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)

In 1990/1991, 885 prostitutes residing in 11 of the 12 Local Government Areas (LGAs) of Lagos State, Nigeria, participated in a cross-sectional study to determine current seroprevalence of antibodies to human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2), and human T-cell lymphotropic virus type I (HTLV-I). The overall prevalence of HIV-1 was 12.3%, of HIV-2, 2.1%, and of HTLV-I, 2.8%. HIV-1 seropositivity did not vary significantly by age, socioeconomic class, or nationality, but HIV-1 seroprevalence was significantly elevated for prostitutes resident in the Port area of Lagos which serves as a crossroads for international and national commerce (OR = 2.3; 95% CI = 1.1, 4.6). HIV-2 infection was significantly associated with low socioeconomic class (OR = 3.7; 95% CI = 1.2, 10.8) and non-Nigerian nationality (OR = 6.7; 95% CI = 2.5, 18.4). Prevalence of HTLV-I infection increased significantly with age (OR = 2.3; 95% CI = 1.0, 5.3). The high seroprevalence of HIV-1 in this survey, compared with previous surveys reported in the last several years and the correlation between high prevalence and areas of international commerce suggest that HIV-1 is spreading in this area of Nigeria. Intensified prevention campaigns are needed to address this possible emerging epidemic.
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PMID:Demographic characteristics of retroviral infections (HIV-1, HIV-2, and HTLV-I) among female professional sex workers in Lagos, Nigeria. 825 75

A 30-year-old man with ulcerative colitis developed oral hairy leukoplakia (OHL). Serological examination for human immunodeficiency virus (HIV)-1 and HIV-2 infection showed no abnormalities. Biopsy specimen of the lateral tongue showed ballooned prickle cells, and electron microscopy revealed herpes-type viruses. Immunologic investigation of the patient showed a marked decrease in T-helper cells as a result of immunosuppressive regimen. The present report appears to be the first well-documented case of OHL in an HIV-negative patient with ulcerative colitis. OHL may be a marker for severe immunosuppression but is not necessarily associated with HIV infection. Patients with iatrogenic immunosuppression should be monitored for OHL. Concerning the marked decrease in T-helper cells in this case, the presence of OHL may imply the examination of T-lymphocyte subsets in patients such as HIV-infected individuals or in organ transplant recipients.
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PMID:Oral hairy leukoplakia in a patient with ulcerative colitis. 829 17

The human immunodeficiency virus type 1 (HIV-1) and HIV-2 enhancers are induced differentially by physiologic T-cell activation signals. In contrast to that of HIV-1, HIV-2 transcription was quite responsive to stimulation of T cells by antigen presentation but weakly induced by tumor necrosis factor alpha. Like tumor necrosis factor alpha, expression of cloned NF-kappa B subunits strongly activated the HIV-1, but not the HIV-2, enhancer. The differences in response to these physiologic T-cell activation pathways may contribute to the differences in persistence of HIV-1 and HIV-2 infection.
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PMID:Differential activation of human immunodeficiency virus type 1 and 2 transcription by specific T-cell activation signals. 833 39

The fourth conserved region (C4) of human immunodeficiency virus type 1 (HIV-1) surface glycoprotein has been shown to participate in CD4 binding and to influence viral tropism (A. Cordonnier, L. Montagnier, and M. Emerman, Nature [London] 340:571-574, 1989). To define the role of the corresponding region of HIV-2, we introduce single amino acid changes into the C4 sequence of HIV-2ROD. The effects of these mutations on glycoprotein function and on virus infectivity have been examined. We have shown that the tryptophan residue at position 428 is necessary primarily for CD4 binding. The isoleucine residue at position 421 is necessary for the establishment of productive infection in the promonocytic cell line U937, while it is dispensable to some extent for infection of primary T lymphocytes or the lymphocytic cell line SUP-T1. This replication defect correlated with the failure of the Ile-421-to-Thr (Ile-421-->Thr) mutant glycoprotein to form syncytia in U937 cells. DNA analysis of revertant viruses revealed that a strong selective pressure was exerted on residue 421 of the surface glycoprotein to allow HIV-2 infection of U937 cells. These results demonstrate that this region of HIV-2 plays an important role in determining fusion efficiency in a cell-dependent manner and consequently can influence viral tropism.
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PMID:Amino acid changes in the fourth conserved region of human immunodeficiency virus type 2 strain HIV-2ROD envelope glycoprotein modulate fusion. 837 58

