IMMUNOELECTRON MICROSCOPIC LOCALIZATION OF THE OMP90 FAMILY ON THE OUTER-MEMBRANE SURFACE OF CHLAMYDIA-PSITTACI

The putative outer membrane location of the OMP90 (formerly POMP) fami ly from the ovine abortion strain of Chlamydia psittaci was investigat ed by immunoelectron microscopy. Using a. non-embedding technique, ant igens were shown to be localised on the outer membrane surface of both elementary and reticulate bodies, the infectious and non-infectious f orms of Chlamydiae respectively. Antibodies affinity-purified against the expressed amino- and carboxy-terminal halves of one of the Family members, OMP90A, demonstrated that the amino half is surface-exposed w hile the carboxyl half is most probably localised internally. Surface localisation on elementary bod:es indicates the importance of these pr oteins as protective antigen candidates. (C) 1998 Federation of Europe an Microbiological Societies. Published by Elsevier Science B.V. All r ights reserved.