New types of T cells seem to pop up in the scientific literature with increasing frequency. Just this June, for instance, University of Melbourne immunologist Angela Pizzolla and her colleagues described a type of tissue-resident memory T (Trm) cell in the nose that, unlike other Trm cells, can develop from “killer T cells” without antigen exposure or growth-factor stimulation. Trm cells are just one of the subtypes (or subtypes of subtypes) in the growing list of T-cell varieties that scientists have discovered.
As researchers continue to probe the immune system in ever-greater detail, they’re learning that this group of cells, once envisioned as a homogeneous group, actually contains many subgroups of cells with distinct characteristics and functions.
“That’s an ever-expanding list,” University of Colorado immunologist Ross Kedl tells The Scientist, when asked to name and define all the T-cell types he could think of. “Subsetting of T cells, both naive ...
