UMLS:C0021051 - FACTA Search

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

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

Recent studies on the coreceptor usage of human immunodeficiency virus (HIV) strains associated with acquired immunodeficiency syndrome (AIDS) dementia have shown that both X4 and R5 viruses are involved in the process. The disease is associated with enhanced virus replication and monocyte chemoattractant protein (MCP)-1 production in macrophages in the brain. Using the macaque model of the disease, the authors show here that X4, macrophage-tropic simian human immunodeficiency virus (SHIV) required the enhancing effect of interleukin (IL)-4 to achieve equivalent concentrations of virus and MCP-1 that are produced in macrophages infected with R5 viruses alone. Confocal microscopy showed that macrophages in the encephalitic brains were the major producers of MCP-1. The authors surmise, therefore, that whereas R5 viruses maybe capable of causing the disease as a primary pathogen, X4 viruses may require IL-4, induced by opportunistic pathogens, for induction of the neuropathological syndrome.
...
PMID:Role of interleukin-4 and monocyte chemoattractant protein-1 in the neuropathogenesis of X4 simian human immunodeficiency virus infection in macaques. 1498 50

Chemokines and cytokines play a critical role in HIV infection, serving both to modulate virus replication and to recruit target cells to the site of infection. Platelet-derived growth factor (PDGF), a mitogen and chemoattractant for a wide variety of cells, is secreted by macrophages. Since macrophages are the target cells for lentiviral infection in the brain and PDGF is a known inducer of macrophage chemoattractant protein-1 (MCP)-1, a potent chemokine closely associated with HIV encephalitis, we investigated the association of PDGF-B chain (PDGF-B) with encephalitis in macaques caused by simian human immunodeficiency virus (SHIV), a chimera of HIV and SIV. Northern blot analysis confirmed elevated expression of PDGF-B chain mRNA in the brains from encephalitic macaques. Validation of these in vivo studies was confirmed in rhesus macrophage cultures infected with SHIV(KU2) in which we demonstrated heightened expression of PDGF-B chain mRNA. Nuclear run-off analysis established transcriptional up-regulation of PDGF-B chain in virus-inoculated macrophage cultures. Reciprocally, addition of exogenous PDGF enhanced virus replication and MCP-1 expression in these cells. Inhibition of virus replication by tyrosine kinase inhibitor, STI-571, and by PDGF-B antisense oligonucleotides confirmed the specificity of the PDGF effect. Relevance of these findings was confirmed by analysis of archival brain tissue from SHIV encephalitic and non-encephalitic macaques for PDGF-B chain expression. PDGF-B chain protein expression was observed in the virus-infected cells in microglial nodules in the brains of SHIV-encephalitic macaques.
...
PMID:Association of platelet-derived growth factor-B chain with simian human immunodeficiency virus encephalitis. 1533 6

It is well established that most G protein-coupled receptors are able to form homo- and heterodimers, although the functional consequences of this process often remain unclear. CCR5 is a chemokine receptor that plays an important role in inflammatory diseases and acts as a major coreceptor for human immunodeficiency viruses. CCR5 was previously shown to homodimerize and heterodimerize with CCR2b, a closely related receptor. In the present study, we have analyzed the functional consequences of this dimerization process, in terms of ligand binding, stimulation of intracellular cascades, and internalization. Bioluminescence resonance energy transfer and coimmunoprecipitation assays demonstrated that CCR5 and CCR2b heterodimerize with the same efficiency as they homodimerize. In contrast to what has been reported previously, no cooperative signaling was observed after costimulation of the two receptors by their respective ligands. However, we observed that CCR5-specific ligands that are unable to compete for monocyte chemoattractant protein (MCP-1) binding on cells expressing CCR2b alone efficiently prevented MCP-1 binding when CCR5 and CCR2b were coexpressed. The extent of this cross-competition was correlated with the amount of CCR5 expressed in cells, as determined by fluorescence-activated cell sorting analysis. Similar observations were made for the CCR2b-selective ligand MCP-1 that competed efficiently for macrophage inflammatory protein-1beta binding on cells expressing both receptors. Internalization assays did not allow us to demonstrate cointernalization of the receptors in response to agonist stimulation. Together, our observations suggest that CCR5 and CCR2b form homo- and heterodimers with similar efficiencies and that a receptor dimer can only bind a single chemokine.
...
PMID:Evidence for negative binding cooperativity within CCR5-CCR2b heterodimers. 1550 16

