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

Lipopolysaccharide (LPS) potently stimulates human immunodeficiency virus type 1 (HIV-1) long terminal repeat-directed transcription in transfected monocyte-macrophage cell lines and dramatically increases HIV-1 production in the latently infected monocyte-macrophage-like cell line U1. This response to LPS, however, can only be observed after pretreatment of the U1 cells with granulocyte-macrophage colony-stimulating factor (GM-CSF). CD14, the differentiation antigen that acts as a receptor for complexes of LPS and LPS-binding protein, is now demonstrated to be involved in LPS-induced stimulation of HIV-1 replication. CD14 is shown to be expressed on a subpopulation of U1 cells only after treatment with GM-CSF and correlates with HIV-1 production stimulated by LPS. Importantly, only those U1 cells that express CD14 can be induced by LPS to upregulate HIV-1 production. In addition, a monoclonal antibody directed against CD14 can block LPS-induced stimulation of HIV-1 production from these latently infected cells.
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PMID:CD14 is involved in control of human immunodeficiency virus type 1 expression in latently infected cells by lipopolysaccharide. 137 24

The myeloid-monocytic cells ML-1, HL-60, THP-1, and U-937 were chronically infected (for > 2 years) with the lymphotropic human immunodeficiency virus type 1 (HIV-1) strain HTLV-IIIB. Reinfection experiments revealed that viruses obtained from chronically infected ML-1/HIV-1 and HL-60/HIV-1 cells showed a low infectivity if tested with uninfected ML-1 and HL-60 cells in contrast to virus preparations from chronically infected THP-1/HIV-1 and U-937/HIV-1 with their corresponding uninfected cell lines. Analyses of selected cell surface markers revealed a differential expression of CD4, CD8, CD11c, CD14, CD15, CD20, HLA-DR, and HLA-DQ in non- or chronically infected cells. In chronically infected cells, the steady-state levels for tumor necrosis factor-alpha, interleukin (IL)-1 beta, and granulocyte-macrophage colony-stimulating factor mRNA remained unchanged whereas the one for IL-6 dropped.
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PMID:Characterization of human immunodeficiency virus-1-infected cells of myeloid-monocytic lineage (ML-1, HL-60, THP-1, U-937). 145 15

Monocytes from healthy blood donors were inoculated in vitro with a monocyte-tropic strain of human immunodeficiency virus type 1 HIVBa-L. HIV replication was first detected at Day 5 postinoculation, with peak virus activity at Day 17. We assessed the kinetics of the expression of four monocyte surface antigens (CD14, CD4, HLA-DR, and HLA-DQ) on HIV-infected and uninfected monocyte/macrophages, (M phi) by flow cytometry. We consistently found a decreased expression of CD4 and CD14 on HIV-infected M phi compared to their expression on M phi of uninfected controls. In contrast, HLA-DR and HLA-DQ expression was unchanged on HIV-infected M phi.
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PMID:In vitro infection of monocytes with HIVBa-L. Effect on cell surface expression of CD4, CD14, HLA-DR, and HLA-DQ. 169 79

The immunomodulatory drug isoprinosine has been found to delay the occurrence of opportunistic infections in HIV-infected individuals. To elucidate the mechanism of action, eight HIV-positive, healthy patients were treated with isoprinosine, 3 g/day for 28 days; six patients received no treatment but were examined in parallel, and two patients were withdrawn. All patients had blood collected just before the start as well as on days 14 and 28 of isoprinosine treatment. Isoprinosine significantly enhanced the lymphoproliferative response after stimulation with phytohaemagglutinin (PHA) and purified derivative of tuberculin (PPD), while isoprinosine had no effect on the following immune parameters: the expression of surface markers on blood mononuclear cells including CD2, CD3, CD4, CD8, CD14, CD19, CD20, CD25, leu-8, and HLA-DR. Furthermore isoprinosine did not influence the ability of interleukin 2 (IL-2) to stimulate the proliferation of lymphocytes or the natural killer (NK) cell activity either unstimulated or stimulated in vitro with alpha interferon (IFN-alpha), IL-2, or indomethacin. Neither did isoprinosine affect the in vitro production of (IL-1) alpha or beta, IL-2, IL-6, or tumour necrosis factor (TNF).
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PMID:Effects of isoprinosine treatment of HIV-positive patients on blood mononuclear cell subsets, NK- and T-cell function, tumour necrosis factor, and interleukins 1, 2, and 6. 170 99

