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)

Stimulation of human immunodeficiency virus type 1 (HIV-1)-infected donor peripheral blood mononuclear cells (PBMCs) via the TCR-CD3 complex induces HIV-1 production in vitro (Zarling JM, et al.: Nature [London] 1990;347:92; Haffar OK, et al.: J Virol 1992;66:4279; Moran PM, et al.: AIDS Res Hum Retroviruses 1993;9:455). However, in addition to the primary stimulatory signal delivered through the TCR-CD3 complex, optimal T cell activation requires secondary or costimulatory signals delivered via various T cell accessory proteins (Alton A, et al.: Adv Immunol 1990;48:227). In this article we explore the role of costimulation of T cells via CD28 in HIV-1 replication. Ligation of CD28 with either a CD28-specific MAb or by coculture of PBMCs with Chinese hamster ovary (CHO) cell lines stably expressing either of the CD28 counterreceptors, B7-1 (CD80) or B7-2 (CD86), concomitant with stimulation via CD3, results in increased virus replication compared to stimulation via CD3 alone. CD28 ligation also augments de novo infection of CD3-stimulated seronegative donor PBMCs with cell-free virus. Increased virus replication following CD28 ligation is not solely attributed to increased levels of endogenous IL-2, because addition of an anti-IL-2-neutralizing antibody only partially inhibits the response. In contrast, interfering with the interaction between CD28 and its counterreceptors on antigen-presenting cells (APCs) using CTLA4Ig effectively inhibits virus replication. At high concentrations CTLA4Ig also reduces cell proliferation. These in vitro results suggest that CD28 plays a central role in HIV-1 replication and that interfering with the CD28 costimulatory pathway may modify the course of HIV-1 infection.
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PMID:Costimulation of CD4+ T cells via CD28 modulates human immunodeficiency virus type 1 infection and replication in vitro. 749 35

Papaverine hydrochloride (PAP) has previously been shown to have a potent inhibitory effect on the replication of viruses such as cytomegalovirus (CMV) and measles. In this report the effect of PAP on human immunodeficiency virus (HIV) replication and T lymphocyte cell function were examined. MT4 cells infected with HIV strain 3b were incubated with serial dilutions of PAP (1-30 microM). At selected times postinfection HIV replication was measured by reverse transcriptase activity (RT) or HIV p24 Ag. PAP significantly inhibited HIV replication by more than 99% at doses of 30 microM with an CD50 and ED50 of 32 microM and 5.8 microM respectively. The mechanism of inhibition of HIV caused by PAP appeared independent form its ability to increase intracellular levels of cAMP and was not mediated via a direct effect on RT activity. To examine T cell function, peripheral blood mononuclear cells (PBMC) from normal donors were stimulated with phytohemagglutinin (PHA) or CMV Ag in the presence or absence of PAP (1-30 microM). At selected times proliferative response to PHA and CMV Ag were determined by [3H]thymidine uptake. In addition, interferon (IFN) gamma and interleukin 2 (IL2) response to mitogens were measured by radioimmunoassay (RIA). PAP enhanced PHA induced IFN production at doses of 1-10 microM and CMV Ag induced IFN production at doses of 1-3 microM. Higher doses were inhibitory. PAP did not affect IL-2 production or IL2 receptor expression and had an inhibitory effect on mitogenic responses.
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PMID:Papaverine hydrochloride: effects on HIV replication and T-lymphocyte cell function. 750 1

Virus-specific cytotoxic T lymphocytes (CTLs), which kill virus-infected cells, are thought to be a major host defense against viral infections. The addition of interleukin 7 (IL-7) at the onset of mitogen-stimulated cultures resulted in a marked (up to threefold) augmentation of env-specific cytotoxicity in human immunodeficiency virus type 1 (HIV-1)-infected individuals (p < 0.001). Addition of IL-7 on day 3 or 5 produced a significant but lesser augmentation of CTL response as compared to day 0. The IL-7-induced proliferative response and augmentation of cytotoxic activity was time and dose dependent, with an optimal IL-7 concentration of 1000 U/ml. Cell surface phenotypic analysis of CTL effector cells indicates that IL-7 primarily affects the proliferation of CD8+ T cells. Anti-IL-2 monoclonal antibody (MAb) substantially inhibited the proliferative effect of IL-2, but did not affect the proliferative effect of IL-7. Endogenous IL-2-induced generation of cytotoxic T cells was blocked by MAbs to IL-2 or IL-2R. The addition of IL-7 restored the process of conversion of precursor CTLs (pCTLs) to mature CTLs (mCTLs) and significantly enhanced specific cytolytic activity. It appears that IL-7 is a potent regulatory cytokine capable of acting independently of IL-2 in mitogen-specific activation of pCTLs to mCTLs. These data suggest that IL-7 should be considered as a potential therapeutic approach in AIDS and other infectious diseases in which CTL response declines.
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PMID:Interleukin 2-independent interleukin 7 activity enhances cytotoxic immune response of HIV-1-infected individuals. 751 56

