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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mannan sulfate, a novel sulfated polysaccharide, was prepared and investigated for its activity against human immunodeficiency virus type 1 (HIV-1) in vitro. Mannan sulfate completely inhibited HIV-1-induced cell destruction and viral antigen expression in HIV-1-infected Molt-4 (clone 8) cells at a concentration of 4 micrograms/ml. The 50% antiviral effective doses obtained with mannan sulfate in Molt-4 (clone 8) cells and in MT-4 cells were 1.5 and 9.3 micrograms/ml, respectively. No toxicity for Molt-4 (clone 8) cells or MT-4 cells was observed at a concentration of 4,000 and 2,500 micrograms/ml, respectively. Mannan sulfate was also inhibitory to other enveloped viruses, i.e. herpes simplex virus types 1 and 2, vaccinia virus and vesicular stomatitis virus. These results suggest that mannan sulfate may be useful for the chemotherapy of various viral infections, including those causing and associated with AIDS.
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PMID:In vitro activity of mannan sulfate, a novel sulfated polysaccharide, against human immunodeficiency virus type 1 and other enveloped viruses. 256 84

The human immunodeficiency virus type 1 (HIV-1) induces a strong cytotoxic T lymphocyte (CTL) response in humans following infection. HIV-specific CTL can be detected directly in the blood and lungs of infected patients, and can be expanded in vitro by stimulation with autologous HIV-infected lymphoblasts. Furthermore, CTL specific for HIV envelope glycoprotein gp160 have been obtained in mice by immunization with recombinant vaccinia virus (VV) that carry the HIV env gene. In this study, we show that mice also produce strong CTL responses to gag and nef proteins following immunization with VV recombinants, thus providing a convenient model system to study T lymphocyte immunity to defined HIV antigens. To determine the specificity of circulating HIV-immune CTL in humans, a panel of doubly transfected mouse P815 tumor cells was produced which express the human HLA-A2 or HLA-A3 transplantation antigen gene and one HIV-1 gene (env, gag or nef). Using these cells as targets to CTL, we show that HIV-infected humans carry co-existing CTL sub-populations of different specificities. Each subpopulation appears to vary in intensity among different individuals. Surprisingly, CTL specific for regulatory, non-structural nef protein appear to be a major constituent of the human immune response to HIV.
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PMID:Multiple subsets of HIV-specific cytotoxic T lymphocytes in humans and in mice. 267 60

The sequences encoding the core proteins p55, p25, and p18 of the human immunodeficiency virus (HIV-1) have been inserted into the vaccinia virus genome. Infection of cultured cells with the live recombinant viruses led to the expression of proteins that were recognized by sera from HIV-seropositive individuals. Immunization of mice with the recombinant virus expressing the HIV p25 protein and the p55 precursor yielded high levels of antibodies directed against the corresponding HIV antigens. The data obtained are discussed in terms of the possible use of these live recombinant viruses in the development of a strategy toward an AIDS vaccine.
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PMID:HIV-1 core proteins expressed from recombinant vaccinia viruses. 271 65

The human immunodeficiency virus (HIV-1) envelope gene was expressed in large-scale microcarrier cultures of Vero cells using a system involving coinfection with two recombinant vaccinia viruses. One recombinant contained the bacteriophage T7 RNA polymerase gene under control of a vaccinia virus promoter. The second contained the HIV-1 gp160 gene flanked by T7 promoter and termination sequences. The protein was expressed on the surface of infected cells, and it was shown to have a molecular weight of 160 kD and to react with gp41 and gp120 specific monoclonal antibodies. After purification by successive affinity and ion-exchange chromatography, the protein was demonstrated to be present in a particulate form with a diameter in the range of 15-30 nm. When injected into goats a high-titer gp160 specific antibody response was elicited and group-specific neutralizing activity could be demonstrated in vitro. The immunogenicity of the protein was also studied in conjunction with a number of adjuvant formulations, and the highest potency in mice was obtained using a preparation with 0.2% Al(OH)3 and 0.25% deoxycholate.
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PMID:Large-scale production and purification of a vaccinia recombinant-derived HIV-1 gp160 and analysis of its immunogenicity. 271 66

Major histocompatibility (MHC)-restricted, human immunodeficiency virus type one (HIV-1)-specific, cytotoxic T lymphocytes (CTLs) were detected in the peripheral blood mononuclear cells (PBMCs) of HIV-1-infected individuals. Using a system of autologous B and T lymphoblastoid cell lines infected with recombinant vaccinia vectors (VVs) expressing HIV-1 gene products, we were able to detect HIV-1-specific cytolytic responses in the PBMCs of 88% of HIV-1-seropositive hemophiliac patients in the absence of in vitro stimulation. These cytolytic responses were directed against both HIV-1 envelope and gag gene products. The responses were resistant to natural killer (NK) cell depletion and were inhibited by monoclonal antibodies (MoAbs) to the T cell receptor, CD8 surface antigens, and MHC class I antigens, suggesting a classical MHC class I restricted, virus-specific CTL response.
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PMID:Detection of major histocompatibility complex class I-restricted, HIV-specific cytotoxic T lymphocytes in the blood of infected hemophiliacs. 278 19

