ENGINEERING OF IN-VIVO IMMUNE-RESPONSES TO DNA IMMUNIZATION VIA CODELIVERY OF COSTIMULATORY MOLECULE GENES

Nucleic acid immunization is a novel vaccination technique to induce a ntigen-specific immune responses. We have developed expression cassett es for cell surface markers CD80 and CD86, two functionally related co stimulatory molecules that play an important role in the induction of T cell-mediated immune responses, Coimmunization of these expression p lasmids, along with plasmid DNA encoding for HIV-1 antigens, did not r esult in any significant change in the humoral response; however, we o bserved a dramatic increase in cytotoxic T-lymphocyte (CTL) induction as well as T-helper cell proliferation after the coadministration of C D86 genes. In contrast, coimmunization with a CD80 expression cassette resulted in a minor, but positive increase in T-helper cell or CTL re sponses. This strategy may be of value for the generation of rationall y designed vaccines and immune therapeutics.