Fig. 3
CCI injury is associated with substantial infiltration of CD45hi immune cells into the brain. A Histogram illustrating the proportion of infiltrating (CD45hi) and resident (CD45mid) immune cells as well as non-immune cells (CD45−) in the injured (ipsilateral) or non-injured (contralateral) brain hemispheres in a representative sample at 18 h post-CCI. B, B′. Total numbers and relative proportions of infiltrating CD45hi immune cells are highly increased by the injury, peak at 18 h post-CCI, and gradually decrease over time, returning to baseline by 2 months post-CCI. No effect of B cell treatment can be observed as compared to saline-treated controls. Similarly, B cell application did not change the proportion of infiltrating neutrophils C or monocytes/macrophages D, which represent the majority of the immune infiltrate at the lesion site. E, E′. Quantitative analysis of CNS-resident immune cells also showed that the total numbers and relative proportion of microglia out of the total live cells only show injury-dependent significant changes. An initial decrease in cell numbers at 18 h was followed by a significant injury-associated increase at 48–10 days post-CCI. There was no significant difference between the injured and non-injured hemispheres by 2 months post-injury. Statistical significance was determined using two-way ANOVA, followed by Tukey's multiple comparisons test. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001