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)

Interleukin (IL)-15 regulates the proliferative activity of the CD8(+) T-cell pool in human immunodeficiency virus (HIV)-infected patients, thereby contributing to the maintenance of the CD8(+) T-cell-mediated immune response against HIV in extravascular tissues, including the lung. However, the effects of IL-15 on antigen-presenting cells (APC) during HIV infection are still unclear. In this study, we evaluated whether IL-15 regulates the macrophage stimulatory pathways governing inflammatory events that take place in the lung of patients with HIV infection. As a first step we evaluated the in vitro effects of IL-15 on lung macrophages retrieved from the respiratory tract of eight normal subjects. Although macrophages from uninfected individuals expressed the IL-15 binding proteins (IL-15Ralpha and the common gammac) at resting conditions, they did not express IL-15 messenger RNA (mRNA). However, a 24-hour stimulation with IL-15 induced the expression of interferon-gamma (IFN-gamma) and IL-15 itself, suggesting a role for this cytokine in the activation of the pulmonary macrophage pool during inflammation. As a confirmation of the role of IL-15 in this setting, at resting conditions, alveolar macrophages of patients with HIV infection and T-cell alveolitis expressed IL-15, IFN-gamma, and IL-15 binding proteins; showed an upmodulation of costimulatory molecules, B7 and CD72, which are involved in the APC of macrophages; and behaved as effective accessory cells because they elicited a strong proliferation of T cells. The accessory effect was inhibited by pretreatment with anti-CD72, anti-B7 (CD80 and CD86), and anti-IL-15 monoclonal antibodies (MoAb). We then investigated the relationship between IL-15 and the expression of costimulatory molecules by macrophages. A 24-hour stimulation of IL-15Ralpha+/gammac+ macrophages with IL-15 upregulated the expression of CD80 and CD86. The evidence that IL-15 upregulates the expression of coligands that favor the contact between T cells and APC, per se, triggers T-cell activation and proliferation and acts as a chemoattractant for T cells, suggests that IL-15 plays a key role in Tc1-mediated defense mechanisms taking place in extravascular tissues of patients with HIV disease.
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PMID:CD8 T-cell infiltration in extravascular tissues of patients with human immunodeficiency virus infection. Interleukin-15 upmodulates costimulatory pathways involved in the antigen-presenting cells-T-cell interaction. 994 71

Determining the effects of HIV infection on the expression of cell surface molecules has been limited by an inability to differentiate between productively infected cells and those without productive infection. We inoculated human peripheral blood mononuclear cells from healthy, human immunodeficiency virus type 1 (HIV) antibody-negative donors with HIV; noninoculated cells were also examined. Using multiparameter flow cytometry, we differentiated cells actively producing HIV cytoplasmic p24 antigen during acute, in vitro HIV infection from those not producing detectable cytoplasmic p24. For both resting and PHA-stimulated cells inoculated with HIV (R/H and P/H), a higher proportion of p24+ cells expressed CD25, compared with p24-cells (p = 0.031 and p = 0.008, respectively), consistent with either increased viral replication in stimulated cells or increased stimulation secondary to productive HIV infection. Findings were similar for the expression of CD38, HLADR, and CD28. A striking proportion of p24+ cells expressed CD80 or CD86, antigens not usually expressed by CD3+ lymphocytes. The increased expression appeared to be independent of stimulation status in that it occurred in both the R/H and P/H treatment groups but not in resting or PHA-stimulated uninfected cells. CD28 expression was generally comparable between CD3+ cells that did and did not express CD80 or CD86. Multiparameter flow cytometry, in association with improved techniques for cell permeabilization and cytoplasmic fluorescent staining, should prove useful in examining the effects of productive HIV infection on surface and cytoplasmic cellular molecules. Using this approach, we found an association between productive infection and increased expression of CD80 and CD86. This association has implications for HIV disease pathogenesis and, potentially, HIV therapy.
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PMID:Increased expression of CD80 and CD86 in in vitro-infected CD3+ cells producing cytoplasmic HIV type 1 p24. 1002 49

The recognition of antigens by specific T- and B-lymphocytic receptors underlies an immune response. However, the formation of a potential signal for the activation of lymphocytes requires an additional their stimulation (costimulation). The main source of costimulation signals is the interaction of the surface molecules of lymphocytes and accessory cells. The interaction between the T-cell surface molecules CD28 and costimulatory molecules of antigen-presenting cells (CD80 or CD86) is the most important point of the T-helper cell activation. The interaction between B-cell molecule CD40 and T-helper surface molecule CD154 is the key event of B-cell (and other antigen-presenting cell) activation. When costimulation is absent, antigen recognition induces specific lymphocytic anergy or apoptosis. Defects of costimulatory molecular expression or function can cause immunodeficiency. For example, hereditary defect of CD154 expression causes the hyper-IgM syndrome. The soluble forms of some costimulatory molecules are considered to be potential immunomodulators.
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PMID:[Cell interaction in immune response]. 1037 80

