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)

Expression of CD4 or CD8 on the cell surface is an important guide for discriminating the immunological functions of T cells. However, a minor T cell subset, which lacks both CD4 and CD8 molecules but bears the usual form of T cell receptor (TCR) alpha beta (CD4-CD8-TCR alpha beta+ T cells), has recently been found not only in mice but also in humans, and its role in immune response is now of considerable interest. In order to clarify the characteristics of this newly defined T cell subpopulation, we established five IL-2-dependent CD4-CD8-TCR alpha beta+ T cell clones from the peripheral blood of a healthy individual, and examined their various biological functions. It was found that all clones not only helped B cells in immunoglobulin production, but also exerted major histocompatibility complex-unrestricted cytotoxicity. Although their CD3/TCR complexes were functionally competent, the cytotoxicity seemed to be mediated via unknown molecules other than the CD3/TCR complex, as evidenced by the failure of CD3 MoAb to inhibit the cytotoxic activity. Our present findings showed that CD4-CD8-TCR alpha beta+ T cells possess potential bifunction, i.e. helper and cytotoxic activities. Their roles in the pathogenesis of immunodeficiency are discussed.
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PMID:Human double-negative (CD4-CD8-) T cells bearing alpha beta T cell receptor possess both helper and cytotoxic activities. 183

To study murine major histocompatibility complex (MHC)-haploidentical bone-marrow transplantation (BMT), B6C3F1 mice (H-2b/k) underwent BMT using syngeneic [B6C3F1 (H-2b/k)], haploidentical [CB6F1 (H-2d/b)], or fully allogeneic [DBA/2 (H-2d)] donor mice. As pretreatment, dimethyl myleran (DMM), an alkylating agent that produces effective myeloablation but little immunosuppression, was used with total body irradiation (TBI). Four conditioning regimens were studied: TBI 800 rads (1 rad = 0.01 Gy), TBI 950 rads, TBI 800 rads plus DMM (0.2 mg per mouse), and TBI 950 rads plus DMM. Survival rates, chimerism, proliferative responses in mixed-lymphocyte culture, specific cell-mediated lympholysis, and in vivo plaque-forming cell responses to several antigens were compared. TBI 800 rads plus DMM was maximally effective. Haploidentical BMT was as successful in inducing long-term survival and immune and hematologic reconstitution as was syngeneic BMT. This regimen plus haploidentical BMT of T-cell-purged marrow yielded survivors tolerant of donor and recipient major histocompatibility complex. Such myeloablation and immunosuppression prevented graft rejection, immunodeficiency due to histoincompatibility, and damage to a radiosensitive cell population. A microenvironmental influence crucial to some antibody responses was thus revealed. Delayed recovery of antibody production after BMT in humans may be due partly to suboptimal myeloablation or excess irradiation.
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PMID:Influence of dimethyl myleran on tolerance induction and immune function in major histocompatibility complex-haploidentical murine bone-marrow transplantation. 183 58

To evaluate whether host genotype influences disease progression among persons infected with human immunodeficiency virus type 1 (HIV-1), molecular techniques were used to determine genotypes at immune response loci for 114 HIV-1-infected homosexual/bisexual white men in the San Francisco Men's Health Study. Candidate genes evaluated were HLA-DQA1 and -DRB1, complement C4A and C4B, alpha- and beta-interferons, and the heavy chain of immunoglobulin gamma 1. Of the 114 men, 29 were asymptomatic, 21 were symptomatic men and AIDS patients (p = 0.02). Specifically, the HLA haplotype DRB1*0702-DQA1*0201 was associated with absence of symptoms (p = 0.003). Conversely, the frequency of the complement C4B-L allele was higher among patients with symptoms or with AIDS than among asymptomatic subjects (p = 0.02). These results suggest that genes in or near the major histocompatibility complex may influence the rate of disease progression among HIV-1-infected men.
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PMID:Influence of host genotype on progression to AIDS among HIV-infected men. 185 93

We performed an immunoperoxidase study on muscle biopsy specimens from 19 patients with polymyositis who were seropositive for human immunodeficiency virus (HIV) (21 specimens) and 5 HIV-seronegative patients with polymyositis and compared the findings. A quantitative analysis of T cells and T-cell subsets, B cells, natural killer cells, interleukin-2 receptor-positive cells, and macrophages was performed on serial sections from all the specimens. Localization of major histocompatibility complex (MHC)-I and -II antigens, alpha and gamma interferon, and HIV antigens (p24, gp120, and gp41) was performed using specific antisera. In specimens from HIV-positive and seronegative patients, the predominant cell population was CD8+ cells and macrophages invading or surrounding healthy muscle fibers that expressed MHC-I antigen on their surface. The endomysial infiltrates in specimens from HIV-positive patients differed from those seen in specimens from the seronegative patients only by a significant reduction of the CD4+ cells (12.6 +/- 3.2% versus 21.1 +/- 4.2%). HIV antigens were seen in occasional interstitial mononuclear cells (but not in muscle fibers) in 6 of the 21 specimens from HIV-positive patients. Interferon was not localized. We conclude that the development of HIV-associated polymyositis does not appear to be related to direct infection of the muscle fibers by HIV but rather is due to a T-cell-mediated and MHC-I-restricted cytotoxic process, perhaps triggered by HIV. Because this immunopathological mechanism is common in both HIV-associated polymyositis and polymyositis alone, it is suggested that viruses may also be responsible in triggering polymyositis.
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PMID:Immunocytochemical and virological characteristics of HIV-associated inflammatory myopathies: similarities with seronegative polymyositis. 185 78

