Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The external envelope glycoprotein (gp120) of the human immunodeficiency virus (HIV) has been shown to be toxic to neurons in culture. To further investigate the neurological effects of gp120, the involvement of this protein with the acquisition of spatial discrimination was assessed. Both native and recombinant gp120 were administered into the cerebral ventricles of adult rats and performance was evaluated in the Morris swim maze. Gp120 treatment retarded acquisition after daily administration of 12 ng. The specificity of this impairment was demonstrated in that the performance of animals given the same amount of gp160 from recombinant baculovirus was not different from animals given saline. Vasoactive intestinal peptide (VIP) has been shown to block gp120-induced neurotoxicity in culture and a VIP receptor antagonist has displayed toxic properties to neurons in culture. We show here that this antagonist, which competitively inhibits VIP binding and blocks VIP-mediated functions in cell cultures from the CNS, also produced an impairment of performance. This retardation was attenuated by cotreatment with VIP, supporting the specificity of the observed impairment. Thus, gp120 and the VIP antagonist produced similar retardation of spatial discrimination, suggesting that both may impair memory for spatially related stimulus control.
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PMID:Learning impairment following intracerebral administration of the HIV envelope protein gp120 or a VIP antagonist. 161 29

A human CD4+ T cell line, Jurkat, was transfected with a constructed plasmid, which has the envelope gene of the human immunodeficiency virus (HIV) under the transcriptional control of the human metallothionein IIA promoter, and these transfected cells were then cloned. JME2, one of the cloned cell lines, expressing the envelope glycoprotein after induction with metal ions, showed the ability to form syncytia involving other CD4+ cells not expressing the HIV envelope protein. When several CD4+ cell lines were examined for their susceptibility to syncytium formation by JME2 cells, the p56lck-expressing cell lines were found to be more susceptible to syncytium formation than the p56lck-non-expressing cell lines. To substantiate the role of p56lck in the syncytium formation, a CD4+, p56lck-non-expressing monocytoid cell line, U937 clone 2, was transfected with an lck-expressing construct. Using such transfectant cell clones, it was demonstrated that p56lck-positive cells are markedly more susceptible to the syncytium formation than p56lck-negative cells, implying a regulatory role for p56lck in syncytium formation mediated by the HIV envelope and CD4 molecule. Moreover, it was suggested, in the experiments using CD45 cross-linking or a protein tyrosine kinase inhibitor, genistein, that p56lck affects syncytium formation through its protein tyrosine kinase activity. A putative mechanism by which p56lck affects the syncytium formation is also discussed.
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PMID:The effect of p56lck, a lymphocyte specific protein tyrosine kinase, on the syncytium formation induced by human immunodeficiency virus envelope glycoprotein. 162 97

The effect of vpu on the release of human immunodeficiency type 1 capsid proteins was examined in the presence or absence of virus-encoded envelope glycoproteins as well as in cells which constitutively express either the CD4 or CD8 protein. The results show that vpu-mediated facilitated export of capsid proteins from HeLa cells does not require expression of the envelope glycoprotein. The experiments also show that export of virus capsid proteins from HeLa cells facilitated by vpu is not affected by coexpression of either the CD4 or CD8 protein. The vpu protein acts in trans to facilitate export of virus capsid proteins from HeLa cells.
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PMID:Envelope glycoprotein and CD4 independence of vpu-facilitated human immunodeficiency virus type 1 capsid export. 162 67

Local secretory immunity in the vagina may confer a degree of protection against heterosexual transmission of human immunodeficiency virus (HIV). Since the vagina has been shown to respond to local immunization, we have undertaken intravaginal immunization of rats with a 20-mer peptide (amino acid residues 102 to 121) of the HIV-1 envelope glycoprotein (gp120). The peptide was administered in combination with an 'absorption enhancer', lysophosphatidyl glycerol (LPG), which has previously been shown to promote the absorption of intravaginally administered peptides, while exerting only mild effects on epithelial membrane integrity. Intravaginal immunization with LPG and the peptide induced serum and vaginal wash IgA and IgG antibody responses which were enhanced in comparison to those after immunization with the peptide alone. Serum antibodies induced by both subcutaneous and intravaginal immunization were able to recognize recombinant HIV-1 gp120. However, the rat antiserum displayed no neutralizing activity against the virus. These results demonstrate that LPG is an effective immunological adjuvant for intravaginally administered peptide antigens. An alternative absorption enhancer, bestatin (BES), was not effective as an immunological adjuvant when administered intravaginally and blocked the adjuvant activity of LPG when BES and LPG were used in combination.
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PMID:Vaginal immunization of rats with a synthetic peptide from human immunodeficiency virus envelope glycoprotein. 164 52

