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

Three-color flow cytometric analysis of CD16+ natural killer (NK) cells was assessed in HIV seropositive patients and healthy heterosexual controls. A selective depletion of lymphocytes with the CD16+ NK phenotype was found among the HIV+ infected patients. When the CD16 lymphocyte subset was further evaluated by three-color flow cytometry, cells bearing both the CD8 and CD56 antigens were significantly decreased. Analysis of activation antigens revealed a large proportion of CD16+ NK cells from HIV+ patients expressed HLA-DR, but this did not correlate with CD25 (IL-2 receptor) expression. The overall loss of the CD8 and CD56 antigens among the NK population with an increase in activation status may be due to differential loss of the NK cell subsets or, alternatively, to the loss of immunoregulatory cytokines, which have been shown to be important in maintaining NK activity. Whether these changes in the NK compartment may influence the outcome of individuals with HIV disease still remains an open question but is an important issue when performing phenotypic analysis of HIV+ subjects.
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PMID:Evidence of a selective depletion of a CD16+ CD56+ CD8+ natural killer cell subset during HIV infection. 758 27

The lymphocyte subset expressing the gamma delta T cell receptor is increased in several infectious diseases including HIV infection. In this study the expression on gamma delta lymphocytes of the T cell activation markers CD25, HLA-DR and CD38, as well as the two isoforms of CD45, namely CD45RA and CD45RO, was determined in the peripheral blood of 56 HIV-infected intravenous drug users and 34 HIV-seronegative blood donors by two-colour flow cytometry. The percentage of gamma delta lymphocytes expressing HLA-DR and CD38 was higher than those in HIV-seronegative controls (P < 0.001 and P < 0.0001, respectively). Furthermore the HLA-DR+gamma delta+ lymphocytes correlated inversely with CD4+ T lymphocyte absolute count (P < 0.02 for both). The levels of gamma delta lymphocytes expressing CD25, CD45RA and CD45RO were similar to those in HIV-seronegative controls. Activated gamma delta lymphocytes may play a role in the HIV disease process and could provide a useful marker for disease progression.
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PMID:Increased level of activated gamma delta lymphocytes correlates with disease severity in HIV infection. 759 Aug 98

Mycoplasma penetrans is a mycoplasma species newly isolated from the urine of human immunodeficiency virus (HIV)-infected individuals and presents the only case in which an association has been found between antibodies against a mycoplasma and HIV infection. To further explore the effects of M. penetrans on the immune system, we studied the influence of this mycoplasma on peripheral blood mononuclear cells (PBMCs) from healthy donors and HIV-infected individuals. M. penetrans induced, in addition to blastogenesis of PBMCs, a significant proliferative response associated with the expression of some activation markers such as CD69, HLA-DR, and CD25. This M. penetrans-dependent lymphocyte activation was observed not only in healthy donors but also in HIV-infected persons at different stages of the disease. In addition, our study revealed that both CD4+ and CD8+ T lymphocytes were responsive to M. penetrans. Interestingly, the mitogenic activity of M. penetrans was associated with mycoplasma cells but not with the supernatants of mycoplasma culture. The potent stimulating activity of M. penetrans on T lymphocytes from HIV-infected individuals is of particular interest in view of the supposed contribution of immune activation to HIV replication and disease progression.
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PMID:In vitro influence of Mycoplasma penetrans on activation of peripheral T lymphocytes from healthy donors or human immunodeficiency virus-infected individuals. 759 Oct 58

In order to clarify the relationship between HLA-DR antigen expression in the liver and human HIV infection, we studied 66 non-autopsy specimens obtained from HIV-infected patients with and without AIDS; 33 biopsies from HIV-negative patients were considered for control purposes. All biopsies were immunohistochemically tested with monoclonal antibody TAL-1B5, reacting with the alpha-chain subunit of HLA-DR in the avidin biotin complex method. We found occasional and usually weak HLA-DR expression on hepatocytes and biliocytes. By comparison with controls, HIV-positive cases showed a significantly higher percentage of HLA-DR immunoreactivity on hepatic artery and portal vein endothelial cells. No relationship was demonstrated between HLA-DR endothelial expression and the CD4+ lymphocyte count or grade of portal/periportal inflammation in the liver. The biological significance of HLA-DR expression on intrahepatic vascular endothelial cells in HIV infection still remains to be clarified.
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PMID:HLA-DR expression in liver in human HIV infection. 767 39

