FIG. 1.

RRV-induced disease is less severe in C3^−/− mice. Twenty-four-day-old C57BL/6J wild-type (WT) or C3^−/− mice were inoculated with 10³ PFU of RRV by injection in the left rear footpad. Mock-infected mice were injected with diluent alone. (A) Mice were scored for the development of hind-limb dysfunction and disease based on the following scale: 0, no disease signs; 1, ruffled fur; 2, very mild hind-limb weakness; 3, mild hind-limb weakness; 4, moderate hind-limb weakness and dragging of hind limbs; 5, severe hind-limb weakness and/or dragging; 6, complete loss of hind limb function; 7, moribund; and 8, death. Each datum point represents the arithmetic mean ± the SD of 4 (mock), 6 (wild type + RRV), or 11 (C3^−/− + RRV) mice and are representative of three independent experiments. *, P < 0.001. (B) Mice were monitored for weight gain or loss at 24-h intervals. Each datum point represents the arithmetic mean ± the standard deviation of 4 (mock), 6 (wild type + RRV), or 11 (C3^−/− + RRV) mice and are representative of three independent experiments.