Abstract

Phosphatidylinositol-3-kinases (PI3K) γ and δ are preferentially enriched in leukocytes, and defects in these signaling pathways have been shown to impair T cell activation. The effects of PI3Kγ and PI3Kδ on alloimmunity remain underexplored. Here, we show that both PI3Kγ−/− and PI3KδD910A/D910A mice receiving heart allografts have suppression of alloreactive T effector cells and delayed acute rejection. However, PI3Kδ mutation also dampens regulatory T cells (Treg). After treatment with low dose CTLA4-Ig, PI3Kγ−/−, but not PI3ΚδD910A/D910A, recipients exhibit indefinite prolongation of heart allograft survival. PI3KδD910A/D910A Tregs have increased apoptosis and impaired survival. Selective inhibition of PI3Kγ and PI3Kδ (using PI3Kδ and dual PI3Kγδ chemical inhibitors) shows that PI3Kγ inhibition compensates for the negative effect of PI3Kδ inhibition on long-term allograft survival. These data serve as a basis for future PI3K-based immune therapies for transplantation.

Details

Title
Regulation of T cell alloimmunity by PI3Kγ and PI3Kδ
Author
Uehara, Mayuko 1 ; McGrath, Martina M 1 ; Ohori, Shunsuke 1 ; Solhjou, Zhabiz 1 ; Banouni, Naima 1 ; Routray, Sujit 1 ; Evans, Catherine 2 ; DiNitto, Jonathan P 2 ; Elkhal, Abdallah 3 ; Turka, Laurence A 4 ; Strom, Terry B 5 ; Tullius, Stefan G 3 ; Winkler, David G 2 ; Azzi, Jamil 1 ; Abdi, Reza 1 

 Transplantation Research Center, Renal Division, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA 
 Infinity Pharmaceuticals, Cambridge, MA, USA 
 Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA 
 Center for Transplantation Sciences, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, USA 
 The Transplant Institute, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, USA 
Pages
1-11
Publication year
2017
Publication date
Oct 2017
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1953960847
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.