million people since records began. According to current World Health Organization statistics, it still kills over 100,000 people a year, mostly children in the developing world. The causative agent, measles virus, is a small enveloped RNA virus that infects a broad range of cells during infection. In particular, immune cells are infected via interactions between glycoproteins found

  13. Mesoporous Silicon with Modified Surface for Plant Viruses and Their Protein Particle Sensing

    Directory of Open Access Journals (Sweden)

    Kae Dal Kwack

    2008-10-01

    Full Text Available Changes in electric parameters of a mesoporous silicon treated by a plasma chemical etching with fluorine and hydrogen ions, under the adsorption of NEPO (Nematodetransmitted Polyhedral plant viruses such as TORSV (Tomato Ringspot Virus, GFLV (Grapevine Fan Leaf Virus and protein macromolecule from TORSV particles are described. The current response to the applied voltage is measured for each virus particle to investigate the material parameters which are sensitive to the adsorbed particles. The peculiar behaviors of the response are modeled by the current-voltage relationship in a MOSFET. This model explains the behavior well and the double gate model of the MOSFET informs that the mesoporous silicon is a highly sensitive means of detecting the viruses in the size range less than 50 nm.

  14. Expression, purification, crystallization and preliminary X-ray crystallographic studies of hepatitis B virus core fusion protein corresponding to octahedral particles

    International Nuclear Information System (INIS)

    Kikuchi, Masaki; Iwabuchi, Shinichiro; Kikkou, Tatsuhiko; Noguchi, Keiichi; Odaka, Masafumi; Yohda, Masafumi; Kawata, Masaaki; Sato, Chikara; Matsumoto, Osamu

    2013-01-01

    Novel hepatitis B virus-like particles of recombinant dimeric core–GFP fusion protein were expressed, purified and crystallized. The crystals diffracted to 2.15 Å resolution and belonged to space group F432, with unit-cell parameters a = b = c = 219.7 Å. Recombinant hepatitis B virus core proteins dimerize to form building blocks that are capable of self-assembly into a capsid. A core capsid protein dimer (CPD) linked to a green fluorescent protein variant, EGFP, at the C-terminus has been designed. The recombinant fusion CPD was expressed in Escherichia coli, assembled into virus-like particles (VLPs), purified and crystallized. The single crystal diffracted to 2.15 Å resolution and belonged to the cubic space group F432, with unit-cell parameters a = b = c = 219.7 Å. The fusion proteins assembled into icosahedral VLPs in aqueous solution, but were rearranged into octahedral symmetry through the crystal-packing process under the crystallization conditions

  15. Multimeric scaffolds displaying the HIV-1 envelope MPER induce MPER-specific antibodies and cross-neutralizing antibodies when co-immunized with gp160 DNA.

    Directory of Open Access Journals (Sweden)

    Shelly J Krebs

    Full Text Available Developing a vaccine that overcomes the diversity of HIV-1 is likely to require a strategy that directs antibody (Ab responses toward conserved regions of the viral Envelope (Env. However, the generation of neutralizing Abs (NAbs targeting these regions through vaccination has proven to be difficult. One conserved region of particular interest is the membrane proximal external region (MPER of Env located within the gp41 ectodomain. In order to direct the immune response to this region, the MPER and gp41 ectodomain were expressed separately as N-terminal fusions to the E2 protein of Geobacillus stearothermophilus. The E2 protein acts as a scaffold by self-assembling into 60-mer particles, displaying up to 60 copies of the fused target on the surface. Rabbits were immunized with E2 particles displaying MPER and/or the gp41 ectodomain in conjunction with DNA encoding full-length gp160. Only vaccines including E2 particles displaying MPER elicited MPER-specific Ab responses. NAbs were elicited after two immunizations that largely targeted the V3 loop. To overcome V3 immunodominance in the DNA component, E2 particles displaying MPER were used in conjunction with gp160 DNA lacking hypervariable regions V2, V3, or combined V1V2V3. All rabbits had HIV binding Ab responses and NAbs following the second vaccination. Using HIV-2/HIV-1 MPER chimeric viruses as targets, NAbs were detected in 12/16 rabbits after three immunizations. Low levels of NAbs specific for Tier 1 and 2 viruses were observed in all groups. This study provides evidence that co-immunizing E2 particles displaying MPER and gp160 DNA can focus Ab responses toward conserved regions of Env.

  16. Decision making under explicit risk is impaired in individuals with human immunodeficiency virus (HIV).

    Science.gov (United States)

    Fujiwara, Esther; Tomlinson, Sara E; Purdon, Scot E; Gill, M John; Power, Christopher

    2015-01-01

    Human immunodeficiency virus (HIV) can affect the frontal-striatal brain regions, which are known to subserve decision-making functions. Previous studies have reported impaired decision making among HIV+ individuals using the Iowa Gambling Task, a task that assesses decision making under ambiguity. Previous study populations often had significant comorbidities such as past or present substance use disorders and/or hepatitis C virus coinfection, complicating conclusions about the unique contributions of HIV-infection to decision making. Decision making under explicit risk has very rarely been examined in HIV+ individuals and was tested here using the Game of Dice Task (GDT). We examined decision making under explicit risk in the GDT in 20 HIV+ individuals without substance use disorder or HCV coinfection, including a demographically matched healthy control group (n = 20). Groups were characterized on a standard neuropsychological test battery. For the HIV+ group, several disease-related parameters (viral load, current and nadir CD4 T-cell count) were included. Analyses focused on the GDT and spanned between-group (t-tests; analysis of covariance, ANCOVA) as well as within-group comparisons (Pearson/Spearman correlations). HIV+ individuals were impaired in the GDT, compared to healthy controls (p = .02). Their decision-making impairments were characterized by less advantageous choices and more random choice strategies, especially towards the end of the task. Deficits in the GDT in the HIV+ group were related to executive dysfunctions, slowed processing/motor speed, and current immune system status (CD4+ T-cell levels, ps Decision making under explicit risk in the GDT can occur in HIV-infected individuals without comorbidities. The correlational patterns may point to underlying fronto-subcortical dysfunctions in HIV+ individuals. The GDT provides a useful measure to assess risky decision making in this population and should be tested in larger studies.

  17. Knowledge and Attitudes toward HIV, Hepatitis B Virus, and Hepatitis C Virus Infection among Health-care Workers in Malawi.

    Science.gov (United States)

    Mtengezo, Jasintha; Lee, Haeok; Ngoma, Jonathan; Kim, Susie; Aronowitz, Teri; DeMarco, Rosanna; Shi, Ling

    2016-01-01

    The highest prevalence of HIV infection occurs in Sub-Saharan Africa and hepatitis B virus (HBV), and hepatitis C virus (HCV) prevalence are the second highest in Sub-Saharan Africa including Malawi. Health-care workers (HCWs) play an important role in the prevention of, response to, and management of these infectious diseases. There is, however, no published research about the level of knowledge and attitudes toward HIV, HBV, and HCV infection among Malawian HCWs. The purpose of this study was to explore and determine the knowledge of and attitudes toward HIV, HBV, and HCV among a targeted population of Malawian HCWs. A cross-sectional community-based participatory research with 194 HCWs was completed employing health survey method. The project was a collaborative effort between nursing faculties in the USA and Malawian. A one-way analysis of variance (ANOVA) with the Bonferroni adjustment for multiple comparisons was used to assess the differences in knowledge and attitude among three subgroups of HCWs. Of 194 of Malawian HCWs surveyed, 41% were support staff, 37% were nursing students, and 22% were health-care professionals. Both health-care professionals and support staff had high knowledge scores related to HIV/AIDS, and their attitudes were mainly positive. However, a series of one-way ANOVAs revealed significant differences in knowledge and attitude toward HIV/AIDs, HBV, and HCV among HCWs ( P attitudes toward hepatitis. This study highlights the ongoing need for reducing negative attitudes toward HIV, HBV, and HCV; and providing health education among HCWs, especially focusing on HBV and HCV prevention. The findings of the research project can be used to develop interventions addressing low HBV- and HCV-related knowledge and attitudes.

  18. Virus-producing cells determine the host protein profiles of HIV-1 virion cores

    Science.gov (United States)

    2012-01-01

    incorporation of some RNA binding (RHA and HELIC2) and DNA binding proteins (MCM5 and Ku80) in the viral cores from T cells was higher than in the cores from both mMΦ and mMN and did not correlate with the abundance of these proteins in virus producing cells. Conclusions Profiles of host proteins packaged in the cores of HIV-1 virions depend on the type of virus producing cell. The pool of proteins present in the cores of all virions is likely to contain factors important for viral functions. Incorporation ratio of certain RNA- and DNA-binding proteins suggests their more efficient, non-random packaging into virions in T cells than in mMΦ and mMN. PMID:22889230

  19. Aqueous Extracts of the Marine Brown Alga Lobophora variegata Inhibit HIV-1 Infection at the Level of Virus Entry into Cells

    KAUST Repository

    Kremb, Stephan

    2014-08-21

    In recent years, marine algae have emerged as a rich and promising source of molecules with potent activities against various human pathogens. The widely distributed brown alga Lobophora variegata that is often associated with tropical coral reefs exerts strong antibacterial and antiprotozoal effects, but so far has not been associated with specific anti-viral activities. This study investigated potential HIV-1 inhibitory activity of L. variegata collected from different geographical regions, using a cell-based full replication HIV-1 reporter assay. Aqueous L. variegata extracts showed strong inhibitory effects on several HIV-1 strains, including drug-resistant and primary HIV-1 isolates, and protected even primary cells (PBMC) from HIV-1-infection. Anti-viral potency was related to ecological factors and showed clear differences depending on light exposition or epiphyte growth. Assays addressing early events of the HIV-1 replication cycle indicated that L. variegata extracts inhibited entry of HIV-1 into cells at a pre-fusion step possibly by impeding mobility of virus particles. Further characterization of the aqueous extract demonstrated that even high doses had only moderate effects on viability of cultured and primary cells (PBMCs). Imaging-based techniques revealed extract effects on the plasma membrane and actin filaments as well as induction of apoptosis at concentrations exceeding EC50 of anti-HIV-1 activity by more than 400 fold. In summary, we show for the first time that L. variegata extracts inhibit HIV-1 entry, thereby suggesting this alga as promising source for the development of novel HIV-1 inhibitors.

