Mucosal immunization with HIV-1 gag DNA on cationic microparticles prolongs gene expression and enhances local and systemic immunity

There is an urgent need to develop vaccines against transmission of HIV thr ough the vaginal and rectal mucosa. In the present study we tested the abil ity of DNA encoding HIV-1 gag adsorbed onto the surface of cationic polylac tide co-glycolide microparticles (PLG-DNA) to induce local and systemic gag -specific immunity following mucosal delivery. We found gag-specific cell- and antibody-mediated responses in local as well as systemic lymphoid tissu es following intranasal (IN) immunizations with PLG-DNA but not with naked DNA. IN immunizations with PLG-DNA, but not naked DNA. induced prolonged ex pression of gag protein in local and systemic lymphoid tissues. These data have important implications for DNA vaccine development. (C) 2001 Elsevier Science Ltd. All rights reserved.