Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 25-year-old woman with AIDS was submitted to HLA-identical allogeneic BMT after cytoablation with busulphan and cyclophosphamide and combined anti-HIV-1 therapy with zidovudine, IFN-alpha 2 and anti-HIV-1-specific T cell clones. Marrow engraftment occurred after 18 days and tests for HIV-1 were negative after 30 days but the hematologic reconstitution of the patient was poor. A second BM infusion from the same donor was ineffective and treatment with GM-CSF only induced a transient increase of the blood cell count, suggesting iatrogenic damage to the BM microenvironment. The development of ARDS led to the death of the patient 10 months after transplantation. Post-mortem investigation did not reveal any active infections and PCR on autopsy tissues was negative for HIV-1.
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PMID:Allogeneic bone marrow transplantation combined with multiple anti-HIV-1 treatment in a case of AIDS. 813 53

Members of the NF-kappa B/Rel family of transcription factors are involved in the transcriptional regulation of numerous polypeptides important to the immune response and cellular growth. Several genes regulated in part by NF-kappa B/Rel such as interleukin 2, IL-2 receptor alpha, and GM-CSF are trans-activated via an indirect association with the HTLV-I Tax protein in virus-infected and transformed T cells. In this study, we have investigated the interactions between Tax and NF-kappa B/Rel in an attempt to elucidate the mechanism of Tax mediated trans-activation and its role in leukemogenesis. Transfection studies were performed in Jurkat T cells using expression vectors for individual NF-kappa B subunits and the Tax protein as well as an NF-kappa B regulated reporter plasmid. NF-kappa B proteins differentially trans-activated the HIV-1 enhancer-CAT reporter; co-expression of Tax abrogated the inhibitory effect of I kappa B alpha and a trans-dominant negative mutant of p65 (p65 delta), indicating that Tax was a trans-dominant activator of NF-kappa B-regulated genes. Co-immunoprecipitation studies with extracts from transfected cells and NF-kappa B and Tax subunit specific antibodies revealed that Tax did not co-immunoprecipitate with p50/p105, c-Rel, or I kappa B; however, antibody specific to p65 was able to co-immunoprecipitate a 40kDa protein from Tax-transfected cells. Previous studies have demonstrated a physical interaction between Tax protein and p100, indicating that Tax may preferentially associate with specific NF-kappa B proteins.
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PMID:Interactions between HTLV-I Tax and NF-kappa B/Rel proteins in T cells. 815 9

A mannoprotein fraction (MP-F2: mannan, > 90%; protein, 4.5%) from the human commensal microorganism Candida albicans was as efficient as interleukin-2 (IL-2) in generating cytotoxicity against the uninfected or human immunodeficiency virus type-1 (HIV-1) persistently infected monocytoid U937 cell line in cultured peripheral blood mononuclear cells (PBMC) from healthy human subjects. MP-F2-activated killing of U937 cells (U937-MAK) decreased progressively with advancing stages of HIV-1 infection to virtually no killing effect in PBMC from advanced AIDS subjects (AIDS PBMC). This decrease paralleled a lowered susceptibility of U937 cells to natural killer cell activity. In contrast, IL-2-activated killing of U937 cells (U937-LAK) was not affected by the progression of HIV infection and persisted at high levels in AIDS PBMC. To shed light on the mechanisms of U937-MAK and its decrease during HIV infection, IL-1 beta, IL-6, TNF-alpha, GM-CSF, and IFN-gamma production was analyzed. Decreases in TNF-alpha, GM-CSF, and IFN-gamma, but not IL-1 beta or IL-6, levels were observed in MP-F2-stimulated PBMC from HIV-infected subjects, compared to healthy controls. Interestingly, these cytokine levels fell before the onset of AIDS. The greatest relative drop was that of IFN-gamma, from 4600 (+/- 600) to 290 (+/- 160) and 217 (+/- 110) mean pg/ml (+/- SE) in PBMC from healthy donors (11 subjects), CDC stages II + III (14 subjects), and CDC stage IV (10 subjects), respectively. The following observations suggest that decreased IFN-gamma production plays a role in the abrogation of U937-MAK activity: (i) addition of neutralizing anti-IFN-gamma antibodies abolished both IFN-gamma and U937-MAK activity in PBMC from healthy subjects; (ii) substantial levels of IFN-gamma were detected in supernatants of PBMC cultures stimulated by IL-2, in line with preserved U937-LAK activity. Interestingly, anti-IFN-gamma antibodies also abolished TNF-alpha production, and the anti-TNF-alpha antiserum effect was comparable to that of anti-IFN-gamma in U937-MAK inhibition. In contrast, anti-TNF-alpha antibodies abrogated TNF-alpha activity, but only partially reduced IFN-gamma production. Thus, in human PBMC, U937-MAK activity progressively decreases with advancing stages of HIV infection, whereas U937-LAK activity is sustained. Furthermore, the present results indicate a pivotal role for IFN-gamma in U937 MAK activity, possibly through activation of TNF-alpha production.
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PMID:Mannoprotein-induced anti-U937 cell cytotoxicity in peripheral blood mononuclear cells from uninfected or HIV-infected subjects: role of interferon-gamma and tumor necrosis factor-alpha. 825 54