In these studies we show that although purified B cells of patients with common variable immunodeficiency (CVI) have a normal capacity to proliferate, they manifest differentiation defects at multiple levels. Compared with controls, circulating CVI B cell populations contain reduced numbers of sIgG+ and sIgA+ cells with a commensurate increase in sIgM+ B cells, suggesting an in vivo defect in isotype switch. In addition, CVI B cells manifest Ig secretion defects on stimulation with either anti-CD40 and IL-10 or SAC and IL-2 and IL-10, which are of increasing severity for IgM, IgG, and IgA, respectively. These Ig secretion defects are not overcome by addition of a variety of cytokines, including TGF-beta, to anti-CD40-driven cultures. In further studies we show that despite the above abnormalities, CVI B cells are induced to express normal or near-normal levels of C mu, C gamma, and C alpha mRNA after 7 days of stimulation with anti-CD40 and IL-10. That this CH mRNA expression represents a recovery of CVI B cell differentiation is supported by studies of Ig secretion in which CVI B cells that are first stimulated for 7 days with anti-CD40 and IL-10 and then restimulated in coculture with activated normal allogeneic T cells and IL-10, secrete substantial levels of IgM and IgG and increased amounts of IgA. Overall, therefore, CVI B cell function can be significantly improved by maintenance in culture. These data suggest the abnormalities of B cell differentiation in CVI are reversible and that the defect is a form of B cell anergy.
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PMID:B cell differentiation defects in common variable immunodeficiency are ameliorated after stimulation with anti-CD40 antibody and IL-10. 751 19

Activation of B cells by anti-CD40 provides an excellent model to investigate the direct effect of various cytokines on Ig production. Using this culture system, we examined the effect of IL-2 alone or in combination with other cytokines. IL-2 alone had only a moderate effect on Ig production by anti-CD40-activated B cells if compared with the effect of IL-10. However, IL-2 significantly augmented the synthesis of IgM, IgA, and IgG, including all IgG subclasses by anti-CD40-activated B cells cultured in the presence of IL-10. Both IgD- and IgD+ B cells showed an increase of IL-10-induced Ig production if IL-2 was added to the culture. The addition of IL-2 also increased immunoglobulin synthesis by anti-CD40/IL-10-activated B cells from patients with common variable immunodeficiency (CVI) and defective IL-2 production, suggesting that in a subgroup of CVI patients the IL-2 deficiency may contribute to the observed hypogammaglobulinemia. In contrast, the addition of IL-2 had a suppressive effect on IgE and IgG4 production by B cells cultured in the presence of anti-CD40 and IL-4. These data demonstrate that IL-2 plays an active role in the regulation of Ig production via CD40 by anti-CD40-activated B cells.
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PMID:Effect of IL-2 on immunoglobulin production by anti-CD40-activated human B cells: synergistic effect with IL-10 and antagonistic effect with IL-4. 752 Mar 76

Several years of clinical trials with IL-2, including modifications of dose and schedule and combinations with other biologic agents or chemotherapy, have shown much more limited anticancer activity for this agent than was anticipated from the preclinical studies. Even for its FDA-approved indication (metastatic renal cell carcinoma patients with good performance status), IL-2 probably benefits only a small subset of patients, and no prognostic factors have yet been identified to pinpoint these patients. In addition, clinical activity in patients with renal cell carcinoma treated with high-dose IL-2 is achieved at the expense of substantial acute toxicity. Nonetheless, the durable complete responses observed in a small percentage of patients with metastatic renal cell carcinoma and metastatic melanoma, and the potent immunomodulatory effects of IL-2, suggest that it may yet become an important anticancer agent, perhaps in association with active and adoptive immunotherapy. The agent also has shown potential for the treatment of infectious diseases and immunodeficiency states.
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PMID:Clinical applications of IL-2. 752 Nov 97

