Entendendo como o HIV infecta células humanas: quimiocinas e seus receptores

Resumo

This review refers to very recent and strikingly important discoveries that have explained the nature of accessory molecules required by HIV to infect human cells, providing information about mechanism of host resistance and opening perspectives for new drug and vaccine targets. One year after the discovery of the HIV, the CD4 molecule was identifíed as the primary receptor used by the virus to infect T lymphocytes. However, for more than a decade there hás been a long and difficult search for the coreceptors, since it was known that CD4 alone was not enough to promote infection of target cells. In 1996, several research groups discovered that receptors for chemokines, chemotactic cytokines, function as coreceptors, together with CD4 molecules allowing infection of target cells. Chemokines are classified into four distinct families, two of them well described: the a chemokines (CXCR) with 4 receptors (CXCR-1) to 4) and the P chemokines (CC) and their 8 receptors (CCR-1 to 8). The first HIV coreceptor characterized was the receptor CXCR-4 that permits infection of CD4+ T lymphocytes. Soon after this, the coreceptor that allows infection of macrophages was identifíed as the CCR-5 molecule. During early stages of infection., HIV strains which have tropism for macrophages and use CCR-5 prevail and these strains slowly evolve to strains that have tropism for CD4+ T lymphocytes infecting them through CXCR-4. These strains are probably responsible for the depletion of CD4+ T lymphocytes observed in advanced stages of the disease. Exposed-uninfected subjects may be homozygous or heterozygous for a mutant CCR-5 allele with a 32 base pair deletion, which is not compatible with CCR-5 expression on cell surface, suggesting a protective effect. These recent discoveries altogether start a new era of hopes with different targets for prophylactic and therapeutic interventions against HIV/AIDS.

Descrição

Palavras-chave

HlV/AIDS, Co-receptores, Quimiocinas, Coreceptors, Chemokines

Citação

STEFANI, Mariane Martins de Araújo; VIEIRA, Regina Beatriz Bevilacqua; PEREIRA, Gisner Alves de Souza; TEIXEIRA JR., João; FERRO, Maria Qrdália. Entendendo como o HIV infecta células humanas: quimiocinas e seus receptores. Revista de Patologia Tropical, Goiânia, v. 27, n. 1, p. 1-10, jan./jun. 1998. Disponível em: <https://www.revistas.ufg.br/iptsp/article/view/17192/10364>.