Examination of spleens and DTH response after infection with Lm and the recombinant L.inn::vgc strain.
A. Morphological examination of spleens from mice inoculated i.v. with the wild type Lm and the recombinant L.inn::vgc strain. Spleens of mice infected i.v. as mentioned in Fig. 1 were isolated on day 3 after infection. Shown is a spleen from mice infected with the wild type Lm, the wild type L.inn and its recombinant mutant strain L.inn::vgc. Infiltration of monocytic cells and granulomatous lesions are only detectable in the spleens isolated from mice infected with the wild type Lm. B. Spleen sections were stained with HE and examined. Granulomas with massive leukocyte aggregates can only be detected in spleens of mice infected with Lm. C. DTH response to listerial antigen 9 days after primary infection. Mice were infected with 103 CFU of Lm, 107 CFU of L.inn, or 107 CFU of L.inn::vgc strain. 9 days after infection, DTH was triggered through injection of soluble somatic listerial antigen. Twenty-four hours later, the specific skin response was determined. The mean value ± S.E. of five animals of a representative experiment is shown.*P<0.05 (EGD-e vs. L.inn::vgc strain).
