GENES ENCODING ANTIGENIC SURFACE GLYCOPROTEINS IN PNEUMOCYSTIS FROM HUMANS

Pneumocystis is a eukaryotic microbe that causes pneumocystosis, an AI DS-associated pneumonia. Pneumocystosis also occurs in many other mamm alian species, and animal-derived organisms have been extensively util ized in Pneumocystis research. Pneumocystis from diverse hosts contain a large glycoprotein (gpA/MSG) on the surface. Antibodies elicited ag ainst gpA/MSG of Pneumocystis from humans sometimes cross-react with e pitopes on proteins of similar size from Pneumocystis from other host species. Here we report the isolation and partial sequence of two pres umptive gpA/MSG genes from human-derived Pneumocystis. The cloned huma n-derived Pneumocystis gpA/MSG genes and predicted peptides were diffe rent from those previously isolated from Pneumocystis from rats and fe rrets. The genome of human-derived Pneumocystis contained multiple cop ies of sequences related to the two cloned gpA/MSG genes.