NF-κB activation and HIV-1 induced apoptosis

HIV infection leads to the progressive loss of CD4(+) T cells and the near complete destruction of the immune system in the majority of infected individuals. High levels of viral gene expression and replication result in part from the activation of NF-kappa B transcription factors, which in addition to orchestrating the host inflammatory response also activate the HIV-1 long terminal repeat. NF-kappa B induces the expression of numerous cytokine, chemokine, growth factor and immunoregulatory genes, many of which promote HIV-1 replication. Thus, NF-kappa B activation represents a double edged sword in HIV-1 infected cells, since stimuli that induce an NF-kappa B mediated immune response will also lead to enhanced HIV-I transcription. NF-kappa B has also been implicated in apoptotic signaling, protecting cells from programmed cell death under most circumstances and accelerating apoptosis in others. Therefore, activation of NF-kappa B can impact upon HIV-I replication and pathogenesis at many levels, making the relationship between HIV-1 expression and NF-kappa B activation multi-faceted. This review will attempt to analyse the many faces and functions of NF-kappa B in the HIV-I lifecycle. (C) 2000 Elsevier Science Ltd. All rights reserved.