Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The specific cellular immune response toward envelope and core proteins of human immunodeficiency virus-1 (HIV-1) was investigated in gibbon apes chronically infected with the HTLV-IIIB isolate. After in vitro stimulation of PBMC from infected and control animals with HIV-1 Ag, DNA synthesis, IL-2R expression and IL-2 release were assayed. Cells from infected gibbon apes demonstrated a group-specific response toward whole virus preparations from three divergent HIV-1 isolates (HTLV-IIIB, HTLV-IIIRF, HTLV-IIIMN). Consistent responses were also detected against purified HIV-1 Ag, i.e., native gp120 envelope glycoprotein, recombinant gp160 glycoprotein, a synthetic peptide (peptide 7) representing a highly conserved region of gp120, and purified native core protein p24. In addition, lymphocytes from infected gibbon apes displayed a specific, MHC-restricted, cytotoxic activity against autologous cells expressing HIV-1 envelope or gag proteins. The specific T cell reactivity toward HIV-1 proteins observed in infected gibbons contrasts with findings in HIV-1 infected humans, and may help to explain the apparent discrepancy in the natural history of the infection between the two species.
 ...
PMID:Cell-mediated immune response toward viral envelope and core antigens in gibbon apes (Hylobates lar) chronically infected with human immunodeficiency virus-1. 326 61

Infection of monocyte-macrophages with human immunodeficiency virus may be central to the pathogenesis of the acquired immunodeficiency syndrome. The ability of infected macrophages to prime T cells through IL-1 production was investigated in vitro. Purified human monocytes maintained in suspension culture were infected with strain HIV-DV. Intracellular expression of virus p24 antigen increased from undetectable levels immediately after infection to 13-59% of cells by 10-14 d; infected macrophages remained viable for up to 60 d. Supernatants collected between 14 and 20 d after infection were examined in the murine thymocyte co-mitogenesis assay and demonstrated to contain a potent IL-1 inhibitor, designated contra-IL-1. Contra-IL-1 activity was present in all supernatants examined after 4 d of infection, and peaked coincident with peak p24 antigen expression. Inhibitory activity was not present in uninfected cells. Contra-IL-1 activity eluted after gel filtration with an approximate molecular weight of 9 kD. Inhibitory activity was removed by exposure to heat or acid pH, or by incubation with chymotrypsin or staphylococcal V8 protease. Contra-IL-1 did not inhibit IL-2- or IL-4-dependent proliferation of murine T cell lines. Despite its ability to inhibit IL-1 activity, contra-IL-1 did not interfere with the binding of recombinant IL-1 beta to a fibroblast cell line. Contra-IL-1 inhibited the proliferation of normal peripheral blood mononuclear cells to both concanavalin A and tetanus toxoid; inhibition could be attenuated by the addition of exogenous IL-1. Messenger RNA extracted from infected macrophages was examined by Northern analysis for the presence of message to IL-1 beta. No message was apparent, suggesting that the presence of contra-IL-1 was not obscuring the concomitant release of IL-1. Infected macrophages stimulated with endotoxin generated readily detectable message for IL-1 beta. Spleen macrophages purified from two patients with AIDS complicated by immune thrombocytopenia spontaneously expressed p24 antigen in vitro and released contra-IL-1 activity into the media. Contra-IL-1 may contribute to the immune dysfunction of AIDS.
 ...
PMID:Release of interleukin 1 inhibitory activity (contra-IL-1) by human monocyte-derived macrophages infected with human immunodeficiency virus in vitro and in vivo. 326 91

A model system for cytokine-induced up-regulation of human immunodeficiency virus type 1 (HIV-1) expression in chronically infected promonocyte clones was established. The parent promonocyte cell line U937 was chronically infected with HIV-1 and from this line a clone, U1, was derived. U1 showed minimal constitutive expression of HIV-1, but virus expression was markedly up-regulated by a phytohemagglutinin-induced supernatant containing multiple cytokines and by recombinant granulocyte/macrophage colony-stimulating factor alone. Recombinant interleukin-1 (IL-1), IL-2, interferon-gamma, and tumor necrosis factor-alpha did not up-regulate virus expression. Concomitant with the cytokine-induced up-regulation of HIV-1, expression of membrane-bound IL-1 beta was selectively induced in U1 in the absence of induction of other surface membrane proteins. This cytokine up-regulation of IL-1 beta was not seen in the uninfected parent U937 cell line. These studies have implications for the understanding of the mechanism of progression from a latent or low-level HIV-1 infection to a productive infection with resulting immunosuppression. In addition, this model can be used to delineate the potential mechanisms whereby HIV-1 infection regulates cellular gene expression.
 ...
PMID:Cytokine-induced expression of HIV-1 in a chronically infected promonocyte cell line. 331 29

