Figure 2. Induction of cytokine in spleen after L. casei administration.

Heat-killed preparations of L. casei ATCC 27139 or isogenic Tn5 insertion mutants (800 µg) were injected i.v. into BALB/c mice. Six mice per group were sacrificed 8 h after injection, and IL-12 (A), TNF-α (B), and IFN-γ (C) proteins were measured from spleen homogenates by ELISA. Columns: white, saline; black, L. casei wild-type; slashed, L. casei J1 phage-resistant mutant; gray, L. casei asnH mutant complemented with the cloned asnH. Results are depicted as the means ± standard deviations (SD). Statistical significance was calculated using the Student's t-test. Significant differences indicated between the control and treated groups. ***, p<0.001.