The CD8+ T cell population is believed to play an important role in the control of viral infection, both for suppression of viral replication and for cytotoxic activity against viral infected cells. Elevated numbers of CD8+ T cells have been demonstrated in HIV infection, and CD8+ cytotoxic T cell (CTL) activity is associated with the early, asymptomatic stage of disease. We investigated the phenotypic characteristics of the CD8 population, in whole blood, in HIV disease and determined the predominant CD8+ subpopulation involved in anti-HIV CTL activity. We found that CD8+ T cells co-expressing markers of activation (HLA-DR), memory (CD45RO, CD29), and cytotoxic activity (S6F1) were significantly elevated in the early stages of disease, while the numbers of naive (CD45RA) cells remained unchanged. Progression to AIDS resulted in an overall loss of absolute CD8+ T cells, though the percentages of CD8+ HLA-DR+ and CD8+ S6F1+ remained elevated. In contrast to patients in the late stages of disease, anti-HIVgag CTL activity, following in vitro stimulation, was present in most HIV+ asymptomatic subjects and was associated with an expansion of CD8+ HLA-DR+ and CD8+ CD45RO+ cells. The absence of CTL activity was associated with a reduced ability of these populations to expand in vitro and with a significant loss of peripheral CD4+ T cells, independent of clinical stage. We suggest that CD8+ expressing HLA-DR+ CD45RO+ and S6F1+ play an important role in anti-HIV cytotoxicity.
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PMID:Phenotypic characterization of CD8+ T cell populations in HIV disease and in anti-HIV immunity. 768 64

In this study we evaluated the phenotype of alveolar mononuclear phagocytes recovered from the bronchoalveolar lavage fluid of 24 patients with human immunodeficiency virus infection (AIDS-related complex 8 patients. AIDS 16 patients) and 8 healthy individuals by using a panel of monoclonal antibodies known to react with tissue macrophages, in combination with a flow cytometer. The results showed that 90% of patients with AIDS present a marked reduction in the expression of several antigenic determinants (in decreasing order: CD68, CD36, CR1, CD11c, HLA-DR). The levels of antigen expression by flow cytometry seem to decline with disease progression, showing the most dramatic perturbations in patients with full-blown AIDS associated with pulmonary infections (especially Pneumocystis carinii pneumonia) and lower peripheral CD4 lymphocyte counts. In contrast, patients with AIDS-related complex or AIDS without histological or cultural evidence of pulmonary involvement showed, respectively, only minimal or medium antigenic decreases. However, only a minor proportion (16%, 20%, 20%, 25%, and 25% respectively) of human immunodeficiency virus infected patients (mostly with AIDS) had a significant reduction of the levels of CD4, CD14, CD45R, CD11b, and CD16 antigens in the alveolar macrophages. Since macrophages play a central role in the pathogenesis of AIDS, it may be postulated that the loss of various phenotypic markers on alveolar mononuclear phagocytes (some of them known for their important immunoregulatory actions) could have an important part in the pathogenesis of human immunodeficiency virus induced immunosuppression, and thereby condition the abnormal susceptibility to pulmonary diseases typical of human immunodeficiency virus-infected patients.
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PMID:Reduced expression of macrophage-associated antigens on alveolar mononuclear phagocytes from acquired immunodeficiency syndrome. 769 Dec 71

To investigate the local immunological situation in the lung of HIV-infected patients with Pneumocystis carinii pneumonias (HIV-PCP), we analyzed the proportion and the distribution of lymphocyte subpopulations and their state of activation in bronchoalveolar lavage (BAL) and peripheral blood of 21 HIV-PCP patients (CDC classification group IV) compared to 24 HIV-negative patients with interstitial lung diseases (ILD). Peripheral blood lymphocytes (PBL) and BAL cells were stained with monoclonal antibodies. Two-color cytofluorometric analysis (flow cytometry) was performed with a cytofluorograph (Epics Profile, Coulter Corp., Hialeah, Fla., USA). In BAL from HIV-PCP patients the number of CD3-positive lymphocytes was significantly increased, yet there was no difference in the number of macrophages and neutrophils when compared to patients with ILD. Quantification of lymphocyte subpopulations showed that the increased number of BAL CD3-positive lymphocytes in HIV-PCP patients was mainly due to a significantly increased number of CD8-positive T cells, while the pulmonary CD4-positive T cells were decreased both in relative and absolute numbers. As a consequence, an inverted pulmonary CD4/CD8 ratio resulted for HIV-infected patients with PCP. Analysis of in-vivo-activated T cells in BAL and peripheral blood when measured by the expression of IL-2R, HLA-DR and VLA-1 revealed increased numbers of IL-2R and HLA-DR bearing CD8-positive T cells but significantly decreased numbers of IL-2R and HLA-DR bearing CD4-positive T cells as well as a higher number of CD8/CD57 double positive T cells in HIV-infected individuals when compared to patients with ILD.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:High proportion of gamma-delta T cell receptor positive T cells in bronchoalveolar lavage and peripheral blood of HIV-infected patients with Pneumocystis carinii pneumonias. 769 76

