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)

We have observed that CD4 T lymphocytes from human immunodeficiency virus (HIV)-infected patients marginally express interleukin-2 receptor (IL-2R) beta and IL-2R gamma chains which are essential for IL-2 signal transduction. To analyze this observation further, we studied the influence of gp120 on the cell surface expression of IL-2R beta and IL-2R gamma by purified CD4 lymphocytes in vitro. Cross-linking of the T cell receptors of these lymphocytes initiates entry into the cell cycle as measured by CD69 and CD71 cell surface expression and [3H]thymidine incorporation. It also induces the cell surface expression of IL-2R beta and IL-2R gamma. We have shown that treatment of the CD4 T lymphocytes with HIV-1 gp120 before anti-CD3 stimulation impedes cell cycle progression as measured by reduced CD71 expression and inhibition of [3H]thymidine incorporation. Furthermore, cell surface expression of IL-2R beta and IL-2R gamma subunits, which from the functional intermediate-affinity IL-2R, are significantly inhibited. More importantly, addition of exogenous IL-2 does not restore the proliferation of the CD4 T cells treated with gp120, suggesting that cells are anergic and/or that the remaining IL-2R are not functional. This is the first study of IL-2R beta and IL-2R gamma dysregulation in the context of HIV infection and shows that CD4 is also involved in IL-2R expression.
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PMID:Interleukin-2 receptor beta and gamma chain dysregulation during the inhibition of CD4 T cell activation by human immunodeficiency virus-1 gp120. 934 58

Human herpes virus, type 8, also called Kaposi's sarcoma-associated virus, is associated with primary effusion lymphoma, an uncommon and unusual subset of acquired immunodeficiency syndrome-related lymphomas mostly confined to body cavities, which primarily affects human immunodeficiency virus-positive men. We report the case of a 40-year-old male with primary effusion lymphoma that presented initially with generalized lymphadenopathy and hepatosplenomegaly, followed by pericardial effusion and cardiac tamponade, in a previously undiagnosed human immunodeficiency virus patient. Cytomorphological studies disclosed a large-cell lymphoma with a population of cells demonstrating intermediate CD45 expression and partial coexpression of CD20 and CD23 markers, as well as universal expression of HLA-DR, CD71, CD38, and CD-30. Molecular studies showed clonal B-cell gene rearrangements and molecular evidence of human herpes virus, type 8. This case stresses the necessity, even in the absence of the 'classical clinical features,' of molecular testing for human herpes virus, type 8 in a subset of patients with high risk for human herpes virus, type 8-associated lymphomas.
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PMID:Unusual presentation of "extracavitary" primary effusion lymphoma in previously unknown HIV disease. 1110 Jun 30

Although it is well known that patients with type 1 diabetes mellitus are susceptible to other autoimmune diseases, the simultaneous occurrence of clustered distinct autoimmune diseases is uncommon. We report a 16-year-old girl, previously diagnosed as having coeliac disease and IgA deficiency, who at 13 years of age developed a clustering of distinct autoimmune diseases, including type 1 diabetes mellitus, rheumatoid arthritis (RA) and euthyroid autoimmune thyroiditis, eventually resulting in a simultaneous long-term remission. The clinical picture was associated with a functional immunodeficiency characterized by a defect in proliferative responses to T cell predominant mitogens and a normal response to the B cell predominant mitogen. In addition, the T cell activation markers HLA-DR, IL-2 receptor and transferrin receptor) were not upregulated. The clinical course of this immunodeficiency paralleled the outcome of the autoimmune diseases. After the abrupt onset, spontaneous clinical remission of both diabetes mellitus and RA was observed. Insulin was first reduced in dose and then discontinued completely at 15 months, in the presence of normal C peptide secretion and normal metabolic control (HbA1c 5.8%). Anti-glutamate decarboxylase (GAD65) and anti-IA-2 antibodies remained persistently high. During the remission phase a normalization of the functional immune defect was observed. The gradual resolution of the multisystemic diseases as well as the normalization of immune function in our patient is unusual. This case may be of considerable value in furthering our knowledge of the immunological mechanisms implicated in these rare multireactive syndromes.
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PMID:Simultaneous peripubertal onset of multireactive autoimmune diseases with an unusual long-lasting remission of type 1 diabetes mellitus. 1110 28

