Microparticle Adsorption Augments Efficacy.(Brief Article)

2001 OCT 3 - (NewsRx.com & NewsRx.net) --

by Michael Greer, senior medical writer - DNA-based HIV vaccines are more effective when delivered on the surface of charged particles, according to researchers in the United States.

Derek O'Hagen and colleagues Chiron Corporation in Emeryville, California, and Panacos Pharmaceuticals in Gaithersburg, Maryland, evaluated the "effectiveness of cationic microparticles with adsorbed DNA at inducing immune responses...in mice, guinea pigs, and rhesus macaques."

In these animal models, microparticle adsorption significantly enhanced the immune response to HIV proteins, O'Hagen and team reported.

The researchers adsorbed HIV Env and Gag onto the surface of poly(lactide-coglycolide) (PLG) microparticles. Antibody responses to Env were significantly faster and more robust when triggered by the adsorbed protein instead of free Env DNA, they said. Immune reactions to adsorbed Gag were even more potent, with antibody and cytotoxic T-cell responses augmented up to 1000(times).

A combination vaccine coding for Env and Gag was also found to be more effective when delivered on the surface of PLG particles, inducing faster, more powerful, and longer-lasting antibody responses to both proteins. A deficit in Env-specific responses seen in the non-adsorbed version of this combination vaccine was apparently fixed by PLG delivery, ...