Effect of early therapeutic anti-VLA-4 mAb on microglia/macrophage activation in the CNS.

<p>(A) The conversion of resting microglia/macrophages into activated microglia/macrophages is associated with disease progression. Phenotypes of resting and activated microglia/macrophages are CD45^lowCD11b⁺ and CD45^hiCD11b⁺, respectively. Expression levels of MHC class II and CD40 on the resting and activated microglia/macrophages are shown. Resting microglia/macrophages: CD40 (Mean Fluorescence Intensity (MFI): 2.4) and MHC class II (MFI: 7.33). Activated microglia/macrophages: CD40 (MFI: 4.24) and MHC class II (MFI: 40.5). The percentage ratio between activated and resting macrophages (Act./Rest. Ratio) increased with disease progression. (B) Early therapeutic anti-VLA-4 mAb treatment suppresses the activation of microglia/macrophages. Mice were sacrificed one day after the last treatment and the conversion of resting microglia/macrophages into activated microglia/macrophages was examined by measuring the percentage ratio between activated vs. resting microglia/macrophages in anti-VLA-4 mAb-treated (n = 5) compared to IgG-treated (n = 6) mice. Data represent mean +/− SEM. *; p-value <0.05.