Cellular immune responses in vitro were studied in 24 patients on chronic hemodialysis and 16 healthy volunteers with normal kidney function. Patients on maintenance hemodialysis had lymphopenia with diminished numbers of both T4+ and T8+ T-lymphocytes. The T4/T8 ratios were within the normal range. Peripheral blood lymphocytes (PBL) showed a diminished proliferative response upon stimulation with concanavalin A, phytohemagglutinin and pokeweed mitogen. When cell surface antigens were used for stimulation (mixed lymphocyte culture) uremic lymphocytes also showed a lower proliferation rate. Although without statistical conformation, there was a tendency by uremic PBL to produce less IL-2 as compared to healthy controls. Moreover, in a PWM driven system, peripheral blood lymphocytes from uremics produced significantly less IgG than PBL from normals. These results support the notion that a profound defect in lymphocyte function accounts at least, in part, for the observed immunodeficiency of uremic patients.
 ...
PMID:Impaired cellular immune responses in chronic renal failure: evidence for a T cell defect. 348 22

The antigen receptor expressed on most T lymphocytes is a disulphide-linked heterodimer (Ti) that is composed of alpha-chain and beta-chain subunits. On the surface of human T lymphocytes, Ti is non-covalently associated with three invariant proteins, designated CD3-gamma, -delta, and -epsilon. It has been suggested that Ti is obligatory for CD3 expression. But a T leukaemia cell line, IL-2 (interleukin 2) dependent T-cell clones established from fetal blood and IL-2 dependent cell lines established from immunodeficiency patients with bare lymphocyte syndrome and ectodermal dysplasia syndrome have recently been shown to express CD3, but not Ti (detected due to monoclonal antibody WT31). These lymphocytes may express the product of the T-cell antigen receptor gamma (TCR-gamma) gene, rather than the alpha/beta heterodimer, in association with CD3. Preliminary studies suggested that T cells expressing CD3 but lacking Ti are present in low frequency in normal lymphoid tissues. Here we show that in normal blood and thymus CD3+, WT31-T cells express neither CD4 nor CD8. The low frequency (less than 0.2-0.9% of total thymocytes) of CD3+, WT31- cells in the thymus suggests that this population does not represent a major stage of thymic development and may be a distinct lineage of T cells.
 ...
PMID:Presence of Ti (WT31) negative T lymphocytes in normal blood and thymus. 349 23

The mAb L10 was used to determine the distribution and the function of sialophorin, the heavily glycosylated surface molecule that is deficient/defective in lymphocytes of patients with the X-linked immunodeficiency Wiskott-Aldrich syndrome. Dual-parameter FACS analysis indicated that sialophorin is expressed on CD4+ and CD8+ lymphocytes, on a subpopulation of peripheral blood B lymphocytes, on all thymocytes, and on a subpopulation of bone marrow cells. Functional studies demonstrated that L10 mAb stimulates the proliferation of peripheral blood T lymphocytes as measured by stimulation of [3H]thymidine incorporation. The time course and magnitude of increased [3H]thymidine incorporation by T lymphocytes in response to L10 mAb paralleled that induced by anti-CD3 mAb. Effective stimulation was dependent on the presence of monocytes and the Fc portion of L10 mAb. Stimulation of lymphocytes by L10, like stimulation by anti-CD3 mAb, involves increased expression of 4F2, HLA-DR, and IL-2-R. These observations suggest that sialophorin functions in T cell activation.
 ...
PMID:Sialophorin, a surface sialoglycoprotein defective in the Wiskott-Aldrich syndrome, is involved in human T lymphocyte proliferation. 357 1

