Issues

Immune evasion of HIV-infected cells mediated by the viral nef gene. Nef is expressed early in the viral life cycle and targeted to the plasma membrane. Through the interaction with cellular factors, two mechanisms of immune evasion are triggered. First, Nef activates TCR-zeta which leads to the upregulation of Fas ligand (FasL). FasL induces apoptosis in attacking, Fas-positive cytotoxic T lymphocytes (CTLs). Second, Nef causes downregulation of MHC I and CD4, reducing immune recognition of and by the infected cells. See related article in this issue by Xu et al., pp. 1489–1496.