Recombinant fowlpox viruses (FPV) containing the env or gag-pol genes of simian immunodeficiency virus from macaques (SIVmac) were constructed. The env, gag, and pol-encoded polypeptides were efficiently expressed and processed in avian cells productively infected with FPV as well as in mammalian cells, in which FPV infection is abortive. In addition, the recombinant FPV expressing the gag-pol genes directed the formation of defective, lentivirus-like particles which were released into the culture medium of infected cells. Coinfection of cells with the env and gag-pol recombinant viruses resulted in the generation of particles containing SIVmac envelope glycoprotein. The applications of this system to vaccine development are discussed.
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PMID:Formation of lentivirus particles by mammalian cells infected with recombinant fowlpox virus. 166 77

Anti-idiotypic antibodies to anti-CD4 monoclonal antibodies (MAbs) have been reported to bind to the human immunodeficiency virus (HIV) envelope glycoprotein gp120. To establish whether HIV-infected patients can mount an anti-idiotypic response to murine MAb, four individuals with symptoms of AIDS-related complex (ARC) were immunized over 10 weeks with six intramuscular injections of anti-Leu 3a (1 mg). Despite their immunocompromised state, all patients made anti-constant region and anti-idiotypic antibodies, although the amplitude of the responses varied between individuals. No significant toxic or allergic reactions were seen, and there were no changes in clinical status during the 6 months after immunization. No increase in serum HIV-neutralization titers was seen, and purified anti-idiotypic antibodies did not bind gp120.
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PMID:Antiidiotypic responses to immunization with anti-Leu 3a in human immunodeficiency virus-seropositive individuals. 167 Oct 54

The presence of anti-CD4 antibodies in sera of human immunodeficiency virus (HIV)-seropositive individuals has been recently documented, but its origin remains unknown. To test the hypothesis that anti-idiotypic antibodies to gp120, the HIV envelope glycoprotein with high affinity for CD4, mimic the configuration of gp120 and bind CD4, we performed two sets of experiments. First, we tested the possibility that anti-CD4 antibodies present in sera of a proportion of HIV-positive individuals exhibit variable region complementarity to autologous anti-gp120 antibodies. We show here that affinity-purified human anti-gp160 antibodies recognize specifically autologous affinity-purified anti-CD4 antibodies. We also demonstrate that antibodies to CD4 competitively inhibit anti-gp160 autologous antibodies binding to gp160. This implies that at least some anti-CD4 antibodies are directed towards idiotypic motifs located on anti-gp120 antibodies and that they may result from an anti-idiotypic response to anti-gp120 antibodies. In a second set of experiments, we examined the effect of anti-idiotypic immunization of experimental animals against human anti-gp120 antibodies. We found that anti-idiotypic antibodies produced in a rabbit immunized against affinity-purified human anti-gp120 antibodies specifically recognize recombinant and cellular human CD4, and that this interaction is competitively inhibited by soluble CD4. The data support the concept of idiotypic mimicry whereby anti-idiotypic antibodies produced against anti-gp120 antibodies recognize CD4, the cellular receptor of HIV.
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PMID:Anti-idiotypic antibodies to human anti-gp120 antibodies bind recombinant and cellular human CD4. 167 46

