ISSN:0889-2229    

DOI:10.1089/aid.1993.9.1

年代:1993

数据来源: MAL

摘要:

The immunogenicity of the equine infectious anemia virus (EIAV) reverse transcriptase (RT) was examined by immunoblot assay with recombinant EIAV RT. All of the 19 sera from EIAV-infected horses tested contained antibodies that recognized EIAV RT and directly inhibited the polymerase activity of the enzyme. An examination of sera obtained sequentially from two experimentally infected animals revealed that anti-RT antibodies arise early in infection and increase in level. The appearance of the antibodies correlated with progression toward the asymptomatic period of infection.

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.7

年代:1993

数据来源: MAL

摘要:

Inactivated, partially purified simian immunodefiency virus (SIVmac) protected macaques from intravenous challenge with homologous and heterologous strains of SIV that had been grown on human cells but no protection against challenge with monkey peripheral blood mononuclear cell-grown SIVmacwas afforded. Human immunodeficiency virus type 1 prepared in an analogous way to the SIVmacvaccine on the C8166 human T cell line protected macaques against challenge with human cell-grown SIVmac. These results suggest that protection may be mediated by xenoimmunization with the vaccine cell substrate proteins. All vaccinated macaques had anti-cell antibodies. Major reactivity to MHC class I antigens was found as well as to a 70-kD protein detectable only under nonreducing conditions.

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.13

年代:1993

数据来源: MAL

摘要:

Our goal has been to develop a safe and effective system that would allow us to explore the functions of the human immunodeficiency virus (HIV) envelope. We have generated a human lymphoid cell line (TF228.1.16) that stably expresses functional HIV envelope proteins on its cell surface, and therefore closely mimics the viral envelope and virus-infected cells. The TF228.1.16 line forms syncytia with human cells of the CD4+phenotype and provides a facile virus-free cell-based assay for examining the mechanism of syncytia formation and for evaluating novel agents that may disrupt this process. The TF228.1.16 cells also provide an opportunity to present the HIV envelope proteins to the immune system in cellular form. In vitro immunization of human peripheral blood mononuclear cells (PBMC) and in vivo immunization of rhesus monkeys with this reagent results in the production of antibodies with neutralizing (anti-syncytia) activities. When the HIV envelope is expressed against the background of human lymphoid cells, it may exhibit immune protection with unique properties that have not yet been explored. Our results indicate that a virus-free cell system can play an important role in exploring the biology and function of HIV-envelope proteins without the interference of other viral components present in infected cells. This paper discusses these results, and examines the potential use of TF228.1.16 as a vaccine.

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.23

年代:1993

数据来源: MAL

摘要:

A sequence of four amino acid residues amino-terminal to the only intramolecular disulphide bond of the human immunodeficiency virus type 1 (HIV-1) transmembrane protein gp41 is recognized by an anti-idiotypic antibody (9G5A) raised against another monoclonal antibody (M38), which recognizes the C5 region of gp120. 9G5A is an Ab2β antibody (internal image of the M38 epitope) in that it inhibits the interaction of M38 to its antigen. The binding of 9G5A to gp41 can be inhibited by M38 showing that the two antibodies interact via their paratopes. 9G5A neutralizes HIV-1 infection and syncytia formation. Ab3 antibodies induced in mice and rabbits immunized with 9G5A also can neutralize virus in both assays. These data show that the M38-defined epitope of the carboxy-terminal region of gp120 interacts with the 9G5A-defined epitope of gp41, and that this interaction can be reproduced by the idiotypic mimicry of the two antibodies. The results are consistent with a proposed molecular model of the twoenvregions which predicts the presence, within the C5 region of gp120, of a large intramolecular pocket that is contacted by the gp41 cysteine loop

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.33

年代:1993

数据来源: MAL

摘要:

The heavy (VH) and light (VL) chain variable region nucleotide sequences of four neutralizing anti-human immunodeficiency virus type 1 (HIV-1) murine monoclonal antibodies (mAbs) were determined. These mAbs bind to native gp120, recombinant gp120, and a linear HIV-1 principal neutralizing determinant (PND) peptide that spans amino acid 308-328. Three mAbs that bind to the same linear determinant, 110.3, 110.4, and 110.5, all use the same VLgene elements, a VK21 gene and JK2. These three mAbs also share the same VKJKjunctional diversity and specific somatic mutations. They have identical VLimmunoglobulin gene rearrangement patterns on Southern blot. Two of the antibodies, 110.4 and 110.5, also use the same VHgene elements, SB32-D-JH4, and have identical VD and DJ junctions and N sequences. Two different anti-HIV-1 PND murine mAbs reported by others, BAT123 and 0.5β, also use VK21-JK2, and BAT123 also uses the SB32 VHgene element. Although 110.3 uses the same VLregion gene as 110.3 and 110.4, it uses a different VHgene that appears to be a member of the 7183 VHfamily. 110.6, an mAb that recognizes a discrete, overlapping PND compared to 110.3, 110.4, and 110.5, uses entirely different VHand VLgene elements and has unique immunoglobulin VHand VLrearrangement patterns. Our data, taken together with reports of the BAT123 and 0.5β mAb sequences, suggest that the murine antibody response to HIV-1 PND may be restricted to a small subset of VHand VLgene element

