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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Quantification of human immunodeficiency virus (HIV) proviral DNA in peripheral blood mononuclear cells (PBMC) was performed in 13 HIV-seropositive asymptomatic individuals during 10-24 months by polymerase chain reaction amplification of multiple half-log dilutions of cellular DNA. At enrollment, subjects had a geometric mean titer of 100 copies of HIV provirus per 10(6) PBMC (mean +/- SD, 2 +/- 0.9 log10). In four untreated individuals there was no significant change in provirus levels during a mean period of 13.3 months. In eight patients treated with zidovudine (ZDV) and human recombinant interleukin 2 (rIL-2), HIV provirus copies declined to 13 per 10(6) cells (1.1 +/- 0.8 log10) at the end of the first course of ZDV and rIL-2 at week 20 (p less than 0.01), and to 40 per 10(6) cells (1.6 +/- 0.9 log10) after 12 months of treatment (p less than 0.04). Subsequent courses, which included 12 weeks of ZDV alone or 4 weeks of IL-2 alone, did not significantly change the already depressed provirus copy numbers. Proviral copy number also remained depressed during drug-free "washout periods" between courses. Finally, we observed a return to a geometric mean of 400 copies per 10(6) cells (2.6 +/- 0.3 log10) a mean of 7.9 months after discontinuation of therapy. Measurement of changes in HIV provirus should provide a direct marker for defining antiviral activity of drugs, biologics, and combination therapy.
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PMID:Decrease in HIV provirus in peripheral blood mononuclear cells during zidovudine and human rIL-2 administration. 173 87

Many defense mechanisms are located in the respiratory tract, since they are constantly exposed to a variety of pathogens from both inside and outside the body. Among the various defense mechanisms, the immune system is so potent that immunodeficiency results in proneness to infections and repeated and/or intractable infection. It is not uncommon to encounter patients with congenital immunodeficiency in clinical practice because of recent advances in supportive therapy. This paper describes cases of primary immunodeficiency that developed respiratory infections, together with the results of investigations of their immune status. Doctors should suspect the possibility of immunodeficiency in patients with repeated or intractable respiratory infections. Intractable respiratory infections, however, have been seen with increasing frequency in the elderly because of the increase in the elderly population. One reasons for this is the physiologic immunodeficiency associated with aging, which is characterised by decreased antigen-induced lymphocyte proliferation, IL-2 production, IL-2R expression, hsp 70 mRNA production, and demethylation of T lymphocytes, and delayed degradation of c-myc mRNA.
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PMID:[Respiratory tract infection and immunodeficiency]. 175 97

Infection of Human organism by Human Immunodeficiency viruses induces, after a shorter or a longer period, a complex immune Deficiency (ID) that has been named Acquired Immune Deficiency Syndrome (AIDS). Although the designation is not correct, it has been accepted by the scientific community. AIDS includes multiple clinical situations that have in common HIV infection and an almost constant ID, that at the end of natural course of infection manifestated by the presence of opportunistic infections and malignant tumors. HIV-1 and HIV-2 are slow RNA viruses with a common architecture and well known genomic organization. The characteristics that made HIV infectious agent n. 1 in XXth Century are their remarkable heterogeneity, close AA sequence homology between some of their proteins and relevant molecules in human beings: MHC molecules, IL-2, VIP, etc. and a strong affinity of gp 120 to CD4 receptor of T helper lymphocytes (T4), mononuclear phagocytes, natural killer cells, etc. all of them sharing a relevant role in normal immune response (IR). Affected in its cornerstones of cellular defense, human organism starts an immune defense through antibodies, cytotoxic T Lymphocytes (CTL) Natural Killer Cells (NK) antibody dependent cell cytotoxicity (ADCC), that fails. Activating immune system HIV turn that defense strategy to their own profit and enhanced replication. After an apparent latency period--in which the balance seems to favor the host--new viral variants arise due to high rate of HIV mutagenesis, that in turn stimulate immune system, induce new cycles of viral replication and new high virulent mutants, leading to the final collapse of Immune System.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Immunologic aspects of HIV infection]. 180 34

