Differentiation and function of a novel cytotoxic T-cell subset: follicular cytotoxic T cells

Cytotoxic CD8 T (TC) cells constitute the major immune cell type that is responsible for eliminating infected or cancerous cells. TC cells differentiate into specialised subsets that localise to specific tissues and organs to perform their cell killing functions. Very recently, my group discovered a novel subset of TC cells, termed follicular cytotoxic T cells (TFC cells), for their location with B cell follicles. For the first time, we found that TFC cells express a molecule, CXCR5 that enables them to migrate to B cell follicles and kill infected follicular helper T (TFH) cells and B cells. The discovery of TFC cells has exciting and far-reaching implications for the development of strategies to control infections that target B cells and TFH cells, such as in HIV infection, and to treat B cell cancers.