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Monoclonal antibodies against Caprine arthritis-encephalitis virus epitopes in the p28 and p55gag viral proteins. J Virol Methods 2013; 187:352-6. [DOI: 10.1016/j.jviromet.2012.10.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 10/23/2012] [Accepted: 10/30/2012] [Indexed: 11/21/2022]
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2
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Chan CM, Woo PCY, Lau SKP, Tse H, Chen HL, Li F, Zheng BJ, Chen L, Huang JD, Yuen KY. Spike protein, S, of human coronavirus HKU1: role in viral life cycle and application in antibody detection. Exp Biol Med (Maywood) 2008; 233:1527-36. [PMID: 18849544 DOI: 10.3181/0806-rm-197] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We recently described the discovery, genome, clinical features, genotypes and evolution of a novel and global human respiratory virus named human coronavirus HKU1 (HCoV-HKU1) which is not yet culturable. We expressed a C-terminal FLAG-tagged CoV-HKU1 spike (S) protein by the Semliki Forest Virus (SFV) system and investigated its maturation profile. Pulse chase labeling revealed that S-FLAG was expressed as high-mannose N-glycans of monomers and trimers. It was predominantly cleaved into subdomains S1 and S2 during maturation. S1 was secreted into the medium. Immunofluorescence analysis visualized S along the secretory pathway from endoplasmic reticulum to plasma membrane. Cleavage of S and release of HCoV-HKU1 S pseudotyped virus were inhibited by furin or furin-like enzyme inhibitors. The cell-based expressed full-length S-FLAG could be recognized by the convalescent serum obtained from a patient with HCoV-HKU1 pneumonia. The data suggest that the native form of HCoV-HKU1 spike expressed in our system can be used in developing serological diagnostic assay and in understanding the role of S in the viral life cycle.
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Affiliation(s)
- Che-Man Chan
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administration Region, Hong Kong
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Halsey RJ, Tanzer FL, Meyers A, Pillay S, Lynch A, Shephard E, Williamson AL, Rybicki EP. Chimaeric HIV-1 subtype C Gag molecules with large in-frame C-terminal polypeptide fusions form virus-like particles. Virus Res 2008; 133:259-68. [PMID: 18329748 DOI: 10.1016/j.virusres.2008.01.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 01/16/2008] [Accepted: 01/21/2008] [Indexed: 10/22/2022]
Abstract
HIV-1 Pr55 Gag virus-like particles (VLPs) are strong immunogens with potential as candidate HIV vaccines. VLP immunogenicity can be broadened by making chimaeric Gag molecules: however, VLPs incorporating polypeptides longer than 200 aa fused in frame with Gag have not yet been reported. We constructed a range of gag-derived genes encoding in-frame C-terminal fusions of myristoylation-competent native Pr55Gag and p6-truncated Gag (Pr50Gag) to test the effects of polypeptide length and sequence on VLP formation and morphology, in an insect cell expression system. Fused sequences included a modified reverse transcriptase-Tat-Nef fusion polypeptide (RTTN, 778 aa), and truncated versions of RTTN ranging from 113 aa to 450 aa. Baculovirus-expressed chimaeric proteins were examined by western blot and electron microscopy. All chimaeras formed VLPs which could be purified by sucrose gradient centrifugation. VLP diameter increased with protein MW, from approximately 100 nm for Pr55Gag to approximately 250 nm for GagRTTN. The presence or absence of the Gag p6 region did not obviously affect VLP formation or appearance. GagRT chimaeric particles were successfully used in mice to boost T-cell responses to Gag and RT that were elicited by a DNA vaccine encoding a GagRTTN polypeptide, indicating the potential of such chimaeras to be used as candidate HIV vaccines.
