Figure 5.

IL-6 is essential for the clearance of the parasite in Mdr2^−/− and is sufficient to abrogate parasite development in WT mice. (A) Quantification of IL-6 in total liver mRNA by RT-qPCR in isolated primary hepatocytes and in sorted bone marrow neutrophils of 6-week-old female WT FVB and Mdr2^−/− (FVB) mice naive and infected with 10⁴ PbANKA SPZ (Mann–Whitney test; *p < 0.05; **p < 0.01; ***p < 0.001). (B) Parasitemia of infected 6-week-old female WT FVB, C57BL/6, Mdr2^−/− (FVB), Mdr2^−/− (C57BL/6) and Mdr2^−/−IL-6^−/− (C57BL/6) mice inoculated with 10⁴ PbANKA SPZ (n = 6 per group) were recorded over time. To highlight the subtle differences in parasitemia between different groups of mice, the insert represents the parasitemia between days 4 and 7 p.i. expressed in log scale. The asterisks indicate that significant differences exist between Mdr2^−/−IL-6^−/− (C57BL/6) and Mdr2^−/− (C57BL/6) groups using the Mann–Whitney test (*p < 0.05). (C, D) Parasitemia and survival of 6-week-old female WT FVB mice (n = 6 per group) treated with several doses (1, 5, and 10 μg/mouse) of murine recombinant IL-6 (rmIL-6) and infected with 10⁴ PbANKA SPZ. Control mice were injected with PBS. (D) Survival rate was recorded over time (Kaplan–Meier survival plot, Mantel–Cox test **p < 0.0061, ***p = 0.001). Results are from two independent experiments.