T lymphocyte (activated)

An activated T lymphocyte is an adaptive immune cell that has encountered its cognate antigen and received the necessary co-stimulatory signals, resulting in proliferation, cytokine secretion, and effector functions such as cytotoxicity (CD8+ T cells) or immune coordination (CD4+ T cells). Activation alters the T cell's phenotype, increases expression of DNA synthesis and activation markers, and enables orchestrated responses to pathogens or abnormal cells. While activation is a critical checkpoint in immunity, dysregulation can lead to autoimmunity, immunodeficiency, or therapeutic side effects in contexts such as cancer immunotherapy[1][2][3][4][5][6][7][9][10].

Other names

Activated T cellActivated lymphocyte