The interaction between the CD40 ligand (gp39), expressed by activated T cells, and CD40, constitutively expressed by B cells, is critical for an effective antibody response to T cell dependent antigens. Patients with X-linked hyper IgM (HIM) syndrome fail to express a functional CD40 ligand due to a mutation within the gene for gp39. As a direct consequence, HIM patients, when immunized with T dependent antigens, produce only small amounts of IgM antibody without the development of immunologic memory, amplification and switch from IgM to IgG. Mutations affecting the gene for the HIM syndrome are localized throughout the coding region of gp39 and consist predominantly of point mutations. The resulting amino acid substitutions interfere directly with the receptor binding site or lead to stop codons or deletions secondary to splice site mutations. Expression of gp39 by activated T cells from patients with common variable immunodeficiency (CVI) is low in approximately half of the patients and is associated with depressed expression of IL-2. These findings suggest that inefficient signaling via CD40 may be responsible in part for failure of B cell differentiation in CVI.
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PMID:The role of CD40L (gp39)/CD40 in T/B cell interaction and primary immunodeficiency. 753 62

A few protein targets were found to display a specific high-affinity interaction with the immunosuppressant cyclosporin A (CsA): cytosolic cyclophilins (CyP)A, B, C, D, E containing from 122 to 174 amino acid residues in a polypeptide chain, and secreted forms of CyP; CyP-40, 40-kDa CsA-binding polypeptide complexed with steroid receptor (SR); CyP-related 150-kDa receptor of natural killer (NK) cells; interleukin 8 (IL-8); actin; a family of molecular chaperones hsp70 and P-glycoprotein (P-GP). All CyPs possess peptidyl-prolyl cis-trans isomerase activity (PPIase) and may serve as ATP-independent molecular chaperone proteins. The CsA-CyP complexes are specific inhibitors of Ca(2+)-and calmodulin-dependent protein phosphatase calcineurin (CaN). The inhibition of CaN blocks the activation of genes of IL-2, IL-2R, IL-4, etc. in T cells. In addition, immunosuppressive and/or antiinflammatory activity of CsA can be executed via CyP-40 and hsp 70 complexed with SR, and following the interaction with CyP-related receptor of NK and with IL-8. CsA binding to CyPC, P-GP and actin may throw light on the biochemical events leading to nephrotoxicity and graft vessel disease, two major side effects produced by CsA. The discovery of the interaction of human immunodeficiency virus type 1 (HIV-1) Gag protein with CyP and effective disruption of this interaction by CsA may be important for our understanding of the pathology caused by this immunosuppressive virus and will inspire therapeutic strategies to nip HIV in the bud. Bacterial immunophilins (ImPs) contribute to the virulence of pathogenic microorganisms. Elucidation of molecular mechanisms of microbial ImPs' action in the pathogenesis of bacterial infections may lead to new strategies for designing antibacterial drugs.
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PMID:Some new aspects of molecular mechanisms of cyclosporin A effect on immune response. 754 42

Cartilage-hair hypoplasia (CHH) is an autosomal recessive disease of unknown etiology characterized by metaphyseal dysostosis, unpigmented hair, and defective cellular immunity. We studied peripheral blood mononuclear cells (PBMC) of a boy with CHH and combined immunodeficiency in an attempt to characterize further the immune defect in this disease. Stimulation of his PBMC with mitogens was associated with severely depressed IL-2 and interferon-gamma (IFN-gamma) synthesis and IL-2 receptor alpha-chain (IL-2R alpha) expression and resulted in poor lymphocyte proliferation that was only modestly upregulated by the addition of recombinant IL-2 (rIL-2). The defective proliferation and lymphokine synthesis were not corrected by the addition of phorbol myristate acetate (PMA) and ionomycin, agents that bypass receptor-mediated signalling, indicative of a distal abnormality. Importantly, the levels of mRNA encoding c-myc, IL-2R alpha, IL-2 and IFN-gamma were markedly decreased in patient lymphocytes stimulated with PMA+ionomycin as compared to control lymphocytes. The defect in the expression of these early activation genes was selective in that induction by mitogens of mRNA encoding other early activation gene products such as c-fos and c-jun was not impaired. These results suggest that the underlying defect in this patient and perhaps others with CHH may be an abnormality in a component of intracellular signalling pathways or in a trans-acting factor which regulates the expression of a selected number of early activation genes.
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PMID:Defective expression of early activation genes in cartilage-hair hypoplasia (CHH) with severe combined immunodeficiency (SCID). 755 1

Interleukin-2-deficient mice (IL-2-/-) generated by targeted mutagenesis proved to be an excellent system to study the function of this lymphokine in the context of whole immune system. In addition, they provide an animal model of a primary immunodeficiency caused by a single-gene defect. Our results indicate that the essential degect in IL-2-/- mice is the lack of a negative regulatory function, which leads to breakdown of self tolerance. The development of autoimmune diseases in IL-2-deficient mice stresses the link between autoimmunity and primary immunodeficiencies.
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PMID:Immunodeficiency in IL-2-knockout mice. 755 63


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