Arbortristosides Modulate Murine Peritoneal Macrophages For Phagocytosis And Intracellular Killing Of Candida Albicans

Abstract

Studies indicate that arbortristoside C (50 µg/ml)-primed murine peritoneal macrophages (MuPMØs) provide high phagocytosis (85%) in a concentration-dependent manner at a target: effector ratio of 1:5, with an optimal Phagocytic Index (PI) of 8.2 at 6 hr, compared to arbortristoside A or control. Recombinant murine interferon gamma (rMuIFN-?)-primed MuPMØ, at 100 U, provided 98% phagocytosis with a PI 8.5 at 24 hr. The intracellular killing of C. albicans in arbortristoside C-primed MuPMØ was enhanced to 10% at 1 hr, and 25% at 3 hr, compared to control. The rMuIFN-?-primed MuPMØ, at 100 U, yielded 50% killing of blastospores at 3 hr, compared to 10 U of rMuIFN-? which was less detrimental (45%) in a concentration- and time-dependent manner. The intracellular residence of blastospores beyond 3 hr caused rupturing and killing of MuPMØs due to extensive germ tube formation. Transmission electron microscopic evidence further indicates arbortristoside C-primed MuPMØ activated lysosomal machinery causes fusion of phagolysosome with digested blastospores.