3.1. HMGB1 A Box inhibits macrophage infiltration in SN.
In previous studies, we detected that T cell infiltration in SN could be significantly inhibited by HMGB1 A Box, and in vitro experiments confirmed that midbrain microglia promoted Th17 differentiation. However, the proportion of microglia promoting Th17 differentiationin vitro was significantly lower than that of MPTP model mice. Therefore, we assume that peripheral antigen-presenting cells may also contribute to Th17 differentiation in SN. In this study, we detected CD45+F4/80+ macrophages and CD45+CD11c+ DCs in the SN of MPTP mice, and found that macrophages were outside the blood vessels or lymphatic vessels marked by CD31-positive endothelial cells, this indicates that macrophages are infiltrating the parenchyma of the SN, and HMGB1 A Box significantly inhibited this process (Fig. 1A). However, although MPTP also induced a certain increase in CD45+CD11c+ DCs, they were localized inside the blood vessels rather than the parenchyma (Fig. 1B).