The expression of human immunodeficiency virus type 1 (HIV-1) is enhanced after cell activation because of the interaction of cell-encoded nuclear factors that interact with binding sites in the long terminal repeats (LTRs). Here we studied the contribution of cell type-specific activation signals to differences in cytotropism of HIV-1 variants. Four closely related molecular HIV-1 clones with distinct biological phenotypes and different capacities to replicate in primary monocyte-derived macrophages (MDMs) or T cell lines were used. Sequence analysis of these LTRs revealed variation in functionally important regions. Adaptation of virus variants to particular host cells by differences in LTR responsiveness was analyzed. LTR-CAT constructs were transiently transfected in T cells that were stimulated with T cell-specific activation signals such as combinations of anti-CD3 or anti-CD28 MoAB or in primary monocytes that were stimulated with IL-3, IL-4, or GM-CSF. No differences in responsiveness to cell type-specific signals were demonstrated. To further elucidate the level of restriction in cell tropism, transfection of four full-length infectious molecular HIV-1 clones into 5-day cultured MDMs was performed. From all clones, competent virus could be rescued from MDMs by coculture with PHA-stimulated PBLs. However, following cell-free inoculation, proviral DNA could be detected by PCR analysis only in monocytes exposed to HIV-1 clones that previously were shown to establish productive infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Early replication steps but not cell type-specific signalling of the viral long terminal repeat determine HIV-1 monocytotropism. 836 71

The present study compares the in vitro effect of (+/-)-2'-deoxy-3'-thiacytidine (BCH 189) a new synthetic anti-HIV-1 dideoxynucleoside, with 3'-azido-3'-deoxythymidine (AZT) on the immune function of lymphocytes from 10 normal and 12 HIV-1+ patients (CDC II and III). The effect of different doses of BCH 189 and AZT was analysed in vitro on: (i) T cell proliferation after stimulation with concanavalin A (Con A) or anti-CD3 MoAb; (ii) B cell proliferation and immunoglobulin production after stimulation with pokeweed mitogen (PWM); (iii) cytokine production (IL-2, IL-6, GM-CSF, tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) from lymphocytes stimulated with anti-CD3 MoAb or phytohaemagglutinin (PHA). BCH 189 inhibited the proliferation of B and T lymphocytes from normal and HIV+ subjects less than AZT; even if lymphocytes from HIV+ (CDC III) subjects produced higher levels of IL-6 and TNF-alpha, neither BCH 189 nor AZT molecule interfered with cytokine release. Immunoglobulin production from B lymphocytes was inhibited only by a high concentration (50 microM) of BCH 189 or AZT. These results show that BCH 189 affects lymphocyte proliferation in vitro less than AZT, and support its use in clinical trials in HIV-infected patients.
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PMID:In vitro immunotoxicity of +/- 2'-deoxy-3'-thiacytidine, a new anti-HIV agent. 839 Mar 35

HIV encephalitis is unusual in that neurologic damage occurs in the absence of significant infection of neuronal or glial cells. Because the predominant infected cell in the brain is the macrophage, it has been proposed that release of viral or immune activation factors from macrophages may mediate neurologic damage. Numerous studies have examined the concentration of immune activation factors in the cerebrospinal fluid (CSF), however, there has been no correlation between these CSF measurements and severity of HIV encephalitis (Wiley, C.A., C.L. Achim, R.D. Schrier, M.P. Heyes, J.A. McCutchen, and I. Grant. 1992. AIDS (Phila.). 6:1299-1307. Because CSF measurements may not represent tissue concentrations of these factors, we examined the concentrations of HIV p24, quinolinic acid (QUIN), IL-1, IL-3, IL-6, TNF-alpha, and GMCSF within the brains of 10 AIDS autopsies. Homogenization and extraction of cortical gray, cortical white and deep gray matter showed a good correlation between the amount of HIV gp41 immunostaining and extracted HIV gag protein p24. The concentrations of cytokines were low in the tissue extracts and showed no correlation with severity of HIV encephalitis. Brain extracts from mild cases of HIV encephalitis showed elevated levels of TNF-alpha in deep gray matter, while in more severe cases, elevated TNF-alpha levels were also found within cortical white and cortical gray matter. Brain tissue and CSF QUIN concentrations were substantially increased compared to control values. QUIN concentrations were not correlated with the severity of HIV encephalitis. We conclude that increased tissue levels of TNF-alpha and QUIN may have a role in the etiology of HIV-related neurologic dysfunction.
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PMID:Quantitation of human immunodeficiency virus, immune activation factors, and quinolinic acid in AIDS brains. 851 84