Inflammatory cells in lymph nodes of eighteen patients suffering from culture-proven tuberculous lymphadenitis were examined by histological and immunohistochemical techniques. Ten patients suffered from symptomatic HIV-infection and eight patients were immunocompetent individuals without HIV-1 serology. Characteristic granulomas with or without caseation were observed in eight immunocompetent and four HIV-1-infected patients with less marked lymphopenia of CD4 positive peripheral blood lymphocytes. No epitheloid cell formation was present in lymph nodes of HIV1-infected patients with more severe depression of CD4 positive peripheral blood lymphocyte count. Foamy macrophages were found instead of these cells. While many cells--predominantly lymphocytes--express CD25 (IL-2 receptor) in cases with typical epitheloid granulomas there is no such CD25 expression in cases without any epitheloid cell formation. This result suggest that T cell function is necessary for epitheloid granuloma formation in human tuberculosis. The phenotype of macrophages underwent progressive changes parallel to decreasing numbers of CD4 positive peripheral blood lymphocytes. Foamy macrophages in Mycobacterium avium-intracellulare infection represented an end-stage phenotype. They were positive for S100 protein and they did not express lysozyme, alpha-1-anti-chymotrypsin, L1 antigen (Mac387) and CD4, whereas positivity for HLA-DR, CD68 and Ki-M8 was preserved. In situ immunohistochemical demonstration of IFN-alpha, IFN-beta, TNF-alpha, IL-1 and IL-6 revealed that foamy cells in M. tuberculosis infection were highly active effector cells. They contained higher concentrations of the examined cytokines than epitheloid cells in the lesions of HIV+ and HIV-patients. Corresponding to these findings the histological proof of acid-fast bacilli was generally not successful in typical HIV-associated tuberculosis. The foamy appearance may result from the lipid-rich cell membranes of destroyed acid-fast bacilli. In contrast acid-fast bacilli-packed foamy macrophages in AIDS patients with M. avium-intracellulare (MAI) infection did not produce any of the examined cytokines.
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PMID:Immunohistochemical analysis of cell composition and in situ cytokine expression in HIV- and non-HIV-associated tuberculous lymphadenitis. 771 49

HLA class II molecules and the HIV envelope glycoprotein gp120 are ligands of CD4. Reciprocal interaction sites have been well characterized for gp120 and CD4, but require further definition for HLA class II and CD4. A major CD4 binding site encompassing amino acids 134-148 in the beta 2 domain of HLA-DR has been previously identified. Recently, we have shown, by extensive characterization of mutated CD4 molecules expressed in COS cells, that HLA class II antigens interact mainly through the HIV gp120 binding site and possibly through a second minor interaction site mapping on the same face of the molecule. Based on the direct binding in vitro of iodinated affinity-purified HLA-DR1 molecules to polystyrene immobilized human IgG3-CD4, we now report on reciprocal binding inhibition of gp120, HLA-DR1 and the DR beta 2 synthetic peptide to CD4. The results strongly suggest that gp120 and the beta 2 region (amino acids 134-148) of HLA-DR1 bind mainly to the same part of CD4 domain 1 and that the CD4 binding site of HLA-DR requires the existence of a class II homodimer. In that case, alpha 2 chain residues might interact with CD4 residues different from those involved in the binding of gp120 but located close to them in the first domain.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Competition of HLA-DR and a beta 2 domain peptide for HIV envelope glycoprotein gp120 binding to CD4. 773 15

We performed repeated continuous flow cytaphereses (CFC) on 13 asymptomatic HIV-1-infected patients to study the feasibility of cell separation procedures to recover high yields of peripheral blood T-lymphocytes for adoptive immunotherapy in HIV-infected patients and to determine immunological and virological alterations following such procedures. A mean yield of 6.23 x 10(9) lymphocytes could be obtained by each cytapheresis, containing 1.82 x 10(9) CD4+, 3.23 x 10(9) CD8+ T-lymphocytes and 8.39 x 10(6) CD34+ peripheral progenitor cells. The CD4/CD8 ratio (mean 0.53, SD +/- 0.15) in the cell samples reflected the distribution of the lymphocyte subsets in vivo. Absolute lymphocyte counts decreased at a mean of 404/mm3 (25%) immediately after CFC but were replaced from the extravascular pool within 1 h. The CD4/CD8 ratios, p24-antigenaemia, HLA-DR expression and neopterin levels did not change significantly after cell separation. No alteration of the number of T-cells with integrated proviral DNA copies (1/10(3) to 1/10(6)) could be detected in peripheral T-helper cells by PCR after lymphapheresis. We conclude that high yields of peripheral T-lymphocytes can be obtained by continuous flow lymphapheresis for cell-mediated immunotherapy, without deterioration of virological or immunological parameters in HIV-infected patients. The separated T-cells are fully replaced from extravascular pools after 1 h.
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PMID:Recovery of T-lymphocytes for adoptive immunotherapy by lymphapheresis of HIV-infected patients without alterations of virological, immunological or clinical parameters. 780 55


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