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Query: UMLS:C0001175 (AIDS)
 120,706 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Expression of a gene encoding the diphtheria toxin A (DT-A) fragment, controlled by tissue specific regulatory elements, has previously been used to kill selected cell populations. Here, we have examined the feasibility of controlling DT-A expression using regulatory systems from the human immunodeficiency virus (HIV-1) genome. Plasmids were constructed which express either DT-A or, as a model system, the luciferase (luc) reporter gene, under control of HIV-1 long terminal repeat (LTR) sequences (-167 to +80). While trans-activation by expression of the viral protein Tat was demonstrated, significant basal expression was observed. To reduce basal expression, cis-acting negative regulatory elements from the env region of the HIV-1 genome were inserted in the 3' untranslated region of both the luc and DT-A constructs. This dramatically reduced basal expression from the HIV LTR, and now both viral regulatory proteins Tat and Rev were required for maximal trans-activation. Such regulation of DT-A expression might be therapeutically applied to selectively kill HIV-infected cells in acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC).
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PMID:Activation of a diphtheria toxin A gene by expression of human immunodeficiency virus-1 Tat and Rev proteins in transfected cells. 186 40

The polymerase chain reaction (PCR) was used to detect HIV-1 sequences (gag, pol, and env) in the cerebrospinal fluid (CSF) and serum samples from 53 HIV-1-positive patients and the results correlated with clinical evidence of neurological disease. Twenty-three out of 24 patients with neurological disease had HIV-1-specific sequences in CSF compared with four out of 20 asymptomatic patients who had no evidence of neurological involvement. The detection of HIV RNA sequences by PCR in the CSF of HIV-positive patients may provide early, rapid and direct evidence of neurological involvement in asymptomatic subjects.
AIDS 1991 Jul
PMID:Expression of HIV-1 in the cerebrospinal fluid detected by the polymerase chain reaction and its correlation with central nervous system disease. 189 87

To examine cross-reactivity of antibodies to heterologous antigens, on HIV-1 and HIV-2 Western blots, we tested sera from 1362 consecutive tuberculosis (TB) patients and 2127 consecutive blood donors. Specimens positive on enzyme-linked immunosorbent assay (ELISA) for HIV-1 or HIV-2 were further characterized by synthetic peptide-based tests, and tested by HIV-1- and HIV-2-specific Western blots. Dual serologic reactivity on synthetic peptide tests was proportionately more frequent in HIV-positive TB patients than in blood donors, and HIV-2 reactivity less frequent. Positive HIV-1 Western blots were seen in 73-83% of specimens specifically characterized as positive for HIV-2 on synthetic peptide tests. Cross-reactivity to HIV-2 Western blots by HIV-1-positive specimens was significantly more frequent in TB patients (35%) than in asymptomatic donors (9%; P less than 0.001). Using recently recommended criteria for HIV-2 Western blot interpretation (presence of two env bands) reduced the overall proportion of HIV-1-positive specimens having a positive HIV-2 Western blot from 27.5 to 16.4%, with [corrected] minimal effect on sensitivity in the diagnosis of HIV-2 reactivity on specimens positive on synthetic peptide tests.
AIDS 1991 Jul
PMID:Cross-reactivity on western blots in HIV-1 and HIV-2 infections. 189 91

CV-1 cells were infected with two recombinant vaccinia viruses carrying the gag gene with deletion of 231 bp from 3' terminus (strain vC5) and env gene (strain vE234L) of human immunodeficiency virus type 1 (HIV-1). Both recombinant proteins synthesized in the cells (p50gag and gp160/120env) were localized predominantly in cell membranes; however, some amount of p50 was found in cell nuclei. Thin-section immunoelectron microscopy showed accumulation of viruslike particles undistinguished from immature HIV-1 virions in the culture medium of the cells infected with vC5. The similar particles containing gag and env proteins were produced into the culture medium when the cells were coinfected with vC5 and vE234L strains. The particles contained heterogeneous cellular RNA, but no virus-specific RNA as shown by Northern blot hybridization. Immunization of the rabbits with purified viruslike particles produced virus-specific antibodies against gag and env proteins. The titer of antibodies was significantly higher than after immunization with cell lysate or recombinant proteins purified from the infected cells. Highly immunogenic HIV-1-like particles containing gag and env proteins but no virus-specific RNA are good candidates for potential vaccine.
AIDS Res Hum Retroviruses 1991 Jan
PMID:Highly immunogenic human immunodeficiency viruslike particles are produced by recombinant vaccinia virus-infected cells. 190 21

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 ultra violet 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, our 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.
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PMID:HIV-specific humoral and cellular immunity in rabbits vaccinated with recombinant human immunodeficiency virus-like gag-env particles. 190 60

We examined the ability of the various human and non-human cell lines to form syncytia upon coinfection with recombinant vaccinia viruses each carrying the HIV env and the human CD4 gene. We found that three human cell lines and one of three monkey cell lines exhibited syncytium formation, but that one human cell line, two monkey cell lines and all the rabbit and mouse cell lines examined did not. This indicated that factors other than HIV env and CD4 were participating in syncytium formation and that distribution of these factors was restricted by species and by the cell type in a species.
AIDS 1991 Jul
PMID:Syncytium formation of human and non-human cells by recombinant vaccinia viruses carrying the HIV env gene and human CD4 gene. 190 75

