FIG 2.

Transfer of immune sera from Pyfabb/f⁻-immunized mice induces functional antibodies that reduce liver-stage parasite burden. (A) In vivo luminescence imaging of BALB/c and C57BL/6 mice that received 300 μl serum from congenic mice immunized with Pyfabb/f⁻ (or from mock-immunized control mice) 24 h prior to challenge by the bite of 15 to 20 mosquitoes infected with PyGFP-luc sporozoites. Liver-stage parasite burden was measured by bioluminescent imaging 42 to 44 h after challenge. The scale indicates radiance expressed as photons per second per centimeter squared per steradian (p/s/cm²/sr). Min, minimum; Max, maximum. (B) Quantification of the luciferase signal (measured as total flux per second). Data shown were obtained from 3 experiments with BALB/c (n = 9) and 2 experiments with C57BL/6 (n = 6) mice. The horizontal bars correspond to the median, and the error bars show the interquartile range. Significant differences between groups were calculated using the Mann-Whitney test; *** = P < 0.001; n.s. = nonsignificant.