ADAP-SLP-76 binding differentially regulates supramolecular activation cluster (SMAC) formation relative to T cell-APC conjugation.
T cell-APC conjugation as mediated by leukocyte function-associated antigen-1 (LFA-1)-intercellular adhesion molecule (ICAM)-1 binding is followed by formation of the supramolecular activation cluster (SMAC) at the immunological synapse. The intracellular processes that regulate SMAC formation and its influence on T cell function are important questions to be addressed. Here, using a mutational approach, we demonstrate that binding of adaptor adhesion and degranulation promoting adaptor protein (ADAP) to SLP-76 differentially regulates peripheral SMAC (pSMAC) formation relative to conjugation. Although mutation of the YDDV sites (termed M12) disrupted SLP-76 SH2 domain binding and prevented the ability of ADAP to increase conjugation and LFA-1 clustering, M12 acted selectively as a dominant negative (DN) inhibitor of pSMAC formation, an effect that was paralleled by a DN effect on interleukin-2 production. ADAP also colocalized with LFA-1 at the immunological synapse. Our findings identify ADAP-SLP-76 binding as a signaling event that differentially regulates SMAC formation, and support a role for SMAC formation in T cell cytokine production.
Molecular Immunology Section, Department of Immunology, Imperial College London, Hammersmith Campus, London W12 ONN, England, UK.
Hongyan
H
Wang
Fiona E
FE
McCann
John D
JD
Gordan
Xiang
X
Wu
Monika
M
Raab
Talat H
TH
Malik
Daniel M
DM
Davis
Christopher E
CE
Rudd
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D000938:Antigen-Presenting Cells / Q000502:physiology*; D001665:Binding Sites; D015938:Complement Membrane Attack Complex; D003165:Complement System Proteins; D006023:Glycoproteins; D016023:Integrins / Q000502:physiology; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology; D051379:Mice; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*; D018909:src Homology Domains
D048868:Adaptor Proteins, Signal Transducing; D015938:Complement Membrane Attack Complex; C491468:Fyb protein, mouse; D006023:Glycoproteins; D016023:Integrins; D007376:Interleukin-2; D016169:Lymphocyte Function-Associated Antigen-1; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; C047610:SC5b-9 protein complex; C092947:SLP-76 signal Transducing adaptor proteins; D003165:Complement System Proteins