Two severe combined-immunodeficiency patients successfully transplanted with fetal thymus and liver or haploidentical lectin-treated marrow cells lacked NK activity, with a normal number of HNK1+ cell-defined NK cells. The defect was not due to the inhibiting factor in patients' sera. Their NK cells bound to their targets, but did not lyse them in a single-cell agarose assay, and did not respond to alpha-IFN or IL-2. IL-2 did not stimulated the development of mature NK cells that bear M1 antigens from precursors that lack M1 antigens.
 ...
PMID:Deficiency of NK activity of HNK-1+ cells after transplantation of fetal thymus and liver or haploidentical soybean agglutinin-treated marrow cells in two severe combined immunodeficiency patients. 390 4

Impairment in T cell proliferation in response to E. coli and in CML to unrelated alloantigens was usually observed in patients early after marrow grafting and persisted in long-term patients with chronic GVHD but not in those without chronic GVHD. We analyzed various cellular functions in the pathway of T cell activation and found that in patients with immunodeficiency, (1) their M phi usually could process and present antigens to normal T cells, (2) their T cells did not proliferate even in the presence of normal antigen-pulsed M phi, (3) IL-2 production by T cells was deficient, and (4) exogenous IL-2 restored CML activity in cells of most patients early after grafting but not in cells of most patients with chronic GVHD. Therefore, failure to induce proliferation and cytotoxicity in T cells of marrow recipients is not likely due to M phi defects but because of ineffective communication among T cell subsets, probably related to impaired IL-2 production and/or unresponsiveness to IL-2.
 ...
PMID:Ineffective cellular interaction and interleukin 2 deficiency causing T cell defects in human allogeneic marrow recipients early after grafting and in those with chronic graft-versus-host disease. 639 Aug 48

Several isolates of a human type-C retrovirus belonging to one group, known as human T-cell leukemia virus (HTLV), have previously been obtained from patients with adult T-cell leukemia or lymphoma. The T-cell tropism of HTLV and its prevalence in the Caribbean basin prompted a search for it in patients with the epidemic T-cell immune deficiency disorder known as AIDS. Peripheral blood lymphocytes from one patient in the United States and two in France were cultured with T-cell growth factor (TCGF) an shown to express HTLV antigens. Virus from the U.S. patient was isolated and characterized and shown to be related to HTLV subgroup I. The virus was also transmitted into normal human T cells from umbilical cord blood of a newborn. Whether or not HTLV-I or other retroviruses of this family with T-cell tropism cause AIDS, it is possible that patients from whom the virus can be isolated can also transmit it to others. If the target cell of AIDS is the mature T cell as suspected, the methods used in these studies may prove useful for the long-term growth of these cells and for the identification of antigens specific for the etiological agent of AIDS.
 ...
PMID:Isolation of human T-cell leukemia virus in acquired immune deficiency syndrome (AIDS). 660 23

CD8+ cells from long-term survivors [LTS; infected with human immunodeficiency virus (HIV) for 10 or more years and having CD4+ cell counts of > or = 500 cells per microliters] have a 3-fold greater ability to suppress HIV replication than do CD8+ cells from patients who have progressed to disease (progressors) during the same time period. A change in the pattern of cytokines produced in the host from those that typically favor cell-mediated immunity (T helper 1, TH1 or type 1) to those that down-regulate it (T helper 2, TH2 or type 2) was investigated as a cause of this reduced CD8+ cell anti-HIV function. Treatment of CD8+ cells from LTS with the TH1 cytokine interleukin (IL)-2 enhanced their anti-HIV activity, whereas exposure of these cells to TH2 cytokines IL-4 or IL-10 reduced their ability to suppress HIV replication and to produce IL-2. IL-2 could prevent and reverse the inhibitory effects of IL-4 and IL-10. Moreover, prolonged exposure of CD8+ cells from some progressors to IL-2 improved the ability of these cells to suppress HIV replication. These observations support previous findings suggesting that strong CD8+ cell responses play an important role in maintaining an asymptomatic state in HIV infection. The data suggest that the loss of CD8+ cell suppression of HIV replication associated with disease progression results from a shift in cytokine production within the infected host from a TH1 to a TH2 pattern. Modulation of these cytokines could provide benefit to HIV-infected individuals by improving their CD8+ cell anti-HIV activity.
 ...
PMID:Effects of TH1 and TH2 cytokines on CD8+ cell response against human immunodeficiency virus: implications for long-term survival. 747 52


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>