Surface Labeling of Pneumocystis carinii from in Vitro Culture

Pneumocystis carinii is an opportunistic pathogen of man, carried as a commensal in healthy subjects. It frequently causes a fatal pneumonia in the immunosupprcssed host. It is a major complication of HIV-1 infection in man (AIDS). Using surface radioiodination of rat-denved P. carinii trophozoites obtained from in vitro culture, a major surface glycoprotein (gp120) has been identified. The glycoprotein exhibits adherent behavior similar to that of the intact organism. Purification of gp120 by conventional methods was unsuccessful as the glycoprotein irreversibly bound lo numerous column matrices. A combination of gel chromatography and hydroxyapatile chromatography in sodium dodecylsulfaie v. as utilized to purify the glycoprotein. Some preliminary characterization of the glycoprotein is presented.