Interleukin-16 (IL-16), a natural ligand for the CD4 receptor, has been found to modulate T-lymphocyte function and to inhibit human immunodeficiency virus type 1 (HIV-1) replication. Antigen-presenting cells (APC), including macrophages and dendritic cells, are known to express functional surface CD4 molecules, to be susceptible to HIV-1 infection and to play a critical role in different immune processes. Therefore, we evaluated the ability of recombinant IL-16 (rIL-16) to regulate receptor expression and cytokine release in monocyte-derived macrophages (MDM) and monocyte-derived dendritic cells (MDDC). Recombinant IL-16 was found to up-regulate CD25 and CD80 but to down-regulate CD4 and CD86 surface expression in MDM cultures. However, no change could be observed on the level of CD4, CD80 and CD86 expression in IL-16-stimulated MDDC, although a significant up-regulation of CD25 and CD83 was consistently detected. Furthermore, the level of gene expression of the chemokine receptors CCR5 and CXCR4 was significantly reduced in rIL-16-treated MDM and costimulation with IL-2 did not modify the activity of the recombinant cytokine. The effects on chemokine receptor gene expression were less evident in MDDC and only a transient down-regulation of weak intensity could be detected following stimulation with rIL-16. Analysis of supernatants from rIL-16-stimulatedcultures revealed a different profile of released cytokines/chemokines among the two cell populations studied. These findings establish an important role for IL-16 in modulating the activity of APC and may have relevance regarding the protection of reservoir cells against HIV-1 infection.
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PMID:Recombinant interleukin-16 selectively modulates surface receptor expression and cytokine release in macrophages and dendritic cells. 1044 38

This study shows that characteristic dendritic, antigen presenting cells, can be generated from adherent peripheral blood mononuclear cells (PBMC)/monocytes of uninfected and SIVsm-infected cynomolgus monkeys after stimulation in vitro with granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin (IL)-4. The recruitment of monocyte derived dendritic cells (MDDC) was usually possible irrespective of the level of immunodeficiency (CD4-level) and viremia. The cynomolgus MDDC closely resembled their human counterpart (immature MDDC) with regard to capacity to upregulate CD1a, CD40, CD86 and human leukocyte antigen (HLA)-DR and develop dendrites and veiled processes. Such MDDC also increased their capacity for antigen uptake (dextran endocytoses/macropinocytosis) and for induction of T-cell proliferation in mixed leukocyte reaction (MLR) assays. However, although no clear difference with regard to phenotype and morphology was seen between MDDC from SIV-infected and uninfected monkeys, a reduction in MLR responsiveness in MDDC from SIV infected monkeys was consistently detected within each experiment.
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PMID:Recruitment of monocyte derived dendritic cells ex vivo from SIV infected and non-infected cynomolgus monkeys. 1065 63

Adult T cell leukemia (ATL) is induced by an infection with human T lymphotropic virus type I (HTLV-I) and is accompanied by immunodeficiency. Monocyte-derived immature dendritic cells (DCs) donated by 11 ATL patients were suppressed in the ability to take up fluorescein isothiocyanate (FITC)-dextran and were down-regulated in the expression of CD1a and CD86 antigens (Ags). Monocytes from the patients showed impaired expression of CD14 and HLA-DR Ags. These results suggest intrinsic abnormalities of monocytes and a defect of DC maturation in ATL patients. Therefore, we examined the influence of HTLV-I infection of monocytes on their differentiation to DCs. Monocytes obtained from healthy donors were susceptible to HTLV-I infection in vitro. HTLV-I-infected monocytes were down-regulated in the expression of CD14 Ags, and immature DCs obtained from them expressed CD1a poorly and were impaired in the ability to take up FITC-dextran. Mature DCs differentiated from these cells could not stimulate autologous CD4(+) T cell or CD8(+) T cell proliferation, even after being secondarily pulsed with HTLV-I at an immature DC stage. These results suggest that HTLV-I-infected monocytes cannot properly differentiate to DCs and that this might be one of the important mechanisms producing dysfunctional DCs in ATL patients.
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PMID:Production of functionally deficient dendritic cells from HTLV-I-infected monocytes: implications for the dendritic cell defect in adult T cell leukemia. 1093 95

The mechanism underlying a transition of the oral cavity mucosal epithelium towards susceptibility to opportunistic infections in HIV-seropositive patients was investigated. Phenotypic markers CD1a, HLA-DR, and CD86 of oral mucosal Langerhans' cells (LCs), p17 core protein of human immunodeficiency virus (HIV), and CD45RO of memory T cells were labeled on oral hairy leukoplakia lesional biopsies and clinically normal autologous tissue of HIV-infected patients. HIV p17 protein was detected in association with mucosal LCs, mainly within the lesional epithelium. There were significant correlations between the detection of HIV p17 and the depletion of LCs, and between the depletion of LCs and the presence of hairy leukoplakia lesions. Conjugates of activated LCs and memory T cells were also evident in the submucosal area of lesional biopsies. The findings from this study support the hypothesis that oral mucosal LCs are also the target of HIV infection. Cytopathic changes of LCs caused by productive HIV infection may contribute to selective depletion of LCs, which may impair the mucosal immunologic protection against colonization by microorganisms causing HIV-associated oral mucosal lesions.
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PMID:Oral mucosal Langerhans' cells as target, effector and vector in HIV infection. 1097 48

