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)

For many years tuberculosis has been known to occur with greater frequency among persons with disorders that impair host defenses. In most instances these processes interfere with the immune response to Mycobacterium tuberculosis, whereas, in a few, such as silicosis, the probable abnormality is a nonimmune defect in macrophage function. Infection with the human immunodeficiency virus (HIV) causes progressive and ultimately profound depression of both humoral and cell-mediated immunity and, thus, is an extremely potent risk-factor for tuberculosis. Presumably the major effect of HIV infection that predisposes persons to developing tuberculosis is the reduction in circulating T-helper (CD4+) lymphocytes which causes a reduction in cytokine production and a consequent decrease in the functional capabilities of macrophages. However, a number of questions concerning pathogenesis of tuberculosis related to HIV remain. Available data suggest that the magnitude of the risk for developing tuberculosis among persons infected with both HIV and M. tuberculosis is very high, 8% in one prospective study. Because of the epidemic of HIV infection, the progressive downward trend in the incidence of tuberculosis in the United States has reversed and in 1989 there was a 5% increase in the number of cases. Preliminary data for 1990 suggest that there will be an 8 to 10% increase over 1989. Also in the United States approximately 3% of tuberculosis patients have been found to be HIV seropositive. The clinical features of tuberculosis in patients with HIV infection vary depending on the degree of immunosuppression. With mild immunosuppression early in the course of HIV infection tuberculosis presents in a "typical" way with positive tuberculin skin tests, upper lobe cavitary infiltrates on chest film and positive sputum smears and cultures. As the HIV infection progresses, the mode of presentation of tuberculosis becomes more "atypical" with negative skin tests, multiple sites of involvement, chest films showing diffuse noncavitary infiltrates often accompanied by intrathoracic lymphadenopathy. The key to diagnosis is maintaining a high index of suspicion for tuberculosis, especially in patients with advanced HIV disease and including appropriate laboratory examinations in the evaluations of such persons. Regardless of the stage of HIV infection the response to treatment for tuberculosis is generally favorable if it is begun promptly. Standard therapy utilizing isoniazid, rifampin, and pyrazinamide with or without ethambutol have been associated with high rates of cure. Relapse has been uncommon. There has been, however, at least one outbreak of tuberculosis caused by isoniazid and rifampin resistant organisms in which the response to therapy was very poor.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Clinical features, diagnoses, and management of tuberculosis in immunocompromised hosts. 194 27

Macrophages are important target cells for human immunodeficiency virus type 1 (HIV-1). The ability of HIV-1 to productively infect macrophages may be influenced by endogenous cytokines that alter the activation state of these cells. In this study, the effect of tumor necrosis factor-alpha/cachectin (TNF alpha), a cytokine with macrophage-activating properties, on HIV-1 replication in primary blood monocyte-derived macrophages was examined. Treatment of macrophages with recombinant human TNF alpha (rTNF alpha), starting before or after HIV-1 infection, consistently enhanced viral production fivefold or greater above control (P less than .01). rTNF alpha was active at low concentrations (0.05-50 ng/ml) and increased the replication of both lymphocyte-tropic (human T lymphotropic virus type IIIB) and macrophage-tropic (human T lymphotropic virus type III BaL) strains of HIV-1. These findings provide additional evidence that TNF alpha may play a role in the pathogenesis of HIV-1 infection by upregulating viral expression in macrophages.
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PMID:Tumor necrosis factor-alpha/cachectin enhances human immunodeficiency virus type 1 replication in primary macrophages. 198 79

The long terminal repeat (LTR) of the human immunodeficiency virus (HIV) contains three binding sites for the transcriptional factor Sp1. In order to investigate the role that the Sp1-binding sites play in regulation of HIV replication, we have introduced a deletion of all three Sp1-binding sites into the LTR of an infectious molecular clone of HIV. Viral stocks have been prepared from this mutant virus, designated dl-Sp, and these stocks have been used to study its replicative ability in human T cells. The dl-Sp virus replicated efficiently in MT4 cells and in phytohemagglutinin-stimulated human peripheral blood lymphocytes, but it replicated poorly and with delayed kinetics in A3.01 (CEM) T cells unless those cells had been treated with the cytokine tumor necrosis factor alpha. Gel retardation assays to study the levels of DNA-binding proteins present in these cells showed that NF-kappa B activity could be detected in the nuclei of MT4 cells but not in A3.01 cells unless they had been treated with tumor necrosis factor alpha. Thus, the presence of NF-kappa B activity appeared to be required for efficient replication of an HIV whose LTR Sp1-binding sites had been deleted. This suggests that NF-kappa B can functionally compensate for Sp1 in activating HIV replication. The HIV LTR is therefore similar to the promoter-enhancer units of other viruses in that it is composed of multiple functional elements that may contribute differently to viral replication depending on the levels of DNA-binding proteins present in the target cells.
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PMID:Variable role of the long terminal repeat Sp1-binding sites in human immunodeficiency virus replication in T lymphocytes. 199 51

