title: Increased sensitivity of antigen-experienced T cells through the enrichment of oligomeric T cell receptor complexes.
abstract: Although memory T cells respond more vigorously to stimulation and they are more sensitive to low doses of antigen than naive T cells, the molecular basis of this increased sensitivity remains unclear. We have previously shown that the T cell receptor (TCR) exists as different-sized oligomers on the surface of resting T cells and that large oligomers are preferentially activated in response to low antigen doses. Through biochemistry and electron microscopy, we now showed that previously stimulated and memory T cells have more and larger TCR oligomers at the cell surface than their naive counterparts. Reconstitution of cells and mice with a point mutant of the CD3ζ subunit, which impairs TCR oligomer formation, demonstrated that the increased size of TCR oligomers was directly responsible for the increased sensitivity of antigen-experienced T cells. Thus, we propose that an "avidity maturation" mechanism underlies T cell antigenic memory.
authors: Departamento de Biología Celular e Inmunología, Centro Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors: Rashmi
authors: R
authors: Kumar
authors: María
authors: M
authors: Ferez
authors: Mahima
authors: M
authors: Swamy
authors: Ignacio
authors: I
authors: Arechaga
authors: María Teresa
authors: MT
authors: Rejas
authors: Jose M
authors: JM
authors: Valpuesta
authors: Wolfgang W A
authors: WW
authors: Schamel
authors: Balbino
authors: B
authors: Alarcon
authors: Hisse M
authors: HM
authors: van Santen
mesh_terms: D000818:Animals; D017252:CD3 Complex / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D006801:Humans; D015151:Immunoblotting; D007156:Immunologic Memory; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008954:Models, Biological; D009838:Oligodeoxyribonucleotides / Q000235:genetics / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology*
chemical_list: D017252:CD3 Complex; D009838:Oligodeoxyribonucleotides; D011948:Receptors, Antigen, T-Cell