Defining the Molecular Hallmarks of T-Cell Memory

The pool of memory CD8 T cells is comprised of highly specialized subpopulations of cells with both shared and distinct functions. The ongoing study of T-cell memory is focused on how these different subpopulations arise, how the cells are maintained over the life of the host, and how the cells protect a host against reinfection. As a field we have used the convenience of a narrow range of surface markers to define and study these memory T-cell subsets. However, as we learn more about these cells, it is becoming clear that these broad definitions are insufficient to capture the complexity of the CD8 memory T-cell pool, and an updated definition of these cellular states are needed. Here, we discuss data that have recently arisen that highlight the difficulty in using surface markers to functionally characterize CD8 T-cell populations, and the possibility of using the epigenetic state of cells to more clearly define the functional capacity of CD8 memory T-cell subsets.

Automated summary

The pool of memory CD8 T cells consists of highly specialized subpopulations of cells with both shared and distinct functions. Current research on T-cell memory focuses on how these subpopulations arise, how the cells are maintained over the host's lifespan, and how they protect the host against reinfection. However, the use of surface markers to define and study these memory T-cell subsets is proving to be inadequate, and there is a need for an updated definition using the epigenetic state of cells to better characterize the functional capacity of CD8 memory T-cell subsets.