part_of part of part of lymphocyte activation involved in immune response T cell activation involved in immune response T-cell activation during immune response biological_process The change in morphology and behavior of a mature or immature T cell resulting from exposure to a mitogen, cytokine, chemokine, cellular ligand, or an antigen for which it is specific, leading to the initiation or perpetuation of an immune response. T-lymphocyte activation during immune response T lymphocyte activation during immune response T cell activation during immune response GO:0002286 immune response T cell activation