The multifunctional cytokine, transforming growth factor beta (TGF-beta), was identified by immunocytochemistry in the brain tissues of four patients with acquired immune deficiency syndrome (AIDS), but not in control brain tissue. The TGF-beta staining was localized to cells of monocytic lineage as well as astrocytes, especially in areas of brain pathology. In addition, the brain tissues from the AIDS patients contained transcripts for human immunodeficiency virus 1 (HIV-1) by in situ hybridization, suggesting a correlation between the presence of HIV-1 in the brain and the expression of TGF-beta. However, the expression of TGF-beta was not limited to HIV-1-positive cells, raising the possibility of alternative mechanisms for the induction of TGF-beta in these AIDS patients' brains. To investigate these mechanisms, purified human monocytes were infected in vitro with HIV-1 and were shown to secrete increased levels of TGF-beta. In addition, HIV-1-infected monocytes released a factor(s) capable of triggering cultured astrocytes that are not infected with HIV-1 to secrete TGF-beta. The release of TGF-beta, which is an extremely potent chemotactic factor, may contribute to the recruitment of HIV-1-infected monocytic cells, enabling viral spread to and within the central nervous system (CNS). Moreover, TGF-beta augments cytokine production, including cytokines known to be neurotoxic. The identification of TGF-beta within the CNS implicates this cytokine in the immunopathologic processes responsible for AIDS-related CNS dysfunction.
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PMID:Macrophage- and astrocyte-derived transforming growth factor beta as a mediator of central nervous system dysfunction in acquired immune deficiency syndrome. 200 61

With progressive disease, the majority of patients with human immunodeficiency virus (HIV) infection develop bone marrow failure with anemia, leukopenia, and thrombocytopenia, the cause of which has not yet been clarified. Besides direct infection of bone marrow progenitor cells and immune-mediated cytolysis, the action of inhibitory cytokines, like transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNF-alpha), has to be discussed with regard to their pathophysiological role in HIV-induced bone marrow failure. Therefore, the influence of recombinant human TGF-beta and TNF-alpha on colony growth of pluripotent (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells from the bone marrow of HIV-1-infected persons and normal controls was assessed in methylcellulose cultures. Both cytokines inhibited the colony formation of hematopoietic progenitor cells from HIV-positive persons. When added to unseparated bone marrow cells from HIV-infected persons and normal controls, the 50% inhibition (ID50) of BFU-E by TGF-beta occurred at 1.3 ng/ml and 3.7 ng/ml, respectively, while the ID50 of CFU-GM occurred at 15.5 ng/ml and 142.7 ng/ml. Concentrations of TNF-alpha, causing 50% inhibition of colony formation by bone marrow cells from HIV-infected or noninfected individuals were 6.3 U/ml and 17.0 U/ml for BFU-E, and 24.4 U/ml and greater than 3,000 U/ml for CFU-GM, respectively. The ID50 of the CFU-GEMM growth was below the lowest concentration of both cytokines tested. The suppressive effects were specifically abolished by antibodies against TGF-beta and TNF-alpha, thus confirming that the inhibitory activities were due to the cytokine preparation used.
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PMID:Effect of recombinant human transforming growth factor beta and tumor necrosis factor alpha on bone marrow progenitor cells of HIV-infected persons. 204 59

There are several lines of evidence which provide support for an important relationship between immune cells and bone. Clinical studies of immunodeficiency syndromes have shown that abnormalities in bone shape are evident on x-rays, and peculiarities in the structure of the growth plate have been identified by histopathology. Studies of bone histology, and quantitation of cellular abnormalities, are scarce. Abnormalities in bone turnover, have, however, been identified in the nude mouse model. Many lines of evidence derived from in vitro bone studies have shown that lymphokines and monokines can influence bone formation and bone resorption. Some clinical studies of postmenopausal osteoporosis have indicated the possible presence of immune cell changes in this condition. Although several hypotheses have been formed regarding the exact mechanisms of the effect of immune cytokine on bone, this is clearly a very large area of study and there is a need for additional carefully controlled experiments with special emphasis on bone cells and bone matrix, especially in the human. As knowledge progresses regarding immunology and hematology, a clearer understanding of the lineages of the osteoblast and osteoclast will emerge and we will better understand how specialized bone cells interact with and react to their immune cell neighbors in the bone marrow and to immune system signals. These findings will have especially important implications for the local bone loss seen in rheumatoid arthritis, periodontal disease, and chronic osteomyelitis.
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PMID:Bone and the immune system. 206 16

