Abstract
A humoral and cellular response was detected in C57BL mice 14-21 days after experimental infection with Encephalitozoon cuniculi. In athymic (nu/nu) mice a severely limited cellular response and no antibodies were detected, but masses of spores were found in the liver and other viscera. These spores were probably responsible for the death of the nude mice. Antibodies in C57BL mice remained at high levels for at least 17 months after infection,