  20. Global Dynamics of HIV Infection of CD4+ T Cells and Macrophages

    Directory of Open Access Journals (Sweden)

    A. M. Elaiw

    2013-01-01

    Full Text Available We study the global dynamics of an HIV infection model describing the interaction of the HIV with CD4+ T cells and macrophages. The incidence rate of virus infection and the growth rate of the uninfected CD4+ T cells and macrophages are given by general functions. We have incorporated two types of distributed delays into the model to account for the time delay between the time the uninfected cells are contacted by the virus particle and the time for the emission of infectious (matures virus particles. We have established a set of conditions which are sufficient for the global stability of the steady states of the model. Using Lyapunov functionals and LaSalle's invariant principle, we have proven that if the basic reproduction number R0 is less than or equal to unity, then the uninfected steady state is globally asymptotically stable (GAS, and if the infected steady state exists, then it is GAS.

  1. A high throughput Cre–lox activated viral membrane fusion assay identifies pharmacological inhibitors of HIV entry

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, Anthony M. [Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Immunology Institute, New York, NY (United States); Cheung, Pamela [Integrated Screening Core, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Swartz, Talia H.; Li, Hongru [Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Immunology Institute, New York, NY (United States); Tsibane, Tshidi [Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Durham, Natasha D. [Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Immunology Institute, New York, NY (United States); Basler, Christopher F. [Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Felsenfeld, Dan P. [Integrated Screening Core, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Chen, Benjamin K., E-mail: benjamin.chen@mssm.edu [Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Immunology Institute, New York, NY (United States)

    2016-03-15

    Enveloped virus entry occurs when viral and cellular membranes fuse releasing particle contents into the target cell. Human immunodeficiency virus (HIV) entry occurs by cell-free virus or virus transferred between infected and uninfected cells through structures called virological synapses. We developed a high-throughput cell-based assay to identify small molecule inhibitors of cell-free or virological synapse-mediated entry. An HIV clone carrying Cre recombinase as a Gag-internal gene fusion releases active Cre into cells upon viral entry activating a recombinatorial gene switch changing dsRed to GFP-expression. A screen of a 1998 known-biological profile small molecule library identified pharmacological HIV entry inhibitors that block both cell-free and cell-to-cell infection. Many top hits were noted as HIV inhibitors in prior studies, but not previously recognized as entry antagonists. Modest therapeutic indices for simvastatin and nigericin were observed in confirmatory HIV infection assays. This robust assay is adaptable to study HIV and heterologous viral pseudotypes. - Highlights: • Cre recombinase viral fusion assay screens cell-free or cell–cell entry inhibitors. • This Gag-iCre based assay is specific for the entry step of HIV replication. • Screened a library of known pharmacologic compounds for HIV fusion antagonists. • Many top hits were previously noted as HIV inhibitors, but here are classified as entry antagonists. Many top hits were previously noted as HIV inhibitors, but not as entry antagonists. • The assay is compatible with pseudotyping with HIV and heterologous viruses.

  2. A high throughput Cre–lox activated viral membrane fusion assay identifies pharmacological inhibitors of HIV entry

    International Nuclear Information System (INIS)

    Esposito, Anthony M.; Cheung, Pamela; Swartz, Talia H.; Li, Hongru; Tsibane, Tshidi; Durham, Natasha D.; Basler, Christopher F.; Felsenfeld, Dan P.; Chen, Benjamin K.

    2016-01-01

    Enveloped virus entry occurs when viral and cellular membranes fuse releasing particle contents into the target cell. Human immunodeficiency virus (HIV) entry occurs by cell-free virus or virus transferred between infected and uninfected cells through structures called virological synapses. We developed a high-throughput cell-based assay to identify small molecule inhibitors of cell-free or virological synapse-mediated entry. An HIV clone carrying Cre recombinase as a Gag-internal gene fusion releases active Cre into cells upon viral entry activating a recombinatorial gene switch changing dsRed to GFP-expression. A screen of a 1998 known-biological profile small molecule library identified pharmacological HIV entry inhibitors that block both cell-free and cell-to-cell infection. Many top hits were noted as HIV inhibitors in prior studies, but not previously recognized as entry antagonists. Modest therapeutic indices for simvastatin and nigericin were observed in confirmatory HIV infection assays. This robust assay is adaptable to study HIV and heterologous viral pseudotypes. - Highlights: • Cre recombinase viral fusion assay screens cell-free or cell–cell entry inhibitors. • This Gag-iCre based assay is specific for the entry step of HIV replication. • Screened a library of known pharmacologic compounds for HIV fusion antagonists. • Many top hits were previously noted as HIV inhibitors, but here are classified as entry antagonists. Many top hits were previously noted as HIV inhibitors, but not as entry antagonists. • The assay is compatible with pseudotyping with HIV and heterologous viruses.

  3. Spread of human T-cell leukemia virus (HTLV-I) in the Dutch homosexual community

    NARCIS (Netherlands)

    Goudsmit, J.; de Wolf, F.; van de Wiel, B.; Smit, L.; Bakker, M.; Albrecht-van Lent, N.; Coutinho, R. A.

    1987-01-01

    Sequential sera of 697 homosexual men, participating in a prospective study (1984-1986) of the risk to acquire human immunodeficiency virus (HIV) or AIDS, were tested for antibodies to human T-cell leukaemia virus (HTLV-I) by particle agglutination and immunoblotting. No intravenous drug users were

  4. DMPD: Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15031527 Toll-like receptor 3: a link between toll-like receptor, interferon and virus... (.csml) Show Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. PubmedID 1503...1527 Title Toll-like receptor 3: a link between toll-like receptor, interferon and virus

  5. Liver-related death among HIV/hepatitis C virus-co-infected individuals

    DEFF Research Database (Denmark)

    Grint, Daniel; Peters, Lars; Rockstroh, Juergen K

    2015-01-01

    BACKGROUND: Potent, less toxic, directly acting antivirals (DAAs) for treatment of hepatitis C virus (HCV) infection promise to improve HCV cure rates among HIV/HCV-co-infected individuals. However, the costs of treatment will necessitate prioritization of those at greatest risk of liver-related ......BACKGROUND: Potent, less toxic, directly acting antivirals (DAAs) for treatment of hepatitis C virus (HCV) infection promise to improve HCV cure rates among HIV/HCV-co-infected individuals. However, the costs of treatment will necessitate prioritization of those at greatest risk of liver.......7-2.9), but substantial in those with F2/F3 and F4 fibrosis (sHR 10.3%, 95% CI 7.6-13.5; and sHR 14.0%, 95% CI 10.3-18.3, respectively). CONCLUSION: Treatment with DAAs should be prioritized for those with at least F2 fibrosis. Early initiation of cART with the aim of avoiding low CD4 cell counts should be considered...

  6. Transmission of HCV to a chimpanzee using virus particles produced in an RNA-transfected HepG2 cell culture.

    Science.gov (United States)

    Dash, S; Kalkeri, G; McClure, H M; Garry, R F; Clejan, S; Thung, S N; Murthy, K K

    2001-10-01

    It was demonstrated previously that HepG2 cells produce negative strand RNA and virus-like particles after transfection with RNA transcribed from a full-length hepatitis C virus (HCV) cDNA clone [Dash et al. (1997) American Journal of Pathology, 151:363-373]. To determine in vivo infectivity of these in vitro synthesized viral particles, a chimpanzee was inoculated intravenously with HCV derived from HepG2 cells. The infected chimpanzee was examined serially for elevation of liver enzymes, for the presence of HCV RNA in the serum by reverse transcription nested polymerase chain reaction (RT-PCR), anti-HCV antibodies in the serum, and inflammation in the liver. The chimpanzee developed elevated levels of liver enzymes after the second week, but the levels fluctuated over a 10-week period. HCV RNA was detected in the serum of the chimpanzee at the second, seventh and ninth weeks after inoculation, and remained positive up to 25 weeks. Liver biopsies at Weeks 18 and 19 revealed of mild inflammation. Nucleotide sequence analysis of HCV recovered from the infected chimpanzee at the second and ninth weeks showed 100% sequence homology with the clone used for transfection studies. Serum anti-HCV antibodies were not detected by EIA during the 25 weeks follow-up period. These results suggest that intravenous administration of the virus-like particles derived from RNA-transfected HepG2 cells are infectious, and therefore, the pMO9.6-T7 clone is an infectious clone. These results provide new information that in vitro synthesized HCV particles produced from full-length HCV clone can cause infection in a chimpanzee. This study will facilitate the use of innovative approaches to the study of assembly of HCV particles and mechanisms of virus infectivity in cell culture. Copyright 2001 Wiley-Liss, Inc.

  7. Antiretroviral Drugs and Risk of Chronic Alanine Aminotransferase Elevation in Human Immunodeficiency Virus (HIV)-Monoinfected Persons

    DEFF Research Database (Denmark)

    Kovari, Helen; Sabin, Caroline A; Ledergerber, Bruno

    2016-01-01

    Background.  Although human immunodeficiency virus (HIV)-positive persons on antiretroviral therapy (ART) frequently have chronic liver enzyme elevation (cLEE), the underlying cause is often unclear. Methods.  Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) Study participants without ...

