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1.
J Virol ; 73(3): 2450-9, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9971830

RESUMO

A polymorphism in the gene encoding CCR2 is associated with a delay in progression to AIDS in human immunodeficiency virus (HIV)-infected individuals. The polymorphism, CCR2-64I, changes valine 64 of CCR2 to isoleucine. However, it is not clear whether the effect on AIDS progression results from the amino acid change or whether the polymorphism marks a genetically linked, yet unidentified mutation that mediates the effect. Because the gene encoding CCR5, the major coreceptor for HIV type 1 primary isolates, lies 15 kb 3' to CCR2, linked mutations in the CCR5 promoter or other regulatory sequences could explain the association of CCR2-64I with slowed AIDS pathogenesis. Here, we show that CCR2-64I is efficiently expressed on the cell surface but does not have dominant negative activity on CCR5 coreceptor function. A panel of peripheral blood mononuclear cells (PBMC) from uninfected donors representing the various CCR5/CCR2 genotypes was assembled. Activated primary CD4(+) T cells of CCR2 64I/64I donors expressed cell surface CCR5 at levels comparable to those of CCR2 +/+ donors. A slight reduction in CCR5 expression was noted, although this was not statistically significant. CCR5 and CCR2 mRNA levels were nearly identical for each of the donor PBMC, regardless of genotype. Cell surface CCR5 and CCR2 levels were more variable than mRNA transcript levels, suggesting that an alternative mechanism may influence CCR5 cell surface levels. CCR2-64I is linked to the CCR5 promoter polymorphisms 208G, 303A, 627C, and 676A; however, in transfected promoter reporter constructs, these did not affect transcriptional activity. Taken together, these findings suggest that CCR2-64I does not act by influencing CCR5 transcription or mRNA levels.


Assuntos
Receptores CCR5/fisiologia , Receptores de Quimiocinas , Receptores de Citocinas/genética , Receptores de HIV/fisiologia , Doadores de Sangue , Linhagem Celular , Quimiocinas/biossíntese , Genótipo , HIV/crescimento & desenvolvimento , Humanos , Polimorfismo Genético , Regiões Promotoras Genéticas , RNA Mensageiro/análise , Receptores CCR2 , Receptores CCR5/análise , Receptores CCR5/genética , Receptores CXCR4/análise , Receptores de Citocinas/análise , Linfócitos T/virologia
2.
Pediatr Res ; 27(2): 109-12, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1690383

RESUMO

The particulate fractions of culture supernatants from peripheral blood mononuclear cells from 39 patients with Kawasaki disease (KD) were examined for the presence of particle-associated reverse transcriptase activity. The peak polymerase activity was significantly higher in cultures from KD patients compared to controls (mean = 6.4 versus 3.6 pmol of dTMP incorporated, p = 0.001). PBMC cultured between the 3rd and 9th wk after onset of fever were most likely to be associated with reverse transcriptase activity. Peak polymerase activity was positively associated with older age (r = 0.41, p = 0.01) and greater magnitude of the serum IgA response at 7-14 d after onset of fever (r = 0.45, p = 0.01) and IgM response at 6-9 wk after onset of fever (r = 0.46, p = 0.01). The appearance of enzyme activity was not associated with a decrease in viability of the cultured cells. A purified enzyme preparation showed radiolabel incorporation only with an RNA template with DNA primer. These data suggest that circulating mononuclear cells from KD patients may harbor a polymerase-associated agent and that these cells can be most readily detected in the early convalescent phase of KD from older patients who mount a marked humoral immune response.


Assuntos
Síndrome de Linfonodos Mucocutâneos/enzimologia , DNA Polimerase Dirigida por RNA/sangue , Fatores Etários , Células Cultivadas , Criança , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina M/biossíntese , Leucócitos Mononucleares/enzimologia , Síndrome de Linfonodos Mucocutâneos/imunologia , Fatores de Tempo
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