Lack of negative influence on the cellular transcription factors NF-κB and AP-1 by the Nef protein of human immunodeficiency virus type 1

In order to investigate the molecular mechanism of the reported negative effect of the Nef protein of human immunodeficiency virus type 1 (HIV-1) on the cellular transcription factors NF-κB and AP-1, human T cell lines (both populations and subclones) expressing the nef gene from HIV-1 clone pNL432 were constructed. Functional expression of the nef gene was confirmed by downregulation of CD4 and MHC class I proteins on the cell surface as measured by fluorescence-activated cell sorter analysis. However, contrary to previous reports, no significant difference was found in the induced level of NF-κB and AP-1 activity between nef⁺ and nef^- cell lines upon stimulation by phorbol 12-myristate 13-acetate and phytohaemagglutinin, as measured by transient transfection and eledromobility shift assays. These data indicate that the Nef protein does not have a negative effect on the induction of NF-κB and AP-1.