FIG. 4.

Vaccination efficacy of Rpf-like proteins. Mycobacterial multiplication in lungs (A) and spleens (B) at week 3 postinfection, and survival rates (C) were estimated for groups of B6 mice vaccinated with Rpf (group 1), RpfE (group 2), or PBS (group 3, control) in IFA and challenged intravenously with 10⁶ M. tuberculosis H37Rv CFU (see Materials and Methods). (C) For the mortality experiment whose results are shown, mean survival times ± standard errors of the means were 64.3 ± 6.9 (10 mice), 52.2 ± 6.3 (11 mice), and 24.7 ± 1.0 (7 repetitions) for groups 1, 2, and 3, respectively. In each experiment, 5 mice per group were used to assess mean numbers of CFU ± SDs in organs, and 7 to 12 mice per group were used to assess mortality. Results of one out of two similar experiments are depicted; the protective effect of the Rpf protein in terms of mortality was estimated with consistent results in three independent experiments.