In the highly active antiretroviral therapy (HAART) era, the role of the inflammatory response in acquired immunodeficiency syndrome (AIDS)-related progressive multifocal leukoencephalopathy (PML) remains controversial. In this study, JC virus DNA load and levels of cytokines were determined in cerebrospinal fluid (CSF) from 32 human immunodeficiency virus (HIV)-1-infected patients with confirmed PML who underwent HAART; cytokines were also measured in 12 HIV-positive controls. Predictors of survival were analyzed by Cox's models. Macrophage chemoattractant protein (MCP)-1 levels were significantly higher in PML patients than in controls (mean +/- SD, 2.45 +/- 0.64 versus 1.32 +/- 0.64 log(10) pg/ml, P<.0001). In PML patients, the higher concentration of MCP-1 correlated with lower JC viral load (r=-.405, P=.036). Higher concentrations of MCP-1 in CSF were associated with longer survival on HAART after adjusting for CD4 counts (for each log(10) pg/ml higher, hazard ratio for death 0.28, 95% confidence interval 0.08--1.00). Predictors of shorter survival were lower baseline CD4 counts, higher JCV DNA concentrations, lower Karnofsky, and no prior HAART exposure. These results showed that higher CSF levels of MCP-1, an inflammatory cytokine, were correlated with better prognosis in HAART-treated patients with PML.
...
PMID:Macrophage chemoattractant protein-1 levels in cerebrospinal fluid correlate with containment of JC virus and prognosis of acquired immunodeficiency syndrome--associated progressive multifocal leukoencephalopathy. 1603

Opiates exacerbate human immunodeficiency virus type 1 (HIV-1) Tat(1-72)-induced release of key proinflammatory cytokines by astrocytes, which may accelerate HIV neuropathogenesis in opiate abusers. The release of monocyte chemoattractant protein-1 (MCP-1, also known as CCL2), in particular, is potentiated by opiate-HIV Tat interactions in vitro. Although MCP-1 draws monocytes/macrophages to sites of CNS infection, and activated monocytes/microglia release factors that can damage bystander neurons, the role of MCP-1 in neuro-acquired immunodeficiency syndrome (neuroAIDS) progression in opiate abusers, or nonabusers, is uncertain. Using a chemotaxis assay, N9 microglial cell migration was found to be significantly greater in conditioned medium from mouse striatal astrocytes exposed to morphine and/or Tat(1-72) than in vehicle-, mu-opioid receptor (MOR) antagonist-, or inactive, mutant Tat(delta31-61)-treated controls. Conditioned medium from astrocytes treated with morphine and Tat caused the greatest increase in motility. The response was attenuated using conditioned medium immunoneutralized with MCP-1 antibodies, or medium from MCP-1(-/-) astrocytes. In the presence of morphine (time-release, subcutaneous implant), intrastriatal Tat increased the proportion of neural cells that were astroglia and F4/80+ macrophages at 7 days post-injection. This was not seen after treatment with Tat alone, or with morphine plus inactive Tat(delta31-61) or naltrexone. Glia displayed increased MOR and MCP-1 immunoreactivity after morphine and/or Tat exposure. The findings indicate that MCP-1 underlies most of the response of microglia, suggesting that one way in which opiates exacerbate neuroAIDS is by increasing astroglial-derived proinflammatory chemokines at focal sites of CNS infection and promoting macrophage entry and local microglial activation. Importantly, increased glial expression of MOR can trigger an opiate-driven amplification/positive feedback of MCP-1 production and inflammation.
...
PMID:HIV-1 Tat and opiate-induced changes in astrocytes promote chemotaxis of microglia through the expression of MCP-1 and alternative chemokines. 1620 61