The relationships among hemoglobin, ferritin, and transferrin receptor levels and 2 markers of human immunodeficiency virus (HIV) disease severity--HIV load and CD4(+) lymphocyte count--were characterized among 483 pregnant women in Malawi, Africa. The only significant correlation was an inverse correlation between hemoglobin level and plasma HIV load (r=-.104; P<.03). The prevalence of iron deficiency anemia was not significantly different across quartiles of HIV load or CD4(+) lymphocyte count. In contrast to previous studies, these data suggest that iron status is not related to markers of HIV disease severity in pregnant women in Africa.
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PMID:Iron status and indicators of human immunodeficiency virus disease severity among pregnant women in Malawi. 1171 3

There is increasing evidence that CD8 lymphocytes may represent targets for infection by human immunodeficiency virus type 1 (HIV-1) in vivo whose destruction may contribute to the loss of immune function underlying AIDS. HIV-1 may infect thymic precursor cells destined to become CD4 and CD8 lymphocytes and contribute to the numerical decline in both subsets on disease progression. There is also evidence for the induction of CD4 expression and susceptibility to infection by HIV-1 of CD8 lymphocytes activated in vitro. To investigate the relationship between CD8 activation and infection by HIV-1 in vivo, activated subsets of CD8 lymphocytes in peripheral blood mononuclear cells (PBMCs) of HIV-seropositive individuals were investigated for CD4 expression and HIV infection. Activated CD8 lymphocytes were identified by expression of CD69, CD71, and the human leukocyte antigen (HLA) class II, the beta-chain of CD8, and the RO isoform of CD45. CD4(+) and CD4(-) CD8 lymphocytes, CD4 lymphocytes, other T cells, and non-T cells were purified using paramagnetic beads, and proviral sequences were quantified by PCR using primers from the long terminal repeat region. Frequencies of activated CD8 lymphocytes were higher in HIV-infected study subjects than in seronegative controls, and they frequently coexpressed CD4 (mean frequencies on CD69(+), CD71(+), and HLA class II(+) cells of 23, 37, and 8%, respectively, compared with 1 to 2% for nonactivated CD8 lymphocytes). The level of CD4 expression of the double-positive population approached that of mature CD4 lymphocytes. That CD4 expression renders CD8 cell susceptible to infection was indicated by their high frequency of infection in vivo; infected CD4(+) CD8 lymphocytes accounted for between 3 and 72% of the total proviral load in PBMCs from five of the eight study subjects investigated, despite these cells representing a small component of the PBMC population (<3%). Combined, these findings provide evidence that antigenic stimulation of CD8 lymphocytes in vivo induces CD4 expression that renders them susceptible to HIV infection and destruction. The specific targeting of responding CD8 lymphocytes may provide a functional explanation for the previously observed impairment of cytotoxic T-lymphocyte (CTL) function disproportionate to their numerical decline in AIDS and for the deletion of specific clones of CTLs responding to HIV antigens.
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PMID:Activated peripheral CD8 lymphocytes express CD4 in vivo and are targets for infection by human immunodeficiency virus type 1. 1168 37