An in vitro culture system was developed that facilitates detailed studies of the interaction of Human Immunodeficiency Virus (HIV) with dendritic cells (DC). Cultured immature DC were generated from adherent peripheral blood mononuclear cells in the presence of GM-CSF and IL-4. These cells were non-adherent, non-phagocytic and had a veiled surface appearance. They expressed high levels of MHC class I and II proteins, CD1a, B7/BB1 and low levels of CD4, and were known to possess a potent soluble antigen presenting capacity. Upon infection with the HIV-1 strains Lai (lymphocytotropic) and BaL (monocytotropic), the viral RNA was reverse transcribed to complete DNA provirus. However the infection was non-productive as judged from measuring the activity of the virus encoded reverse transcriptase in the culture supernatant. Thus HIV infection was restricted at a step post entry.
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PMID:Infection of cultured immature dendritic cells with human immunodeficiency virus type 1. 852 22

The human immunodeficiency virus type (HIV-1) Rev protein stimulates the export to the cytoplasm of unspliced HIV-1 mRNAs carrying the Rev response element (RRE). However, simple addition of the RRE to beta-globin pre-mRNA does not confer a Rev response on this heterologous transcript. In this paper, we demonstrate that a strong Rev response is conferred on beta-globin pre-mRNA when an inhibitory (INS) element is inserted into the gene together with the RRE. In the presence of INS element, Rev was able to stimulate the export to the cytoplasm of unspliced mRNA 10 to 15-fold. INS elements from the HIV-1 p17 gag and pol genes were equally active in complementing Rev-dependent nuclear export of unspliced mRNA. By contrast, mutated p17 gag INS element, known to be inactive in gag mRNA instability assays, was unable to complement the Rev/RRE system and stimulate nuclear export. Similarly, AUUUA-instability elements from the granulocyte-macrophage colony stimulating factor mRNA (GM-CSF) destabilised beta-globin mRNA but could not substitute for the HIV INS elements. Complementation between the Rev/RRE system and the INS elements was only observed when splicing was efficient. When splicing of the beta-globin gene receptor is impaired by mutations in the 5' splice donor, the 3' splice acceptor sequence, or the polypyrimidine tract, the majority of the unspliced mRNA is exported from the nucleus in the absence of Rev. In the presence of splice site mutations, Rev is able to act independently of a functional INS element and increase the export of unspliced mRNA three to fivefold. We propose that nuclear factor(s) binding to INS elements separate unspliced beta-globin pre-mRNA from the splicing apparatus. Pre-mRNA in this "INS compartment" remains accessible to Rev. Thus, there is a synergy between the INS elements and Rev which leads to enhanced nuclear export of unspliced mRNA.
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PMID:Interactions of INS (CRS) elements and the splicing machinery regulate the production of Rev-responsive mRNAs. 860 21