Human immunodeficiency virus-1 (HIV-1) infection of the brain causes elevation in pro-inflammatory cytokines and inflammatory changes in the striatum. HIV-1-infected individuals who also abuse drugs including the psychostimulant methamphetamine (MA) develop more severe encephalitis and neuronal damage compared to HIV-1-infected patients who do not abuse drugs. In previous studies, we demonstrated that the HIV-1 protein Tat and MA interacted to cause enhanced loss of dopamine in the rat striatum via the destruction of dopaminergic terminals. Since both Tat and MA activate glia and induce cytokine production, we investigated the role of cytokines in the synergistic neurotoxicity induced by Tat and MA using cytokine arrays. Significant increases in monocyte chemotactic protein (MCP-1), interleukin-1 alpha (IL-1alpha) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were noted 4 h following Tat + MA treatment compared to saline, Tat or MA. MCP-1 and TIMP-1 levels remained elevated 16 h after Tat + MA compared to saline or MA but were not different from the Tat-treated group at this time point. Weak, but significant elevations in cytokine-induced neutrophil chemoattractant-3 (CINC-3), ciliary neurotrophic factor (CNTF) and macrophage inflammatory protein-3 alpha (MIP-3alpha) were also noted with Tat + MA. The interaction of Tat and MA was prevented in mice genetically deficient in MCP-1 with a consequent attenuation of Tat + MA neurotoxicity. Our findings suggest that HIV-1 infection with concurrent drug abuse might profoundly increase chemokine levels in the striatum resulting in enhanced damage to the dopaminergic system.
...
PMID:Involvement of cytokines in human immunodeficiency virus-1 protein Tat and methamphetamine interactions in the striatum. 1651 Jan 41

Whereas adaptive immunity has been extensively studied, very little is known about the innate immunity of the host to HTLV-I infection. HTLV-I-infected ATL patients have pronounced immunodeficiency associated with frequent opportunistic infections, and in these patients, concurrent infections with bacteria and/or parasites are known to increase risks of progression to ATL. The Toll-like receptor-4 (TLR4) activation in response to bacterial infection is essential for dendritic cell maturation and links the innate and adaptive immune responses. Recent reports indicate that TLR4 is targeted by viruses such as RSV, HCV, and MMTV. Here we report that HTLV-I has also evolved a protein that interferes with TLR4 signaling; p30 interacts with and inhibits the DNA binding and transcription activity of PU.1 resulting in the down-regulation of the TLR4 expression from the cell surface. Expression of p30 hampers the release of pro-inflammatory cytokines MCP-1, TNF-alpha, and IL-8 and stimulates release of anti-inflammatory IL-10 following stimulation of TLR4 in human macrophage. Finally, we found that p30 increases phosphorylation and inactivation of GSK3-beta a key step for IL-10 production. Our study suggests a novel function of p30, which may instigate immune tolerance by reducing activation of adaptive immunity in ATL patients.
...
PMID:The HTLV-I p30 interferes with TLR4 signaling and modulates the release of pro- and anti-inflammatory cytokines from human macrophages. 1678 40

Acyclic nucleoside phosphonates are potent antiviral agents effective against replication of DNA viruses and retroviruses including human immunodeficiency virus (HIV). In addition to their antimetabolic mode of antiviral action, acyclic nucleoside phosphonates also possess immunomodulatory properties. We have shown recently that a number of them stimulate secretion of cytokines including chemokines RANTES/CCL5 ("regulated upon activation, normal T cell expressed and secreted") and MIP-1 alpha/CCL3 (macrophage inflammatory protein-1 alpha) that may inhibit entry of HIV in cells. In present experiments we analyzed effects of acyclic nucleoside phosphonates on gene expression of other members of the beta family of chemokines, monocyte chemotactic proteins (MCPs), which have also been implicated in the control of HIV infection. The following compounds differing at the type of heterocyclic base, i.e. adenine (A), or 2,6-diaminopurine (DAP), at the 6-amino group of the base, and at the N ( 9 )-side chain represented by 9-[2-(phosphonomethoxy)ethyl] (PME) and 9-[2-(phosphonomethoxy)propyl] (PMP) moieties were included in the study: (1) (R)-PMPA, ie. tenofovir, (2) N ( 6 )-cyclopropyl-(R)-PMPDAP, (3) N ( 6 )-cyclopentyl-(R)-PMPDAP, (4) N ( 6 )-dimethylaminoethyl-(R)-PMPDAP, (5) N ( 6 )-cyclopentyl-PMEDAP, (6) N ( 6 )-isobutyl-PMEDAP, (7) N ( 6 ) -cyclohexylmetyl-PMEDAP, and (8) N ( 6 ) -cyclooctyl-PMEDAP. These compounds are able to activate production of MCP-1 and MCP-3, and none of them influences gene expression of MCP-2, and MCP-5. Enhancement of monocyte chemotactic protein expression was found to be mediated by transcriptional factor nuclear factor-kappaB (NF-kappaB).
...
PMID:Acyclic nucleoside phosphonate antivirals activate gene expression of monocyte chemotactic protein 1 and 3. 1703 77

