Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The cytokines interleukin-12 (IL-12) and IL-4 play important roles in the development of Th1-like (type-1) and Th2-like (type-2) T-cell responses, respectively, and there is evidence that type-1/type-2 T helper imbalances are important in the pathogenesis of human immunodeficiency virus (HIV) disease. With this background, we examined the effects of these cytokines on HIV replication. Neither stimulated HIV replication in fresh peripheral blood mononuclear cells (PBMC). However, in prestimulated PBMC, IL-12, and to a greater extent, IL-4 as well as IL-2, induced production of HIV p24 antigen over 7 days of culture (no cytokine 3,900 x/divided by 1.31 [GM x/divided by SEM] pg/mL; IL-12, 34,300 x/divided by 1.39 pg/mL; IL-4, 283,000 x/divided by 1.14 pg/mL; and IL-2, 328,000 x/divided by 1.31 pg/mL). Neither IL-12- nor IL-4-induced HIV replication was attributable to induction of IL-1, IL-2, tumor necrosis factor (TNF)-alpha, or TNF-beta. Both IL-12- and IL-4-induced HIV replication was associated with selective loss of the CD4+ subset in stimulated cultures. IL-4 stimulated HIV replication in monocyte/macrophages, while IL-12 had little or no effect in these cells. Finally, HIV replication stimulated by IL-12 or IL-4 was inhibited by dideoxynucleosides. Thus, IL-12 and IL-4 enhance HIV replication and HIV-induced cell death in prestimulated PBMC. Through killing of the CD4+ T cells stimulated by these cytokines, this may result in inappropriate type-1/type-2 responses in HIV-infected patients and contribute to their Th1 immunodeficiency.
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PMID:Effects of the Th1 and Th2 stimulatory cytokines interleukin-12 and interleukin-4 on human immunodeficiency virus replication. 771 82

We have previously shown that the Tat protein of human immunodeficiency virus type 1 (HIV-1) transactivates tumor necrosis factor alpha and beta (TNF alpha and TNF beta) gene expression in HIV-1-infected and in tat-transfected T-lymphocytic and monocytic cell lines. The product encoded by the first exon of the tat gene (amino acids 1 to 72) is sufficient for this transactivation. Here we show that (i) the NF-kappa B and Sp1 binding sites of the TNF beta promoter are required for Tat-mediated transactivation and (ii) a predicted stem-loop structure in the TNF beta mRNA leader region, which resembles the Tat-responsive element of the HIV-1 long terminal repeat (TAR) and which is therefore termed TAR-like, is essential for TNF beta transactivation by Tat. These data suggest that similar promoter regulatory elements are necessary for Tat-mediated transactivation of both TNF beta and HIV-1 gene expression. This represents the first demonstration of a cellular gene with a regulatory element downstream of the transcriptional initiation site that, like TAR, may function as an RNA element.
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PMID:The human immunodeficiency virus type 1 Tat protein transactivates tumor necrosis factor beta gene expression through a TAR-like structure. 813 45

From the sera of patients with advanced cancer, a novel factor called SDF (serum-derived factor) was partially purified. SDF was shown to stimulate transcription from the long terminal repeat (LTR) of human immunodeficiency virus type 1 (HIV-1) by transient CAT assay. It did not stimulate gene expression of various control promoters including Rous sarcoma virus, human c-fos, c-myc, c-H-ras and chicken beta-actin genes. The SDF preparation did not contain any detectable TNF-alpha or TNF-beta, and differed in its physicochemical properties from TNFs. We concluded that SDF might be a novel factor associated with the clinical features of advanced cancer. It is speculated that SDF might have some role in disease progression of AIDS as well as in the development of the cachectic conditions in AIDS associated with malignancies.
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PMID:Identification in the sera from patients with advanced cancer of a factor which stimulates gene expression from human immunodeficiency virus type 1. 823 10

