Phosphatidylinositol 3-kinase-independent signaling pathways contribute to ICOS-mediated T cell costimulation in acute graft-versus-host disease in mice

Jun Li, Jessica Heinrichs, Julien Leconte, Kelley Haarberg, Kenrick Semple, Chen Liu, Mathieu Gigoux, Mara Kornete, Ciriaco A. Piccirillo, Woong Kyung Suh, Xue Zhong Yu

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

We and others have previously shown that ICOS plays an important role in inducing acute graft-versus-host disease (GVHD) in murine models of allogeneic bone marrow transplantation. ICOS potentiates TCR-mediated PI3K activation and intracellular calcium mobilization. However, ICOS signal transduction pathways involved inGVHD remain unknown. In this study, we examined the contribution of ICOS-PI3K signaling in the pathogenic potential of T cells using a knock-in mouse strain, ICOS-YF, which selectively lost the ability to activate PI3K. We found that when total T cells were used as alloreactive T cells, ICOS-YF T cells caused less severe GVHD compared with ICOS wild-type T cells, but they induced much more aggressive disease than ICOS knockout T cells. This intermediate level of pathogenic capacity of ICOS-YF T cells was correlated with similar levels of IFN-γ-producing CD8 T cells that developed in the recipients of ICOS-WT or ICOS-YF T cells. We further evaluated the role of ICOSPI3K signaling in CD4 versus CD8 T cell compartment using GVHD models that are exclusively driven by CD4 or CD8 T cells. Remarkably, ICOS-YF CD8 T cells caused disease similar to ICOS wild-type CD8 T cells, whereas ICOS-YF CD4 T cells behaved very similarly to their ICOS knockout counterparts. Consistent with their in vivo pathogenic potential, CD8 T cells responded to ICOS ligation in vitro by PI3K-independent calcium flux, T cell activation, and proliferation. Thus, in acute GVHD in mice, CD4 T cells heavily rely on ICOS-PI3K signaling pathways; in contrast, CD8 T cells can use PI3K-independent ICOS signaling pathways, possibly through calcium.

Original languageEnglish (US)
Pages (from-to)200-207
Number of pages8
JournalJournal of Immunology
Volume191
Issue number1
DOIs
StatePublished - Jul 1 2013
Externally publishedYes

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Fingerprint

Dive into the research topics of 'Phosphatidylinositol 3-kinase-independent signaling pathways contribute to ICOS-mediated T cell costimulation in acute graft-versus-host disease in mice'. Together they form a unique fingerprint.

Cite this