Prostaglandin E2 enhances and gamma interferon inhibits germ tube formation in Candida albicans.

Prostaglandin E2 (PGE2), an immunosuppressive monokine that increases intracellular cyclic AMP (cAMP) levels, stimulated Candida albicans germ tube formation. Dibutyryl cAMP (dB-cAMP) and isoproterenol, other compounds that increase cAMP levels, also stimulated germination. Gamma interferon (IFN-gamma), a product of cellular immune system activation, inhibited Candida germ tube formation, even in the presence of PGE2, dB-cAMP, and isoproterenol. Thus, PGE2 and IFN-gamma as well as having opposing roles in the suppression or activation of cell-mediated immunity, are also antagonists for the yeast-to-hyphal transition of C. albicans.