CELL AND VIRAL REGULATORY ELEMENTS ENHANCE THE EXPRESSION AND FUNCTION OF A HUMAN-IMMUNODEFICIENCY-VIRUS INHIBITORY GENE

Regulated expression of recombinant genes in CD4(+) cells is an import ant objective for gene therapy of AIDS, as these cells represent the p rincipal target for viral replication of human immunodeficiency virus (HIV). We report here that specific combinations of CD4 cell-specific and viral regulatory elements can enhance expression of an antiviral g ene product. Different viral regulatory elements were incorporated int o a previously reported CD4 locus control region to increase the expre ssion of reporter genes in T and monocytic cell lines, The CD4-specifi c regulatory elements were included to enhance expression in CD4 tells , and viral regulatory regions, including the cytomegalovirus immediat e-early (CMV IE) upstream enhancer, which contains the kappa B and Ap1 regulatory elements and a Tat-responsive element of the HIV type 1 lo ng terminal repeat, were used to increase gene expression and modulate its activity in response to viral infection, In transient transfectio n assays, this vector was 100- to 1,000-fold more active than the orig inal CD4 regulatory elements alone, Expression of an inhibitory form o f the Rev protein, Rev M10, was more effective than previously describ ed vectors and protected against productive viral replication in CD4() peripheral blood mononuclear cells, The combination of CD4 lineage-s pecific and viral regulatory elements will facilitate the development of more effective antiviral genetic strategies for AIDS.