We investigated whether the enhancement, by prothymosin alpha (Pro alpha), of the phytohaemagglutinin-stimulated proliferation of human peripheral blood mononuclear cells (PBMC) is due to its affect on the number of cells expressing the interleukin 2 receptor (IL-2R) or the surface density of IL-2R on PBMC. Peripheral blood mononuclear cells were obtained from 21 donors. For both an optimal phytohaemagglutinin (PHA) concentration (H) and a 10-fold dilution (L), their responses fell in two classes, high (h) and low (l), making four dose--response situations. Pro alpha significantly increased the number and IL-2R density of cells expressing IL-2R only when the response in its absence was about half maximal, i.e. for PBMC responding well to the low PHA stimulus (group Lh) or PBMC responding poorly to the optimal stimulus (group Hl). The enhancement of IL-2R expression in group Lh by Pro alpha was dose-dependent and paralleled by increased proliferative response. It appears not to be mediated by IL-2, since it was unaffected when IL-2 production was suppressed by cyclosporin A. The early interaction of Pro alpha with lymphocytes did not require the presence of macrophages, but macrophages were necessary during lymphocyte activation for modulation of PHA-stimulated IL-2R expression to be affected. The immunoregulatory activity of Pro alpha may prove useful for improving the decreased T-cell function associated with immunodeficiency, or for restoration of normal IL-2R expression by the lymphocytes of aged individuals.
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PMID:Prothymosin alpha enhances interleukin 2 receptor expression in normal human T-lymphocytes. 181 46

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

DNA synthesis in response to mitogens has been studied in T cells from nine patients with common variable immunodeficiency (CVI) and seven normal individuals. Five out of the nine patients had cells with subnormal responses to the mitogen phytohaemagglutinin (PHA). As PHA-induced responses are largely mediated through activation of Ca(2+)-dependent protein kinase C, we studied whether the defective response was still present on direct activation of protein kinase C. This was done using combinations of concentrations of phorbol 12,13,-dibutyrate and the calcium ionophore ionomycin which induced proliferation in normal T cells. We found that in CVI patients with T cells which had normal responses to PHA, responses to phorbol ester and ionomycin were at the same level as in normal T cells. However, with this treatment, in which the linkage between the membrane receptor and protein kinase C is bypassed, the level of DNA synthesis was still depressed in the patient group whose T cells had subnormal responses to PHA. IL-2 failed to restore the DNA synthesis to normal levels when added with the phorbol ester and ionomycin to T cells from one patient in this group. These data suggest that in a group of CVI patients there are defects in T cell activation pathways at or down-stream of protein kinase C.
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PMID:Defects in proliferative responses of T cells from patients with common variable immunodeficiency on direct activation of protein kinase C. 186 99

More than 50 patients with common variable immunodeficiency have been classified into 5 groups representing different blocks in B cell function. To do this, B cells were assessed in vitro by secretion of IgM or IgG in response to anti-IgM and IL-2 or to EBV alone. Some clinical features and the patients' sex ratio correlated with this B cell classification. In vitro attempts were made to identify and overcome these blocks using physiological ligands (e.g. cytokines), and agents that induce transcription (e.g. retinoic acid). The patient group with the most severely affected B cells also contained some patients whose T cells showed depressed DNA synthesis in response to mitogens. In vitro data indicate that the abnormality may be in the T cell itself rather than in monocytes failing to provide essential cytokines (e.g. IL-6). In 3 patients, splenic B cells were able to secrete IgM more effectively than circulating B cells, but still they produced no IgG.
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PMID:T and B cell defects in common variable immunodeficiency. 186 33

