Fig 1.

Cd22^−/− mice are more susceptible to WNV infection than WT mice. WT, Cd22^−/−, and μMT mice were inoculated s.c. with 10³ PFU of WNV-TX and monitored daily for survival (A) and morbidity (B and C). (A) Cd22^−/− mice had a mean survival time (MST) of 9.5 days, and μMT mice had an MST of 10 days. Statistics were performed using a log rank test for significance, comparing the percentage of surviving WT mice to that of Cd22^−/− mice (P < 0.0001). Numbers in parentheses indicate numbers of mice that succumbed out of total mice infected. (B and C) Clinical scores for mice inoculated s.c. with 10³ PFU of WNV-TX (infected) are represented. Scoring is as follows: 1, ruffled fur, lethargy, hunched posture, no paresis; 2, very mild to mild paresis; 3, frank paresis involving at least one hind limb and/or conjunctivitis or mild paresis in two hind limbs; 4, severe paresis while still retaining feeling and possibly limbic; 5, true paralysis; and 6, moribund. Error bars represent variance of clinical scores. Statistics were performed using Student's t test to compare means of clinical scores at individual time points. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. n.s., not significant. Data show one representative of three independent experiments with four mice per group.