Fig. 3

Microglia and T-cell interactions further amplify the inflammatory response to PD. The interaction of PD microglia and T cells amplifies the inflammatory response. In the presence of TGF-β in the microenvironment, IL-6 and IL-1β released from neurotoxic microglia act on naïve T cells had to induce their differentiation to Th17 cells and inhibit their differentiation to Treg cells, respectively. The chemokines CXCL9, CXCL10, CXCL11, CCL5, and CXCL16 released by neurotoxic microglia can bind to CD8⁺ T cells and CXCR3, CCR5 and CXCR6 on the surface of Th1 cells to further increase cell activation and release of inflammatory cytokines. Notably, inflammatory cytokines released from T cells can promote microglial activation and function. At the same time, microglia respond to inflammatory cytokines and increase their cellular activation by releasing cytokines and chemokines. Overall, the interaction between neurotoxic microglia and pro-inflammatory types of T cells in PD further amplifies the inflammation of the microenvironment and exacerbates neuronal damage