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Affiliation(s)
- Richard J Halsey
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, PO Observatory 7925, Cape Town, South Africa
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Deml L, Speth C, Dierich MP, Wolf H, Wagner R. Recombinant HIV-1 Pr55gag virus-like particles: potent stimulators of innate and acquired immune responses. Mol Immunol 2005; 42:259-77. [PMID: 15488613 DOI: 10.1016/j.molimm.2004.06.028] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several previous reports have clearly demonstrated the strong effectiveness of human immunodeficiency virus (HIV) Gag polyprotein-based virus-like particles (VLP) to stimulate humoral and cellular immune responses in complete absence of additional adjuvants. Yet, the mechanisms underlying the strong immunogenicity of these particulate antigens are still not very clear. However, current reports strongly indicate that these VLP act as "danger signals" to trigger the innate immune system and possess potent adjuvant activity to enhance the immunogenicity of per se only weakly immunogenic peptides and proteins. Here, we review the current understanding of how various particle-associated substances and other impurities may contribute to the observed immune-activating properties of these complex immunogens.
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Affiliation(s)
- Ludwig Deml
- Institute of Medical Microbiology, University of Regensburg, Franz-Josef-Straurr-Allee 11, D-93053 Regensburg, Germany.
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Gupta S, Arora K, Sampath A, Singh SS, Gupta A, Chaudhary VK. Mapping of hiv-1 Gag epitopes recognized by polyclonal antibodies using gene-fragment phage display system. Prep Biochem Biotechnol 2001; 31:185-200. [PMID: 11426705 DOI: 10.1081/pb-100103383] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Phage display has emerged as a powerful technique for mapping epitopes recognised by monoclonal and polyclonal antibodies. We have recently developed a simple gene-fragment phage display system and have shown its utility in mapping epitope recognised by a monoclonal antibody. In the present study, we have employed this system in mapping epitopes recognised by polyclonal antibodies raised against HIV-1 capsid protein, p24 which is derived from proteolytic cleavage of Gag polyprotein. HIV-1 gag DNA was fragmented by DNase I and the fragments (50-250 bp) were cloned into gene-fragment phage display vector to construct a library of phages displaying peptides. This phage library was used for affinity selection of phages displaying epitopes recognised by rabbit anti-p24 polyclonal antibodies. Selected phages contained sequences from two discrete regions of p24, demonstrating the presence of two antigenic regions. The DNA sequences encoding these regions were also cloned and expressed as GST fusion proteins. The immunoreactivity of these epitopes as GST fusion proteins, or as phage-displayed peptides, was comparable in ELISA system using same anti-p24 polyclonal antibodies. The results indicate that the gene-fragment based phage display system can be used efficiently to identify epitopes recognised by polyclonal antibodies, and phage displayed epitopes can be directly employed in ELISA to detect antibodies.
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Affiliation(s)
- S Gupta
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
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Hourioux C, Brand D, Sizaret PY, Lemiale F, Lebigot S, Barin F, Roingeard P. Identification of the glycoprotein 41(TM) cytoplasmic tail domains of human immunodeficiency virus type 1 that interact with Pr55Gag particles. AIDS Res Hum Retroviruses 2000; 16:1141-7. [PMID: 10954889 DOI: 10.1089/088922200414983] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We investigated the protein/protein interactions that occur during human immunodeficiency virus (HIV-1) budding. We evaluated the binding to Pr55Gag particles of peptides mapping to the cytoplasmic tail of gp41TM and of host-cell proteins, in a cell-free, in vitro assay. Host-cell proteins and irrelevant viral envelope peptides did not bind. Peptides corresponding to a large central domain of the gp41TM cytoplasmic tail (93 residues) bound to Pr55Gag particles. This demonstrates that a Gag/Env interaction is responsible for the specific incorporation of the Env glycoprotein into nascent HIV-1 virions, and defines more accurately the gp41TM domain involved in this interaction.
