Memory T Cells

Only long-lived and relatively quiescent antigen-experienced T cells are considered memory T cells.
Comet & Gerlach 2025 Trends in Immunology 46(7): 505

CD45RO is often called a memory marker. However, its expression is due to T cell receptor stimulation. As a result, many short-lived, activated T cells also express CD45RO.
Miller et al. 2008 Immunity 28: 710-722

Memory T cells are a type of long-lived T lymphocytes that are formed after the initial exposure to a specific antigen. They play a crucial role in the adaptive immune system by providing rapid and enhanced immune responses upon subsequent encounters with the same antigen.

Once primed, effector T helper cells produce lineage-defining cytokines to combat the original pathogen. A subset of these cells persists as memory or effector-memory populations. These memory T cells play a dual role in host protection by:

1. Responding rapidly to reinfection.


2. Directly instructing myeloid cells to express licensing cytokines.

McDaniel et al. 2021 Curr Opin Immunol 73: 25-33

see also:
Acquired Immune System / Adaptive Immune System