Selective defect in antigen-induced TCR internalization at the immune synapse of CD8 T cells bearing the ZAP-70(Y292F) mutation.
Cbl proteins have been implicated in ligand-induced TCR/CD3 down-modulation, but underlying mechanisms are unclear. We analyzed the effect of mutation of a cbl-binding site on ZAP-70 (ZAP-Y292F) on dynamics, internalization, and degradation of the TCR/CD3 complex in response to distinct stimuli. Naive CD8 T cells expressing the P14 transgenic TCR from ZAP-Y292F mice were selectively affected in TCR/CD3 down-modulation in response to antigenic stimulation, whereas neither anti-CD3 Ab-, and PMA-induced TCR down-modulation, nor constitutive receptor endocytosis/cycling were impaired. We further established that the defect in TCR/CD3 down-modulation in response to Ag was paralleled by an impaired TCR/CD3 internalization and CD3zeta degradation. Analysis of T/APC conjugates revealed that delayed redistribution of TCR at the T/APC contact zone was paralleled by a delay in TCR internalization in the synaptic zone in ZAP-Y292F compared with ZAP-wild-type T cells. Cbl recruitment to the synapse was also retarded in ZAP-Y292F T cells, although F-actin and LFA-1 redistribution was similar for both cell types. This study identifies a step involving ZAP-70/cbl interaction that is critical for rapid internalization of the TCR/CD3 complex at the CD8 T cell/APC synapse.
Davanture
Suzel
S
Centre d'Immunologie de Marseille-Luminy, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale/Université de la Méditerranée, Marseille, Cedex, France.
Leignadier
Julie
J
Milani
Pascale
P
Soubeyran
Philippe
P
Malissen
Bernard
B
Malissen
Marie
M
Schmitt-Verhulst
Anne-Marie
AM
Boyer
Claude
C
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology* / Q000378:metabolism; D000941:Antigens / Q000276:immunology; D020126:Brefeldin A / Q000494:pharmacology; D017252:CD3 Complex / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000502:physiology; D050721:Proto-Oncogene Proteins c-cbl; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000502:physiology; D051746:ZAP-70 Protein-Tyrosine Kinase
D000941:Antigens; D017252:CD3 Complex; C121704:CD3 antigen, zeta chain; D011518:Proto-Oncogene Proteins; D011948:Receptors, Antigen, T-Cell; D020126:Brefeldin A; D050721:Proto-Oncogene Proteins c-cbl; D044767:Ubiquitin-Protein Ligases; D011505:Protein-Tyrosine Kinases; D051746:ZAP-70 Protein-Tyrosine Kinase; C497262:Zap70 protein, mouse; C493849:Cbl protein, mouse