RESUMO
The major surface glycoprotein (Msg) of Pneumocystis jiroveci (P. jiroveci) is important in the immunopathogenesis of Pneumocystis pneumonia (PcP), but is difficult to study in humans. We generated 3 overlapping recombinant Msg fragments (MsgA, MsgB and MsgC), and analyzed their reactivity with serum samples from 95 healthy blood donors and 94 human immunodeficiency virus (HIV)-infected persons. Reactivity to the Msg fragments varied with HIV infection and prior episodes of PcP but not with geographic origin. Recognition of MsgA was lower-and recognition of MsgB was significantly lower-in HIV(+) serum compared with donor serum. Serum samples from HIV-positive patients with prior PcP recognized MsgC more frequently than did serum samples from those without PcP. None of the serum samples drawn from 9 patients before they had developed PcP recognized MsgC. These data suggest that these novel recombinant proteins are useful for the analysis of antibody responses to Msg.