The tat gene product (Tat) of human immunodeficiency virus type 1 (HIV-1) is an early regulatory protein which transactivates HIV-1 gene expression by interacting with the trans-activation response element (TAR) present in the HIV-1 long terminal repeat (LTR). In HIV-1-infected cells Tat can also activate the expression of tumor necrosis factor (TNF). Recent results indicate that essential for this effect is the interaction of Tat with a TAR-like structure present in the TNF beta messenger RNA leader region that closely resembles the TAR of the HIV-LTR. Here we show that because of this similarity of mechanisms, the expression of an RNA species encoding polymeric-TAR sequences and known to inhibit Tat-mediated HIV-1 gene expression also blocks TNF gene expression in response to Tat, but not TNF promoter activation induced by human T cell leukemia/lymphotropic virus type I Tax protein. Since TNF is increased in HIV-1-infected individuals and can activate HIV-1 gene expression or rescue Tat-defective HIV-1 proviruses, activation of TNF by Tat may be part of a complex pathway in which HIV-1 uses its own expression to increase infectivity and to induce disease. This study shows a dual role for the polymeric-TAR construct in inhibiting HIV-1 replication and strengthens the potential use of this protective gene in gene therapy for AIDS.
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PMID:Block of Tat-mediated transactivation of tumor necrosis factor beta gene expression by polymeric-TAR decoys. 880 5

Despite the fact that nucleoside analogues, such as aciclovir and ganciclovir, and DNA-polymerase inhibitors, such as foscarnet, have a proven antiviral effect on oropharyngeal-Epstein-Barr virus (EBV) replication, they have been unable to show any effect on the severity or duration of infectious mononucleosis (IM), a condition for which there is currently no established treatment. Clinical symptoms may be due to an EBV-induced polyclonal humoral, as well as cellular, immunoreactivity with limited pathology caused by viral replication itself. However, despite an extensive immune response, 90% of tested IM patients (n = 36) had a spontaneous outgrowth of in vivo EBV-infected B-lymphocytes at onset of disease, indicating lack of specific EBV-restricted cellular cytotoxicity at this time. Establishment of an EBV-specific T-lymphocyte response occurred 90-180 days after onset of disease (human leukocyte antigen-restricted cytotoxicity against EBV-infected B-cells). Thus, development of a specific cytotoxic response was a gradual and slow process. Assessment of cytokine pattern, at the single cell level, was performed by immunocytochemical technique and by enzyme-linked immunosorbent assay. This revealed an increased production of interleukin (IL)-2, interferon (IFN)-gamma, IL-6 and tumour necrosis factor (TNF) beta in all IM patients. Those with disseminated disease were characterized by lack of IFN-gamma production. This loss was selective since in vitro stimulation with superantigen, such as streptococcal pyrogenic exotoxin A, induced a normal response. These patients lacked signs of EBV-specific T-cell cytotoxicity in vitro. Treatment with intravenous or subcutaneous IFN-gamma, 1.5 MU every second day, in combination with intravenous immunoglobulin G (0.5 g/kg three times per week) and oral aciclovir, 800 mg 5 times daily, has shown promising results in some patients. Cytokine production in tonsil tissue in 4 patients with fulminant IM and respiratory tract obstruction showed a concomitant expression of IL-2, IFN-gamma, IL-6, TNF beta, transforming growth factor (TGF) beta 1-3, granulocyte colony stimulating factor, granulocyte macrophage colony stimulating factor, IL-4 IL-1alpha, IL-beta and TNF alpha. The number of IL-2, IFN-gamma, IL-6 and TNF beta producing cells was significantly higher compared to tonsil tissue obtained from children with tonsillar hypertrophy. Thus, IM is associated with extensive local cytokine production. It is suggested that this extensive cytokine production is closely involved in the pathology of IM and that patients with atypical IM have a dysregulation in the cytokine network. However, the mechanism by which EBV-infected B-lymphocytes triggers this cytokine cascade is still unknown. These findings show the need for evaluation of patients with immunodeficiency and EBV-induced lymphoproliferative disorders and perhaps the introduction of new immunoregulatory treatment strategies.
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PMID:Clinical and immunological considerations in Epstein-Barr virus-associated diseases. 886 Mar 57

