Figure 7.

IL-10 prevents and lessens disease severity in Igh6^−/− mice infected with B. turicatae serotypes 1 or 2. A: IL-10 prevents development of clinical disease. Fifty μg/kg/day of rIL-10 in 300 μl of PBS or PBS alone as a control were injected intraperitoneally into 5-week-old Igh6^−/− mice (n = 4/group) for 9 consecutive days starting 3 hours before inoculation of 10⁴ Bt2 spirochetes intraperitoneally. Clinical scores were obtained daily by an examiner masked to treatment and infection status until necropsy. Results are given as sum score for clinical signs of involvement of skin, eyes, joints, and for reduced activity as described in Materials and Methods. B: IL-10 reverses established clinical disease in RF borreliosis. One hundred μg/kg/day of rIL-10 in 300 μl of PBS was injected intraperitoneally on days 11 to 13 or 150 μg/kg as a single dose on day 13 into 5-week-old Igh6^−/− mice (n = 4) persistently infected with Bt1. The control group (n = 4) received 300 μl of PBS only. For each graph, the highest value on the y axis equals the maximum possible sum score per group.