Figure 7

Focal inflammatory reaction appeared in the DRG and the roots of pre-symptomatic L31/CD4 ^-/- mice, preceding the disease onset. While there were only few resident macrophages and no CD8⁺ T cells in the DRG and the roots of wild type mice (A), both types of immune cells were found in these two organs in pre-symptomatic L31/CD4^-/- mice (B). Some mice showed a slightest degree of infiltration, presumably the earliest pathologic changes (B-upper panels), some had significant amount of both Iba1⁺ macrophages and CD8⁺ T cells with increased B7.2 expression (B-bottom panels) suggesting the status close to the disease onset (B). In symptomatic L31/CD4^-/- mice, the DRG and the roots were fulfilled with infiltrated Iba1⁺ macrophages and CD8⁺ T cells. Both expressed high levels of B7.2 (C). Scale bar: 100 μm.