Epstein-Barr virus (EBV) and human immunodeficiency virus type 1 (HIV-1), as well as human T-cell leukemia-lymphoma virus type I (HTLV-I), may interact in the pathogenesis of human retroviral infections. The placental syncytiotrophoblast layer represents a barrier protecting the fetal compartment from exposure to retroviruses. We studied the interactions of EBV with HIV-1 and HTLV-I in human term syncytiotrophoblast cells to investigate the significance of double infections in transplacental transmission of human retroviruses. We found that syncytiotrophoblast cells could be productively infected with EBV. Dual infection of the cells with EBV and HTLV-I resulted in full replication cycle of otherwise latent HTLV-I. In contrast, the restricted permissiveness of syncytiotrophoblasts for HIV-1 was not influenced by coinfection of the cells with EBV. Infection of syncytiotrophoblast cells with EBV, but not HTLV-I, induced interleukin-2 and interleukin-6 secretion, and augmented secretion occurred on coinfection with both viruses. Coinfection of syncytiotrophoblast cells with EBV and HTLV-I induced tumor necrosis factor-beta and transforming growth factor-beta 1 secretion, but infection with either virus alone did not lead to secretion of these cytokines. Permissive replication cycle of HTLV-I was induced by the EBV immediate-early gene product Zta. Pseudotype formation between EBV and HTLV-I in coinfected syncytiotrophoblast cells was not found. Our data suggest that activation of HTLV-I gene expression by EBV in coinfected syncytiotrophoblast cells may be a mechanism for transplacental transmission of HTLV-I.
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PMID:Epstein-Barr virus permissively infects human syncytiotrophoblasts in vitro and induces replication of human T cell leukemia-lymphoma virus type I in dually infected cells. 912 52

The effects of pentoxifylline on immunologic and virologic parameters were evaluated in 10 human immunodeficiency virus-infected patients not receiving antiretroviral treatment. Patients were asymptomatic, had 300-500 CD4 cells/microL, and received pentoxifylline (1200 mg/day orally) for 4 months. Peripheral blood mononuclear cells were tested before and at five time points during therapy. A transient increase in CD4 cells was observed in 8 of 9 patients, and CD8 cells increased in 7 of 9 patients. These increases were negatively correlated with susceptibility to in vitro mitogen-stimulated apoptotic cell death. Pentoxifylline had a temporary effect on mitogen-stimulated cytokine production; thus, interferon-gamma, interleukin (IL)-2, tumor necrosis factor-alpha, and lymphotoxin increased more than IL-10. Pentoxifylline also potentiated antigen-stimulated IL-2 production and proliferation in 8 of 9 patients and induced significant but transient decreases in plasma viremia in 7 of 9 patients. These preliminary findings suggest that pentoxifylline in vivo has an interesting but temporary influence on both immunologic and virologic parameters.
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PMID:Pentoxifylline improves cell-mediated immunity and reduces human immunodeficiency virus (HIV) plasma viremia in asymptomatic HIV-seropositive persons. 912 88

A subgroup of common variable immunodeficiency (CVID) patients have distinct clinical features, particularly granulomata splenomegaly, characteristic blood lymphocyte phenotype, and elevated circulating TNF levels. To investigate the genetic basis for this phenotype, 150 CVID patients and 200 controls were genotyped for six biallelic TNF and lymphotoxin-alpha (LT alpha) polymorphisms and eight class I and II HLA loci using PCR and sequence specific primers (PCR-SSP) sequence-specific primers. Clinical and immunophenotypic data were collected for 90 patients to examine associations with CVID patient subgroups. The presence of granulomata (22% of patients) was strongly associated with splenomegaly, T and B lymphopenia, reduced CD4+ CD45RA+ T cells, and CD8+ CD57+ lymphocytosis, confirming the concept of a subgroup of patients with distinct clinical and laboratory features. The uncommon TNF +488A allele was strongly associated with this subgroup (p = 0.0005). The association between "granulomatous" CVID and TNF +488A was independent of HLA class I and II associations. We postulate that the presence of the TNF +488A allele, or alleles in linkage disequilibrium with it, contributes to the high levels of TNF and granulomatous complications characteristic of this subgroup of patients.
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PMID:TNF and lymphotoxin-alpha polymorphisms associated with common variable immunodeficiency: role in the pathogenesis of granulomatous disease. 955 Apr 27

