The differentiation of ROR-\u03b3t expressing iNKT17 cells is orchestrated by Runx1

Puspa Thapa,Virginia Smith Shapiro,Hai-Hui Xue,Sinibaldo Romera Arocha,Derek B Sant’ Angelo,Bryce Manso,Ji Young Chung

doi:10.1038/s41598-017-07365-8

Puspa Thapa, Virginia Smith Shapiro + Show 5 more

Open Access

https://doi.org/10.1038/s41598-017-07365-8

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Abstract

iNKT cells are a unique lineage of T cells that recognize glycolipid presented by CD1d. In the thymus, they differentiate into iNKT1, iNKT2 and iNKT17 effector subsets, characterized by preferential expression of Tbet, Gata3 and ROR-γt and production of IFN-γ, IL-4 and IL-17, respectively. We demonstrate that the transcriptional regulator Runx1 is essential for the generation of ROR-γt expressing iNKT17 cells. PLZF-cre Runx1 cKO mice lack iNKT17 cells in the thymus, spleen and liver. Runx1-deficient iNKT cells have altered expression of several genes important for iNKT17 differentiation, including decreased expression of IL-7Rα, BATF and c-Maf and increased expression of Bcl11b and Lef1. However, reduction of Lef1 expression or introduction of an IL-7Rα transgene is not sufficient to correct the defect in iNKT17 differentiation, demonstrating that Runx1 is a key regulator of several genes required for iNKT17 differentiation. Loss of Runx1 leads to a severe decrease in iNKT cell numbers in the thymus, spleen and liver. The decrease in cell number is due to a combined decrease in proliferation at Stage 1 during thymic development and increased apoptosis. Thus, we describe a novel role of Runx1 in iNKT cell development and differentiation, particularly in orchestrating iNKT17 differentiation.

Highlights

Invariant natural Killer T cells are innate lymphocytes that express a semi-invariant TCR with an invariant TCRα-chain, Vα14-Jα18, paired with limited TCRβ-chains, Vβ7, Vβ8, or Vβ2. iNKT cells recognizes glycolipids presented on an MHC-like molecule CD1d1–4
Cell development and differentiation21. mTORC1 is essential for differentiation of Tbet expressing iNKT1 while mTORC2 is important for iNKT2 and iNKT17 differentiation10, 22, 23. iNKT cells require autophagy for their survival and the differentiation of iNKT1 cells[24, 25]
In PLZF-cre Runx[1] cKO mice, there is a dramatic decrease in Stage 2 (8.5 fold) and Stage 3 (19.5 fold) iNKT cell numbers

Summary

Introduction

Invariant natural Killer T (iNKT) cells are innate lymphocytes that express a semi-invariant TCR with an invariant TCRα-chain, Vα14-Jα18, paired with limited TCRβ-chains, Vβ7, Vβ8, or Vβ2. iNKT cells recognizes glycolipids presented on an MHC-like molecule CD1d1–4. In PLZF-cre Runx[1] cKO mice, Runx[1] protein expression does not decrease until Stage 1 in iNKT cells (Fig. 1c). Examination of the absolute cell count of iNKT cells in thymus of PLZF-cre Runx[1] cKO mice revealed a significant reduction (p < 0.001) in cell number of Stage 2 (8.5 fold) and Stage 3 (19.5 fold) iNKT cells (Fig. 1e).

Results

Conclusion