ICF (immunodeficiency, centromeric region instability and facial anomalies) is a recessive disease caused by mutations in the DNA methyltransferase 3B gene (DNMT3B). Patients have immunodeficiency, chromosome 1 (Chr1) and Chr16 pericentromeric anomalies in mitogen-stimulated lymphocytes, a small decrease in overall genomic 5-methylcytosine levels and much hypomethylation of Chr1 and Chr16 juxtacentromeric heterochromatin. Microarray expression analysis was done on B-cell lymphoblastoid cell lines (LCLs) from ICF patients with diverse DNMT3B mutations and on control LCLs using oligonucleotide arrays for approximately 5600 different genes, 510 of which showed a lymphoid lineage-restricted expression pattern among several different lineages tested. A set of 32 genes had consistent and significant ICF-specific changes in RNA levels. Half of these genes play a role in immune function. ICF-specific increases in immunoglobulin (Ig) heavy constant mu and delta RNA and cell surface IgM and IgD and decreases in Ig(gamma) and Ig(alpha) RNA and surface IgG and IgA indicate inhibition of the later steps of lymphocyte maturation. ICF-specific increases were seen in RNA for RGS1, a B-cell specific inhibitor of G-protein signaling implicated in negative regulation of B-cell migration, and in RNA for the pro-apoptotic protein kinase C eta gene. ICF-associated decreases were observed in RNAs encoding proteins involved in activation, migration or survival of lymphoid cells, namely, transcription factor negative regulator ID3, the enhancer-binding MEF2C, the iron regulatory transferrin receptor, integrin beta7, the stress protein heme oxygenase and the lymphocyte-specific tumor necrosis factor receptor family members 7 and 17. No differences in promoter methylation were seen between ICF and normal LCLs for three ICF upregulated genes and one downregulated gene by a quantitative methylation assay [combined bisulfite restriction analysis (COBRA)]. Our data suggest that DNMT3B mutations in the ICF syndrome cause lymphogenesis-associated gene dysregulation by indirect effects on gene expression that interfere with normal lymphocyte signaling, maturation and migration.
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PMID:DNA methyltransferase 3B mutations linked to the ICF syndrome cause dysregulation of lymphogenesis genes. 1174 35

Anemia of chronic disease (ACD) is frequent in patients with human immunodeficiency virus (HIV) and its etiology is multifactorial. In a group of 111 patients with HIV, 19 were diagnosed with ACD. Parameters related to iron metabolism, such as serum iron (SI), serum ferritin (SF), and soluble transferrin receptor (sTfR) were correlated to levels of interferon-gamma (IFN-gamma) and results compared to a group of 42 nonanemic patients with HIV. Measurements of erythropoietin (EPO), CD4/CD8 T-cell ratio, and reticulocyte count (RTC) were determined to verify aspects related to severity of disease and bone marrow response. The results showed higher SF concentrations in ACD patients and normal or slightly increased sTfR measurements in both groups. There was no correlation between IFN-gamma and SF and between IFN-gamma and sTfR determinations. Lower CD4/CD8 values were obtained in ACD, and an inverse correlation was observed between IFN-gamma and CD4/CD8 in groups with and without anemia. RTC counts and EPO concentrations were similar in both groups: immature RTC were increased in patients with anemia, indicating an apparent attempt of marrow response to compensate the increased demand. Our data showed no correlation between IFN-gamma levels and iron disturbances in ACD, but results reinforced the observation of enhanced immunologic system deterioration in patients with HIV and ACD.
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PMID:Human immunodeficiency virus-related anemia of chronic disease: relationship to hematologic, immune, and iron metabolism parameters, and lack of association with serum interferon-gamma levels. 1222 86

