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)

Endogneous delta and kappa opioid peptides possess a variety of immunomodulatory properties, and kappa-opioid receptor ligands recently were shown to suppress the expression of human immunodeficiency virus type 1 (HIV-1) in microglial cells, the resident macrophages of the brain. To determine whether the newly discovered endogenous mu-opioid receptor ligands endomorphin-1 and -2 would affect HIV-1 replication, these peptides were added to acutely infected brain cell cultures. Endomorphin-1 potentiated viral expression, in a bell-shaped dose-response manner with maximal enhancement approximately equal to 35% at 10(-10) M, in both mixed glial/neuronal cell and purified microglial cell cultures. Endomorphin-1's amplifying effect was blocked by pretreatment of brain cells with either the mu-opioid receptor selective antagonist beta-funaltrexamine or the G protein inhibitor pertussis toxin. However, the classical mu receptor agonists morphine and DAMGO (Tyr-d-Ala-Gly-N-Me-Phe-Gly-ol) had no effect on viral expression or on endomorphin-1's amplifying effect. Taken together, these findings suggest that in this in vitro model of HIV-1 brain infection, endomorphin-1 potentiates viral expression via activation of an atypical mu-selective opioid receptor. They also provide evidence, for the first time, that an endogenous mu-opioid peptide has neuroimmunomodulatory activity.
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PMID:Endomorphin-1 potentiates HIV-1 expression in human brain cell cultures: implication of an atypical mu-opioid receptor. 1021 68

The beta-chemokine RANTES has recently been implicated in the neuropathogenesis of the human immunodeficiency virus. Based upon previous studies of the effects of morphine on microglial cell production of cytokines and chemotaxis towards the activated complement component C5a, we tested the hypothesis that this opiate would alter the production of and migration towards RANTES by human microglia. Treatment of highly purified microglial cell cultures with morphine (10(-8)-10(-6) M) potently inhibited RANTES production by lipopolysaccharide- and interleukin-1beta-stimulated cells. Using a chemotaxis chamber to assess directed migration towards RANTES, treatment of microglial cells with morphine (10(-10)-10(-6) M) was found to suppress chemotaxis. The inhibitory effects of morphine on RANTES production and on chemotaxis were blocked by naloxone and beta-funaltrexamine, indicating that morphine mediated its suppressive effects via activation of microglial p-opioid receptors. Morphine's inhibitory effect on chemotaxis did not appear to be associated with an alteration in RANTES-induced [Ca2+]i mobilization. While the clinical significance of these in-vitro findings is unknown, they suggest that mu-opioid receptor agonists could alter certain neurodegenerative and inflammatory processes within the brain.
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PMID:Morphine inhibits human microglial cell production of, and migration towards, RANTES. 1110 2

Human immunodeficiency virus (HIV) infection selectively targets the striatum, a region rich in opioid receptor-expressing neural cells, resulting in gliosis and neuronal losses. Opioids can be neuroprotective or can promote neurodegeneration. To determine whether opioids modify the response of neurons to human immunodeficiency virus type 1 (HIV-1) Tat protein-induced neurotoxicity, neural cell cultures from mouse striatum were initially characterized for mu and/or kappa opioid receptor immunoreactivity. These cultures were continuously treated with morphine, the opioid antagonist naloxone, and/or HIV-1 Tat (1-72) protein, a non-neurotoxic HIV-1 Tat deletion mutant (TatDelta31-61) protein, or immunoneutralized HIV-1 Tat (1-72) protein. Neuronal and astrocyte viability was examined by ethidium monoazide exclusion, and by apoptotic changes in nuclear heterochromatin using Hoechst 33342. Morphine (10nM, 100nM or 1microM) significantly increased Tat-induced (100 or 200nM) neuronal losses by about two-fold at 24h following exposure. The synergistic effects of morphine and Tat were prevented by naloxone (3microM), indicating the involvement of opioid receptors. Furthermore, morphine was not toxic when combined with mutant Tat or immunoneutralized Tat. Neuronal losses were accompanied by chromatin condensation and pyknosis. Astrocyte viability was unaffected. These findings demonstrate that acute opioid exposure can exacerbate the neurodegenerative effect of HIV-1 Tat protein in striatal neurons, and infer a means by which opioids may hasten the progression of HIV-associated dementia.
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PMID:Synergistic neurotoxicity of opioids and human immunodeficiency virus-1 Tat protein in striatal neurons in vitro. 1122 93

