TY - JOUR
T1 - Biased binding of class IA phosphatidyl inositol 3-kinase subunits to inducible costimulator (CD278)
AU - Acosta, Yenny Y.
AU - Zafra, Maria Paz
AU - Ojeda, Gloria
AU - Bernardone, Ilaria Seren
AU - Dianzani, Umberto
AU - Portolés, Pilar
AU - Rojo, Jose M.
N1 - Funding Information:
The skillful technical assistance of Maria Luisa del Pozo and Marta Blanco-Berrocal is gratefully acknowledged. Y.Y.A. is the recipient of a Predoctoral Fellowship of the “Junta de Ampliación de Estudios” (JAE) Program (C.S.I.C., Ministerio de Ciencia e Innovación, Spain). P.P. is a Tenured Sciencist of C.S.I.C. at the Centro Nacional de Microbiología, I.S.: Carlos III. This work was supported by grants PI070620 and PI070484 (Fondo de Investigación Sanitaria, Ministerio de Ciencia e Innovación, Spain) and by AIRC (Milan) (to U.D.).
PY - 2011/9
Y1 - 2011/9
N2 - To better understand T lymphocyte costimulation by inducible costimulator (ICOS; H4; CD278), we analyzed proteins binding to ICOS peptides phosphorylated at the Y191MFM motif. Phosphorylated ICOS binds class IA phosphatidyl inositol 3-kinase (PI3-K) p85α, p50-55α and p85β regulatory subunits and p110α, p110δ and p110β catalytic subunits. Intriguingly, T cells expressed high levels of both p110α or p110δ catalytic subunits, yet ICOS peptides, cell surface ICOS or PI3-kinase class IA regulatory subunits preferentially coprecipitated p110a catalytic subunits. Silencing p110α or p110δ partially inhibited Akt/ PKB activation induced by anti-CD3 plus anti-ICOS antibodies. However, silencing p110α enhanced and silencing p110δ inhibited Erk activation. Both p110α and p110δ specific inhibitors blocked cytokine secretion induced by TCR/CD3 activation with or without ICOS costimulus, but only p110α inhibitors blocked ICOS-induced cell elongation. Thus, p110α and p110d are essential to optimal T cell activation, but their abundance and activity differentially tune up distinct ICOS signaling pathways.
AB - To better understand T lymphocyte costimulation by inducible costimulator (ICOS; H4; CD278), we analyzed proteins binding to ICOS peptides phosphorylated at the Y191MFM motif. Phosphorylated ICOS binds class IA phosphatidyl inositol 3-kinase (PI3-K) p85α, p50-55α and p85β regulatory subunits and p110α, p110δ and p110β catalytic subunits. Intriguingly, T cells expressed high levels of both p110α or p110δ catalytic subunits, yet ICOS peptides, cell surface ICOS or PI3-kinase class IA regulatory subunits preferentially coprecipitated p110a catalytic subunits. Silencing p110α or p110δ partially inhibited Akt/ PKB activation induced by anti-CD3 plus anti-ICOS antibodies. However, silencing p110α enhanced and silencing p110δ inhibited Erk activation. Both p110α and p110δ specific inhibitors blocked cytokine secretion induced by TCR/CD3 activation with or without ICOS costimulus, but only p110α inhibitors blocked ICOS-induced cell elongation. Thus, p110α and p110d are essential to optimal T cell activation, but their abundance and activity differentially tune up distinct ICOS signaling pathways.
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U2 - 10.1007/s00018-010-0606-1
DO - 10.1007/s00018-010-0606-1
M3 - Research Article
C2 - 21188463
AN - SCOPUS:80052270140
SN - 1420-682X
VL - 68
SP - 3065
EP - 3079
JO - Cellular and Molecular Life Sciences
JF - Cellular and Molecular Life Sciences
IS - 18
ER -