Mucosal candidiasis is one of the first opportunistic diseases in HIV-infected subjects. In order to understand the relationship between this disease and immunodeficiency to chemically defined, immunodominant Candida antigens, a mannoprotein fraction from C. albicans cell wall (GMP) was used to analyse proliferative and non-MHC-restricted cytotoxic responses of peripheral blood mononuclear cells (PBMC) from normal and HIV-infected subjects. In the former, GMP induced extensive blastogenesis, generation of powerful cytotoxicity against a tumour cell line (K562), and production of substantial amounts of interferon-gamma (IFN-gamma). Cultured PBMC from HIV-infected subjects manifested an early decreased ability for proliferative as well as differentiative cytotoxic responses to the candidal mannoproteins. This inability became clearly evident in subjects with stage III (CDC) of the disease, was total in CDC stage IV and occurred even in some subjects with a normal number of CD4+ cells. Low or absent response to GMP correlated with lack of response to tetanus toxoid. In contrast, both lymphoproliferative and cytotoxic responses to exogenous IL-2 was highly preserved at all stages of infection. The production of IFN-gamma in GMP-stimulated PBMC cultures critically fell to negligible values in most of the subjects in CDC stages II and III. Thus, the lowered or absent cell-mediated immune responses to candidal mannoprotein may be one factor to explain the early, elevated susceptibility of HIV-infected subjects to mucosal candidiasis. This study also shows that our mannoprotein preparation may be used as a probe to detect the overall efficiency of T cell responses in the above subjects.
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PMID:Proliferative and cytotoxic responses to mannoproteins of Candida albicans by peripheral blood lymphocytes of HIV-infected subjects. 189 30

Patients with human immunodeficiency virus (HIV) infections have aberrant production of a number of lymphokines and monokines. Envelope glycoproteins are believed to be important in HIV pathogenesis and may influence the production of these cytokines. Therefore, synthetic peptides corresponding to amino acid sequences 735-752 and 846-860 of glycoprotein gp41 and to amino acid sequence 304-328 of gp120 were investigated for their abilities to affect the production of the following cytokines by normal peripheral blood mononuclear cells in the presence of appropriate inducers: interferon (IFN)-alpha, IFN-gamma, interleukin (IL)-1, IL-2, and tumor necrosis factor (TNF). In contrast to cells and inducers alone (or in the presence of a control peptide), gp41 or gp120 synthetic peptides were able to depress the production of IFN-alpha, IFN-gamma and IL-2. In contrast, these peptides produced an elevation of the production of IL-1 and TNF. The effect of the gp41 peptides was more marked than that of gp120 peptides in most cases. These studies indicate that these HIV envelope glycoproteins may be directly responsible for aberrant lymphokine and monokine production in patients infected with this virus and therefore may be at least partially responsible for the pathogenesis of AIDS.
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PMID:Synthetic peptides corresponding to sequences in HIV envelope gp41 and gp120 enhance in vitro production of interleukin-1 and tumor necrosis factor but depress production of interferon-alpha, interferon-gamma and interleukin-2. 190 33

The mechanisms underlying abnormal T-cell function in B-chronic lymphocytic leukemia (B-CLL) are unknown. We have studied B-CLL T-cell activation pathways in the rigorous absence of leukemic cells and with controlled numbers of accessory cells present. The responsiveness to added recombinant IL-1 and IL-2 was assessed. We have found that under optimal culture conditions B-CLL T cells had a normal PHA-induced proliferative response in terms of incorporated 3H-thymidine per T cell. Also the capacity of mitomycin-C treated B-CLL monocytes to support autologous T-cell mitogenesis was normal. However, a subtle difference between normal and B-CLL T cells emerged with respect to cytokine responsiveness. While the PHA response of purified normal T cells in the absence of monocytes was augmented by rIL-1, this could not be demonstrated for B-CLL T cells. A much greater degree of augmentation occurred with added rIL-2 in the case of both normal and B-CLL T cells. In the presence of 20% autologous monocytes rIL-1 and rIL-2 had no effect on mitogenesis. We conclude that B-CLL T cells have an abnormal profile of cytokine responsiveness which is consistent with observed abnormalities of subset distribution, and which may contribute to the clinical immunodeficiency in B-CLL.
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PMID:T-lymphocyte response to cytokines in B-chronic lymphocytic leukemia. 192 61


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