RESUMO
Ethanol may have significant effects on human immunodeficiency virus type I (HIV-1) pathogenesis in vivo. As such, the effects of ethanol treatment were studied on the proapoptotic potential of various HIV-1 proteins in primary isolated human brain microvascular endothelial cells (MVECs), a major cellular component of the blood-brain barrier. Low-passage primary brain MVECs were treated with recombinant HIV-1 proteins Nef, Vpr, Tat and gp120 proteins from X4, R5, and X4R5 viral strains, with and without ethanol at various relevant concentrations. The apoptotic potential of each HIV-1 protein with and without ethanol was compared with cells treated with ethanol alone or GST protein as a control, under similar conditions. Specific HIV-1 proteins induced apoptosis in primary isolated human brain MVECs, which was potentiated on treatment with 0.1 and 0.3% (v/v) ethanol. Cotreatment with ethanol and specific HIV-1 proteins showed enhanced lactate dehydrogenase release, compared with MVECs treated with ethanol alone. The presence of ethanol in in vitro culture medium also enhanced HIV-1 protein-mediated tumor necrosis factor-alpha production, compared with cells treated with ethanol alone or GST protein. Thus, these studies demonstrate ethanol's potential for inducing apoptosis of human MVECs with relevant HIV-1-specific proteins and suggest a potential synergistic effect in augmenting HIV-1 neuroinvasion and neuropathogenesis in vivo.
Assuntos
Apoptose/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Etanol/toxicidade , HIV-1/patogenicidade , Proteínas Virais/toxicidade , Encéfalo/irrigação sanguínea , Células Cultivadas , Endotélio Vascular/citologia , Produtos do Gene nef/toxicidade , Produtos do Gene tat/toxicidade , Produtos do Gene vpr/toxicidade , Proteína gp120 do Envelope de HIV/toxicidade , Humanos , L-Lactato Desidrogenase/metabolismo , Fator de Necrose Tumoral alfa/biossíntese , Produtos do Gene nef do Vírus da Imunodeficiência Humana , Produtos do Gene tat do Vírus da Imunodeficiência Humana , Produtos do Gene vpr do Vírus da Imunodeficiência HumanaRESUMO
We have previously shown that Nef-gene 10 fusion protein induces marked growth arrest of human primary CD4+ T cells. Here, in vitro cytostatic and cytotoxic activities of human immunodeficiency virus type 1 (HIV-1) Nef against CD4+ T cells were extensively investigated. Growth of human CD4+ cells was inhibited significantly just by the addition of purified full-length Nef to cultures. When Nef was cross-linked by anti-Nef antibodies, it became very cytocidal for CD4+ T cells. A high percentage of sera from HIV-1-infected individuals contained soluble Nef. Thus, soluble Nef in vivo may play an important role in immunodysfunction of CD4+ T lymphocytes in HIV-1 infection.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Produtos do Gene nef/toxicidade , Antígenos HIV/toxicidade , HIV-1/imunologia , Divisão Celular , Linhagem Celular , Testes Imunológicos de Citotoxicidade , Produtos do Gene nef/sangue , Infecções por HIV/sangue , Infecções por HIV/imunologia , Humanos , Produtos do Gene nef do Vírus da Imunodeficiência HumanaRESUMO
We have previously shown that the carboxyl-terminal region of human immunodeficiency virus type 1 (HIV-1) Nef antigen present on the outer surface of virus-infected cells has affinity for uninfected T cells. Here, the in vitro cytotoxic potential of HIV-1 Nef on the T cell surface against CD4+ T cells was investigated in detail. Human T cells expressing Nef on the cell surface by transfection with non-infectious mutant HIV-1 proviruses were demonstrated to kill CD4+ T cells efficiently. Furthermore, it was shown that the carboxyl-terminal portion of Nef was cytotoxic for CD4+ T cells and that monoclonal antibody against the carboxyl-terminal region of Nef inhibited Nef induced-cytolysis. Thus, we concluded that Nef protein on CD4+ T cells may play an important role in the specific loss of CD4+ T lymphocytes during HIV-1 infection.