Figure 3. IL-4R signaling was required for Nb-primed macrophage-mediated resistance to Nb.

WT donor mice were administered LPS or Nb infective larvae (a) or WT, Il4ra^–/–, and Il10^–/– donor mice were inoculated with Nb (b-c). At day 7 after inoculation electronically sorted donor macrophages were transferred to naive recipient mice, which were inoculated with Nb 2 days later. Five days post-infection gut parasites were enumerated. At day 7 after inoculation electronically sorted macrophages from WT or Il4ra^–/– mice were seeded to 24-well plates (2 x 10⁶ cells/well) and co-cultured with 200 exsheathed L3 larvae. At day 5 after culture, larval adherence was determined (d), and larval ATP concentration (e) and percent mortality (f) assessed. (g) WT donor mice were inoculated with Nb and, at day 7 after inoculation, electronically sorted macrophages were transferred to naive recipient mice, with or without administered Arg1 inhibitor BEC, which were then infected with Nb 2 days later. A control group was similarly treated but did not receive donor macrophages. Five days later gut parasites were enumerated. Mean and SEM are shown for five mice/treatment group (a, b, c, g), and these experiments were repeated two times with similar results. (h-j) At day 7 after inoculation electronically sorted macrophages from WT were seeded to 24-well plates (2 × 10⁶ cells/well) and co-cultured with 200 exsheathed L3 larvae, with or without the presence of BEC at different concentrations (0.1-5 mM). At day 5 after culture, larval adherence was determined (h), and larval ATP concentration (i) and percent mortality (j) were assessed. Mean and SEM of triplicate samples (d-f, h-j) are shown for pools of 5 mice/treatment group. This experiment was repeated three times with similar results. *p<0.05, **p<0.01.