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Target Concepts:
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Query: UMLS:C0085584 (
encephalopathy
)
18,178
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
CCR5
, a chemokine receptor, serves as a coreceptor for macrophage-tropic HIV-1 (1-3). A 32-bp deletion within the gene encoding
CCR5
, CCR5del32, has been shown to prevent HIV-1 infection of T cells in the absence of a wild-type allele. This alteration is present in low frequency in Caucasian populations (4-6). To investigate the effect of CCR5del32 in perinatal HIV-1 transmission and disease progression, two cohorts of perinatally exposed infected and uninfected children were analyzed for the presence of the allele. Polymerase chain reaction (PCR) was used to identify CCR5del32 in prevalent and prospective cases among 144 African American children from New York City and 73 Caucasian children from Barcelona, Spain. HIV-1 transmission; clinical manifestations of disease, including
encephalopathy
, opportunistic infections, and death before 2 years of age; survival; Centers for Disease Control and Prevention (CDC) classification; and degree of immunosuppression were compared in children with and without CCR5del32. The allele frequency in HIV-1-infected African Americans (0.016) was lower than in Catalan children (0.041). No evidence for a dominant protective effect of CCR5del32 for HIV-1 transmission or disease progression was found in these cohorts.
...
PMID:CCR5del32 in perinatal HIV-1 infection. 940 69
The chemokine receptors
CCR5
and CXCR4 are co-receptors together with CD4 for human immunodeficiency virus (HIV)-1 entry into target cells. Macrophage-tropic HIV-1 viruses use
CCR5
as a co-receptor, whereas T-cell-line tropic viruses use CXCR4. HIV-1 infects the brain and causes a progressive
encephalopathy
in 20 to 30% of infected children and adults. Most of the HIV-1-infected cells in the brain are macrophages and microglia. We examined expression of
CCR5
and CXCR4 in brain tissue from 20 pediatric acquired immune deficiency syndrome (AIDS) patients in relation to neuropathological consequences of HIV-1 infection. The overall frequency of
CCR5
-positive perivascular mononuclear cells and macrophages was increased in the brains of children with severe HIV-1 encephalitis (HIVE) compared with children with mild HIVE or non-AIDS controls, whereas the frequency of CXCR4-positive perivascular cells did not correlate with disease severity.
CCR5
- and CXCR4-positive macrophages and microglia were detected in inflammatory lesions in the brain of children with severe HIVE. In addition, CXCR4 was detected in a subpopulation of neurons in autopsy brain tissue and primary human brain cultures. Similar findings were demonstrated in the brain of adult AIDS patients and controls. These findings suggest that
CCR5
-positive mononuclear cells, macrophages, and microglia contribute to disease progression in the central nervous system of children and adults with AIDS by serving as targets for virus replication.
...
PMID:Localization of HIV-1 co-receptors CCR5 and CXCR4 in the brain of children with AIDS. 942 34
Human immunodeficiency virus (HIV-1) infects the brain and causes a progressive
encephalopathy
in 20 to 30% of infected children and adults called AIDS dementia complex. Evidence from in vitro and in vivo studies suggests a role for the viral envelope glycoprotein gp120, as a mediator of neurotoxicity. However, the site of interaction of gp120 with neurons and astrocytes to mediate neuronal death is still unknown. Recently the chemokine receptors,
CCR5
and CXCR4, have been identified as co-receptors together with CD4 for HIV-1 entry into the target cells, suggesting a possible role for these receptors in the pathogenesis of the HIV-1 infection in the brain. Here we report the expression of
CCR5
and CXCR4 in many different rat brain areas. We also found both receptors in cultured type I astrocytes demonstrating that glial cells may represent an important target for chemokines in vivo. Indeed, the functional capacity of CXCR4 receptor in astrocytes was demonstrated showing that SDF 1 alpha induced an increase of intracellular calcium concentration.
...
PMID:Expression of chemokine receptors in the rat brain. 1041 11
The brain is a target organ for recreational drugs and HIV-1. Epidemiological data demonstrate that opioid abuse is a risk factor for HIV-1 infection and progression to AIDS. Chemokines and their receptors have been implicated in the neuropathogenesis of HIV-1 infections. However, little is known about the effects of opioids on the expression of chemokines and their receptors (the latter also are HIV-1 coreceptors) by cells of the CNS. Herein we describe the effects of morphine on gene expression of the alpha- and beta-chemokines and their receptors by the astrocytoma cell line U87 and by primary normal human astrocyte (NHA) cultures. U87 cells treated with morphine showed significant down-regulation of IL-8 gene expression, whereas expression of the IL-8 receptor CXCR2 was reciprocally up-regulated as detected by RT-PCR. Treatment of NHAs with morphine suppressed IL-8 and macrophage-inflammatory protein-1beta gene expression, whereas expression of their receptor genes, CCR3 and
CCR5
, was simultaneously enhanced. These morphine-induced effects on U87 and NHA cells were reversed by the opioid mu receptor antagonist beta-funaltrexamine. Morphine also enhanced the constitutive expression of the opioid mu receptor on astroglial cells. Our results support the hypothesis that opioids play a significant role in the susceptibility of the CNS to HIV-1 infection and subsequent
encephalopathy
by inhibiting local production of HIV-1-protective chemokines (IL-8 and macrophage-inflammatory protein-1beta) and enhancing expression of HIV-1 entry coreceptor genes (CCR3,
CCR5
, and CXCR2) within the CNS. These effects of opioids appear to be mediated through the opioid mu receptor that we demonstrated on astroglial cells.
...
PMID:Morphine regulates gene expression of alpha- and beta-chemokines and their receptors on astroglial cells via the opioid mu receptor. 1224 49
Despite HAART, a significant number of HIV-1-infected patients develop neurological complications. However, the presence of specific neurotropic HIV-1 strains, the extent of viral replication in the brain, and the type of cells infected remain controversial issues. To address this controversy we have analyzed different V3 loop sequences of viral isolates from four vertically HIV-1-infected children who developed HIV-1-related
encephalopathy
. Moreover, we have determined that some biological and molecular properties of HIV-1 might contribute to AIDS neurological dysfunctions. We detected very different HIV-1 isolates (X4 and R5) in the brain despite no great differences in clinical, pathological, or immunological parameters. In vitro, no differences in replicative competence in glial or neuroblastoma cells were observed between virus isolated from the blood of children with or without clinical neurological symptoms. The expression of both CXCR4 and
CCR5
RNAs was observed in the brain independently of HIV-1 infection and viral strain predominant in this location. Our results failed to show a particular phenotypic property of the HIV-1 virus that might explain its neurovirulence and/or neurotropism.
...
PMID:Lack of association of HIV-1 biological or molecular properties with neurotropism for brain cells. 1695 3