Effector pathways regulating T cell activation.
Activation of T lymphocytes is a key event for an efficient response of the immune system. It requires the involvement of the T cell receptor antigen as well as costimulatory molecules such as CD28. Engagement of these receptors through the interaction with a foreign antigen associated with major histocompatibility complex molecules and CD28 counter-receptors B7.1/B7.2, respectively, results in a series of signaling cascades acting in synergy and which culminate in activation of interleukin-2 gene transcription and eventually cell proliferation. Many studies aimed at characterizing these specific effector pathways have been published; however, the actual signaling molecules that transduce activation signals from the cell membrane to the nucleus and that directly regulate interleukin-2 gene transcription are not yet completely defined and remain a matter of debate. In this commentary, we have attempted to analyze the results, which are sometimes diverging if not totally contradictory, characterizing effector pathways that possibly are triggered during T cell activation.
Favero
J
J
INSERM U 431, Microbiologie et Pathologie Cellulaire Infectieuse, Universite de Montpellier II, France. favero@univ-montp2.fr
Lafont
V
V
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D018106:CD28 Antigens / Q000276:immunology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000276:immunology; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D048369:MAP Kinase Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D017346:Protein Serine-Threonine Kinases / Q000276:immunology; D011505:Protein-Tyrosine Kinases / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*