  8. Antiviral activity of α-helical stapled peptides designed from the HIV-1 capsid dimerization domain

    Directory of Open Access Journals (Sweden)

    Cowburn David

    2011-05-01

    Full Text Available Abstract Background The C-terminal domain (CTD of HIV-1 capsid (CA, like full-length CA, forms dimers in solution and CTD dimerization is a major driving force in Gag assembly and maturation. Mutations of the residues at the CTD dimer interface impair virus assembly and render the virus non-infectious. Therefore, the CTD represents a potential target for designing anti-HIV-1 drugs. Results Due to the pivotal role of the dimer interface, we reasoned that peptides from the α-helical region of the dimer interface might be effective as decoys to prevent CTD dimer formation. However, these small peptides do not have any structure in solution and they do not penetrate cells. Therefore, we used the hydrocarbon stapling technique to stabilize the α-helical structure and confirmed by confocal microscopy that this modification also made these peptides cell-penetrating. We also confirmed by using isothermal titration calorimetry (ITC, sedimentation equilibrium and NMR that these peptides indeed disrupt dimer formation. In in vitro assembly assays, the peptides inhibited mature-like virus particle formation and specifically inhibited HIV-1 production in cell-based assays. These peptides also showed potent antiviral activity against a large panel of laboratory-adapted and primary isolates, including viral strains resistant to inhibitors of reverse transcriptase and protease. Conclusions These preliminary data serve as the foundation for designing small, stable, α-helical peptides and small-molecule inhibitors targeted against the CTD dimer interface. The observation that relatively weak CA binders, such as NYAD-201 and NYAD-202, showed specificity and are able to disrupt the CTD dimer is encouraging for further exploration of a much broader class of antiviral compounds targeting CA. We cannot exclude the possibility that the CA-based peptides described here could elicit additional effects on virus replication not directly linked to their ability to bind

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

    Science.gov (United States)

    Hønge, Bl; Jespersen, S; Medina, C; Té, Ds; da Silva, Zj; Ostergaard, L; Laursen, Al; Wejse, C; Krarup, H; Erikstrup, C

    2014-10-01

    In the case of coinfection with HIV and hepatitis B virus (HBV) and/or hepatitis C virus (HCV), hepatic disease progression is often accelerated, with higher rates of liver cirrhosis and liver-related mortality. We aimed to evaluate the performance of the rapid tests used routinely to detect HBV surface antigen (HBsAg) and anti-HCV among HIV-infected patients in Guinea-Bissau. Blood samples from HIV-infected patients in Guinea-Bissau were stored after testing for HBsAg and anti-HCV with rapid tests. Samples were subsequently re-tested for HBsAg and anti-HCV in Denmark. Two rapid tests were used in Guinea-Bissau: HBsAg Strip Ref 2034 (VEDA.LAB, Alençon, France; sensitivity 62.3%; specificity 99.2%) and HEPA-SCAN (Bhat Bio-Tech, Bangalore, India; sensitivity 57.1%; specificity 99.7%). In the two tests the ability to obtain the correct outcome depended on the antigen and antibody concentrations, respectively. Sex, age, CD4 cell count and antiretroviral therapy status did not differ between false negative and true positive samples in either of the tests. The study is limited by a low number of anti-HCV positive samples. New diagnostic rapid tests should always be evaluated in the setting in which they will be used before implementation. © 2014 British HIV Association.

  10. Functional Interplay Between Murine Leukemia Virus Glycogag, Serinc5, and Surface Glycoprotein Governs Virus Entry, with Opposite Effects on Gammaretroviral and Ebolavirus Glycoproteins

    Directory of Open Access Journals (Sweden)

    Yadvinder S. Ahi

    2016-11-01

    Full Text Available Gammaretroviruses, such as murine leukemia viruses (MLVs, encode, in addition to the canonical Gag, Pol, and Env proteins that will form progeny virus particles, a protein called “glycogag” (glycosylated Gag. MLV glycogag contains the entire Gag sequence plus an 88-residue N-terminal extension. It has recently been reported that glycogag, like the Nef protein of HIV-1, counteracts the antiviral effects of the cellular protein Serinc5. We have found, in agreement with prior work, that glycogag strongly enhances the infectivity of MLVs with some Env proteins but not those with others. In contrast, however, glycogag was detrimental to MLVs carrying Ebolavirus glycoprotein. Glycogag could be replaced, with respect to viral infectivity, by the unrelated S2 protein of equine infectious anemia virus. We devised an assay for viral entry in which virus particles deliver the Cre recombinase into cells, leading to the expression of a reporter. Data from this assay showed that both the positive and the negative effects of glycogag and S2 upon MLV infectivity are exerted at the level of virus entry. Moreover, transfection of the virus-producing cells with a Serinc5 expression plasmid reduced the infectivity and entry capability of MLV carrying xenotropic MLV Env, particularly in the absence of glycogag. Conversely, Serinc5 expression abrogated the negative effects of glycogag upon the infectivity and entry capability of MLV carrying Ebolavirus glycoprotein. As Serinc5 may influence cellular phospholipid metabolism, it seems possible that all of these effects on virus entry derive from changes in the lipid composition of viral membranes.

  11. PREVALENCE OF HYPERTENSION, ANEMIA, ASYMPTOMATIC URINARY TRACT INFECTION, SYPHILIS, HIV AND HEPATITIS B VIRUS INFECTION

    Science.gov (United States)

    Deme, Chala; Edao, Beyene; Jaya, Gemedi; Tisiano, Gebre; Fano, Hayi; Alegria, Iñaki; Reyes, Francisco; Gorgolas, Miguel; Ramos, José M

    2016-09-01

    Antenatal care (ANC) is provided to prevent, diagnose early and treat pregnant women for a variety of diseases. The objective of this study was to determine the seroprevalences of syphilis, human immunodeficiency virus (HIV) and hepatitis B virus (HVB) and asymptomatic urinary tract infections and the prevalence of hypertension and anemia among pregnant women attending the antenatal clinic at Gambo Rural Hospital in southern Ethiopia. The following tests were conducted among study subjects: hemoglobin (Hgb) level, rapid plasma reagin (RPR) for syphilis, anti-HIV antibodies, hepatitis B surface antigen (HBsAg) and urine analysis. A total of 574 pregnant women were included in this study. The mean age of the participants was 25.7 (SD: 4.8) years old; 88.2% were living in urban areas and 11.8% in rural areas. Sixty-seven point two percent of participants began their attended care during the second trimester of their pregnancy. Overall, anemia (Hgb urinary tract infection (having ≥10 white blood cells /high power field in the urine) was present in 12.7% of participants (95% CI: 10.0-15.5). The RPR test was positive in two patients (0.3%; 95% CI: 0.1-1.3). The prevalences of positive test for HBsAg and HIV-1 were 2.3% (95% CI: 1.3-3.8) and 0.2% (95% CI: 0.03-0.9), respectively. No HIV-2 cases were detected. Our data show relatively low prevalences of anemia, hypertension, urinary tract infection, syphilis, HIV, and hepatitis B virus infections among study subjects at a rural antenatal clinic in southern Ethiopia.

  12. Viral (hepatitis C virus, hepatitis B virus, HIV) persistence and immune homeostasis

    Science.gov (United States)

    Zhou, Yun; Zhang, Ying; Moorman, Jonathan P; Yao, Zhi Q; Jia, Zhan S

    2014-01-01

    Immune homeostasis is a host characteristic that maintains biological balance within a host. Humans have evolved many host defence mechanisms that ensure the survival of individuals upon encountering a pathogenic infection, with recovery or persistence from a viral infection being determined by both viral factors and host immunity. Chronic viral infections, such as hepatitis B virus, hepatitis C virus and HIV, often result in chronic fluctuating viraemia in the face of host cellular and humoral immune responses, which are dysregulated by multi-faceted mechanisms that are incompletely understood. This review attempts to illuminate the mechanisms involved in this process, focusing on immune homeostasis in the setting of persistent viral infection from the aspects of host defence mechanism, including interferon-stimulated genes, apolipoprotein B mRNA editing enzyme catalytic polypeptide 3 (APOBEC3), autophagy and interactions of various immune cells, cytokines and regulatory molecules. PMID:24965611

  13. Influence of minor displacements in loops of the porcine parvovirus VP2 capsid on virus-like particles assembly and the induction of antibody responses.

    Science.gov (United States)

    Pan, Qunxing; He, Kongwang; Wang, Yongshan; Wang, Xiaoli; Ouyang, Wei

    2013-06-01

    An antigen-delivery system based on hybrid virus-like particles (VLPs) formed by the self-assembly of the capsid VP2 protein of porcine parvovirus (PPV) and expressing foreign peptides offers an alternative method for vaccination. In this study, the three-dimensional structure of the PPV capsid protein and surface loops deletion mutants were analyzed to define essential domains in PPV VP2 for the assembly of VLPs. Electron microscopic analysis and SDS-PAGE analysis confirmed the presence of abundant VLPs in a loop2 deletion mutant of expected size and appropriate morphology. Loop4 and loop2-loop4 deletion mutants, however, resulted in a lower number of particles and the morphology of the particles was not well preserved. Furthermore, the green fluorescent protein (gfp) gene was used as a model. GFP was observed at the same level in displacements mutants. However, GFP displacement mutants in loop2 construct allowed better adaptation for the fusion GFP to be further displayed on the surface of the capsid-like structure. Immunogenicity study showed that there is no obvious difference in mice inoculated with rAd-VP2(Δloop2), rAd-VP2(Δloop4), rAd-VP2(Δloop2-Δloop4), and PPV inactivated vaccine. The results suggested the possibility of inserting simultaneously B and T cell epitopes in the surface loop2 and the N-terminus. The combination of different types of epitopes (B, CD4+, and CD8+) in different positions of the PPV particles opens the way to the development of highly efficient vaccines, able to stimulate at the same time the different branches of the immune system.

  14. Cervical cytological abnormalities and human papilloma virus infection in women infected with HIV in Southern India.

    Science.gov (United States)

    Thunga, Suchitra; Andrews, Anusmitha; Ramapuram, John; Satyamoorthy, Kapaettu; Kini, Hema; Unnikrishnan, B; Adhikari, Prabha; Singh, Prakhar; Kabekkodu, Shama Prasada; Bhat, Samatha; Kadam, Anagha; Shetty, Avinash K

    2016-12-01

    The aim of this study was to examine the association between CD4 count, human papilloma virus (HPV) infection, and the risk of cervical intraepithelial neoplasia among HIV-infected women. A cross-sectional study was conducted among 104 HIV-infected women attending an antiretroviral therapy clinic. They underwent Pap smear and cervical HPV DNA testing. The overall prevalence of HPV infection was 57.7%. HPV 16 was the commonest genotype found (38.5%); HPV 16 and 18 put together contributed to 73.3% of HPV infection; 27.5% of HIV-infected women had squamous cell abnormalities. Cervical intraepithelial neoplasia was less likely among women with CD4 count > 500/mm 3 (12%) and in those without opportunistic infections (17.8%). The prevalence of high-risk HPV infection was higher in women with high-grade squamous intraepithelial lesions or greater lesions (85.7%) as compared to women with normal cytology (52.1%). The high prevalence of HPV infection and cervical intraepithelial neoplasia in HIV-infected women warrants the need for regular Pap smear screening in these women and routine HPV vaccination for adolescents to reduce the burden of cervical cancer in India. © 2016 Japan Society of Obstetrics and Gynecology.

