FURTHER STUDIES ON IMMUNITY IN EXPERIMENTAL CRYPTOCOCCOSIS

Abstract
Following infection with 103 cells of Cryptococcus neoformans, progressive multiplication occurred in all tissues for 7 to 28 days. Thereafter, most mice gained control of the infection so that 3 to 6 months after inoculation, tissues were usually sterile or contained only small numbers of cryptococci. Survivors challenged 1 to 4 months after infection with 103 cells lived longer than controls and had an increased survival rate. Pretreatment with bacterial endotoxin also resulted in protection against cryptococcal challenge. Endotoxin-protected animals showed no ability to limit the infection until circulating antibody could be demonstrated.