Protective efficacy of mycobacterial 71 kilodalton cell wall associated protein using poly (DL-lactide-co-glycolide) microparticles as carrier vehicles.

A 71 kDa cell wall associated protein ofM.tuberculosis H(37)Ra, on encapsulation in biodegradable microparticles composed of poly-DL-lactide-co-glycolide (DL-PLG) exhibited higher level of T-cell stimulation and cytokine release as compared to 71 kDa-FIA in mice as evaluated till sixteenth week post immunization (p.im.). Further, the protection imparted by immunization with 71 kDa-PLG microparticles (71 kDa-PLG-MPs) was significantly higher (p<0.5) than the 71 kDa-FIA (70%) and BCG (65%) immunized group on the basis of survival rates, when challenged at sixteenth week p.im. The protective effect was consistent with the decreased bacterial load in the infected organs of 71 kDa-PLG primed group as compared to 71 kDa-FIA and BCG immunized groups.