  15. Negative chromatography of hepatitis B virus-like particle: Comparative study of different adsorbent designs.

    Science.gov (United States)

    Lee, Micky Fu Xiang; Chan, Eng Seng; Tan, Wen Siang; Tam, Kam Chiu; Tey, Beng Ti

    2016-05-06

    Purification of virus-like particles (VLPs) in bind-and-elute mode has reached a bottleneck. Negative chromatography has emerged as the alternative solution; however, benchmark of negative chromatography media and their respective optimized conditions are absent. Hence, this study was carried out to compare the performance of different negative chromatography media for the purification of hepatitis B VLPs (HB-VLPs) from clarified Escherichia coli feedstock. The modified anion exchange media, core-shell adsorbents (InertShell and InertLayer 1000) and polymer grafted adsorbents (SQ) were compared. The results of chromatography from packed bed column of core-shell adsorbents showed that there is a trade-off between the purity and recovery of HB-VLPs in the flowthrough fraction due to the shell thickness. Atomic force microscopic analysis revealed funnel-shaped pore channels in the shell layer which may contribute to the entrapment of HB-VLPs. A longer residence time at a lower feed flow rate (0.5ml/min) improved slightly the HB-VLPs purity in all modified adsorbents, but the recovery in InertShell reduced substantially. The preheat-treatment is not recommended for the negative chromatography as the thermal-induced co-aggregation of HCPs and HB-VLPs would flow along with HB-VLPs and thus reduced the HB-VLPs purity in the flowthrough. Further reduction in the feedstock concentration enhanced the purity of HB-VLPs especially in InertLayer 1000 but reduced substantially the recovery of HB-VLPs. In general, the polymer grafted adsorbent, SQ, performed better than the core-shell adsorbents in handling a higher feedstock concentration. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. The Function of CD3+CD56+ NKT-Like Cells in HIV-Infected Individuals

    Directory of Open Access Journals (Sweden)

    Yongjun Jiang

    2014-01-01

    Full Text Available CD3+CD56+ NKT-like cells are one of the critical effectors in the immune response to viral infection and tumors, but the functional features of NKT-like cells in HIV infection have been rarely reported. In this study, we observed and described the state of NKT-like cell functions in primary HIV-infected individuals (PHIs, chronic HIV-infected individuals (CHIs, long-term nonprogressors (LTNPs, and HIV-negative controls (NCs. The results showed that the percentage of IFN-γ+CD3+CD56+ NKT-like cells was notably higher in LTNPs compared with CHIs, and the proportion of CD3+CD56+ NKT-like cells with dual function (IFN-γ+CD107a+ NKT-like cells in LTNPs was also much higher than in CHIs. Additionally, the percentages of IFN-γ+CD107a+ NKT-like cells negatively correlated with viral load. Taken together, our data demonstrated that good functions of CD3+CD56+ NKT-like cells in LTNPs likely occurred as a protective mechanism that slows down HIV disease progression.

  17. The function of CD3+CD56+ NKT-like cells in HIV-infected individuals.

    Science.gov (United States)

    Jiang, Yongjun; Cui, Xiaojian; Cui, Chen; Zhang, Jian; Zhou, Fangyuan; Zhang, Zining; Fu, Yajing; Xu, Junjie; Chu, Zhenxing; Liu, Jing; Han, Xiaoxu; Liao, Christina; Wang, Yanan; Cao, Yaming; Shang, Hong

    2014-01-01

    CD3(+)CD56(+) NKT-like cells are one of the critical effectors in the immune response to viral infection and tumors, but the functional features of NKT-like cells in HIV infection have been rarely reported. In this study, we observed and described the state of NKT-like cell functions in primary HIV-infected individuals (PHIs), chronic HIV-infected individuals (CHIs), long-term nonprogressors (LTNPs), and HIV-negative controls (NCs). The results showed that the percentage of IFN-γ(+)CD3(+)CD56(+) NKT-like cells was notably higher in LTNPs compared with CHIs, and the proportion of CD3(+)CD56(+) NKT-like cells with dual function (IFN-γ(+)CD107a(+) NKT-like cells) in LTNPs was also much higher than in CHIs. Additionally, the percentages of IFN-γ(+)CD107a(+) NKT-like cells negatively correlated with viral load. Taken together, our data demonstrated that good functions of CD3(+)CD56(+) NKT-like cells in LTNPs likely occurred as a protective mechanism that slows down HIV disease progression.

  18. Feline immunodeficiency virus envelope glycoproteins antagonize tetherin through a distinctive mechanism that requires virion incorporation.

    Science.gov (United States)

    Morrison, James H; Guevara, Rebekah B; Marcano, Adriana C; Saenz, Dyana T; Fadel, Hind J; Rogstad, Daniel K; Poeschla, Eric M

    2014-03-01

    BST2/tetherin inhibits the release of enveloped viruses from cells. Primate lentiviruses have evolved specific antagonists (Vpu, Nef, and Env). Here we characterized tetherin proteins of species representing both branches of the order Carnivora. Comparison of tiger and cat (Feliformia) to dog and ferret (Caniformia) genes demonstrated that the tiger and cat share a start codon mutation that truncated most of the tetherin cytoplasmic tail early in the Feliformia lineage (19 of 27 amino acids, including the dual tyrosine motif). Alpha interferon (IFN-α) induced tetherin and blocked feline immunodeficiency virus (FIV) replication in lymphoid and nonlymphoid feline cells. Budding of bald FIV and HIV particles was blocked by carnivore tetherins. However, infectious FIV particles were resistant, and spreading FIV replication was uninhibited. Antagonism mapped to the envelope glycoprotein (Env), which rescued FIV from carnivore tetherin restriction when expressed in trans but, in contrast to known antagonists, did not rescue noncognate particles. Also unlike the primate lentiviral antagonists, but similar to the Ebola virus glycoprotein, FIV Env did not reduce intracellular or cell surface tetherin levels. Furthermore, FIV-enveloped FIV particles actually required tetherin for optimal release from cells. The results show that FIV Envs mediate a distinctive tetherin evasion. Well adapted to a phylogenetically ancient tetherin tail truncation in the Felidae, it requires functional virion incorporation of Env, and it shields the budding particle without downregulating plasma membrane tetherin. Moreover, FIV has evolved dependence on this protein: particles containing FIV Env need tetherin for optimal release from the cell, while Env(-) particles do not. HIV-1 antagonizes the restriction factor tetherin with the accessory protein Vpu, while HIV-2 and the filovirus Ebola use their envelope (Env) glycoproteins for this purpose. It turns out that the FIV tetherin antagonist is

  19. New Taastrup-Like virus, Rhabdoviridae, lethal to leafhoppers

    Science.gov (United States)

    A new viral pathogen (‘Taastrup Virus’) of leafhoppers was discovered. The unclassified virus is a negative sense, single-stranded RNA virus which appears to be a new member of the order Mononegavirales in the family Rhabdoviridae, and thus far it is only the second report of a Taastrup-like virus m...

  20. Predictors of hepatitis B virus genotype and viraemia in HIV-infected patients with chronic hepatitis B in Europe

    DEFF Research Database (Denmark)

    Soriano, Vincent; Mocroft, Amanda; Peters, Lars

    2010-01-01

    Both natural history and treatment outcome of hepatitis B virus (HBV) infection are influenced by genotypes and viral load. Information about factors determining HBV genotype distribution and viraemia in HIV/HBV-co-infected patients is scarce.......Both natural history and treatment outcome of hepatitis B virus (HBV) infection are influenced by genotypes and viral load. Information about factors determining HBV genotype distribution and viraemia in HIV/HBV-co-infected patients is scarce....

  1. Flail arm-like syndrome associated with HIV-1 infection

    Directory of Open Access Journals (Sweden)

    Nalini A

    2009-01-01

    Full Text Available During the last 20 years at least 23 cases of motor neuron disease have been reported in HIV-1 seropositive patients. In this report we describe the clinical picture of a young man with HIV-1 clade C infection and flail arm-like syndrome, who we were able to follow-up for a long period. We investigated and prospectively monitored a 34-year-old man with features of flail arm syndrome, who developed the weakness and wasting 1 year after being diagnosed with HIV-1 infection after a routine blood test. He presented in 2003 with progressive, symmetrical wasting and weakness of the proximal muscles of the upper limb of 2 years′ duration. He had severe wasting and weakness of the shoulder and arm muscles. There were no pyramidal signs. He has been on HAART for the last 4 years and the weakness or wasting has not worsened. At the last follow-up in July 2007, the patient had the same neurological deficit and no other symptoms or signs of HIV-1 infection. MRI of the spinal cord in 2007 showed characteristic T2 hyperintense signals in the central part of the spinal cord, corresponding to the central gray matter. Thus, our patient had HIV-1 clade C infection associated with a ′flail arm-like syndrome.′ The causal relationship between HIV-1 infection and amyotrophic lateral sclerosis (ALS-like syndrome is still uncertain. The syndrome usually manifests as a lower motor neuron syndrome, as was seen in our young patient. It is known that treatment with antiretroviral therapy (ART stabilizes/improves the condition. In our patient the weakness and atrophy remained stable over a period of 3.5 years after commencing HAART regimen.