Molecular diversity within brain-derived HIV-1 sequences is highly variable depending on the individual gene examined and the neurological status of the patient. Herein, we examined different brain-derived human immunodeficiency virus (HIV)-1 tat sequences in terms of their effects on LTR transactivation and host gene induction in neural cells. Astrocytic and monocytoid cells co-transfected with prototypic tat clones derived from non-demented (ND) (n = 3) and demented (HAD) (n = 3) AIDS patients and different HIV-LTR constructs revealed that LTR transactivation mediated by tat clones derived from HAD patients was decreased (p < 0.05). A Tat-derived peptide containing the amino acid 24-38 domain from a ND clone caused down-regulation of the LTR transactivation (p < 0.05) in contrast to peptides from other Tat regions derived from HAD and ND tat clones. Both brain-derived HAD and ND tat constructs were able to induce the host immune genes, MCP-1 and IL-1beta. Microarray analysis revealed several host genes were selectively upregulated by a HAD-derived tat clone including an enzyme mediating heparan sulphate synthesis, HS3ST3B1 (p < 0.05), which was also found to be increased in the brains of patients with HAD. Expression of the pro-apoptotic gene, PDCD7, was reduced in cells transfected with the HAD-derived tat clone and moreover, this gene was also suppressed in monocytoid cells infected with a neurotropic HIV-1 strain. Thus, mutations within the HIV-1 tat gene may exert pathogenic effects contributing to the development of HAD, which are independent of its effects on LTR transactivation.
...
PMID:Brain-derived human immunodeficiency virus-1 Tat exerts differential effects on LTR transactivation and neuroimmune activation. 1750 86

Monocytes and macrophages play a central role in the pathogenesis of human immunodeficiency virus (HIV)-associated dementia. They represent prominent targets for HIV infection and are thought to facilitate viral neuroinvasion and neuroinflammatory processes. However, many aspects regarding monocyte brain recruitment in HIV infection remain undefined. The nonhuman primate model of AIDS is uniquely suited for examination of the role of monocytes in the pathogenesis of AIDS-associated encephalitis. Nevertheless, an approach to monitor cell migration from peripheral blood into the central nervous system (CNS) in primates had been lacking. Here, upon autologous transfer of fluorescein dye-labeled leukocytes, we demonstrate the trafficking of dye-positive monocytes into the choroid plexus stromata and perivascular spaces in the cerebra of rhesus macaques acutely infected with simian immunodeficiency virus between days 12 and 14 postinfection (p.i.). Dye-positive cells that had migrated expressed the monocyte activation marker CD16 and the macrophage marker CD68. Monocyte neuroinvasion coincided with the presence of the virus in brain tissue and cerebrospinal fluid and with the induction of the proinflammatory mediators CXCL9/MIG and CCL2/MCP-1 in the CNS. Prior to neuroinfiltration, plasma viral load levels peaked on day 11 p.i. Furthermore, the numbers of peripheral blood monocytes rapidly increased between days 4 and 8 p.i., and circulating monocytes exhibited increased functional capacity to produce CCL2/MCP-1. Our findings demonstrate acute monocyte brain infiltration in an animal model of AIDS. Such studies facilitate future examinations of the migratory profile of CNS-homing monocytes, the role of monocytes in virus import into the brain, and the disruption of blood-cerebrospinal fluid and blood-brain barrier functions in primates.
...
PMID:Neuroinvasion of fluorescein-positive monocytes in acute simian immunodeficiency virus infection. 1771 37

<< Previous 1 2 3 4 5 6 Next >>