Passive Immunization Against Cryptococcus neoformans.

Abstract

1) Mice were capable of being protected against a number of isolates of C. neoformans by passive immunization with antiserum. This protection was limited to the immunization period and was type-specific. 2) In vivo and in vitro phagocytosis of Cryptococcus cells has been demonstrated. When large and small capsule variants were studied separately, the former were practically resistant and the latter relatively susceptible to ingestion by mouse PMN. 3) The probable mechanism for the protection achieved has been discussed and a possible use for antiserum has been proposed.