We have used a recombinant vaccinia virus (VV) which expresses high levels of human immunodeficiency virus-1 (HIV-1) gag proteins to analyze the processing pathway of the gag p55 precursor. HIV-1 gag proteins were isolated from [3H]leucine-labeled VV:gag-infected H9 T lymphocytes by immunoprecipitation with either anti-p24, anti-p17, or anti-p6 antibodies. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that processing of the p55 precursor involves three major intermediates (p41a, p41b, and p39). The p41a and p39 proteins contain the p17 and p24 protein segments, and the p41b is comprised of p24 and p15 segments. On two-dimensional gels, each intermediate as well as the mature p24 and p17 proteins migrated as distinct species. [3H]Myristic acid labeling of the HIV-1 gag proteins revealed that in addition to p55 and p17, the p41a and p39 intermediates, but not p41b, are myristylated, confirming that myristylation occurs at the NH2 terminus before cleavage of the p55 precursor protein. We conclude that the myristylated HIV-1 gag p55 precursor is initially cleaved at random either at the p17/p24 junction or at two sites between p24 and p15 proteins, resulting in three intermediates (p41a, p41b, and p39) which are subsequently cleaved to yield mature gag proteins.
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PMID:Identification of protein intermediates in the processing of the p55 HIV-1 gag precursor in cells infected with recombinant vaccinia virus. 278 91

For the IIIB isolate of human immunodeficiency virus type-1 (HIV-1), the immunodominant determinant of the envelope protein gp160 for cytotoxic T lymphocytes (CTLs) of H-2d mice is in a region of high sequence variability among HIV-1 isolates. The general requirements for CTL recognition of peptide antigens and the relation of recognition requirements to the natural variation in sequence of the HIV were investigated. For this purpose, a CTL line specific for the homologous segment of the envelope from the MN isolate of HIV-1 and restricted by the same class I major histocompatibility (MHC) molecule (Dd) as the IIIB-specific CTLs was raised from mice immunized with MN-env-recombinant vaccinia virus. The IIIB-specific and MN-specific CTLs were completely non-cross-reactive. Reciprocal exchange of a single amino acid between the two peptide sequences, which differed in 6 of 15 residues, led to a complete reversal of the specificity of the peptides in sensitizing targets, such that the IIIB-specific CTLs lysed targets exposed to the singly substituted MN peptide and vice versa. These data indicate the importance of single residues in defining peptide epitopic specificity and have implications for both the effect of immune pressure on selection of viral mutants and the design of effective vaccines.
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PMID:A single amino acid interchange yields reciprocal CTL specificities for HIV-1 gp160. 278 33

Friend murine leukaemia virus complex (FV) causes an immunosuppressive retrovirus-induced disease. In certain mouse strains, FV shows striking similarities to human immunodeficiency virus (HIV) infection in man in that infected mice have severe T-cell immunosuppression but also develop virus-neutralizing antibodies incapable of eliminating infected cells. Previously we noted the influence of mouse major histocompatibility complex (H-2) genes on both FV-induced immunosuppression and on ability to protect mice against FV by immunizing with a vaccinia-Friend murine leukaemia helper virus (F-MuLV) envelope (env) recombinant virus. Here we show that different subregions of H-2 are involved in susceptibility to virus-induced immunosuppression (H-2D subregion) and protective immunization with a recombinant vaccinia virus (H-2K or I-A subregions). Thus, susceptibility to virus-induced immunosuppression does not preclude protection by vaccinia-Friend immunization. The mechanism of protection seems to involve priming of immune T cells, and not initial induction of neutralizing antibodies or cytotoxic T lymphocytes (CTL) (ref.2). Subsequent virus challenge generates a secondary response, resulting in appearance of IgG antibodies and CTL. In human HIV infection there could also be host genetic influences on elements of disease pathogenesis, such as immunosuppression, and on the success of T-cell priming by potential protective vaccines.
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PMID:Different H-2 subregions influence immunization against retrovirus and immunosuppression. 282 42

Interactions between human immunodeficiency virus type 1 (HIV-1), the etiologic agent of AIDS, and human cytomegalovirus (CMV), a frequent opportunistic agent in AIDS, were studied in vitro. Coinfection of H9 cells with HIV-1 enhances productive CMV infection, as measured by immunofluorescence using monoclonal antibodies to late CMV proteins, slot-blot hybridization for CMV DNA, and cytopathic effects of CMV on human embryonic lung cells. Experiments using vaccinia virus recombinants and Jurkat cells transfected with the transactivating (tat) gene of HIV-1 suggest that this enhancement is not mediated primarily by the tat protein. In addition, coinfection of H9 cells or a monocyte cell line with CMV and HIV-1 results in enhanced HIV-1 replication, as measured in a virus-yield assay or by radioimmunoassay for the p24 antigen of HIV-1. The interactions between HIV-1 and CMV are thus bidirectional.
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PMID:Bidirectional interactions between human immunodeficiency virus type 1 and cytomegalovirus. 283 Mar 43

A recombinant antigen produced in CV-I cells infected with vaccinia virus vC5 carrying the HIV-I gag gene was used to test sera. This antigen (rp50) reacted with 95 serum specimens shown to have anticore antibodies by immunoblot based on natural HIV antigens. Six sera from blood donors positive in ELISA contained antibodies to p17, p24, or p55 by natural antigen-based blot. All these sera did not react with rp50. These patients did not belong to any known risk groups and showed no dynamics in the immunoblot pattern. We consider the reaction of their serum samples as false positive. We believe that the recombinant antigen rp50 may be used for verification of positive ELISA results.
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PMID:[An analysis of blood sera by the immunoblot method using natural and recombinant antigens of the human immunodeficiency virus]. 307 70


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