A new human retrovirus, HIV-2, serologically distinct from human immunodeficiency virus type 1 (HIV-1), was first reported in 1985 and isolated in 1986 from 2 AIDS patients from Guinea-Bissau and Cape Verde Islands. Findings related to the characterization of HIV-2 antigenic and immunogenic sites that stimulate strain and type-cross-reactive immunity are illustrated; data from preliminary studies of simian immunodeficiency virus (SIV) are presented; and epidemiological and biological characteristics of HIV-2 infection are also reviewed. Prevention of HIV-2 and SIVsm infection has been achieved in cynomolgus macaques by passive transfer of an anti-SIVsm serum pool with high antibody titres. The identification of antibody-binding regions of HIV is critical for vaccine development studies. The presence of highly immunogenic domains in the extracellular proteins of HIV-2 has also been demonstrated by Western blot analysis using bacterially expressed contiguous segments representing the HIV-2 envelope products. Over 95% of HIV-2 positive sera from Senegal reacted with these protein segments. The antibody-reactive peptide scanning method defined 8 distinct antibody-binding sites in the transmembrane protein gp36 of the HIV-2 strain ROD in addition to the highly immuno-dominant site present at the amino terminus of gp36. Antibody reactions of SIVm-infected macaque sera against selected SIVm envelope peptides were very similar to those of HIV-2 and HIV-1-infected human sera to the corresponding linear antigenic sites, indicating the existence of immunological parallelism between human and simian lentiviruses. HIV-2-induced immunity in inoculated macaques has been shown to protect against SIV-associated disease, indicating that the 2 viruses share group-specific protective immunity. In a study of human sera, the occurrence of an intertype cross-reacting V3-region-specific activity correlated with the presence of cross-neutralizing activity in sera. These findings indicate that the V3 region may be an important neutralizing site not only in HIV-1 but also in HIV-2.
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PMID:Antigenic and immunogenic sites of HIV-2 glycoproteins. 845 54

We report the development of an immunoassay for the titration of antibody to the CD4-binding site (CD4BS) of the human immunodeficiency virus type 1 (HIV-1) surface glycoprotein gp120. This assay is a competitive enzyme-linked immunosorbent assay in which serum antibodies compete with labeled F105, a human monoclonal antibody whose corresponding epitope overlaps the conformation-dependent CD4BS, for binding to purified recombinant gp120 coated on a solid phase. Ninety-nine percent (109 of 110) of HIV-1-positive French patients and 91% (51 of 56) of HIV-1-positive African patients had CD4BS antibodies, indicating that the conformational CD4BS epitope is well conserved among different subtypes of HIV-1. Titers of CD4BS antibodies according to clinical status appeared to be not statistically different. A longitudinal study in 21 seroconverters showed that, for the majority of individuals, CD4BS antibodies appeared early and persisted at relatively high titers for several years. None of 21 HIV-2-seropositive patients had CD4BS antibodies in our assay, suggesting that the antibodies produced during HIV-2 infection are not cross-reactive with the CD4BS of HIV-1 gp120.
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PMID:Simple enzyme immunoassay for titration of antibodies to the CD4-binding site of human immunodeficiency virus type 1 gp120. 858 27

Sera from human immunodeficiency virus type 1 and type 2 (HIV-1 and HIV-2)-infected humans were tested with autologous (from the same individual) and heterologous (from other individuals) virus isolates in a neutralization assay. Similarly, sera from experimentally simian immunodeficiency virus (SIVsm from sooty mangabey) or HIV-2SBL6669-infected cynomolgus macaques were tested for neutralizing activity against autologous and heterologous reisolates. In the neutralization assay, the virus dose ranged between 10-75 50% infectious dose (ID50), sera were used in five 2- or 4-fold dilutions, beginning with 1:20, and human peripheral blood mononuclear cells (PBMCs) served as target cells. The readout of the 7-day assay was a HIV-1 or HIV-2 antigen enzyme-linked immunosorbent assay (ELISA). Our results show that SIVsm-inoculated monkeys who develop early immunodeficiency lack serum neutralizing activity or develop a neutralizing antibody response with narrow specificity. Long survival is associated with the ability to neutralize several autologous and heterologous SIVsm reisolates. Infection of macaques with HIV-2SBL6669 did not cause disease within the 5 years observation time and elicited a broadly cross-reactive neutralizing antibody response, including neutralization of other, independently obtained, HIV-2 isolates. In HIV-1-infected humans, neutralizing antibodies can only be detected in up to 50% of cases. Neutralizing activity, whenever present, may show a broad specificity, that is, neutralization may occur across genetic subtypes. Presence of broadly cross-reactive neutralizing antibodies is associated with a lower risk of HIV-1 (subtype B) transmission both from mother to child and sexually from male to female. Unlike HIV-1 infection, serum neutralizing activity is regularly present in HIV-2 infection. In view of the differences between HIV-1 and HIV-2 pathogenesis, we suggest that an effective neutralizing antibody response may contribute to a delay in disease progression and to a decrease in risk of transmission.
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PMID:Broad cross-neutralizing activity in serum is associated with slow progression and low risk of transmission in primate lentivirus infections. 881 51

