γδTCR recruits the Syk/PI3K axis to drive proinflammatory differentiation program
Ryunosuke Muro, Takeshi Nitta, Kenta Nakano, Tadashi Okamura, Hiroshi Takayanagi, Harumi Suzuki
Ryunosuke Muro, Takeshi Nitta, Kenta Nakano, Tadashi Okamura, Hiroshi Takayanagi, Harumi Suzuki
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Research Article Cell biology Immunology

γδTCR recruits the Syk/PI3K axis to drive proinflammatory differentiation program

Abstract

γδT cells produce inflammatory cytokines and have been implicated in the pathogenesis of cancer, infectious diseases, and autoimmunity. The T cell receptor (TCR) signal transduction that specifically regulates the development of IL-17–producing γδT (γδT17) cells largely remains unclear. Here, we showed that the receptor proximal tyrosine kinase Syk is essential for γδTCR signal transduction and development of γδT17 in the mouse thymus. Zap70, another tyrosine kinase essential for the development of αβT cells, failed to functionally substitute for Syk in the development of γδT17. Syk induced the activation of the PI3K/Akt pathway upon γδTCR stimulation. Mice deficient in PI3K signaling exhibited a complete loss of γδT17, without impaired development of IFN-γ–producing γδT cells. Moreover, γδT17-dependent skin inflammation was ameliorated in mice deficient in RhoH, an adaptor known to recruit Syk. Thus, we deciphered lineage-specific TCR signaling and identified the Syk/PI3K pathway as a critical determinant of proinflammatory γδT cell differentiation.

Authors

Ryunosuke Muro, Takeshi Nitta, Kenta Nakano, Tadashi Okamura, Hiroshi Takayanagi, Harumi Suzuki

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Figure 4

The PI3K pathway controls γδT17 development.

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The PI3K pathway controls γδT17 development. (A and B) TCR-induced Akt p...
(A and B) TCR-induced Akt phosphorylation in thymic γδT cells from Zap70–/– or Sykb–/– mice. Histograms show staining profiles of p-Akt in cells from WT (black lines) and mutant (red lines) mice, overlaid with nonstimulated profiles (shaded) after a 1-minute stimulation (A). MFI relative to nonstimulated controls (B). Thymocytes from adult Zap70–/– mice (n = 3) and neonatal Sykb–/– mice (n = 4) were used. (C–G) E15.5 fetal thymus from WT mice was cultured with vehicle alone (DMSO, 0.01%), IC87114 (1 μM), or SF1670 (2.5 μM) for 7 days (n = 5–11). (C) Flow cytometric profiles for CD3ε and TCRδ expression and absolute number of γδT cells. (D) Intracellular staining profiles for IL-17A production in γδT cells and absolute number of IL-17A–producing γδT cells (per lobe). (E) Intracellular staining profiles for RORγt expression in γδT cells and frequency of RORγt+ γδT cells. (F) Intracellular staining profiles for IFN-γ production in γδT cells and absolute number of IFN-γ–producing γδT cells (per lobe). (G) mRNA expression of Rorc, Sox13, and Sox4 in isolated γδT cells. Gene expression was normalized to β-actin (Actb) mRNA. (H) Number of Vγ4+ and Vγ6+ γδT cells. Data represent the mean ± SEM. *P < 0.05 and **P < 0.01, by unpaired t test (B and G) and 1-way ANOVA (C–F and H). Data represent 2 independent experiments (A and B) or a single experiment (G), or the combined results of 2 independent experiments (C–F and H).