T helper cell
The induction of anti-inflammatory cytokines (IL-10 and IL-4) and downregulating pro-inflammatory cytokines (IFN-γ) pushes a T helper cell away from T-helper 1 (Th1) to T-helper 2 (Th2). During vascular infection, Th1 is the predominant T cells population and expresses interferon IFN-γ, tumor necrosis factor-α, and other pro-inflammatory cytokines, leading to vessel tissue damage In contrast, Th2 cells secrete IL-4 and IL-10 and downregulate IFN-γ. This dampens the inflammatory response by inhibiting pro-inflammatory gene expression. Additionally, macrophages receiving the IL-19 signal are polarized from M1 (pro-inflammatory) to M2 (anti-inflammatory).