mature alpha-beta T cell effector memory CD45RA-positive, alpha-beta T cell, terminally differentiated 2022-02-01T13:04:46Z effector memory RA T cell Effector memory CD45RA-positive, alpha-beta T cells, or terminally-differentiated (TEMRA) cells, represent a unique sub-population of T cells, characterized by their ability to quickly respond to previously encountered antigens. These highly specialized cells are among the final stages of T cell differentiation, exhibiting both memory and effector characteristics. They express the CD45RA molecule on their surface, which is typically associated with naïve T cells, leading to them often being misidentified as such. However, unlike naïve T cells, TEMRA cells exhibit rapid effector function upon encountering an antigen. The primary function of TEMRA cells is to provide rapid immune responses to antigens that the organism has previously encountered. Unlike central memory T cells, which reside in the lymphoid organs and require time to proliferate, differentiate, and migrate to the site of infection, TEMRA cells can immediately respond to a threat. They circulate through peripheral tissues, constitutively expressing receptors that permit direct migration to inflamed tissues. Upon arrival they exert their effector functions, such as direct cell cytotoxicity or cytokine release, to aid in the removal of the pathogen. Moreover, TEMRA cells are unique for their increased cytotoxic capabilities when compared to other T cells. This is particularly important during viral infections, where rapid response is critical. The presence of this cell population in the peripheral blood has been associated with protective immunity against various viral and bacterial infections. In addition to defending against pathogens, these highly differentiated T lymphocytes also play a role in immunopathological disorders, where they can contribute to tissue damage. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) terminally differentiated effector memory cells re-expressing CD45RA https://cellxgene.cziscience.com/cellguide/CL_4030002 TEMRA TEMRA cell terminally differentiated effector memory CD45RA+ T cells An alpha-beta memory T cell with the phenotype CD45RA-positive.