Simian immunodeficiency virus (SIV), a lymphocytopathic lentivirus, induces an AIDS-like disease in rhesus macaques (Macaca mulatta). A pathogenic molecular clone of rhesus macaque SIV (SIVmac), SIVmac-239, replicates and induces cytopathology in T lymphocytes but is restricted for replication in macrophages. In contrast, a nonpathogenic molecular clone of SIVmac, SIVmac-1A11, replicates and induces syncytia (multinucleated giant cells) in cultures of both T lymphocytes and macrophages. SIVmac-1A11 does not cause disease in macaques. To map the viral determinants of macrophage tropism, reciprocal recombinant genomes were constructed between molecular clones of SIVmac-239 and SIVmac-1A11. Infectious recombinant viruses were rescued by transfection of cloned viral genomes into permissive lymphoid cells. Analysis of one pair of reciprocal recombinants revealed that an internal 6.2-kb DNA fragment of SIVmac-1A11 was necessary and sufficient for both syncytium formation and efficient replication in macrophages. This region includes the coding sequences for a portion of the gag gene, all of the pol, vif, vpr, and vpx genes, the first coding exons of tat and rev, and the external env glycoprotein gp130. Thus, the transmembrane glycoprotein of env, the nef gene, the second coding exons of tat and rev, and the long terminal repeats are not essential for in vitro macrophage tropism. Analysis of additional recombinants revealed that syncytium formation, but not virus production, was controlled by a 1.4-kb viral DNA fragment in SIVmac-1A11 encoding only the external env glycoprotein gp130. Thus, gp130 env of SIVmac-1A11 is necessary for entry of virus into macrophages but is not sufficient for a complete viral replication cycle in this cell type. We therefore conclude that gp130 env and one or more genetic elements (exclusive of the long terminal repeats, transmembrane glycoprotein of env, and second coding exons of tat and rev, and nef) are essential for a complete replication cycle of SIVmac in rhesus macaque macrophages.
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PMID:Identification of viral determinants of macrophage tropism for simian immunodeficiency virus SIVmac. 192 Jun 17

Alterations in two highly conserved N-linked glycosylation sites within the gp120 envelope glycoprotein of human immunodeficiency virus type I (HIV-1) implicated in the phenotype of a noncytopathic HIV-1 variant were introduced independently and in combination into a cytopathic, infectious HIV-1 clone by site-specific mutagenesis. Neither mutation affected the synthesis of HIV-1 envelope glycoproteins. However, one of the mutations restricted the ability of HIV-1 envelope to localize on the cell membrane and thus markedly impaired virus assembly. The HIV-1 assembly defect could be overcome in trans if site-specific mutants were packaged in HeLa cells constitutively producing wild-type HIV-1 envelope glycoprotein. In addition to inefficient virus assembly, this mutation impaired the ability of the virus to infect CD4+ T cells, but did not affect CD4-independent infection of muscle cells. These results suggest additional functions of posttranslational modification in virus replication (i.e., envelope glycoprotein transport). Given that such modifications can restrict CD4-mediated uptake without affecting CD4-independent uptake, variations in posttranslational env processing between different HIV-1 genotypes may affect virus tropism in vivo.
AIDS Res Hum Retroviruses 1991 Jun
PMID:Posttranslational modifications within the HIV-1 envelope glycoprotein which restrict virus assembly and CD4-dependent infection. 193 Dec 29

We report here the results of molecular analysis of a simian immunodeficiency virus (designated SIVstm) which was isolated from a rhesus monkey inoculated with stored lymph node tissue of an Asian stump-tailed macaque. The latter monkey had died in 1977 during an epidemic of acquired immunodeficiency and lymphoma at the California Regional Primate Research Center (L. J. Lowenstine, N. W. Lerche, P. A. Marx, M. B. Gardner, and N. C. Pedersen, p. 174-176, in M. Girard and L. Valette, ed., Retroviruses of Human AIDS and Related Animal Viruses, 1988). Nucleotide sequence analysis of the gag and env regions indicates that SIVstm is an ancient member of the SIV/human immunodeficiency virus type 2 group; it is quite divergent from known SIVs isolated from African sooty mangabeys as well as from Asian macaques. Furthermore, of all SIV strains described to date, SIVstm is the most closely related to human immunodeficiency virus type 2.
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PMID:A highly divergent simian immunodeficiency virus (SIVstm) recovered from stored stump-tailed macaque tissues. 194 58

HIV-1-positive antisera were tested for their ability to lyse HIV-1-infected cells in the presence of active complement. Cytolytic effects caused by sera derived from infected humans were slower than those observed with sera from immunised chimpanzees. Lytic but also negative sera were found among HIV-1-infected asymptomatic men as well as among clinical AIDS cases. Human antisera that lysed infected cells reacted similarly irrespective of whether the complement was heterologous or autologous. Analysis of complement-mediated lysis using defined antisera against recombinant HIV-1 env or core antigens suggested that gp160/gp120 and p24 can act as target antigens for an antibody- and complement-mediated cytolysis of infected cells. Complement alone reduced the spread of HIV-1 infection in CD4+ cells and the ability of HIV-1 and HIV-2 to form plaques in CD4-transfected HeLa cells. Co-operative effects of specific antibodies and complement were the most effective in inhibiting HIV infections.
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PMID:Antibody- and complement-mediated lysis of HIV-infected cells and inhibition of viral replication. 197 45


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