Codependent development and Th17-to-FoxP3+ T cell inter-conversion account for the enigmatic coexistence of IL17-producing and FoxP3+ cells in tumor-associated inflammation. In addition to Treg cells, exTh17-FoxP3+ cells present a novel subpopulation of FoxP3+ cells. Yin-yang of IL17+ and FoxP3+ cells presents an important principle for improved approaches in cancer immunotherapy.
Keywords: T cell plasticity; Th17 cells; myeloid-derived suppressor cells; regulatory T cells; sterile inflammation.