MONOCLONAL-ANTIBODY TO A MAJOR OUTER-MEMBRANE PROTEIN OF FELINE CHLAMYDIA-PSITTACI - ANTIBODY SPECIFICITY AND ANTIIDIOTYPE ANTIBODY-PRODUCTION

A murine monoclonal antibody, F1-8, was developed against the purified major outer membrane protein (MOMP) of Chlamydia psittaci feline pneumonitis (FPn). F1-8 showed a serotype-specific activity against intact Fpn elementary bodies in a micro-immunofluorescence assay. In immunoblot, F1-8 reacted only with the Fpn MOMP but did not react with the MOMPs from other strains of C. psittaci and C. trachomatis. F1-8 neutralized Fpn infectivity in L929 cell culture in a dose-dependent and complement independent fashion. These results suggested that the monoclonal antibody (mAb) binds with an epitope on the MOMP region that is exposed at the cell surface and plays an important role in FPn infection. Polyclonal anti-idiotype (anti-Id) antibodies to mAb F1-8 were elicited by F1-8 coupled to keyhole limpet hemocyanin. These anti-Id antibodies inhibited F1-8 binding to FPn MOMP.