title: Unifying concepts in CD28, ICOS and CTLA4 co-receptor signalling.
abstract: Many studies have shown the central importance of the co-receptors CD28, inducible costimulatory molecule (ICOS) and cytotoxic T lymphocyte antigen 4 (CTLA4) in the regulation of many aspects of T-cell function. CD28 and ICOS have both overlapping and distinct functions in the positive regulation of T-cell responses, whereas CTLA4 negatively regulates the response. The signalling pathways that underlie the function of each of the co-receptors indicate their shared and unique properties and provide compelling hints of functions that are as yet uncovered. Here, we outline the shared and distinct signalling events that are associated with each of the co-receptors and provide unifying concepts that are related to signalling functions of these co-receptors.
authors.affiliation: Molecular Immunology Section, Department of Immunology, Division of Investigative Science, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 ONN, UK. c.rudd@imperial.ac.uk
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Rudd
authors.forename: Helga
authors.initials: H
authors.lastname: Schneider
mesh_terms: D064413:3-Phosphoinositide-Dependent Protein Kinases; D000069594:Abatacept; D000595:Amino Acid Sequence; D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis / Q000276:immunology*; D018106:CD28 Antigens / Q000276:immunology*; D018797:Cell Cycle Proteins; D006801:Humans; D018796:Immunoconjugates / Q000276:immunology*; D060889:Inducible T-Cell Co-Stimulator Protein; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D048728:MAP Kinase Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000096:biosynthesis; D019869:Phosphatidylinositol 3-Kinases / Q000096:biosynthesis; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D051567:Proto-Oncogene Proteins c-vav; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D064413:3-Phosphoinositide-Dependent Protein Kinases; D000069594:Abatacept; D000945:Antigens, Differentiation, T-Lymphocyte; D018106:CD28 Antigens; D018797:Cell Cycle Proteins; D018796:Immunoconjugates; D060889:Inducible T-Cell Co-Stimulator Protein; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D048728:MAP Kinase Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; D016328:NF-kappa B; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D051567:Proto-Oncogene Proteins c-vav; C556692:ICOS protein, human; C496618:VAV1 protein, human; C482576:MAP3K1 protein, human