The epidemiologic findings of Kaposi's sarcoma (KS) among patients with the acquired immunodeficiency syndrome (AIDS) suggest that human immunodeficiency virus (HIV) infection is insufficient for the development of KS. It was speculated that another sexually transmitted infection is responsible for the markedly increased incidence of KS among patients who acquired HIV infection through sexual intercourse. However, no such contributing infectious agent was consistently identified. The canine transmissible venereal tumour (TVT) is a malignant tumour that can be transplanted by viable cells across major histocompatibility complex (MHC) barriers. Recent findings suggest that all canine TVTs originated from the same tumour and were transferred from one animal to the other during sexual intercourse. It is suggested that, in analogy with the canine TVT model, the characteristics of KS epidemic among AIDS patients may be explained by transmission and engraftment of viable malignant cells during intercourse.
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PMID:Kaposi's sarcoma among AIDS patients: transmissible venereal tumour by cell engraftment? 186 40

Using functional and adhesion assays, we have studied the ability of 30 human CD4 mutants to interact with class II major histocompatibility complex (MHC) molecules and also with gp120 from human immunodeficiency virus. The mutants cover the four domains (D1-D4) of CD4 and include several single-site substitutions. Analysis of the results, in the context of the CD4 crystal structure, shows that mutations that affect the interaction with class II MHC molecules are located on three exposed loops from CD4 domains 1 and 2. The specifically implicated residues, 19, 89, and 165, are separated from one another by 9 A, 24 A, and 24 A on one face of the CD4 molecule. Moreover, the class II binding site does not include residues 43 to 49 of the CD4 molecule, a region on an opposite face known to be involved in the binding of gp120.
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PMID:Mutational analysis of the interaction between CD4 and class II MHC: class II antigens contact CD4 on a surface opposite the gp120-binding site. 188 86

Considerations from a network theory of the immune system suggest that human immunodeficiency virus and allogeneic stimuli may act synergistically to cause AIDS. The immune responses to these stimuli include two components that are directed against each other. In some AIDS risk groups other antigens that mimic major histocompatibility complex antigens may substitute for allogeneic stimuli. Implications for the prevention of AIDS are discussed.
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PMID:An idiotypic network model of AIDS immunopathogenesis. 190 53

The class II genes of the major histocompatibility complex (MHC) encode a family of cell surface glycoproteins that present processed antigen to the T cell receptor. Class II genes are regulated coordinately, responding to both immunologic and developmental signals. Conserved sequence elements 5' to class II genes have been shown to be important in transcriptional control. One of these sequences, the X box, is a specific target for the binding of the factor RF-X. In the hereditary HLA class II deficiency, a form of primary immunodeficiency, a regulatory defect in expression of class II genes is associated with a defect in the binding of RF-X. To determine the basepairs that are important for this binding interaction, a series of single basepair substitutions spanning the X box motif of the DRA gene was constructed and tested for binding of RF-X by gel electrophoresis mobility shift assays (EMSAs). Several, but not all, of the mutants severely affected binding of RF-X. In addition, the binding of both the natural and the recombinant form of RF-X was affected with the same specificity. A comparison of X box basepair positions important for RF-X binding to DRA with sequences conserved between X boxes of other class II alpha chain genes suggests that high affinity RF-X binding is important for a high level of expression and may explain differences in the levels of class II expression of different class II alpha chains.
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PMID:Regulatory factor-X binding to mutant HLA-DRA promoter sequences. 190

Alloimmune mice (mice that have been exposed to cells from another murine strain) were shown to make antibodies against gp120 and p24 of human immunodeficiency virus (HIV), and mice of the autoimmune strains MRL-lpr/lpr and MRL-(+)/+ made antibodies against gp120. This is surprising because the mice were not exposed to HIV. Furthermore, anti-anti-MHC antibodies (molecules that have shapes similar to those of major histocompatibility complex molecules) were detected in both alloimmune sera and MRL mice. These results are discussed in the context of a possible role for allogeneic stimuli in the pathogenesis of acquired immunodeficiency syndrome, as suggested by an idiotypic network model.
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PMID:Anti-HIV and anti-anti-MHC antibodies in alloimmune and autoimmune mice. 190 56

A DNA-binding factor with properties of NF-kappa B and another similar activity are rapidly induced when growth-arrested BALB/c 3T3 cells are stimulated with serum growth factors. Induction of these DNA-binding activities is not inhibited by pretreatment of quiescent cells with the protein synthesis inhibitor cycloheximide. Interestingly, the major NF-kappa B-like activity is not detected in nuclear extracts of proliferating cells, and thus its expression appears to be limited to the G0-to-G1 transition in 3T3 cells. These DNA-binding activities bind many of the expected NF-kappa B target sequences, including elements in the class I major histocompatibility complex and human immunodeficiency virus enhancers, as well as a recently identified NF-kappa B binding site upstream of the c-myc gene. Furthermore, both the class I major histocompatibility complex and c-myc NF-kappa B binding sites confer inducibility on a minimal promoter in 3T3 cells stimulated with serum growth factors. The results demonstrate that NF-kappa B-like activities are immediate-early response proteins in 3T3 cells and suggest a role for these factors in the G0-to-G1 transition.
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PMID:Induction of NF-kappa B DNA-binding activity during the G0-to-G1 transition in mouse fibroblasts. 192 27


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