Our research has had a long-standing interest in the effect of antimicrobial antibiotics on the hosts' immune response, and we have found that many drugs from classes such as the macrolides, lincosamides, aminocyclitosis and others have profound effects on the host immune response. Using mouse models we examined drug effect on function of peritoneal-derived phagocytic cells, including neutrophils and macrophages; T cell mediated contact sensitivity; and drug effects on organ clearance of intravenously administered candidal yeasts. Our latest project has involved looking at Troleadomycin, an antibacterial antibiotic made by Pfizer U.S. Pharmaceuticals intended for gram-positive bacterial infections.