ABSTRACT
The mechanisms of host defense against Cryptococcus neofon,Ulns have been extensively studied since the I950s. There is consensus in the field that cellular immunity is the primary host defense mechanism against C. neoformans infection (reviewed in [I]). In contrast, it has been difficult to unequivocally establish a role for humoral immunity against C. neoformans. This is perplexing given that this pathogen has a polysaccharide capsule and antibody responses are usually required for protection against encapsulated pathogens. The importance of humoral immunity to a pathogen is generally established by one or more of the following criteria:
I. Demonstrating that passive transfer of immune sera to a naive host protects against infectious challenge.
