FIG. 7.

Comparison of cytokine concentrations in antigen-stimulated splenocyte cultures and sera from the intradermally and intraperitoneally infected mice on day 7 postinfection. Animals were sacrificed on day 7 postinfection, and spleens and sera were collected. Splenocyte cultures (left panels) were stimulated ex vivo with IOE antigen in the presence of syngeneic naïve splenocytes, and supernatant was collected after 48 h. IFN-γ (P < 0.01) and TNF-α (P < 0.05) concentrations in splenocyte culture supernatants 48 h post-IOE antigen stimulation were significantly higher in the intradermally inoculated animals (top and middle panels, respectively). In contrast, the systemic serum levels of IFN-γ (P < 0.05) and TNF-α (P < 0.05) were significantly higher in the intraperitoneally infected animals (top and middle panels, respectively). The concentration of IL-10 (P < 0.01) was significantly higher in the serum of intraperitoneally infected animals (bottom panels), but the difference in IL-10 produced by the cultured splenocytes was not significant between the two groups. Mice infected intradermally with IOE had significantly lower levels of all three cytokines in the serum (right panels) than the intraperitoneally inoculated mice (all panels). The syngeneic splenocytes (APCs only) did not produce significant concentrations of cytokines after stimulation with IOE antigen. Data are expressed as means plus standard errors, three mice per group were used in the analysis, and similar results were obtained from three independent experiments.