The lung has an array of immunological defenses to protect itself against potentially invasive microorganisms, which include the immunoglobulin-rich alveolar lining fluid, alveolar macrophages, T lymphocytes, and polymorphonuclear neutrophils. Immunosenescence is a major predisposing factor to the increased incidence, morbidity, and mortality of pneumonia in the elderly. The progressive involution of the thymus gland in humans plays a pivotal role in the development of the immunodeficiency state characteristic of the older individual. Age takes its greatest toll on the cell-mediated arm of the immune system. Aged T cells are impaired in their ability to activate and proliferate in response to an antigen. This is partly due to age-associated structural and functional changes within the T cell. In addition, the ability of the T cell to secrete interleukin-2 (a cytokine necessary for the recruitment of other T cells) declines with age. The impaired antibody response of the elderly to foreign antigens, including the pneumococcal polysaccharide and the influenza vaccine, appears to be secondary to a deficiency of T helper cells. The macrophage functions well even in old age, but the recruitment of macrophages by senescent T cells is diminished. There also may be a blunted inflammatory response in the older individual secondary to impaired polymorphonuclear neutrophils chemotaxis and phagocytosis.
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PMID:Altered immune status in the elderly. 209 70

We show that the stimulation of human immunodeficiency virus (HIV) brought about by tumor necrosis factor alpha and phorbol 12-myristate 13-acetate can be inhibited by adding N-acetyl-L-cysteine (NAC). NAC, which replenishes intracellular glutathione, effectively inhibits the tumor necrosis factor alpha- or phorbol ester-stimulated replication of HIV in acutely infected cell cultures. NAC also inhibits the cytokine-enhanced HIV long terminal repeat-directed expression of beta-galactosidase in in vitro HIV model systems. These results show that intracellular thiol levels influence HIV production. Furthermore, because NAC reverses tumor necrosis factor alpha toxicity both in cells and in animals and is a well-known drug that can be administered orally without known toxicity in humans, these results suggest that NAC is a possible therapeutic agent in AIDS.
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PMID:Cytokine-stimulated human immunodeficiency virus replication is inhibited by N-acetyl-L-cysteine. 211 50

Highly purified, small dense splenic B cells from unstimulated mice showed increased expression of class II major histocompatibility complex (MHC) antigens and enhanced viability when cultured with affinity-purified recombinant interleukin 10 (rIL-10), compared with B cells cultured in medium alone. These responses were blocked by a monoclonal antibody (mAb) specific for IL-10, but not by an isotype-matched control antibody. IL-10 did not upregulate the expression of Fc epsilon receptors (CD23) or class I MHC antigens on small dense B cells or induce their replication as monitored by [3H]thymidine incorporation. While these B cell-stimulatory properties of IL-10 are also mediated by IL-4, the two cytokines appear to act independently in these assays; anti-IL-10 antibodies blocked IL-10 but not IL-4-mediated B cell viability enhancement, and vice versa. Similarly, since IL-4 upregulates CD23 on small dense B cells, the inability of IL-10 to do so argues against its acting via endogenously generated IL-4. Finally, IL-10 did not upregulate class II MHC antigens on B cells from X chromosome-linked immunodeficiency (XID) mice, while the same cells showed normal upregulation of class II antigens in response to IL-4. This report also extends our understanding of the relationship between IL-10 and the highly homologous Epstein-Barr virus (EBV)-encoded Bam HI fragment C rightward reading frame no. 1 (BCRFI) protein. It has previously been shown that BCRFI protein exhibits the cytokine synthesis inhibitory activity of IL-10. This report indicates that BCRFI protein also enhances in vitro B cell viability, but does not upregulate class II MHC antigens on B cells. One explanation for these data is that IL-10 contains at least two functional epitopes, only one of which has been conserved by EBV.
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PMID:Interleukin 10, a novel B cell stimulatory factor: unresponsiveness of X chromosome-linked immunodeficiency B cells. 212 52

Interest in human dendritic cells (DC) has been heightened recently by the discovery that this cell type is a primary target of the human immunodeficiency virus, the causative agent of AIDS. DC are bone marrow-derived cells with an extraordinarily potent ability to promote the immunological activity of T lymphocytes. Unfortunately, since DC constitute less than 0.5% of peripheral blood mononuclear cells and die within a few days of their isolation, they are not readily accessible to study. We report here that granulocyte-macrophage colony-stimulating factor (GM-CSF), a cytokine with well-recognized effects on granulocyte and macrophage maturation, profoundly affects the morphology and viability of DC isolated from peripheral blood. GM-CSF not only promotes DC survival but also induces DC differentiation to mobile, reversibly adherent cells with long-branched projections. DC cultured in GM-CSF survive for up to 6 wk and retain their ability to stimulate the proliferation of T cells in allogeneic and autologous mixed leukocyte reactions.
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PMID:Granulocyte-macrophage colony-stimulating factor promotes differentiation and survival of human peripheral blood dendritic cells in vitro. 217 70


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