Keywords: T cell activation.svg The T lymphocyte activation pathway is triggered when a T cell encounters its cognate antigen coupled to a MHC molecule on the surface of an infected cell or a phagocyte T cells contribute to immune defenses in two major ways some direct and regulate immune responses; others directly attack infected or cancerous cells T_cell_activation png 50 2012-01-28 00 51 UTC T_cell_activation png Template drawing and caption text from The Immune System any modifcations made by myself are released into the public domain derivative work Hazmat2 <span class signature-talk >talk</span> Translate PD-USGov Original upload log This image is a derivative work of the following images File T_cell_activation png licensed with PD-USGov PD-user 2007-03-13T21 42 49Z DO11 10 686x1038 237918 Bytes <nowiki> The T lymphocyte activation pathway is triggered when a T cell encounters its cognate antigen coupled to an MHC molecule on the surface of an infected cell or a phagocyte T cells contribute to </nowiki> Uploaded with derivativeFX Biology diagrams Immunology Microbiology T cells |