FIG 9.

Absence of CD4 causes abnormal bulbar (brainstem) vacuolation and neuronal loss in RSA59-infected brains at day 30 p.i. (a) Serial sagittal sections of brains from CD4^+/+ and CD4^−/− mice were analyzed for inflammation at day 30 p.i. by H&E staining and immunohistochemically by CD45 and CD11b staining. The boxed areas are shown at higher magnification below the corresponding brain midsagittal sections. The arrows mark infiltrating inflammatory cells in the H&E-stained sections and immunoreactive leukocytes and microglia/macrophages in the CD45 and CD11b immunohistochemically stained sections. (b and c) Quantification of inflammation was performed for CD45 (b) and CD11b (c) staining. The level of significance was calculated by unpaired Student's t test and Welch correction. ns, not significant; ****, (P < 0.0001). The error bars represent SEM. The data represent results from 4 or 5 independent biological experiments.