FIG. 3.

Comparison of the effects of antibody on the survival and growth of R. conorii in mouse endothelial cells (A) and macrophages (B). Host cells which were pretreated with normal mouse serum (open bars) contained many fewer viable rickettsiae than cells that were not pretreated with normal serum (filled bars). The quantities of viable rickettsiae that had been treated with polyclonal antibody or monoclonal anti-OmpB were reduced at 72 h after infection compared with the quantities of viable intracellular rickettsiae under the corresponding treatment conditions at 3 h after infection. In contrast, the untreated and normal serum-treated or Fab antibody-treated rickettsiae proliferated in the interval between 3 and 72 h of infection. ND, no rickettsiae detected. These results represent the average of three separate experiments.