Resistance of SCID mice to Candida albicans administered intravenously or colonizing the gut: role of polymorphonuclear leukocytes and macrophages.

SCID mice, which lack functional T and B cells, and their immunocompetent counterparts were treated with a monoclonal antibody to murine granulocytes (anti-Gr-1), silica, or carrageenan to assess the role of phagocytic cells (Polymorphonuclear leukocytes and macrophages) in resistance to candidiasis. SCID mice treated with anti-Gr-1 showed enhanced susceptibility to acute systemic candidiasis, disseminated candidiasis of endogenous origin, and orogastric candidiasis. Immunocompetent CB.17 and BALB/c mice treated with anti-Gr-1 showed enhanced susceptibility to acute systemic candidiasis but not to either orogastric or disseminated candidiasis of endogenous origin. Impairment of phagocytic cell functions with silica or carrageenan also enhanced the susceptibility of SCID mice to acute systemic candidiasis. These data in SCID and CB.17 mice support clinical studies in patients that point out the important role that granulocytes play in resistance to candidiasis. The resistance of granulocyte-depleted CB.17 mice to orogastric and disseminated candidiasis of endogenous origin also demonstrates that functional T and B cells play a role in controlling candidiasis.