The alymphoplasia (aly) mutation of mouse is autosomal recessive and characterized by the systemic absence of lymph nodes (LN) and Peyer's patches (PP) and disorganized splenic and thymic structures with immunodeficiency. Although recent reports have shown that the interaction between lymphotoxin (LT) and the LT beta-receptor (Ltbeta r, encoded by Ltbr) provides a critical signal for LN genesis in mice, the aly locus on chromosome 11 is distinct from those for LT and its receptor. We found that the aly allele carries a point mutation causing an amino acid substitution in the carboxy-terminal interaction domain of Nf-kappa b-inducing kinase (Nik, encoded by the gene Nik). Transgenic complementation with wild-type Nik restored the normal structures of LN, PP, spleen and thymus, and the normal immune response in aly/aly mice. In addition, the aly mutation in a kinase domain-truncated Nik abolished its dominant-negative effect on Nf-kappa b activation induced by an excess of Ltbeta r. Our observations agree with previous reports that Ltbeta r-deficient mice showed defects in LN genesis and that Nik is a common mediator of Nf-kappa b activation by the tumour necrosis factor (TNF) receptor family. Nik is able to interact with members of the TRAF family (Traf1, 2, 3, 5 and 6), suggesting it acts downstream of TRAF-associating receptor signalling pathways, including Tnfr, Cd40, Cd30 and Ltbeta r. The phenotypes of aly/aly mice are more severe than those of Ltbr-/- mice, however, indicating involvement of Nik in signal transduction mediated by other receptors.
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PMID:Alymphoplasia is caused by a point mutation in the mouse gene encoding Nf-kappa b-inducing kinase. 1031 65

Numerous cytokines and chemokines are involved in inflammatory and immune response. Whereas some of them inhibit virus replication in vitro directly or increase the patients' T4-lymphocyte level, others effects are not so clear. Using human immunodeficiency virus (HIV) and cell cultures we have studied the antiviral effect of complexes of salmon DNA with metals and of a new factor(s) (antiviral factor, AVF) induced in cells by the complexes. The Fe3+/DNA complex possessed the highest antiviral activity. It was found that MT-2, MT-4, CEM and Jurkat cells treated with the complexes secreted AVF which inhibited the replication of nine HIV-1 isolates, was noncytotoxic and stimulated cell proliferation. AVF did not inactivate HIV. The molecular mass analysis of AVF showed that its antiviral activity is associated with its fraction of M(r) of 3 K. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of mRNA from MT-4 cells treated with the complexes showed an increase in the the expression of genes for interleukin-1 alpha (IL-1 alpha), tumour necrosis factor alpha (TNF-alpha) and TNF-beta while expression of genes for IL-1-beta, IL-2, IL-4, IL-6, IL-8. IL-10, IL-12; 35p, 40p, IL-13, GMCSF, GSF and RANTES was not detected at all. However, the anti-HIV activity of the cell culture supernatant in vitro cannot be explained by mere presence of the inflammatory substances mentioned above, because they do not possess such activity and their M(r) is higher than that of AVF. Our findings raise the possibility that AVF(s) may be involved in the mechanism of cell resistance against HIV.
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PMID:A Fe(3+)/DNA complex induces an anti-human immunodeficiency virus factor(s) in CD4+ lymphocyte cell lines. 1067 40


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