Oral vaccination of mice against rodent malaria with recombinant Lactococcus lactis expressing MSP-119

Figure 4 (A) Blood-stage parasitemia of immunized C57BL/6 mice challenged with P. yoelii 265BY parasites. Mice were orally administered with 5×10⁹ per dose of free L. lactis cells in the control group (-□-), with 5×10⁹ pL2-PSGT plasmid-harbored L. lactis cells per dose in the test group 1 (-▲-), and with 1×10⁸ cells per dose of pL2-PSGT plasmid-harbored L. lactis cells in the test group 2 (-●-). Immunization procedure is described in Materials and Methods, and each mouse was challenged with 1×10⁵ asexual blood-stage P. yoelii parasites. (B) Time course of survivals of the mice in the three groups is indicated in A.