FIG. 1.

Serum anti-TTFC IgG, IgA, and IgM titers elicited by recombinant lactococci or purified TT. Groups of six mice were immunized, either i.g., i.n., or by i.p. injection, with lactococci expressing TTFC (pTREX1-TTFC) or a control strain (pTREX1). For comparison, a group of mice were injected with TT in FCA. On day 35 post-initial treatment, blood samples were collected and TTFC-specific serum IgG (solid bars), IgA (striped bars), and IgM (open bars) titers were measured by ELISA. Bars, mean titers; error bars, standard deviations. Asterisks indicate values significantly different from those for unvaccinated controls (P < 0.01).