Tc17 cells are capable of mediating immunity to vaccinia virus by acquisition of a cytotoxic phenotype.

CD8 T cells can acquire cytokine-secreting phenotypes paralleling cytokine production from Th cells. IL-17-secreting CD8 T cells, termed Tc17 cells, were shown to promote inflammation and mediate immunity to influenza. However, most reports observed a lack of cytotoxic activity by Tc17 cells.

The transcription factor PU.1 is required for the development of IL-9-producing T cells and allergic inflammation.

CD4(+) helper T cells acquire effector phenotypes that promote specialized inflammatory responses. We show that the ETS-family transcription factor PU.1 was required for the development of an interleukin 9 (IL-9)-secreting subset of helper T cells.