Heroin abuse is a common route of acquiring HIV-1 infection. However, the effects of opiates on lentivirus disease progression are not well understood. Feline immunodeficiency virus is recognized as a good animal model for HIV-1, but characterization of the opiate receptor system in cats is lacking. Here we report the partial sequencing of the feline mu opiate receptor (MOR) and demonstrate a homology of 92 and 93% to the published human MOR sequences. Additionally, MOR transcripts were detected in the feline brain and tonsil but not in the spleen. Also, specific receptor ligand interactions were observed using microphysiometry.
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PMID:Partial characterization and tissue distribution of the feline mu opiate receptor. 1124 68

Opioids may play an immunomodulatory role in the pathogenesis of human immunodeficiency virus-1 (HIV-1) infection. Recently, synthetic kappa-opioid receptor (KOR) ligands have been found to have anti-human immunodeficiency virus type 1 activity in acutely infected brain macrophages. In the present study, we investigated whether the selective KOR ligand U50488 would exert such an anti-HIV-1 effect in acutely infected blood monocyte-derived macrophages (MDM). Treatment of acutely infected MDM with U50488 induced a concentration-dependent inhibition of HIV-1 expression. The dose--response relationship of U50488 was U-shaped with a peak effect observed at 10(-13) M, which was evident at both 7 and 14 days post-infection. The KOR antagonist nor-binaltorphimine blocked the anti-HIV-1 effect of U50488 by 73%, indicating involvement of a KOR-mediated mechanism. Also, expression of KOR mRNA and binding activity with a fluorescence-labeled KOR ligand supported the existence of KOR on MDM. Antibodies to the beta-chemokine, RANTES (regulated on activation normal T-cell expressed and secreted), but not to various other cytokines, blocked U50488 inhibition by 56% suggesting that the anti-HIV-1 effect of U50488 involved, in part, the production of RANTES by MDM. Taken together, these in vitro findings support the anti-HIV-1 property of U50488, and suggest that KOR ligands may have therapeutic potential for treating patients with acquired immunodeficiency syndrome.
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PMID:U50488 inhibits HIV-1 expression in acutely infected monocyte-derived macrophages. 1124 71

CD4(+) T lymphocytes are the primary cell target for human immunodeficiency virus-1 (HIV-1), and these cells are known to express opioid receptors. Due to the need for new treatment approaches to HIV-1 infection, we sought to determine whether the non-selective opioid receptor antagonist naltrexone would affect HIV-1 expression in CD4(+) lymphocyte cultures and whether naltrexone would alter the antiviral properties of zidovudine (AZT) or indinavir. Activated CD4(+) lymphocytes were infected with a monocytotropic or T-cell tropic HIV-1 isolate, and p24 antigen levels were measured in supernatants of drug-treated or untreated (control) cultures. While naltrexone alone did not affect HIV-1 expression, at a concentration of 10(-12)-10(-10) M naltrexone increased the antiviral activity of AZT and indinavir 2-3-fold. Similar findings with a kappa-opioid receptor (KOR) selective antagonist supported the possible involvement of KOR in naltrexone's potentiation of the antiretroviral drugs. The results of this in vitro study suggest that treatment of alcohol or opiate dependent HIV-1-infected patients with naltrexone is unlikely to interfere with the activity of antiretroviral drugs. Also, based upon naltrexone's safety profile and its synergistic activity in vitro, these findings suggest clinical trials should be considered of naltrexone as an adjunctive therapy of HIV-1 infection.
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PMID:Naltrexone potentiates anti-HIV-1 activity of antiretroviral drugs in CD4+ lymphocyte cultures. 1167 40

Tuberculosis (TB) flourishes where there is poverty, malnutrition, overcrowding, and deficient health care. Worldwide, 1 billion 1,722 people are infected with dormant TB. 9-11 million people have active TB predominately in Asia, Africa, and Latin America, and almost 3 million people die of TB annually including 1/2 million of children. WHO estimates that 4.5 million people are coinfected with the human immunodeficiency virus (HIV) and TB in whom active TB can flare up because of weakened immunity. In Uganda, confirmed cases of active TB doubled between 1984 and 1987; and in Zambia TB cases increased from 7000 in 1986 to 17,000 in 1990. Under an assumption of low risk of TB infection and low HIV prevalence scientists have projected that active TB cases in the 15-49 age group will rise by 2/3 by the year 2000. Under a worst case scenario of higher TB infection and higher HIV seroprevalence rates, a 12-fold increase of active TB cases is projected by 2000. Thiacetazone is the main antituberculosis drug in standard chemotherapy. According to WHO data TB has been on the rise in 9 out of 14 European countries with TB infection rates of 10% among HIV-infected people in Spain and Italy. Since 1986 the TB caseload, also has been increasing in the US, and the recent appearance of multi-drug resistant TB (MDR-TB) has raised alarm. MOR-TB almost exclusively infants people with HIV and AIDS with a mortality rate of 80%. The Centers for Disease Control in Atlanta, Georgia, advocates the drastic measure of court-ordered, involuntary detention for treatment to halt its spread.
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PMID:A dangerous liaison: tuberculosis and HIV. 1228 82