  2. Bacterium-like Particles for efficient immune stimulation of existing vaccines and new subunit vaccines in mucosal applications

    Directory of Open Access Journals (Sweden)

    Natalija eVan Braeckel-Budimir

    2013-09-01

    Full Text Available The successful development of a mucosal vaccine critically depends on the use of a safe and effective immunostimulant and/or carrier system. This review describes the effectiveness and mode of action of an immunostimulating particle derived from bacteria in mucosal subunit vaccines. The non-living particles, designated Bacterium-like Particles (BLPs are based on the food-grade bacterium Lactococcus lactis. The focus of the overview is on the development of intranasal BLP-based vaccines to prevent diseases caused by influenza and respiratory syncytial virus, and includes a selection of Phase I clinical data for the intranasal FluGEM vaccine.

  3. The etiology of Ebola virus disease-like illnesses in Ebola virusnegative patients from Sierra Leone.

    Science.gov (United States)

    Li, Wen-Gang; Chen, Wei-Wei; Li, Lei; Ji, Dong; Ji, Ying-Jie; Li, Chen; Gao, Xu-Dong; Wang, Li-Fu; Zhao, Min; Duan, Xue-Zhang; Duan, Hui-Juan

    2016-05-10

    During the 2014 Ebola virus disease (EVD) outbreak, less than half of EVD-suspected cases were laboratory tested as Ebola virus (EBOV)-negative, but disease identity remained unknown. In this study we investigated the etiology of EVD-like illnesses in EBOV-negative cases. From November 13, 2014 to March 16, 2015, EVD-suspected patients were admitted to Jui Government Hospital and assessed for EBOV infection by real-time PCR. Of 278 EBOV negative patients, 223 (80.21%), 142 (51.08%), 123 (44.24%), 114 (41.01%), 59 (21.22%), 35 (12.59%), and 12 (4.32%) reported fever, headache, joint pain, fatigue, nausea/vomiting, diarrhea, hemorrhage, respectively. Furthermore, 121 (43.52%), 44 (15.83%), 36 (12.95%), 33 (11.87%), 23 (8.27%), 10 (3.60%) patients were diagnosed as infection with malaria, HIV, Lassa fever, tuberculosis, yellow fever, and pneumonia, respectively. No significant differences in clinical features and symptoms were found between non-EVD and EVD patients. To the best of our knowledge, the present study is the first to explore the etiology of EVD-like illnesses in uninfected patients in Sierra Leone, highlighting the importance of accurate diagnosis to EVD confirmation.

  4. The cellular endosomal sorting complex required for transport pathway is not involved in avian metapneumovirus budding in a virus-like-particle expression system.

    Science.gov (United States)

    Weng, Yuejin; Lu, Wuxun; Harmon, Aaron; Xiang, Xiaoxiao; Deng, Qiji; Song, Minxun; Wang, Dan; Yu, Qingzhong; Li, Feng

    2011-05-01

    Avian metapneumovirus (AMPV) is a paramyxovirus that principally causes respiratory disease and egg production drops in turkeys and chickens. Together with its closely related human metapneumovirus (HMPV), they comprise the genus Metapneumovirus in the family Paramyxoviridae. Little is currently known about the mechanisms involved in the budding of metapneumovirus. By using AMPV as a model system, we showed that the matrix (M) protein by itself was insufficient to form virus-like-particles (VLPs). The incorporation of M into VLPs was shown to occur only when both the viral nucleoprotein (N) and the fusion (F) proteins were co-expressed. Furthermore, we provided evidence indicating that two YSKL and YAGL segments encoded within the M protein were not a functional late domain, and the endosomal sorting complex required for transport (ESCRT) machinery was not involved in metapneumovirus budding, consistent with a recent observation that human respiratory syncytial virus, closely related to HMPV, uses an ESCRT-independent budding mechanism. Taken together, these results suggest that metapneumovirus budding is independent of the ESCRT pathway and the minimal budding machinery described here will aid our future understanding of metapneumovirus assembly and egress.

  5. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... What are HIV and AIDS? HIV (human immunodeficiency virus) is the virus that causes AIDS (acquired immune deficiency syndrome). AIDS ... but no cure, at the present time. The virus (HIV) and the disease it causes (AIDS) are ...

  6. Quantitative comparison of HTLV-1 and HIV-1 cell-to-cell infection with new replication dependent vectors.

    Directory of Open Access Journals (Sweden)

    Dmitriy Mazurov

    2010-02-01

    Full Text Available We have developed an efficient method to quantify cell-to-cell infection with single-cycle, replication dependent reporter vectors. This system was used to examine the mechanisms of infection with HTLV-1 and HIV-1 vectors in lymphocyte cell lines. Effector cells transfected with reporter vector, packaging vector, and Env expression plasmid produced virus-like particles that transduced reporter gene activity into cocultured target cells with zero background. Reporter gene expression was detected exclusively in target cells and required an Env-expression plasmid and a viral packaging vector, which provided essential structural and enzymatic proteins for virus replication. Cell-cell fusion did not contribute to infection, as reporter protein was rarely detected in syncytia. Coculture of transfected Jurkat T cells and target Raji/CD4 B cells enhanced HIV-1 infection two fold and HTLV-1 infection ten thousand fold in comparison with cell-free infection of Raji/CD4 cells. Agents that interfere with actin and tubulin polymerization strongly inhibited HTLV-1 and modestly decreased HIV-1 cell-to-cell infection, an indication that cytoskeletal remodeling was more important for HTLV-1 transmission. Time course studies showed that HTLV-1 transmission occurred very rapidly after cell mixing, whereas slower kinetics of HIV-1 coculture infection implies a different mechanism of infectious transmission. HTLV-1 Tax was demonstrated to play an important role in altering cell-cell interactions that enhance virus infection and replication. Interestingly, superantigen-induced synapses between Jurkat cells and Raji/CD4 cells did not enhance infection for either HTLV-1 or HIV-1. In general, the dependence on cell-to-cell infection was determined by the virus, the effector and target cell types, and by the nature of the cell-cell interaction.

  7. Escape from Human Immunodeficiency Virus Type 1 (HIV-1 Entry Inhibitors

    Directory of Open Access Journals (Sweden)

    Carol D. Weiss

    2012-12-01

    Full Text Available The human immunodeficiency virus (HIV enters cells through a series of molecular interactions between the HIV envelope protein and cellular receptors, thus providing many opportunities to block infection. Entry inhibitors are currently being used in the clinic, and many more are under development. Unfortunately, as is the case for other classes of antiretroviral drugs that target later steps in the viral life cycle, HIV can become resistant to entry inhibitors. In contrast to inhibitors that block viral enzymes in intracellular compartments, entry inhibitors interfere with the function of the highly variable envelope glycoprotein as it continuously adapts to changing immune pressure and available target cells in the extracellular environment. Consequently, pathways and mechanisms of resistance for entry inhibitors are varied and often involve mutations across the envelope gene. This review provides a broad overview of entry inhibitor resistance mechanisms that inform our understanding of HIV entry and the design of new inhibitors and vaccines.

  8. Epstein-Barr virus infects B and non-B lymphocytes in HIV-1-infected children and adolescents

    NARCIS (Netherlands)

    Bekker, Vincent; Scherpbier, Henriëtte; Beld, Marcel; Piriou, Erwan; van Breda, Alex; Lange, Joep; van Leth, Frank; Jurriaans, Suzanne; Alders, Sophie; Wertheim-van Dillen, Pauline; van Baarle, Debbie; Kuijpers, Taco

    2006-01-01

    Epstein-Barr virus (EBV) is a widespread, persistent herpesvirus that can transform B cells and that is associated with malignant lymphomas. EBV dynamics and specific immunity in human immunodeficiency virus (HIV)-1-infected children are unknown. We found that, in 74% of EBV-seropositive,

  9. The Generation of Turnip Crinkle Virus-Like Particles in Plants by the Transient Expression of Wild-Type and Modified Forms of Its Coat Protein.

    Science.gov (United States)

    Saunders, Keith; Lomonossoff, George P

    2015-01-01

    Turnip crinkle virus (TCV), a member of the genus carmovirus of the Tombusviridae family, has a genome consisting of a single positive-sense RNA molecule that is encapsidated in an icosahedral particle composed of 180 copies of a single type of coat protein. We have employed the CPMV-HT transient expression system to investigate the formation of TCV-like particles following the expression of the wild-type coat protein or modified forms of it that contain either deletions and/or additions. Transient expression of the coat protein in plants results in the formation of capsid structures that morphologically resemble TCV virions (T = 3 structure) but encapsidate heterogeneous cellular RNAs, rather than the specific TCV coat protein messenger RNA. Expression of an amino-terminal deleted form of the coat protein resulted in the formation of smaller T = 1 structures that are free of RNA. The possibility of utilizing TCV as a carrier for the presentation of foreign proteins on the particle surface was also explored by fusing the sequence of GFP to the C-terminus of the coat protein. The expression of coat protein-GFP hybrids permitted the formation of VLPs but the yield of particles is diminished compared to the yield obtained with unmodified coat protein. Our results confirm the importance of the N-terminus of the coat protein for the encapsidation of RNA and show that the coat protein's exterior P domain plays a key role in particle formation.

  10. Anti-HIV-1 activity of anionic polymers: a comparative study of candidate microbicides

    Directory of Open Access Journals (Sweden)

    Li Yun-Yao

    2002-11-01

    Full Text Available Abstract Background Cellulose acetate phthalate (CAP in soluble form blocks coreceptor binding sites on the virus envelope glycoprotein gp120 and elicits gp41 six-helix bundle formation, processes involved in virus inactivation. CAP is not soluble at pH Methods Enzyme linked immunosorbent assays (ELISA were used to (1 study HIV-1 IIIB and BaL binding to micronized CAP; (2 detect virus disintegration; and (3 measure gp41 six-helix bundle formation. Cells containing integrated HIV-1 LTR linked to the β-gal gene and expressing CD4 and coreceptors CXCR4 or CCR5 were used to measure virus infectivity. Results 1 HIV-1 IIIB and BaL, respectively, effectively bound to micronized CAP. 2 The interaction between HIV-1 and micronized CAP led to: (a gp41 six-helix bundle formation; (b virus disintegration and shedding of envelope glycoproteins; and (c rapid loss of infectivity. Polymers other than CAP, except Carbomer 974P, elicited gp41 six-helix bundle formation in HIV-1 IIIB but only poly(napthalene sulfonate, in addition to CAP, had this effect on HIV-1 BaL. These polymers differed with respect to their virucidal activities, the differences being more pronounced for HIV-1 BaL. Conclusions Micronized CAP is the only candidate topical microbicide with the capacity to remove rapidly by adsorption from physiological fluids HIV-1 of both the X4 and R5 biotypes and is likely to prevent virus contact with target cells. The interaction between micronized CAP and HIV-1 leads to rapid virus inactivation. Among other anionic polymers, cellulose sulfate, BufferGel and aryl sulfonates appear most effective in this respect.

