Interferon-gamma in starch microparticles: nitric oxide-generating activity in vitro and antileishmanial effect in mice.

Recombinant mouse interferon-gamma (mu IFN-gamma) was covalently coupled to polyacryl starch microparticles, a lysosomotropic drug carrier. The microparticle-bound mu IFN-gamma was found to activate cultured macrophages for nitrite production and had an anti-leishmanial effect in mice. Low doses of mu IFN-gamma, which had no effect in the free form, when bound to microparticles significantly reduced the load of Leishmania donovani in infected mice. Further, inducement of nitrite production in cultured macrophages by microparticle-bound mu IFN-gamma required intact cell membrane receptors.