Several short, highly cationic peptides are able to enter the cytoplasm and nucleus of cells from the extracellular medium. The mechanism of entry is unknown. A number of fluorescence-based studies suggested that these molecules cross the plasma membrane by an energy-independent process, directly gaining access to the cytoplasm. Recent reports have questioned this conclusion, attributing the prior observations to artifacts resulting from fixation procedures used to prepare cells for fluorescence microscopy. These studies analyzed live cells and showed that the peptides entered through endocytosis and accumulated in endocytic vesicles, without necessarily entering the cytoplasm. To resolve this controversy and to extend the analyses to non-natural beta-peptide sequences, we studied the cytoplasmic and nuclear delivery of a fluorescein-labeled 9-residue sequence derived from the human immunodeficiency virus transactivator of transcription (TAT) peptide, TAT-(47-57), as well as a similarly labeled 12-residue beta-peptide, beta-(VRR)4, in live cells. Using fluorescence confocal microscopy, we show that when added to cells, both peptides are found in endocytic vesicles containing the transferrin receptor as well as in the cytoplasm and nucleus (TAT-(47-57)) or nucleolus (beta-(VRR)4). The cells were verified to be intact through all experimental procedures by demonstrating their ability to exclude propidium iodide. Endocytic entry of the peptides was blocked by the energy poisons sodium azide and 2-deoxyglucose, whereas staining of the nucleus (nucleolus), but not endocytic vesicles, was abrogated by treating the cells with ammonium chloride. Our observations are consistent with the proposal that TAT-(47-57) and beta-(VRR)4 enter cells by endocytosis and then exit an endosomal compartment to enter the cytoplasm by means of a mechanism requiring endosome acidification.
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PMID:Cytoplasmic and nuclear delivery of a TAT-derived peptide and a beta-peptide after endocytic uptake into HeLa cells. 1451 18

Interactions of membrane proteins are important in various aspects of cell function. However, weak membrane protein-protein interactions are difficult to study using techniques such as co-immunoprecipitations. CD4 is a cell surface protein involved in T cell activation and the binding of the human immunodeficiency virus to HIV target cells. Here we report the use of cross-linking followed by affinity purification of CD4 in combination with mass spectrometry for identification of proteins that are in the proximity of CD4. Besides the components of the CD4 receptor complex, CD4 and lck, we have identified by tandem mass spectrometry 17 tryptic peptides from transferrin receptor CD71, three peptides from protein phosphatase CD45, and one peptide from 4F2 lymphocyte activation antigen CD98. The efficiency of the cross-linking did not correlate with the level of cell surface expression of the detected molecules, excluding a possible bias of the cross-linking toward the most abundant cell surface molecules. Whereas the association of CD4 with CD45 has been reported, the associations with CD71 and CD98 have not been previously described. We used small-scale immunoprecipitation after cross-linking in combination with fluorescence resonance energy transfer (FRET) measurements to investigate the association between CD4 and CD71. Our data show that CD71 self-associates on the cell surface, that a small fraction of CD4 can be detected by copurifying it with CD71 after cross-linking, and that the level of association between CD4 and CD71 significantly increases after phorbol 12-myristate 13-acetate-induced endocytosis of CD4. This suggests that a small fraction of CD4 associates with clusters of CD71. As both molecules undergo endocytic recycling, the association and cross-linking result from their clustering in the same pit and/or vesicle. The CD4-CD98 association probably results from nonspecific cross-linking.
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PMID:Lateral membrane protein associations of CD4 in lymphoid cells detected by cross-linking and mass spectrometry. 1470 53

A relationship of the levels of thymic peptide antibodies to those of the population and subpopulations of T lymphocytes was studied in patients with pulmonary tuberculosis, lung or breast cancer. Indirect immunofluorescence was used to determine the count of CD3-, CD4-, CD80, CD38-, CD25-, CD71-, and CD95-lymphocytes. The levels of thymic peptide antibodies were estimated by enzyme immunoassay. Unlike cancer diseases, pulmonary tuberculosis was characterized by the combination of a significantly inverse correlation between the relative count of CD3-, CD4-, CD8-lymphocytes the levels of thymogen antibodies with a significantly direct correlation between the absolute count of CD25- and CD38-lymphocytes. The studies may recommend that the levels of thymic peptide antigens should be determined to select persons with immunodeficiency particularly those with inflammatory diseases.
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PMID:[The levels of T lymphocytes and thymic peptide antibodies in patients with infiltrative pulmonary tuberculosis and in those with cancer diseases]. 1556 17


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