  11. Murine polyomavirus virus-like particles carrying full-length human PSA protect BALB/c mice from outgrowth of a PSA expressing tumor.

    Directory of Open Access Journals (Sweden)

    Mathilda Eriksson

    Full Text Available Virus-like particles (VLPs consist of capsid proteins from viruses and have been shown to be usable as carriers of protein and peptide antigens for immune therapy. In this study, we have produced and assayed murine polyomavirus (MPyV VLPs carrying the entire human Prostate Specific Antigen (PSA (PSA-MPyVLPs for their potential use for immune therapy in a mouse model system. BALB/c mice immunized with PSA-MPyVLPs were only marginally protected against outgrowth of a PSA-expressing tumor. To improve protection, PSA-MPyVLPs were co-injected with adjuvant CpG, either alone or loaded onto murine dendritic cells (DCs. Immunization with PSA-MPyVLPs loaded onto DCs in the presence of CpG was shown to efficiently protect mice from tumor outgrowth. In addition, cellular and humoral immune responses after immunization were examined. PSA-specific CD4(+ and CD8(+ cells were demonstrated, but no PSA-specific IgG antibodies. Vaccination with DCs loaded with PSA-MPyVLPs induced an eight-fold lower titre of anti-VLP antibodies than vaccination with PSA-MPyVLPs alone. In conclusion, immunization of BALB/c mice with PSA-MPyVLPs, loaded onto DCs and co-injected with CpG, induces an efficient PSA-specific tumor protective immune response, including both CD4(+ and CD8(+ cells with a low induction of anti-VLP antibodies.

  12. Murine Polyomavirus Virus-Like Particles Carrying Full-Length Human PSA Protect BALB/c Mice from Outgrowth of a PSA Expressing Tumor

    Science.gov (United States)

    Eriksson, Mathilda; Andreasson, Kalle; Weidmann, Joachim; Lundberg, Kajsa; Tegerstedt, Karin

    2011-01-01

    Virus-like particles (VLPs) consist of capsid proteins from viruses and have been shown to be usable as carriers of protein and peptide antigens for immune therapy. In this study, we have produced and assayed murine polyomavirus (MPyV) VLPs carrying the entire human Prostate Specific Antigen (PSA) (PSA-MPyVLPs) for their potential use for immune therapy in a mouse model system. BALB/c mice immunized with PSA-MPyVLPs were only marginally protected against outgrowth of a PSA-expressing tumor. To improve protection, PSA-MPyVLPs were co-injected with adjuvant CpG, either alone or loaded onto murine dendritic cells (DCs). Immunization with PSA-MPyVLPs loaded onto DCs in the presence of CpG was shown to efficiently protect mice from tumor outgrowth. In addition, cellular and humoral immune responses after immunization were examined. PSA-specific CD4+ and CD8+ cells were demonstrated, but no PSA-specific IgG antibodies. Vaccination with DCs loaded with PSA-MPyVLPs induced an eight-fold lower titre of anti-VLP antibodies than vaccination with PSA-MPyVLPs alone. In conclusion, immunization of BALB/c mice with PSA-MPyVLPs, loaded onto DCs and co-injected with CpG, induces an efficient PSA-specific tumor protective immune response, including both CD4+ and CD8+ cells with a low induction of anti-VLP antibodies. PMID:21858228

  13. [Vaccine for human immunodeficiency virus (HIV)--relevance of these days].

    Science.gov (United States)

    Laiskonis, Alvydas; Pukenyte, Evelina

    2005-01-01

    Since 1980 more than 25 million people have died from acquired immunodeficiency syndrome (AIDS), which results from infection with human immunodeficiency virus (HIV). Number of new cases increases very threateningly. One and the most effective method to stop the progress of epidemic is the development of the vaccine for HIV. There is the presentation of the first stage of the vaccine for HIV testing (structure, methodology), which is now on trial in St. Pierre hospital, Brussels University. HIV characteristics which inflame the process of the vaccine development, historical facts and facts about vaccines on trial in these days are reviewed in this article. More than 10,000 volunteers have been participating in various clinical trials since 1987. The development of the vaccine is a very difficult, long-terming (about 8-10 years) and costly process. The process of the vaccine testing is very difficult in developing countries where the infection spreads the most rapidly. Available data confirm that the vaccine must be multi-componential, inducing cellular, humoral immunity against various subtypes of HIV. The vaccine cannot protect fully but the changes of the natural infection course could decrease virulence, distance the stage of AIDS, and retard the spread of the epidemic.

  14. Defining the Interaction of HIV-1 with the Mucosal Barriers of the Female Reproductive Tract

    Science.gov (United States)

    Carias, Ann M.; McCoombe, Scott; McRaven, Michael; Anderson, Meegan; Galloway, Nicole; Vandergrift, Nathan; Fought, Angela J.; Lurain, John; Duplantis, Maurice; Veazey, Ronald S.

    2013-01-01

    Worldwide, HIV-1 infects millions of people annually, the majority of whom are women. To establish infection in the female reproductive tract (FRT), HIV-1 in male ejaculate must overcome numerous innate and adaptive immune factors, traverse the genital epithelium, and establish infection in underlying CD4+ target cells. How the virus achieves this remains poorly defined. By utilizing a new technique, we define how HIV-1 interacts with different tissues of the FRT using human cervical explants and in vivo exposure in the rhesus macaque vaginal transmission model. Despite previous claims of the squamous epithelium being an efficient barrier to virus entry, we reveal that HIV-1 can penetrate both intact columnar and squamous epithelial barriers to depths where the virus can encounter potential target cells. In the squamous epithelium, we identify virus entry occurring through diffusive percolation, penetrating areas where cell junctions are absent. In the columnar epithelium, we illustrate that virus does not transverse barriers as well as previously thought due to mucus impediment. We also show a statistically significant correlation between the viral load of inocula and the ability of HIV-1 to pervade the squamous barrier. Overall, our results suggest a diffusive percolation mechanism for the initial events of HIV-1 entry. With these data, we also mathematically extrapolate the number of HIV-1 particles that penetrate the mucosa per coital act, providing a biological description of the mechanism for HIV-1 transmission during the acute and chronic stages of infection. PMID:23966398

  15. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Directory of Open Access Journals (Sweden)

    Damien C Tully

    2016-05-01

    Full Text Available Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU, we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission.

  16. Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein.

    Science.gov (United States)

    de Souza, Theo Luiz Ferraz; de Lima, Sheila Maria Barbosa; Braga, Vanessa L de Azevedo; Peabody, David S; Ferreira, Davis Fernandes; Bianconi, M Lucia; Gomes, Andre Marco de Oliveira; Silva, Jerson Lima; de Oliveira, Andréa Cheble

    2016-01-01

    Hepatitis C virus (HCV) core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124) is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs) in vitro . The specificity and propensity of C124 to the assembly and its implications on HCV pathogenesis are not well understood. Spectroscopic techniques, transmission electron microscopy and calorimetry were used to better understand the propensity of C124 to fold or to multimerize into NLPs when subjected to different conditions or in the presence of unspecific nucleic acids of equivalent size to cellular microRNAs. The structural analysis indicated that C124 has low propensity to self-folding. On the other hand, for the first time, we show that C124, in the absence of nucleic acids, multimerizes into empty NLPs when subjected to a pH close to its isoelectric point (pH ≈ 12), indicating that assembly is mainly driven by charge neutralization. Isothermal calorimetry data showed that the assembly of NLPs promoted by nucleic acids is enthalpy driven. Additionally, data obtained from fluorescence correlation spectroscopy show that C124, in nanomolar range, was able to interact and to sequester a large number of short unspecific nucleic acids into NLPs. Together, our data showed that the charge neutralization is the major factor for the nucleocapsid-like particles assembly from C-terminal truncated HCV core protein. This finding suggests that HCV core protein may physically interact with unspecific cellular polyanions, which may correspond to microRNAs and mRNAs in a host cell infected by HCV, triggering their confinement into infectious particles.

  17. DNA vaccines based on chimeric potyvirus-like particles carrying HPV16 E7 peptide (aa 44-60)

    Czech Academy of Sciences Publication Activity Database

    Pokorná, D.; Čeřovská, Noemi; Šmahel, M.; Moravec, Tomáš; Ludvíková, V.; Machková, J.; Synková, Helena; Dušková, M.; Hozák, P.; Velemínský, Jiří

    2005-01-01

    Roč. 14, č. 4 (2005), s. 1045-1053 ISSN 1021-335X R&D Projects: GA ČR GA310/00/0381 Grant - others:IGA MHCR NC7552-3/2003 Institutional research plan: CEZ:AV0Z50380511 Keywords : human papillomavirus * E7 * virus-like particles Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.572, year: 2005

  18. Spontaneous viral clearance, viral load, and genotype distribution of hepatitis C virus (HCV) in HIV-infected patients with anti-HCV antibodies in Europe

    DEFF Research Database (Denmark)

    Soriano, Vincent; Mocroft, Amanda; Rockstroh, Juergen

    2008-01-01

    BACKGROUND: Variables influencing serum hepatitis C virus (HCV) RNA levels and genotype distribution in individuals with human immunodeficiency virus (HIV) infection are not well known, nor are factors determining spontaneous clearance after exposure to HCV in this population. METHODS: All HCV...... for hepatitis B surface antigen (HBsAg) were more likely to have spontaneously cleared HCV than were those negative for HBsAg (43% vs. 21%; aOR, 2.91 [95% CI, 1.94-4.38]). Of patients with HCV viremia, 786 (53%) carried HCV genotype 1, and 53 (4%), 440 (29%), and 217 (15%) carried HCV genotype 2, 3, and 4...

