title: Do CD4 and CD8 control T-cell activation via a specific tyrosine protein kinase?
abstract: The CD4 and CD8 glycoproteins play an important role in T-cell activation by binding to major histocompatibility complex (MHC) class II or class I molecules, respectively, and stabilizing their interactions with the T-cell receptor-CD3 complex during antigen presentation. Recent evidence suggesting that the cytoplasmic domains of CD4 and CD8 are physically, and perhaps functionally, linked to the T-cell specific tyrosine protein kinase, p56lck, adds a new dimension to our current understanding of their physiological function. Based on these and other recent findings, Tomas Mustelin and Amnon Altman present a working hypothesis that defines a novel role for CD4 or CD8 in regulating T-cell activation, and perhaps other processes, such as thymic repertoire selection and human immunodeficiency virus (HIV)-induced immunosuppression.
authors.forename: T
authors.initials: T
authors.lastname: Mustelin
authors.forename: A
authors.initials: A
authors.lastname: Altman
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D011505:Protein-Tyrosine Kinases