Enhanced clearance of Candida albicans from lung after intratracheal immunization

The comparative effect of immunization by intratracheal and intraperitoneal routes was assessed against intratracheal challenge with Candida albicans. When mice were immunized intratracheally with 5 X 10(6) cfu of viable or heat-killed C. albicans 2 weeks before challenge, they showed an enhanced resistance against intratracheal challenge with C. albicans, in spite of a decrease in phagocytosis of C. albicans in vitro by alveolar macrophages from intratracheally immunized mice. In these mice, 100% survival and an accelerated elimination of C. albicans from their lungs were observed after intratracheal challenge with C. albicans. In contrast, intratracheal immunization with same high dose of viable or heat-killed C. albicans 1 week before challenge, and intraperitoneal immunization with same high or low doses of viable or heat-killed C. albicans 1 or 2 weeks before intratracheal challenge with C. albicans, could not induce such high resistance against intratracheal challenge with same high dose of viable C. albicans. Comparing to normal and intraperitoneally immunized mice, number of C. albicans recovered from the lung 48 hr after challenge was approximately 100 fold smaller in mice immunized by intratracheal route 2 weeks before challenge. When cellular response was determined by bronchoalveolar lavage after intratracheal inoculation of C. albicans, a prominent recruitment of polymorphonuclear cells was observed 12 and 36 hr after challenge in control mice, intraperitoneally and intratracheally immunized mice. Among these groups, sustained polymorphonuclear cell recruitment by 72 hr after challenge was seen only in the group immunized by intratracheal route with high dose of heat-killed C. albicans 2 weeks before challenge.(ABSTRACT TRUNCATED AT 250 WORDS)