CD4 on blood monocytes is generally regarded as being found on a subset of blood monocytes. However, our results show that all monocytes are CD4+ but the number of molecules per cell is lower than T cells. We have performed immunofluorescent (flow cytometry, microscopy) analysis of monocytes from normal donors and HIV-1-infected patients using anti-CD4 (Leu-3a) and the monocyte-specific marker anti-CD14 (Leu-M3) monoclonal antibodies. Specifically: (1) 91% of monocytes from normal individuals show dual positivity for CD14 and CD4 (n = 14) as measured by flow cytometry; (2) 76% of monocytes expressed surface bound CD4 and CD14 when an enhanced two colour immunofluorescence microscopic technique was employed; (3) all CD14+ monocytes stained with an intensity of 3+(-)4+ for cytoplasmic CD4. Few monocytes were CD14- and CD4+. Cell surface CD4 expression was blocked with unconjugated anti-CD4 prior to staining; (4) the staining intensity for cytoplasmic CD4 in T cells was negligible; (5) CD4 expression on monocytes obtained from patients was as observed with normal individuals. The conclusion drawn is that all monocytes are CD4+ and the CD4 expression in monocytes is mainly cytoplasmic. Thus, all monocytes are potentially infectable with HIV-1.
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PMID:Detection of surface and cytoplasmic CD4 on blood monocytes from normal and HIV-1 infected individuals. 170 91

CD4 is the surface receptor for HIV envelope. Some evidence exists, however, that other cell surface receptors may be involved in viral entry subsequent to the initial binding of gp120 to CD4. Antibodies to leukocyte integrin LFA-1, a major component of intercellular adhesive interactions, have been shown to inhibit HIV-induced syncytia formation. Using a stringent system for in vitro HIV infection of human leukocytes, we examine the ability of some monoclonal antibodies (mAb) against various adhesion-related molecules to block or partially inhibit productive viral replication. HIV-1 infection of target monocytes or T cells by cell-free virus was blocked completely or partially by some mAb that prevent cell-cell interactions (CD4, HLA-DR, LFA-1, LFA-3), but not by others (ICAM-1, MAC-1, gp150.95, CD2, CD3, CD14). The capacity for mAb to block HIV infection appears to be epitope-specific, and does not relate to the ability to block homotypic adhesion. HIV transmission from infected cells was more difficult to block than was infection by cell-free virus. Adhesion molecules may be involved in facilitating early stages of HIV infection, following gp120/CD4 binding but prior to viral integration, in a manner distinct from cell-cell adhesion.
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PMID:Inhibition of human immunodeficiency virus infection in monocytes by monoclonal antibodies against leukocyte adhesion molecules. 175 7

In order to further investigate immune dysfunctions in HIV-1 infection, we studied the intensity of leukocyte function-associated antigen-1 (LFA-1) expression using a novel application of immunofluorescence analysis in 14 adults and 5 children seropositive for HIV-1 and in 14 healthy adults and 5 healthy children seronegative for HIV-1. While almost all lymphocytes in human peripheral blood expressed LFA-1 and while the percentage of the LFA-1 positive cells was not modified during the course of the HIV-1 infection in both adults and children, our results showed an increase of the LFA-1 expression on selected peripheral blood mononuclear cell subsets. Some LFA-1-labeled functional peripheral blood mononuclear cell subsets such as the CD16, CD14, CD3, and CD8 lymphocyte subpopulations expressed higher levels of the LFA-1 molecule during the HIV-1 infection. The LFA-1 dim cell subsets (CD4 cells) and the LFA-1 low cell subpopulation (CD19 lymphocytes) were not affected by the HIV-1 infection. Moreover, in the CD8 and CD3 cell subsets displaying a heterogeneous LFA-1 expression (dim and bright), we also observed a decrease of the LFA-1 dim/LFA-1 bright cell ratio.
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PMID:Leukocyte function-associated antigen-1 expression on peripheral blood mononuclear cell subsets in HIV-1 seropositive patients. 214 25

