Protection against <i>L. major</i> infection correlates with <i>Leishmania</i>-specific T_H1 response in immunized animals.

<p>Mice were immunized three times subcutaneously with PBS or different strains of <i>L. lactis</i> and challenged with <i>L. major</i>. Mice were sacrificed eight days (A, B), or ten weeks (C–G) after challenge (pm: <i>post mortem</i>). Lymph node cells (A–E), or splenocytes (F, G) were restimulated with SLA <i>ex vivo</i>. IFN-γ, IL-10, and IL-2 secretion by restimulated draining lymph node cells and splenocytes were determined by ELISA. Mean and SEM of four to five mice per group are shown. * <i>P</i><0.05; ** <i>P</i><0.01 by unpaired T-test to PBS and <i>L. lactis</i>/vector. ^▴<i>P</i><0.05 by unpaired T-test to PBS. Data shown are representative of two independent experiments with similar results.