has_participant has participant lymphocyte costimulation T cell costimulation T-cell co-stimulation GO:0031295 T lymphocyte costimulation T-cell costimulation T-lymphocyte costimulation biological_process T cell co-stimulation The process of providing, via surface-bound receptor-ligand pairs, a second, antigen-independent, signal in addition to that provided by the T cell receptor to augment T cell activation. positive regulation of T cell activation tyrosine-protein kinase Lck (human) tyrosine-protein kinase Fyn (human) tyrosine-protein kinase Yes (human) tyrosine-protein kinase Lyn (human) proto-oncogene tyrosine-protein kinase Src (human) tyrosine-protein kinase CSK (human) serine/threonine-protein kinase mTOR (human)