Liposome mediated antigen delivery leads to induction of CD8(+) T lymphocyte and antibody responses against the V3 loop region of HIV gp120

There is general consensus that the use of whole viruses for the developmen t of a vaccine against human immunodeficiency virus (HIV) would be unsafe. While currently available nonreplicating vaccines, composed of synthetic pe ptides or purified subunit antigens, can help in tricking the humoral immun e responses, they fail to incite the other major arm of the immune defense system, i.e., cell mediated immunity (CMI). To overcome the difficulty in g enerating CMI, we have entrapped an immunodominant HIV envelope glycoprotei n peptide in liposomes made up of fusogenic lipids isolated from Escherichi a coli. We have established the role of fusogenic liposomes in stimulation of HIV-specific CDS' cytotoxic T lymphocytes. Interestingly, the same lipos omes elicit strong HIV-specific antibody production as well. Moreover, unto ward manifestations such as skin damage or antibody production against lipi d components were also not observed. Thus, E. coli lipid liposomes (escheri osomes) could prove to be a potent candidate vaccine, capable of eliciting both humoral and cell mediated immune responses against HIV infection. (C) 2001 Academic Press.