In an urban community in Guinea-Bissau, we followed a cohort of human immunodeficiency virus type 2 (HIV-2) seropositive individuals (N = 47) and seronegative controls (N = 82). T-lymphocyte subset determinations were done in 1988, 1990, and 1992. Serial determinations of CD4 percentages, CD8 percentages, and CD4/CD8 ratios for the same individual were stable for 31 seropositive and 51 seronegative individuals with repeated measurements. We found no significant differences in the changes during a 2- or 4-year period in CD4 percentages, CD8 percentages, absolute CD8 T-lymphocyte counts, CD4/CD8 ratio, white blood cell counts, lymphocyte percentages, and absolute lymphocyte counts for HIV-2-seropositive compared with HIV-2-seronegative individuals. Only absolute CD4 T-lymphocyte counts changed more for the HIV-2-seropositive than for HIV-2-seronegative individuals (p = 0.037). HIV-2-infected individuals who lived with an HIV-2-infected spouse had a lower CD4/CD8 ratio and had higher mortality than HIV-2 infected individuals who lived with an uninfected spouse. However, there were no significant differences in immunological and hematological values for the 8 HIV-2 seropositive individuals who died and the 39 who survived in the 8-year follow-up period. In conclusion, progression of immunosuppression in HIV-2 infection seems to be slower than in HIV-1 infection and may not be inevitable in all individuals.
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PMID:Serial CD4 and CD8 T-lymphocyte counts and associated mortality in an HIV-2-infected population in Guinea-Bissau. 894 74

The extent of zoonotic infections in rural Sierra Leone, where both feral and pet sooty mangabeys harbor divergent members of the human immunodeficiency virus type 2 (HIV-2)-sooty mangabey simian immunodeficiency virus (SIVsm) family, was tested in blood samples collected from 9,309 human subjects in 1993. Using HIV-1- and HIV-2-specific enzyme immunoassays and confirmatory Western blot analysis to test for antibodies to SIVsm-related lentiviruses, we found only nine subjects (0.096%) who tested positive for HIV: seven tested positive for HIV-1 and two tested positive for HIV-2. Compared with other rural West African communities, Sierra Leone displayed the lowest seroprevalence (0.021%) of HIV-2 infection yet reported, much lower than the previously reported seroprevalence in SIVsm-infected feral and household pet sooty mangabeys. Heteroduplex analysis demonstrated that two of the newly found HIV-1 strains belonged to subtype A, the most common HIV-1 subtype in Africa, but this is the first report of subtype A in Sierra Leone. The two HIV-2-infected individuals harbored two distinct HIV-2 strains, designated 93SL1 and 93SL2. Phylogenetic analysis indicated that HIV-2 93SL1 is a member of HIV-2 subtype A, the first strain of this HIV-2 subtype found in Sierra Leone. In contrast, HIV-2 93SL2 belongs to none of the five previously characterized HIV-2 subtypes (A to E) but is a new subtype, herein designated F, having the most divergent transmembrane sequences yet reported for HIV-2. The fact that both of the two most divergent HIV-2 subtypes known, E and F, are rare and found as single occurrences in persons from Sierra Leone may be related to the fact that this small region of West Africa also contains free-living and household pet sooty mangabeys with highly divergent variants of SIVsm. This finding provides support for the hypotheses that new HIV-2 subtypes result from independent cross-species transmission of SIVsm to the human population and that these single-occurrence transmission events had not spread widely into the population by 1993.
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PMID:Human immunodeficiency virus type 2 (HIV-2) seroprevalence and characterization of a distinct HIV-2 genetic subtype from the natural range of simian immunodeficiency virus-infected sooty mangabeys. 909 72

We report here that human immunodeficiency virus type 2 (HIV-2) envelope glycoprotein (gp105), but not HIV-1 gp120, can bind to CD8 molecules as well as to CD4 molecules on human T cells. This phenomenon may lead to differences in the life cycles of HIV-1 and HIV-2, and it may be related to the differences in disease manifestations of HIV-1 and HIV-2 infection, including longer survival of HIV-2-infected patients.
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PMID:Human immunodeficiency virus type 2 envelope glycoprotein binds to CD8 as well as to CD4 molecules on human T cells. 934 59


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