Influence of indinavir on virulence and growth of Cryptococcus neoformans

Indinavir selectively inhibited production of some virulence factors of Cryptococcus neoformans, such as urease and protease, but not melanin and phospholipase; moreover, it interfered with capsule formation. These effects led to increased susceptibility of C. neoformans to intracellular killing by natural effector cells. Prolonged incubation with indinavir resulted in inhibition of fungal growth. Indinavir can attenuate the virulence of the fungus, thus augmenting its susceptibility to the antimicrobial activity of natural effector cells. The reduction in cryptococcal infections in human immunodeficiency virus-positive patients might also be related to the antifungal activity of highly active antiretroviral therapy.