Fig. 2.

Induction of T_H2-type immune responses downstream of TSLP. DCs in tumor microenvironments are exposed to cancer-derived factors—for example, TSLP—that skew their maturation toward T_H2-type inflammation, including their expression of OX40L. In this environment, responding T_H2 cells (CD4⁺ T cells) secreting IL-4 and IL-13 promote tumor development either directly or indirectly via macrophages. Direct effects include triggering anti-apoptotic pathways and steroid metabolism in epithelial cancer cells, as well as promoting stromal fibroblast proliferation and differentiation. Indirect effects include triggering secretion of growth (EGF) and pro-angiogenic (VEGF) factors by tumor-infiltrating macrophages that also express inducible nitric oxide synthase (iNOS) and arginase (73) and thereby blunt CD8⁺ T cell proliferation.