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.41

年代:1993

数据来源: MAL

摘要:

The V3 loop of human immunodeficiency virus (HIV) glycoprotein gp160 is of interest as a possible site for protective immune responses. This article examines the murine T cell response to peptide 315-329 derived from HIV gp160. Surprisingly, immunization with peptide in complete Freund's adjuvant induced class I-restricted T cells as well as class II-restricted T cells. These data suggest that this peptide may have the unusual ability to enter the class I antigen processing pathway. Strategies that employ V3 loop peptides to induce protective immunity must generate T cells that can recognize epitopes derived from whole molecules in vivo. Therefore, peptide-induced T cells were tested for their ability to respond to naturally processed forms of gp120 and gp 160 whole-molecule preparations. Peptide induced class I-restricted cells were capable of recognizing transfectants expressing gp160. However, only one of two class II-restricted T cell lines was capable of recognizing soluble whole molecules. This indicates that peptide immunization induces T cells that recognize a class II-restricted determinant that is not generated during normal processing of whole molecules. We have also examined the response of peptide primed T cells to lipidated peptide antigens. Lipidated peptides are generally considered to have increased antigenicity and immunogenicity as compared to normal peptides. However, lipidation of peptide 315-329 damaged both the class I- and II-restricted determinants, indicating that lipidation is not always desirable. The data presented here highlight a potential serious problem in the use of peptide vaccines, in that peptide immunization may not always induce T cells that can protect against a viral challenge.

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.51

年代:1993

数据来源: MAL

摘要:

Virus-specific cytotoxic T lymphocytes (CTL) are frequently of the CD8+surface phenotype, although CTL of the CD4+surface phenotype have also been described. Published reports of CTL derived from peripheral blood mononuclear cells (PBMC) of individuals infected with human immunodeficiency virus type 1 (HIV-1) have described primarily cells of the CD8+surface phenotype. However, CD4+HIV-1 envelope-specific CTL have been reported after in vitro stimulation with HIV-1 envelope protein of peripheral blood cells obtained from HIV-1-seronegative donors, in peripheral blood cells after vaccination of HIV-1-seronegative persons with HIV-1 envelope proteins, and in cerebrospinal fluid cells of HIV-1-infected individuals. Recently, CD4+HIV-1 gag-specific CTL were also reported. We now report a patient from whom we derived HIV-1 envelope-specific CTL cell lines of the CD4+surface phenotype. Our cell culture technique did not employ exogenous viral antigenic stimulation, and may therefore yield cells that more closely reflect those in the underlying populations from which they were derived. These CTL did not appear to have the clear human leukocyte antigen (HLA) class II restriction pattern typically seen in CD4-expressing cells and were not functionally inhibited by anti-CD3 antibody. Further work will be required to define the role of CD4+CTL in the pathogenesis of HIV-1 disease.

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.61

年代:1993

数据来源: MAL

摘要:

Human immunodeficiency virus type 1 (HIV-1) infects a variety of cell types in vivo. Monocyte/macrophages may be the major reservoir for HIV-1 in the solid tissues of HIV-1-infected individuals. Conflicting data have been reported, though, regarding the presence of HIV-1 provirus in peripheral blood monocytes isolated from HIV-1-seropositive humans. We have evaluated monocytes from the peripheral blood of eleven HIV-1-infected individuals utilizing a new, highly sensitive and specific in situ polymerase chain reaction. We demonstrate HIV-1 provirus in 73% (8/11) of these samples. None of these monocyte samples was demonstrated to contain cells expressing high levels of HIV-1-specific RNA, by standard in situ hybridization. The evaluation of the HIV-1 genome in peripheral blood monocytes of certain infected individuals may assist in the understanding of HIV-1 proviral latency and pathogenesis, in vivo.

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.69

年代:1993

数据来源: MAL

摘要:

The aim of this study was to investigate whether stimulus-induced up-regulation of human immunodeficiency virus type 1 (HIV-1) expression in peripheral blood mononuclear cells (PBMC) could enhance the diagnostic sensitivity of the polymerase chain reaction (PCR). PBMC derived from 11 HIV-1-infected asymptomatic adults were cultured with a stimulus of phytohemagglutinin (PHA) plus phorbol 12-myristate 13-acetate (PMA) for 36 h prior to lysing the cells for PCR. In all 11 patients studied, the intensity of PCR-assisted HIV RNA amplification (RNA-PCR) performed on stimulated cells was significantly (p<0.001) higher than that obtained on unstimulated cells. A comparison of conventional PCR-assisted DNA amplification (DNA-PCR) with that of RNA-PCR was made on seven patients. The sensitivity of DNA-PCR was also increased by prior stimulation of cells, although not to the same extent as was observed for RNA-PCR. The results of our study indicate that the sensitivity of PCR can be significantly enhanced by prior activation of cells with PHA and PMA.

ISSN:0889-2229    

DOI:10.1089/aid.1993.9.77

年代:1993

数据来源: MAL