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Affiliation(s)
- C Hourioux
- Laboratoire de Virologie, EA 2639, Faculté de Médecine, Université François Rabelais, Tours, France
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Ota A, Tanaka-Taya K, Ueda S. Cross-reactivity of anti-HIV-1-p17-derivative peptide (P30-52) antibody to Env V3 peptide. Hybridoma (Larchmt) 1999; 18:149-57. [PMID: 10380014 DOI: 10.1089/hyb.1999.18.149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Strong antibody responses are often seen in human immunodeficiency virus type 1 (HIV-1) carriers, but it is not known whether these antibodies are effective in the inhibition of disease progression. In this study, we examined antigenic epitopes for anti-HIV-1 p17 antibody (p17 Ab) in an HIV-1 carrier's serum, and found that the residues of amino acid numbers 1 to 12 (P1-12), 12 to 29 (P12-29) and 30 to 52 (P30-52) of p17 were highly recognized in the serum. Our examination of purified antibodies from the patient using the p17-derivative-peptide-immunoaffinity columns showed that the reactivity of anti-p30-52 Ab (p30-52Ab) was high for p30-52 and the naive protein, p17. In addition, this P30-52Ab cross-reacted with the third variable region of the envelope glycoprotein (Env V3). To confirm this cross-reactivity, we immunized mice with P30-52, and established a monoclonal antibody (MAb), 8H10. We found that 8H10 was also reactive to Env V3. It is unclear whether this cross-reactivity of P30-52 Ab can function as the inhibitor of HIV-1, but these results will be of help in clarifying the interaction of Env protein with HIV-1 gag polyprotein and the relationship of the decline of the p17 antibody titer with the disease progression in HIV-1 carriers.
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Affiliation(s)
- A Ota
- Department of Neurovirology, Research Institute for Microbial Diseases, Osaka University, Suita City, Japan
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Ota A, Bautista AN, Yadav ML, Ueda S. Anti-P30-52 monoclonal antibody cross-reacted to Env V3 and inhibited the viral multiplication of HIV-1-infected MT-4 cells. Hybridoma (Larchmt) 1999; 18:139-47. [PMID: 10380013 DOI: 10.1089/hyb.1999.18.139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
It is well known that the anti-p17 antibody titer decreases with the disease progression among human immunodeficiency virus type 1 (HIV-1) carriers. We previously established several murine anti-p17 monoclonal antibodies (MAbs) to investigate the immunological role of p17, and to further characterize these MAbs, we examined the anti-p17 antibody titer in serum of a patient who was a long-term nonprogressor with hemophilia, and found that the antibody for the p17-derivative peptide from amino acid residues 30 to 52 (P30-52) cross-reacted to the third variable region of the envelope glycoprotein of HIV-1, Env V3. In the present study, we primed mice with P30-52 to establish anti-P30-52 MAbs (P30-52 MAbs), and examined their affinity and whether they suppressed the viral multiplication of HIV-1-infected MT-4 (HTLV-1-transformed CD4+ T-cell line) cells, in a TCID50 assay. At the same time, an anti-Env V3 MAb (Env V3 MAb) was also established and examined as above. The IgM-type P30-52 MAb and Env V3 MAb showed heteroclitic binding, and the IgM-type P30-52 MAb inhibited the viral multiplication. We also found that an increase of fragmented DNA of HIV-1-infected MT-4 cells co-cultured with P30-52 MAbs. Because DNA fragmentation is one of the features of programmed cell death, the viral multiplication may be suppressed by the apoptosis of HIV-1-infected MT-4 cells co-cultured with P30-52 MAbs. Though the relationship between cross-reactivity and the inhibition mechanism of multiplication of HIV-1 is unclear, P30-52 of p17 may well be a useful region of viral proteins for the development of therapeutic and vaccination strategies.
