FIG. 1.

Effect of IL-4 and IL-4Rα ablation on ankle swelling in B. burgdorferi-infected BALB/cJ mice. Mice were infected with 2,000 B. burgdorferi cells, and joints were measured at 4 weeks postinfection as described in Materials and Methods. Open circles, values for joints with the greatest swelling from each mouse; black bars, average values for the group. The number of mice in each group is represented below the strain name. Results are combined from four individual experiments. The difference in joint swelling between infected mice on the BALB/cJ background and C3H mice was statistically significant (P < 0.001). No statistical difference was seen between mice on the BALB/cJ background.