We have investigated the features and distribution of accessory cells (ACs) and the relationship of these cells to each other and to lymphocytes in the epithelium and lamina propria of oral hairy leukoplakia (HL), with the objective of better defining the differentiation and mutual interactions of immune-response cells within HL as a preliminary step to understanding the onset and significance of this lesion during human immunodeficiency virus (HIV) infection. Twenty-four HIV-infected patients with HL, two asymptomatic HIV-positive subjects, and three HIV-negative subjects were studied by immunohistochemistry; five HIV-positive patients with HL and three asymptomatic HIV-positive subjects were studied by electron microscopy. In both the epithelium and the lamina propria of HL, we found cells with the immunohistochemical and ultrastructural features of variably differentiated ACs; differences were found between the epithelium and lamina propria. In the lamina propria, ACs were characterized by dendritic shape, multiple contacts with lymphocytes, expression of CD1a antigen, and ultrastructural features of fully differentiated ACs. Conversely, in the epithelium ACs showed bluntly dendritic shape, low expression of CD1a, absent expression of HLA-DR, constant expression of CD11c and CD14 antigens, only occasional contacts with lymphocytes, and ultrastructural features of variably, but always incompletely, differentiated cells of monocyte-dendritic lineage. Seventy-nanometer wide intracisternal particles, closely resembling A particles described in retroviral infections, were found in the intraepithelial ACs in two patients with HL. The defective differentiation of ACs in the epithelium of HL--possibly influenced by the perturbation of the epithelial microenvironment induced by Epstein-Barr virus, and following the direct HIV infection of these cells--and the exceptional finding of close contacts with lymphocytes suggest that the lesional epithelium of HL may constitute a pathway for the entry of foreign antigens which circumvent monitoring by ACs and can induce immune tolerance. The impairment of the local immune response in HL may contribute to the development of full blown, systemic immunodeficiency.
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PMID:Morphology and membrane antigens of nonlymphoid accessory cells in oral hairy leukoplakia. 239 34

HIV-1 acquires cell membrane proteins during budding. The cell membrane proteins (CMP) profile of laboratory HIV-1 strains grown in different host cells was established, by using an immobilized antibody capture (IAC), to verify whether CMPs present on HIV-1 correlate with its host cell origin. HIV-1 grown in different cell lines incorporates cell markers such as CD3, CD19, CD14, CD31 and IL 2-R, according to the distinctive expression of these antigens on the host cells. Furthermore, also T-tropic and monocytotropic HIV-1 strains display host cell specific markers, supporting the hypothesis that virus associated CMPs are a marker of host cell origin.
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PMID:Host cell antigenic profile acquired by HIV-1 is a marker of its cellular origin. 750 84

Employing a discontinuous Percoll gradient following Ficoll-Hypaque separation of peripheral blood mononuclear cells from normal subjects (n = 14) and patients with HIV-1 infection (n = 50), we separated a population of low-density cells consisting of monocytoid cells, lymphocytes, and some granulocytes. In cytospin preparations, less than 5% of the monocytoid cells were positive for nonspecific esterase and CD14. However, CD1a was positive in 5-20% of these cells. Ultrastructurally, CD1a-labeled immunogold particles were demonstrated on the monocytoid cells which bore some features of dendritic cells. Flow cytometry of the low-density cells identified a subset of buoyant, large cell population, which excluded lymphocytes. This large low-density cell (LLDC) population was significantly expanded in patients with HIV infection and comprised 32.3 +/- 21.3% of low-density cells compared to 7.0 +/- 2.8% in normal subjects (P < 0.0001). Of the LLDC population 45.2 +/- 23.4% were CD1a+ in patients compared to 17.5 +/- 13.3% in normal subjects (P < or = 0.0001). HLA-DR and HLA-DQ were coexpressed in approximately 70 and 50% of these CD1a+ LLDC, respectively. A simple nonculture assay method employed by us facilitates rapid screening of infected blood specimens for the CD1a+ large low-density cells with dendritic cell features, which could be an additional parameter to monitor HIV disease progression.
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PMID:The number of CD1a+ large low-density cells with dendritic cell features is increased in the peripheral blood of HIV+ patients. 750 34


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