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Affiliation(s)
- A Ota
- Department of Neurovirology, Research Institute for Microbial Diseases, Osaka University, Suita City, Japan
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Luo L, Li Y, Chang JS, Cho SY, Kim TY, Choi MJ, Cheong HS, Kim HJ, Ahn HJ, Min MK, Chun BH, Jung SM, Woo SG, Park SY, Kang CY. Induction of V3-specific cytotoxic T lymphocyte responses by HIV gag particles carrying multiple immunodominant V3 epitopes of gp120. Virology 1998; 240:316-25. [PMID: 9454705 DOI: 10.1006/viro.1997.8922] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Effort to develop a vaccine to prevent infection of human immunodeficiency virus (HIV) have focused on the induction of neutralizing antibodies. In our previous study, we reported that chimeric gag-env virus-like particles (VLPs) induce neutralizing antibodies which block HIV infection. In addition to the neutralizing antibodies, the cytotoxic T-lymphocyte (CTL) response is considered to be another major immune defense mechanism required for recovery from many different viral infections. In the present study, we have constructed chimeric fusion proteins using HIV-2 gag precursor protein with (1) four neutralizing epitopes from HIV-1 gp160; (2) three tandem copies of consensus V3 domain, which have been derived from 245 different isolates of HIV-1 and carries both the principal neutralizing determinant (PND) and CTL epitopes; and (3) V3 domains from HIV-1IIIB, HIV-1MN, HIV-1RF, and HIV-1SF2. These chimeric fusion proteins were expressed in a large quantity within insect cells, and released as VLPs into the cell culture medium. The purified gag-env VLPs from all three constructs appear to be spherical particles similar to immature HIV but slightly larger than the gag VLPs. Immunoprecipitation analysis showed that the chimeric proteins were recognized not only by HIV-1 positive patient sera, but also by monoclonal and polyclonal antisera raised against V3 peptides of HIV-1IIIB, HIV-1MN, HIV-1RF, and the gp120 antiserum against HIV-1SF2. Balb/C mice immunized with these chimeric VLPs successfully induced CTL activity against V3 peptide-stimulated target cells. In addition, a high degree of cross-reactivity was observed among the four different strains of HIV-1 V3 domain, indicating that the tandem multiple consensus V3 peptide sequence carried by HIV-2 gag can be used as a potential HIV vaccine against various HIVs.
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Affiliation(s)
- L Luo
- Western Science Centre, University of Western Ontario, London, Canada
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Nakamura Y, Kameoka M, Tobiume M, Kaya M, Ohki K, Yamada T, Ikuta K. A chain section containing epitopes for cytotoxic T, B and helper T cells within a highly conserved region found in the human immunodeficiency virus type 1 Gag protein. Vaccine 1997; 15:489-96. [PMID: 9160516 DOI: 10.1016/s0264-410x(96)00224-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cell-mediated immune responses constitute a major defense against the spread of human immunodeficiency virus type 1 (HIV-1). However, multiple alterations within a particular epitope may accumulate during disease progression, allowing the virus to escape cytotoxic T lymphocytes (CTLs). Therefore, the best candidate for a peptide vaccine that would prevent the onset of the disease might be a chain section containing epitopes for the generation of CTLs in regions of conserved sequences among different HIV-1 isolates. We previously showed that immunizing mice with synthetic peptides consisting of 23-amino acids (Gag-23mer; 287-309 amino acid residues) in a highly conserved region derived from the major core protein p24 of HIV-1 generates specific CTLs as well as antibodies. Here, we identified one CTL (T-1; 291-300) and two B-cell (B-1; 290-299 and B-2; 300-309) epitopes, all of which consisted of 10 amino acids within the region. In addition, helper T cells primed by the Gag-23mer peptide were proliferated by in vitro stimulation with a 21mer (H-1; 289-309) or a 19mer (H-2; 291-309) peptide, but not with a 17mer peptide (293-309) or 19mer peptide (287-305). Immunization with the H-1 peptide generated an antibody reactive to B-1, but not B-2, whereas that with H-2 generated an antibody reactive to B-2, but not B-1. CTLs were not generated by immunization with these peptides, indicating that the entire sequence of Gag-23mer is the helper epitope for CTLs. Thus, the Gag-23mer is a chain section containing epitopes for cytotoxic T, B and helper T-cells within a highly conserved region of HIV-1 Gag protein.
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Affiliation(s)
- Y Nakamura
- Section of Serology, Institute of Immunological Science, Hokkaido University, Sapporo, Japan
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Truong C, Brand D, Mallet F, Roingeard P, Barin F. Comparison of antibody responses to different forms of HIV-1 core antigens by epitope mapping. J Med Virol 1997. [DOI: 10.1002/(sici)1096-9071(199703)51:3<145::aid-jmv2>3.0.co;2-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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