  19. Adherence to hepatitis A virus vaccination in HIV-infected men who have sex with men.

    Science.gov (United States)

    Kourkounti, Sofia; Paparizos, Vassilios; Leuow, Kirsten; Paparizou, Eleni; Antoniou, Christina

    2015-10-01

    Although vaccination against hepatitis A virus (HAV) is essential for human immunodeficiency virus (HIV)-infected patients, the uptake of HAV vaccine is reported to be very low. From 2007 to 2012, 912 HIV-infected men in Athens, Greece were screened for exposure to HAV. Two doses of an HAV vaccine were recommended to 569 eligible patients. Reminder cards with scheduled vaccination visits were given to each patient. Among eligible patients, 62.2% (354/569) received both doses. Patients who were fully vaccinated compared with non-adherent patients were natives, older, had undetectable HIV viral load, higher CD4 T cell counts and lower nadir CD4 T cell counts. Multivariate logistic regression revealed that the patient's country of origin (p = 0.024; OR = 2.712; 95% CI, 1.139-6.457), CD4 T cell count (p < 0.001) and nadir CD4 T cell count (p < 0.001) were factors directly associated with adherence. In conclusion, adherence to HAV vaccination was better than in previously published data. Because many of the factors related to vaccination completion are parameters of HIV infection, it appears that physician interest in HIV care and vaccination planning is crucial to enhancing vaccine uptake. © The Author(s) 2015.

  20. A picorna-like virus from the red imported fire ant, Solenopsis invicta: initial discovery, genome sequence, and characterization

    International Nuclear Information System (INIS)

    Valles, Steven M.; Strong, Charles A.; Dang, Phat M.; Hunter, Wayne B.; Pereira, Roberto M.; Oi, David H.; Shapiro, Alexandra M.; Williams, David F.

    2004-01-01

    We report the first discovery and genome sequence of a virus infecting the red imported fire ant, Solenopsis invicta. The 8026 nucleotide, polyadenylated, RNA genome encoded two large open reading frames (ORF1 and ORF2), flanked and separated by 27, 223, and 171 nucleotide untranslated regions, respectively. The predicted amino acid sequence of the 5' proximal ORF1 (nucleotides 28 to 4218) exhibited significant identity and possessed consensus sequences characteristic of the helicase, cysteine protease, and RNA-dependent RNA polymerase sequence motifs from picornaviruses, picorna-like viruses, comoviruses, caliciviruses, and sequiviruses. The predicted amino acid sequence of the 3' proximal ORF2 (nucleotides 4390-7803) showed similarity to structural proteins in picorna-like viruses, especially the acute bee paralysis virus. Electron microscopic examination of negatively stained samples from virus-infected fire ants revealed isometric particles with a diameter of 31 nm, consistent with Picornaviridae. A survey for the fire ant virus from areas around Florida revealed a pattern of fairly widespread distribution. Among 168 nests surveyed, 22.9% were infected. The virus was found to infect all fire ant caste members and developmental stages, including eggs, early (1st-2nd) and late (3rd-4th) instars, worker pupae, workers, sexual pupae, alates ( male and female ), and queens. The virus, tentatively named S. invicta virus (SINV-1), appears to belong to the picorna-like viruses. We did not observe any perceptible symptoms among infected nests in the field. However, in every case where an SINV-1-infected colony was excavated from the field with an inseminated queen and held in the laboratory, all of the brood in these colonies died within 3 months

  1. Hepatitis C virus infection in Ghana: time for action is now

    African Journals Online (AJOL)

    Introduction. Chronic hepatitis C virus (HCV) infection is a blood borne infection just like hepatitis B virus (HBV) and. Human Immunodeficiency Virus (HIV) with a signifi- cant global health impact. Since the discovery of the. HCV, several developments including a better under- standing of the clinical epidemiology, ...

  2. Slow progression of paediatric HIV disease: Selective adaptation or ...

    African Journals Online (AJOL)

    In the European Caucasian populations, the chemokine-cell receptor variant CCR5 \\"Delta 32\\" is a the genetic determinant of HIV disease progression that is believed to have been selected for in the general population by exposure to antigens closely interlinked to HIV like Yersinia pestis or small pox virus. Among African ...

  3. HIV Risk Behavior in Persons with Severe Mental Disorders in a ...

    African Journals Online (AJOL)

    HIV risk behavior was significantly related to alcohol use (P = 0.03). Conclusion: Mental health services provide an important context for HIV/AIDS interventions in resource‑constrained countries like Nigeria. Keywords: Human immuno virus, Mental health, Psychiatric patients, Risk behavior, Severe mental disorders ...

  4. Equine rhinitis A virus and its low pH empty particle: clues towards an aphthovirus entry mechanism?

    Directory of Open Access Journals (Sweden)

    Tobias J Tuthill

    2009-10-01

    Full Text Available Equine rhinitis A virus (ERAV is closely related to foot-and-mouth disease virus (FMDV, belonging to the genus Aphthovirus of the Picornaviridae. How picornaviruses introduce their RNA genome into the cytoplasm of the host cell to initiate replication is unclear since they have no lipid envelope to facilitate fusion with cellular membranes. It has been thought that the dissociation of the FMDV particle into pentameric subunits at acidic pH is the mechanism for genome release during cell entry, but this raises the problem of how transfer across the endosome membrane of the genome might be facilitated. In contrast, most other picornaviruses form 'altered' particle intermediates (not reported for aphthoviruses thought to induce membrane pores through which the genome can be transferred. Here we show that ERAV, like FMDV, dissociates into pentamers at mildly acidic pH but demonstrate that dissociation is preceded by the transient formation of empty 80S particles which have released their genome and may represent novel biologically relevant intermediates in the aphthovirus cell entry process. The crystal structures of the native ERAV virus and a low pH form have been determined via highly efficient crystallization and data collection strategies, required due to low virus yields. ERAV is closely similar to FMDV for VP2, VP3 and part of VP4 but VP1 diverges, to give a particle with a pitted surface, as seen in cardioviruses. The low pH particle has internal structure consistent with it representing a pre-dissociation cell entry intermediate. These results suggest a unified mechanism of picornavirus cell entry.

  5. Vaccine delivery system for tuberculosis based on nano-sized hepatitis B virus core protein particles

    Directory of Open Access Journals (Sweden)

    Dhanasooraj D

    2013-02-01

    Full Text Available Dhananjayan Dhanasooraj, R Ajay Kumar, Sathish MundayoorMycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Kerala, IndiaAbstract: Nano-sized hepatitis B virus core virus-like particles (HBc-VLP are suitable for uptake by antigen-presenting cells. Mycobacterium tuberculosis antigen culture filtrate protein 10 (CFP-10 is an important vaccine candidate against tuberculosis. The purified antigen shows low immune response without adjuvant and tends to have low protective efficacy. The present study is based on the assumption that expression of these proteins on HBc nanoparticles would provide higher protection when compared to the native antigen alone. The cfp-10 gene was expressed as a fusion on the major immunodominant region of HBc-VLP, and the immune response in Balb/c mice was studied and compared to pure proteins, a mixture of antigens, and fusion protein-VLP, all without using any adjuvant. The humoral, cytokine, and splenocyte cell proliferation responses suggested that the HBc-VLP bearing CFP-10 generated an antigen-specific immune response in a Th1-dependent manner. By virtue of its self-adjuvant nature and ability to form nano-sized particles, HBc-VLPs are an excellent vaccine delivery system for use with subunit protein antigens identified in the course of recent vaccine research.Keywords: Mycobacterium tuberculosis, VLP, hepatitis B virus core particle, CFP-10, self-adjuvant, vaccine delivery

  6. Human immunodeficiency virus (HIV) is highly associated with giant idiopathic esophageal ulcers in acquired immunodeficiency syndrome (AIDS) patients.

    Science.gov (United States)

    Lv, Bei; Cheng, Xin; Gao, Jackson; Zhao, Hong; Chen, Liping; Wang, Liwei; Huang, Shaoping; Fan, Zhenyu; Zhang, Renfang; Shen, Yinzhong; Li, Lei; Liu, Baochi; Qi, Tangkai; Wang, Jing; Cheng, Jilin

    2016-01-01

    This study aimed to determine whether the human immunodeficiency virus (HIV) exists in giant idiopathic esophageal ulcers in the patients with acquired immune deficiency syndrome (AIDS). 16 AIDS patients with a primary complaint of epigastric discomfort were examined by gastroscopy. Multiple and giant esophageal ulcers were biopsied and analyzed with pathology staining and reverse transcription-polymerase chain reaction (RT-PCR) to determine the potential pathogenic microorganisms, including HIV, cytomegalovirus (CMV) and herpes simplex viruses (HSV). HIV was detected in ulcer samples from 12 out of these 16 patients. Ulcers in 2 patients were infected with CMV and ulcers in another 2 patients were found HSV positive. No obvious cancerous pathological changes were found in these multiple giant esophageal ulcer specimens. HIV may be one of the major causative agents of multiple benign giant esophageal ulcers in AIDS patients.

  7. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Send the Message . Get the Facts What are HIV and AIDS? HIV (human immunodeficiency virus) is the virus that ... AIDS) are often linked and referred to as "HIV/AIDS." HIV can be transferred between people if an ...

  8. Increased carotid intima-media thickness associated with antibody responses to varicella-zoster virus and cytomegalovirus in HIV-infected patients.

