Effects of human immunodeficiency virus type 1 on CD4 lymphocyte subset activation.
Eur J Immunol
; 29(6): 1879-89, 1999 06.
Article
em En
| MEDLINE
| ID: mdl-10382750
ABSTRACT
The pathogenesis of the decline of CD4 lymphocyte counts accompanying the typical course of HIV-1 infection is not completely defined and might be related to a differential susceptibility of naive and memory cells to HIV-1 exposure. Here, we examined the effects induced by heat-inactivated HIV-1 virions on these lymphocyte populations. Exposure of CD45RA naive T cells to inactivated viral particles induced a marked decrease of both mitogenic responses and activation-induced apoptosis. Conversely, the growth of CD45RO cells was less severely restrained. Analysis of intracellular levels of cell cycle regulatory proteins revealed an arrest at the G1/S restriction point of the naive but not memory subset. This effect was associated with alterations in phosphotyrosine profile and with a marked decrease of ERK and NJK kinase activation. Finally, up-regulation of the cAMP-dependent protein kinase A (PKA) activity induced by mitogens was not affected by virus. Altogether, these findings show that interaction of HIV-1 with the T cell surface is sufficient to inhibit the proliferative response of the CD4CD45RA subset by disturbing proximal TCR signaling. This mechanism would affect renewal of naive lymphocytes, contributing in such a way to the impairment of T cell turnover during the course of HIV-1 infection.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ativação Linfocitária
/
Linfócitos T CD4-Positivos
/
HIV-1
/
Quinases relacionadas a CDC2 e CDC28
Limite:
Humans
Idioma:
En
Revista:
Eur J Immunol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Itália