Previous studies have shown that human immunodeficiency virus type-1 (HIV-1) can incorporate several surface proteins of host origin. Recent findings indicate that host-encoded cell surface constituents retain their functionality when found embedded into the viral envelope. The primary objective of the current study was to define whether interaction between some specific virion-bound host proteins with their natural cognate ligands present on target cells could mediate intracellular signaling cascade(s). For this purpose, we have generated a whole series of isogenic virus stocks (NL4-3 backbone) bearing or not bearing on their surface foreign CD28, CD54 (ICAM-1), CD80 (B7-1) or CD86 (B7-2) proteins. Our results indicate that incubation of human T lymphoid cells with virions bearing host-derived B7-2 proteins and anti-CD3 antibody can potently activate HIV-1 long terminal repeat-driven gene expression. This up-regulating effect necessitates the involvement of nuclear factor-kappa B (NF-kappa B) and nuclear factor of activated T cells (NFAT) as revealed by the use of vectors coding for dominant negative versions of both transcription factors (i.e. I kappa B alpha S32A/36A and dnNFAT) and band shift assays. The increase of NF-kappa B activity was abolished when infection with B7-2-bearing HIV-1 particles was performed in the presence of the fusion protein CTLA-4 Ig suggesting that the interaction between virally embedded B7-2 and CD28 on the target cell is responsible for the observed NF-kappa B induction. The findings presented here provide the first demonstration that host-encoded proteins acquired by HIV-1 can mediate signal transduction events.
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PMID:Attachment of human immunodeficiency virus-1 (HIV-1) particles bearing host-encoded B7-2 proteins leads to nuclear factor-kappa B- and nuclear factor of activated T cells-dependent activation of HIV-1 long terminal repeat transcription. 1109 63

The case of a 29-year-old Caucasian woman with 45 X0 karyotype, known as Turner's syndrome, and a recently diagnosed selective T-cell deficiency is reported. The main clinical features of the patient were recurrent sinopulmonary infections and a negative skin test with seven common recall antigens. Laboratory findings included lymphocytopenia, highly elevated CD45RA/CD45R0 ratio, as well as reduced expression of the co-stimulatory molecules CD154, CD86, CD80 and CD28 on CD4+ cells in combination with disturbed lymphocyte transformation in vitro. Markedly decreased levels of interleukin (IL)-2R, both on lymphocyte surface as well as the soluble analog, suggest a new form of x-linked immunodeficiency associated with Turner's syndrome.
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PMID:Selective T-cell deficiency in Turner's syndrome. 1110 46

Human immunodeficiency virus (HIV) infection results in a functional impairment of CD4(+) T cells long before a quantitative decline in circulating CD4(+) T cells is evident. The mechanism(s) responsible for this functional unresponsiveness and eventual depletion of CD4(+) T cells remains unclear. Both direct effects of cytopathic infection of CD4(+) cells and indirect effects in which uninfected "bystander" cells are functionally compromised or killed have been implicated as contributing to the immunopathogenesis of HIV infection. Because T-cell receptor engagement of major histocompatibility complex (MHC) molecules in the absence of costimulation mediated via CD28 binding to CD80 (B7-1) or CD86 (B7-2) can lead to anergy or apoptosis, we determined whether HIV type 1 (HIV-1) virions incorporated MHC class I (MHC-I), MHC-II, CD80, or CD86. Microvesicles produced from matched uninfected cells were also evaluated. HIV infection increased MHC-II expression on T- and B-cell lines, macrophages, and peripheral blood mononclear cells (PBMC) but did not significantly alter the expression of CD80 or CD86. HIV virions derived from all MHC-II-positive cell types incorporated high levels of MHC-II, and both virions and microvesicles preferentially incorporated CD86 compared to CD80. CD45, expressed at high levels on cells, was identified as a protein present at high levels on microvesicles but was not detected on HIV-1 virions. Virion-associated, host cell-derived molecules impacted the ability of noninfectious HIV virions to trigger death in freshly isolated PBMC. These results demonstrate the preferential incorporation or exclusion of host cell proteins by budding HIV-1 virions and suggest that host cell proteins present on HIV-1 virions may contribute to the overall pathogenesis of HIV-1 infection.
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PMID:Differential incorporation of CD45, CD80 (B7-1), CD86 (B7-2), and major histocompatibility complex class I and II molecules into human immunodeficiency virus type 1 virions and microvesicles: implications for viral pathogenesis and immune regulation. 1139 Jun 19


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