Stem cell-like memory T cells: Role in viral infections and autoimmunity

Figure 1 Varying roles of stem cell-like memory T cells during chronic (human immunodeficiency virus-1) and acute (COVID-19) viral infections and autoimmune diseases (type 1 diabetes). In chronic human immunodeficiency virus-1 (HIV-1) infection, the CD4+ stem cell-like memory T (T_SCM) cells act as latent reservoirs of HIV-1, whereas the CD8+ T_SCM cells exhibit an exhausted phenotype with upregulation of inhibitory molecules like programmed cell death 1. In case of post coronavirus disease 2019 infection or vaccination, viral specific T_SCM cells are generated that provide long term protective immunity. In autoimmune responses, such as during type 1 diabetes, T_SCM cells generate autoreactive effector-memory (T_EM) and effector T (Teff) cell subsets that perpetuate the ongoing inflammatory responses. HIV-1: Human immunodeficiency virus-1; PD-1: Programmed cell death 1; T1D: Type 1 diabetes; T_SCM: Stem cell-like memory T; COVID: Coronavirus disease 2019.