    Directory of Open Access Journals (Sweden)

    Mar Masiá

    Full Text Available OBJECTIVE: We investigated the relationship of the Herpesviridiae with inflammation and subclinical atherosclerosis in HIV-infected patients. METHODS: Prospective study including virologically suppressed HIV-infected patients. IgG antibodies against herpesviruses, carotid intima-media thickness (cIMT, endothelial function through flow-mediated dilatation (FMD of the brachial artery, and blood atherosclerosis biomarkers (hsCRP, TNF-α, IL-6, MCP-1, MDA, sCD14, sCD163, VCAM-1, ICAM-1, D-dimer, and PAI-1 were measured. RESULTS: 136 patients with HIV viral load <200 copies/ml were included. 93.4% patients were infected with herpes simplex virus type-1, 55.9% with herpes simplex virus type-2, 97.1% with varicella-zoster virus, 65.4% with human herpesvirus-6, 91.2% with cytomegalovirus, and 99.3% with Epstein-Barr virus. Previous AIDS diagnosis was associated with higher cytomegalovirus IgG titers (23,000 vs 17,000 AU, P = 0.011 and higher varicella-zoster virus IgG titers (3.19 vs 2.88 AU, P = 0.047, and there was a positive correlation of the Framingham risk score with IgG levels against cytomegalovirus (Spearman's Rho 0.216, P = 0.016 and Herpes simplex virus-2 (Spearman's Rho 0.293, P = 0.001. IgG antibodies against cytomegalovirus correlated in adjusted analysis with the cIMT (P = 0.030. High seropositivity for varicella-zoster virus (OR 2.91, 95% CI 1.05-8.01, P = 0.039, and for cytomegalovirus (OR 3.79, 95% CI 1.20-11.97, P = 0.023 were predictors for the highest quartile of the cIMT in adjusted analyses. PAI-1 levels were independently associated with cytomegalovirus IgG titers (P = 0.041, IL-6 and ICAM-1 levels with varicella-zoster virus IgG (P = 0.046 and P = 0.035 respectively, and hsCRP levels with Herpes simplex virus-2 IgG (P = 0.035. CONCLUSION: In virologically suppressed HIV-infected patients, antibody responses against herpesviruses are associated with subclinical atherosclerosis, and with increased inflammation and coagulation

  9. Prevalence of human immunodeficiency virus, hepatitis C virus ...

    African Journals Online (AJOL)

    Background. Human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis remain major infections around the world. In Angola, about 166 000 individuals are living with HIV, representing a prevalence of 1.98% in adults between 15 and 49 years of age. In a 2003 study in Luanda, 4.5% ...

  10. Seroprevalence of hepatitis C virus among people living with HIV/AIDS in Latin America and the Caribbean: a systematic review

    Directory of Open Access Journals (Sweden)

    Fatima Mitiko Tengan

    2016-11-01

    Full Text Available Abstract Background Studies have shown that the immunosuppression induced by the human immunodeficiency virus (HIV accelerates the natural history of liver disease associated with hepatitis C virus (HCV, with 3- to 5-fold higher odds of coinfected individuals developing cirrhosis. However, estimates of the seroprevalence of hepatitis C among people living with HIV/acquired immune deficiency syndrome (AIDS (PLHA in Latin America and the Caribbean (LAC are widely variable. Methods We performed a systematic review to estimate the seroprevalence of HCV among PLHA. We searched studies on HIV and HCV infections in LAC included in the PubMed, LILACS and Embase databases in December of 2014 with no time or language restrictions. The following combinations of search terms were used in the PubMed and Embase databases: (HIV OR Acquired Immunodeficiency Syndrome Virus OR AIDS OR HTLV OR Human Immunodeficiency Virus OR Human T Cell AND (HCV OR HEPATITIS C OR HEPATITIS C VIRUS OR HEPACIVIRUS AND (name of an individual country or territory in LAC. The following search terms were used in the LILACS database: (HIV OR AIDS OR Virus da Imunodeficiencia Humana AND (HCV OR Hepatite C OR Hepacivirus. An additional 11 studies were identified through manual searches. A total of 2,380 publications were located, including 617 duplicates; the remaining articles were reviewed to select studies for inclusion in this study. Results A total of 37 studies were selected for systematic review, including 23 from Brazil, 5 from Argentina, 3 from Cuba, 1 from Puerto Rico, 1 from Chile, 1 from Colombia, 1 from Mexico, 1 from Peru and 1 from Venezuela. The estimated seroprevalence of HCV infection varied from 0.8 to 58.5 % (mean 17.37; median 10.91, with the highest in Argentina and Brazil and the lowest in Venezuela and Colombia. Conclusions Investigation of HCV infection among PLHA and of HIV infection among people living with HCV is highly recommended because it allows for better

  11. Genetic variation in toll-like receptors and retinoic acid-inducible gene I and outcome of hepatitis C virus infection

    DEFF Research Database (Denmark)

    Clausen, L N; Ladelund, S; Weis, N

    2014-01-01

    We evaluated the effects of genetic variation in toll-like receptors (TLR), retinoic acid-inducible gene I (RIG-I) and their signalling pathways on spontaneous hepatitis C virus (HCV) resolution. We screened 95 single-nucleotide polymorphisms (SNPs) in 22 genes. SNPs significantly associated...... with resolution in the discovery cohort were genotyped in a validation cohort. Multivariate logistic regression adjusted for sex, hepatitis B surface antigen, HIV infection and the interleukin-28B rs12979860 SNP was performed in the combined cohort. Haplotype reconstruction and linkage disequilibrium analysis...

  12. Inactivation of human immunodeficiency virus (HIV) by ionizing radiation in body fluids and serological evidence

    International Nuclear Information System (INIS)

    Bigbee, P.D.; Sarin, P.S.; Humphreys, J.C.; Eubanks, W.G.; Sun, D.; Hocken, D.G.; Thornton, A.; Adams, D.E.; Simic, M.G.

    1989-01-01

    A method to use ionizing radiation to inactivate HIV (Human Immunodeficiency Virus) in human body fluids was studied in an effort to reduce the risk of accidental infection to forensic science laboratory workers. Experiments conducted indicate that an X-ray absorbed dose of 25 krad was required to completely inactivate HIV. This does not alter forensically important constituents such as enzymes and proteins in body fluids. This method of inactivation of HIV cannot be used on body fluids which will be subjected to deoxyribonucleic acid (DNA) typing

  13. Hepatitis C virus treatment rates and outcomes in HIV/hepatitis C virus co-infected individuals at an urban HIV clinic.

    Science.gov (United States)

    Murray, Melanie C M; Barrios, Rolando; Zhang, Wendy; Hull, Mark; Montessori, Valentina; Hogg, Robert S; Montaner, Julio S G

    2011-01-01

    The factors associated with hepatitis C virus (HCV) treatment uptake and responses were assessed among HCV/HIV co-infected individuals referred for HCV therapy at an urban HIV clinic. Retrospective review of HIV/HCV patients enrolled in the HCV treatment program at the John Ruedy Immunodeficiency Clinic in Vancouver. The factors associated with treatment uptake were assessed using multivariate analysis. A total of 134 HCV/HIV co-infected individuals were recalled for assessment for HCV therapy. Overall 64 (48%) initiated treatment, and of those treated 49 (76.6%) attained end treatment response, whereas 35 (57.8%) achieved sustained virological response (SVR). When evaluated by genotype, 53% (17/32) of those with genotype 1, and 65% (20/31) of those with genotype 2 or 3 infections attained SVR. In treated individuals, alanine aminotransferase dropped significantly after treatment (P<0.001). During treatment, CD4 counts dropped significantly (P<0.001) in all patients. The counts recovered to baseline in patients who achieved SVR, but remained lower in patients who failed the therapy (P=0.015). On multivariate analysis, history of injection drug use (odds ratio: 3.48; 95% confidence interval: 1.37-8.79; P=0.009) and low hemoglobin levels (odds ratio: 4.23; 95% confidence interval: 1.36-13.10; P=0.013) were associated with those who did not enter the treatment. Only half of treatment-eligible co-infected patients referred for the therapy initiated treatment. Of those referred for the therapy, history of injection drug use was associated with lower rates of treatment uptake. Treated HIV/HCV co-infected individuals benefitted from both decreased alanine aminotransferase (independent of SVR), and rates of SVR similar to those described in HCV monoinfected patients.

  14. Viral outbreak in corals associated with an in situ bleaching event: atypical herpes-like viruses and a new megavirus infecting Symbiodinium

    Directory of Open Access Journals (Sweden)

    Adrienne M.S. Correa

    2016-02-01

    Full Text Available Previous studies of coral viruses have employed either microscopy or metagenomics, but few have attempted to comprehensively link the presence of a virus-like particle (VLP to a genomic sequence. We conducted transmission electron microscopy imaging and virome analysis in tandem to characterize the most conspicuous viral types found within the dominant Pacific reef-building coral genus Acropora. Collections for this study inadvertently captured what we interpret as a natural outbreak of viral infection driven by aerial exposure of the reef flat coincident with heavy rainfall and concomitant mass bleaching. All experimental corals in this study had high titers of viral particles. Three of the dominant VLPs identified were observed in all tissue layers and budding out from the epidermis, including viruses that were ~70 nm, ~120 nm, and ~150 nm in diameter; these VLPs all contained electron dense cores. These morphological traits are reminiscent of retroviruses, herpesviruses, and nucleocytoplasmic large DNA viruses (NCLDVs, respectively. Some 300-500 nm megavirus-like VLPs also were observed within and associated with dinoflagellate algal endosymbiont (Symbiodinium cells. Abundant sequence similarities to a gammaretrovirus, herpesviruses, and members of the NCLDVs, based on a virome generated from five Acropora aspera colonies, corroborated these morphology-based identifications. Additionally sequence similarities to two diagnostic genes, a MutS and (based on re-annotation of sequences from another study a DNA polymerase B gene, most closely resembled Pyramimonas orientalis virus, demonstrating the association of a cosmopolitan megavirus with Symbiodinium. We also identified several other viral particles in host tissues, along with sequences phylogenetically similar to circoviruses, phages, and filamentous viruses. This study suggests that viral outbreaks may be a common but previously undocumented component of natural bleaching events

  15. Stimulation of HIV-1-specific cytolytic T-lymphocytes facilitates elimination of latent viral reservoir after virus reactivation

    Science.gov (Uni