Antigenic Differences between Coxiella burnetii Cells Revealed by PostembeddingImmunoelectron Microscopy and Immunoblotting

摘要

The aim of this study was to investigate the antigenic structures of themorphologically distinct cells of the Coxiella burnetii developmental cycle. Postembedding immunoelectron microscopy with polyclonal antibodies produced in rabbits to (1) phase I cells, (2) a chloroform-methanol residue fraction of cells, (3) the cell walls (CW0 of large and small cells and small dense cells (SDC), and (4) the peptidoglycan-protein complexes of small cells and SDC labelled the continuum of morphologically distinct cells. But these antibodies did not distinguish between the antigenic structures of the various cells. Monoclonal antibodies to the phase I lipopolysaccharide labelled the CW of a majority of the smaller cells, but there was diminished reactivity to the larger cells. Although monoclonal antibodies to a 29.5-kDa outer membrane protein labelled the CW of the large mother cells, the large cells, and the small cells, a minority of the SDC with compact CW were not labelled. The endogenous spore within the mother cell was not labelled by the polyclonal or monoclonal antibodies to cellular components.