Kappa-opioid receptor (KOR) ligands have been reported to alter many cell functions and to exert an immunomodulatory role in the CNS. Astrocytes, the predominant brain cell type, have been implicated in the neuropathogenesis of human immunodeficiency virus type 1 (HIV-1). HIV-1 nuclear protein Tat has been reported to induce production of the chemokine monocyte chemoattractant protein-1 (MCP-1 or CCL2) and to activate nuclear factor kappaB (NF-kappaB) in human astrocytes. In the present study, we investigated whether the synthetic KOR ligand trans-3,4-dichloro-N-methyl-N[2-(1-pyrolidinyl)cyclohexyl]benzeneacetamide methanesulfonate (U50,488) would down-regulate MCP-1 production in primary human astrocytes stimulated by Tat. Treatment of astrocytes with U50,488 inhibited Tat-induced MCP-1 production in a concentration-dependent manner. The KOR-selective antagonist nor-binaltrophimine (nor-BNI) completely blocked the inhibitory effect of U50,488, indicating involvement of KOR. While U50,488 alone had a partial inhibitory effect on constituent NF-kappaB activation, it potently suppressed Tat-induced NF-kappaB activation. These findings suggest that KOR ligands could have an anti-inflammatory effect in the CNS and thereby be beneficial in the treatment of HIV-1-associated brain disease.
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PMID:U50,488 inhibits HIV-1 Tat-induced monocyte chemoattractant protein-1 (CCL2) production by human astrocytes. 1247 73

Opiates such as morphine or heroin may promote cell apoptosis and cause dysfunction of immune cells. In simian immunodeficiency virus (SIV)-infected lymphocytic cells, however, morphine may protect the cells from apoptotic lysis and allow the virus to continue to replicate. To further explore this apparently antithetical effect of opiates, we evaluated in the present study the effects of morphine on human lymphocytic CEM x174 cells induced to undergo apoptosis in the presence of actinomycin D. It was found that induction of apoptosis (characterized by DNA laddering) by actinomycin D was accompanied by a stimulation of the expression of active (phosphorylated) form of p53. Pretreatment of the cells with 10nM morphine caused a transient, naloxone-reversible suppression of the appearance of activated p53 and the generation of DNA laddering. Parallel evaluation of the growth of CEM x174 indicated that morphine treatment delays the inception of cell death triggered by actinomycin D. Inasmuch as Bcl-2 suppresses while Bax accelerates apoptosis, treatment of cells with morphine reduced the expression of Bax and enhanced the expression of Bcl-2. Taken together, morphine, through binding at the opioid receptor, may protect lymphocytic cells from apoptotic lysis if cell death is initiated by apoptosis-inducing agents such as human immunodeficiency virus (HIV), SIV or actinomycin D.
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PMID:Morphine suppresses lymphocyte apoptosis by blocking p53-mediated death signaling. 1292 89

The opiates are well-established immunomodulatory factors, and recent evidence suggests that mu- and delta-opioid receptor ligands alter chemokine-driven chemotactic responses through the process of heterologous desensitization. In the present report, we sought to examine the capacity of mu- and delta-opioids to modulate the function of chemokine receptors CCR5 and CXCR4, the two major human immunodeficiency virus (HIV) coreceptors. We found that the chemotactic responses to the CCR1/5 ligand CCL5/regulated on activation, normal T expressed and secreted, but not the CXCR4 ligand stromal cell-derived factor-1alpha/CXCL12 were inhibited following opioid pretreatment. Studies were performed with primary monocytes and Chinese hamster ovary cells transfected with CCR5 and the micro-opioid receptor to determine whether cross-desensitization of CCR5 was a result of receptor internalization. Using radiolabeled-binding analysis, flow cytometry, and confocal microscopy, we found that the heterologous desensitization of CCR5 was not associated with a significant degree of receptor internalization. Despite this, we found that the cross-desensitization of CCR5 by opioids was associated with a decrease in susceptibility to R5 but not X4 strains of HIV-1. Our findings are consistent with the notion that impairment of the normal signaling activity of CCR5 inhibits HIV-1 coreceptor function. These results have significant implications for our understanding of the effect of opioids on the regulation of leukocyte trafficking in inflammatory disease states and the process of coreceptor-dependent HIV-1 infection. The interference with HIV-1 uptake by heterologous desensitization of CCR5 suggests that HIV-1 interaction with this receptor is not passive but involves a signal transduction process.
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PMID:Selective inactivation of CCR5 and decreased infectivity of R5 HIV-1 strains mediated by opioid-induced heterologous desensitization. 1297 7


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