Memory T cell (T_M cell)

Memory T cell is a long-lived, antigen-experienced subset of T lymphocytes that carries immunological memory after an initial infection or antigen exposure and enables an enhanced, rapid response upon re-encounter with the same antigen. Memory T cells are central to the adaptive immune system, contributing to persistent protective immunity against pathogens and tumors. They exist in several functional subtypes: central memory (T_CM, residing in lymphoid organs), effector memory (T_EM, circulating and cytotoxic), tissue-resident memory (T_RM, residing in barrier tissues), and stem-cell-like memory (T_SCM, with self-renewal capacity and the ability to generate other memory subsets). Their rapid recall responses form the basis for durable vaccine protection, but memory T cells also play critical roles in transplantation, cancer immunotherapy, autoimmunity, and chronic infectious disease. Memory T cells are defined molecularly by expression of surface markers (CD45RO+, CD44^hi^, CCR7, CD62L, among others), and functionally by their ability to persist long-term, proliferate, and mount efficient effector responses even in the absence of persistent antigen stimulation.

Other names

Memory CD4 T cellMemory CD8 T cellCentral memory T cell (T_CM)Effector memory T cell (T_EM)Tissue-resident memory T cell (T_RM)Stem-cell-like memory T cell (T_SCM)Polyfunctional memory T cellAntigen-experienced T cell

Activation and expansion, Suppression/blocking proliferation, Modulation of cytokine secretion, Promotion of apoptosis or exhaustion, Alteration of homing/recirculation, Enhancement of antigen recall responses, Checkpoint inhibition (restores memory T cell function)