To date, hematopoietic stem and progenitor cells from human umbilical cord blood (CB) have been employed in approximately 90 allogeneic (56 sibling and 34 unrelated) matched and mismatched transplantations worldwide with easy and successful restoration of hematopoiesis. Requests for stem cell preparations from CB will continue to increase. Thus, as a pilot study, the examination and standardization of unrelated cord blood-derived stem cell preparations and banking as well as their biologic characterization were initiated. Up to October 1995, a total of 574 samples [mean volume 79 +/- 26 ml, total nucleated cells (NC) 8.5 +/- 5 x 10(8), BFU-E 9.5 +/- 8.6 x 10(5), CFU-GM 5.7 +/- 6.3 x 10(5), CFU-GEMM 1.6 +/- 1.9 x 10(5)] from cord-derived or placental-derived residual blood have been defined by hematologic, immunologic, and microbiologic criteria. These CB samples were collected from the umbilical cord vein immediately after vaginal full-term delivery (n = 450) or cesarean section (n = 124) and stored frozen in liquid nitrogen. Seven percent of all samples collected could not be considered for potential transplants because of volumes < 40 ml. Only 5.0 ml of a CB sample is required for routine laboratory testing, consisting of HLA class I typing, HLA class II typing by sequence-specific oligonucleotide probes (PCR-SSOP), ABO typing, sterility control, assessment of progenitor and stem cells by colony-forming and LTC-IC assays, and CD34+ status. To assess the potential problem of contaminating maternal cells, a PCR was performed on 7 representative samples. During the initial 6 months of the unrelated CB collection program, a median bacterial contamination rate of 18% (20% skin flora species, 80% perineal flora species) was encountered, which has since been reduced to < 1% through practical experience. With regard to viral infections, maternal sera was tested for HBsAg (0.6% positive), anti-HCV (0%), anti-HAV (IgG 18%, IgM 0%), anti-HIV-1-2 (0%), anti-EBV (IgG 98%, IgM 0%), anti-HTLVI-II (0%), anti-CMV (IgG 43%, IgM 0.4%), toxoplasmosis (46%) and syphilis (0%). In addition, all cord blood samples were tested by PCR for CMV infection. With regard to its clinical relevance, it is important that only 0.3% of all the samples were positive for CMV by this sensitive method. This may represent a critical advantage of CB grafts over bone marrow (BM) since, in contrast, > 40% of the unrelated BM donors have been identified to be positive for CMV. An additional advantage of CB is that since 20% of CB samples were collected from ethnic minorities, it appears possible to balance common HLA types and uncommon HLA types represented in this group. In summary, with the extensive practical experience of the obstetric collection team as well as the stem cell-processing laboratory, it appears feasible to obtain a 90% yield of unrelated CB-derived stem cell preparations for banking, which clearly should meet the medical and regulatory qualification criteria required for clinical transplantation. To test the feasibility of hematopoietic transplant potential of unrelated CB for adult patients, ex vivo expansion of CD34+-enriched stem/progenitor cell populations isolated from fresh or frozen CB was attempted in the presence of rh-IL-3, rh-IL-6, rh-EPO, rh-GM-CSF, and rh-SCF with or without fit 3. At varying time points (days 0, 2, 4, 7, 14, 21), the contents of these cultures were analyzed for the numbers of cells, CFC (BFU-E, CFU-GM, CFU-GEMM), and LTC-IC. In this setting, the increase of cells was 200-fold, that of CFC 70-fold, and most importantly that of LTC-IC was 4.5-fold after 7 days in culture in the presence of flt3. In conclusion, LTC-IC derived from CB can be maintained and considerably expanded ex vivo from highly enriched CD34 + CB cell populations from fresh or frozen CB samples.
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PMID:Hematopoietic transplant potential of unrelated cord blood: critical issues. 872 85

Human polymorphonuclear neutrophils (PMN) and cytokines play a critical role in host defences against invading microorganisms. In response to a variety of stimuli, PMN are a major source of reactive oxygen species (ROS) which are essential for bacterial killing and may induce oxidative stress in tissue environment. A precise regulation of the oxidase activity is therefore necessary. Cytokines such as TNF alpha, GM-CSF, IL-8, IL-6, IL-1 alpha and IL-1 beta produced during the immune and inflammatory responses to pathogens have been reported to interact with PMN activities. However, contradictory results have been reported on their direct and priming effects on the PMN release of ROS (oxidative burst). We have used a flow cytometry method to study the effects of these cytokines on the oxidative burst of PMN in whole blood, in order to avoid PMN activation related to isolation procedures. None of the cytokines tested directly activated the PMN oxidative burst, but they did have differential priming effects on the oxidative burst in response to N-formyl peptides. TNF, GM-CSF and IL-8 strongly primed a subpopulation of PMN to produce H2O2 in response to fMLP, while IL-1 alpha, IL-1 beta and IL-6 failed to do so. Furthermore, the addition of TNF, GM-CSF or IL-8 to whole blood increased the capacity of a subpopulation of PMN to bind N-formyl peptides, a phenomenon that could account for the strong H2O2 production in response to fMLP following priming by the cytokines. These results show that, among the various cytokines tested, TNF, GM-CSF and IL-8 strongly prime the PMN oxidative burst in response to bacterial peptides in whole blood and suggest that these cytokines may play a critical role in bacterial killing in vivo and also in the surrounding tissue injury secondary to pathological inflammatory reactions. In particular, TNF and IL-8 plasma levels as well as LPS-induced monocytic production of these cytokines ex vivo have been correlated with the production of ROS by stimulated PMN and with the lung injury score in patients with Adult Respiratory Distress Syndrom (ARDS). However, desensitization phenomena have also been described. In particular, in HIV infected patients we demonstrated a decrease of H2O2 production by PMN in whole blood after ex vivo priming by IL-8 and TNF followed by fMLP stimulation. This decrease increased with the progression of the disease and was inversely correlated with IL-8 plasma level. Different mechanisms could explain such desensitization phenomena at the receptor and post receptor level. In addition cytokines are involved in a complex network of regulation and anti inflammatory cytokines, such as IL-10, could act as a negative signal on the proinflammatory cytokines induced-priming of oxidative burst.
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PMID:[Modulation of the oxidative burst of human neutrophils by pro- and anti-inflammatory cytokines]. 873 98


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