CCL28 promotes locomotor recovery after SCI through recruiting Treg cells. (A, B) Mice were pre-injected with Ctrl Ab or anti-CCL28 into the intraspinal cord for 12 hrs, and then subjected to sham or SCI surgery. The injection of Ctrl Ab or anti-CCL28 was repeated at 14 days after injury. The locomotion recovery was monitored using the BMS open-field test to determine locomotor capabilities (A) and the percentage of Treg cells at 28 days after injury was assessed by FACS analysis (n=8). Data are mean ± SEM. Data were analyzed by repeated measures analysis of variance (ANOVA). ** P<0.01 represents the comparison between SCI + Ctrl Ab group and SCI + anti-CCL28 group. (C) Mice were pre-injected with Ctrl Ab, anti-CCR10, anti-CD25, rMCCL28 or 1% mouse control serum as indicated into the intraspinal cord for 12 hrs, and then subjected to sham or SCI surgery. The injection of Ctrl Ab, anti-CCR10, anti-CD25, rMCCL28 or 1% mouse control serum was repeated at 14 days after injury. The locomotion recovery was monitored (n=8). Data are mean ± SEM. Data were analyzed by repeated measures analysis of variance (ANOVA). ** P<0.01 represents the comparison between SCI + Ctrl serum group and SCI + rMCCL28. # P<0.01 represents the comparison between SCI + rMCCL28 + Ctrl Ab group and SCI + rMCCL28 + anti-CCR10 group. & P<0.01 represents the comparison between SCI + rMCCL28 + Ctrl Ab group and SCI + rMCCL28 + anti-CD25. (D) The percentage of CD4+CD25+FOXP3+ Treg cells in the spinal cord from SCI + rMCCL28 + Ctrl Ab group and SCI + rMCCL28 + anti-CD25 group was determined (n=8). Data are mean ± SD. The statistical analysis was performed using Student’s t-test. **, P<0.01.