A novel membrane-bound serine esterase, named tryptase TL2, which is immunologically reactive with the antibody inhibiting induction of syncytia by human immunodeficiency virus-1 (HIV-1) (HATTORI, T., KOITO, A., TAKATSUKI, K., KIDO, H., and KATUNUMA, N., 1989, FEBS Lett., 248, 48-52), has been purified from a human T4+ lymphocyte clone. The enzyme has a molecular mass of 198 +/- 15 kDa, and is composed of two subunits of 32 kDa and four subunits of 28 kDa. The enzyme was strongly inhibited by the envelope glycoprotein gp120 of HIV-1, by synthetic peptides of V3 domains of gp120 s with the sequence GPGR in their center, which correspond to the principal neutralizing epitopes of the gp120s of various HIV-1 strains, by Kunitz-type inhibitors with the sequence GPCR in their active site, such as trypstatin, H130, and [Arg15, Glu52] aprotinin and by the microbial inhibitors leupeptin and antipain. This enzyme was specifically bound to the inhibitor V3 domain of gp120 of HIV-1, and this binding was blocked by the inhibitors of tryptase TL2, with a central motif GPCR or GPGR sequence in their center, but not by leupeptin and antipain without the motif. These findings suggest that tryptase TL2 is important in target site recognition and binding of HIV-1 in co-operation with CD4 receptor in the initial process of HIV-1 infection.
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PMID:A novel membrane-bound serine esterase in human T4(+)-lymphocytes is a binding protein of envelope glycoprotein gp120 of HIV-1. 168 71

A mouse monoclonal anti-idiotypic antibody (anti-Id), designated MC1, was generated against chimpanzee antibodies specific for a synthetic peptide corresponding to a native epitope associated with gp41 of human immunodeficiency virus (HIV). This anti-Id recognized a shared idiotope/idiotype (Id) on a second chimpanzee anti-gp41 peptide preparation but failed to detect this Id on rabbit and mouse anti-gp41 peptide antibodies induced by immunization with the gp41 synthetic peptide. The chimpanzee Id-MC1 reaction was not inhibited by either synthetic peptide or recombinant gp160 suggesting that MC1 exhibits noninternal image, Ab-2 alpha-like characteristics. Immunization of syngeneic Balb/c mice with MC1 induced an antigen-positive (Ag+) response capable of binding the synthetic peptide, recombinant gp160, and gp41, whereas MC1-immunized rabbits did not produce any detectable anti-peptide and/or anti-HIV envelope glycoprotein antibody response. The MC1-induced anti-Id response (Ab-3) in both mice and rabbits expressed a similar Id with the Ab-1, which is not normally expressed in the anti-gp41 peptide antibody response induced by the nominal antigen in Balb/c mice and in rabbits. Together, these studies indicate that a mouse monoclonal anti-Id of the Ab-2 alpha class can induce an anti-HIV response specific for a gp41 epitope defined by a synthetic peptide, which does not cross species barriers.
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PMID:Administration of noninternal image monoclonal anti-idiotypic antibodies induces idiotype-restricted responses specific for human immunodeficiency virus envelope glycoprotein epitopes. 168 76

The role of the interaction of CD2 molecules with lymphocyte function-associated antigen 3 (LFA-3) in facilitating nominal antigen recognition by T lymphocytes was studied by utilizing an HLA-DR4-restricted CD4+ cytotoxic human T-cell clone specific for human immunodeficiency virus envelope glycoprotein gp120 as a responder and murine fibroblasts transfected with human class II major histocompatibility complex (MHC) and/or human LFA-3 molecules as antigen-presenting cells (APC). Although expression of the DR4 restriction element in fibroblasts is sufficient for T-cell recognition of a gp120 peptide as judged by induction of proliferation coexpression of human LFA-3 on DR4+ APC decreases the molar requirement of nominal antigen by greater than one order of magnitude. Both LFA-3 and the relevant class II MHC molecules are necessary for antigen-independent conjugate formation, but the binding is further enhanced by specific nominal antigen. CD2-LFA-3 interaction is independent of T-cell receptor-MHC interaction and contributes directly to the stabilized conjugate between the T cell and LFA-3-bearing APC; soluble CD2 and monoclonal antibodies to LFA-3 and CD2 reduce T-cell-APC binding to the level mediated by nominal antigen and MHC. During conjugate formation, CD2 but not CD3 molecules are reorganized into the cell-cell interaction site in an antigen-independent manner. Thus, reorganization and/or coassociation of CD2 with CD3 molecules is not essential for T-cell activation.
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PMID:Role of interaction of CD2 molecules with lymphocyte function-associated antigen 3 in T-cell recognition of nominal antigen. 169 Aug 89


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