Only the MOSPC-like domains are opsonic targets.
A, percentages of rabbit peritoneal macrophages containing internalized treponemes. Results shown are means ± S.E. (error bars) for three independent experiments. B, representative micrographs. Each image is a composite of bright field images, nuclei stained with DAPI, and FITC-labeled T. pallidum. Arrowheads, degraded treponemes inside macrophages. C, percentages of treponemes recovered following a 4-h incubation of rabbit peritoneal macrophages and treponemes with the indicated sera. Results shown are means ± S.E. for three independent experiments. p values of <0.05 (Student's t test) were considered significant.