Glucocorticoid-induced tumor necrosis factor receptor–related protein co-stimulation facilitates tumor regression by inducing IL-9–producing helper T cells

Abstract

T cell stimulation via glucocorticoid-induced tumor necrosis factor receptor (TNFR)-related protein (GITR) elicits antitumor activity in various tumor models; however, the underlying mechanism of action remains unclear. Here we demonstrate a crucial role for interleukin (IL)-9 in antitumor immunity generated by the GITR agonistic antibody DTA-1. IL-4 receptor knockout (Il4ra(-/-)) mice, which have reduced expression of IL-9, were resistant to tumor growth inhibition by DTA-1. Notably, neutralization of IL-9 considerably impaired tumor rejection induced by DTA-1. In particular, DTA-1-induced IL-9 promoted tumor-specific cytotoxic T lymphocyte (CTL) responses by enhancing the function of dendritic cells in vivo. Furthermore, GITR signaling enhanced the differentiation of IL-9-producing CD4(+) T-helper (TH9) cells in a TNFR-associated factor 6 (TRAF6)- and NF-κB-dependent manner and inhibited the generation of induced regulatory T cells in vitro. Our findings demonstrate that GITR co-stimulation mediates antitumor immunity by promoting TH9 cell differentiation and enhancing CTL responses and thus provide a mechanism of action for GITR agonist-mediated cancer immunotherapies.

Alkaline Cytosolic pH and High Sodium Hydrogen Exchanger 1 (NHE1) Activity in Th9 Cells

“…The Th9/iTregs axis in cancer is further affected by GITR signaling (29,30). Our studies suggest that NHE1 could also be instrumental for the Th9/iTregs balance.…”

“…The cell suspension was centrifuged at 600 ϫ g at 4°C for 5 min and the cell pellet was treated with RBC lysis buffer for 1 min and washed three times. After washing, the cells were kept on a roller at 4°C (cold room) for 30 Th Cell Subsets Differentiation-Naive CD4 ϩ CD62L highϩ CD25 Ϫ T cells were activated in the presence of plate-bound anti-CD3/anti-CD28 antibodies (eBioscience, Frankfurt, Germany) with a ratio of 1:2 anti-CD3:anti-CD28 (1:2 g/ml, anti-CD3:anti-CD28) for Th1, Th2, and iTregs and 1:10 anti-CD3: anti-CD28 (1 g/ml of anti-CD3: 10 g/ml of anti-CD28) for Th9 and Th17. Briefly, T naive cells were differentiated into Th1 using 20 ng/ml of recombinant IL-12 (eBioscience), anti-IL-4 (5 g/ml; eBioscience), Th2 using 20 ng/ml of recombinant-IL-4 (eBioscience), anti-IFN-␥ (5 g/ml; eBioscience), Th9 using 2.5 ng/ml of recombinant-TGF-␤, 40 ng/ml of recombinant-IL-4, anti-IFN-␥ (10 g/ml), Th17 using 2.5 ng/ml of recombinant-TGF-␤, 50 ng/ml of recombinant-IL-6 (eBioscience), anti-IFN-␥ (5 g/ml), anti-IL-4 (5 g/ml), and anti-IL-2 (5 g/ml; eBioscience) and iTregs using 2.5 ng/ml of recombinant-TGF-␤, 5 ng/ml of recombinant-IL-2 (eBioscience), and cultured for 3-4 days (2,3,19,47,70).…”

“…However, a single faithful transcription factor for Th9 cell development has not yet been described. Recent studies have also implicated glucocorticoid-induced TNFR family-related gene (GITR; gene name Tnfrsf18) signaling in Th9 cell development (29,30). Xiao et al (29) found that GITR signaling controlled chromatin remodeling at the Foxp3 and Il9 loci, and consequently was able to convert induced Tregs (iTregs) into Th9 cells.…”

Characterization of MK-4166, a Clinical Agonistic Antibody That Targets Human GITR and Inhibits the Generation and Suppressive Effects of T Regulatory Cells

“…Published reports indicate that GITR signaling is mediated by NFkB and MAP kinases p38, JNK, and ERK in mice (31)(32)(33)(34)(35). To determine whether binding of the agonist mAb, MK-4166, to GITR elicits similar early signaling events, phosphorylation of MAPK/Erk and NFkB was evaluated by flow cytometry.…”

Les lymphocytes Th9

“…Après activation du TCR (T cell receptor), les Vignette (Photo © Delphine Sauce). agonistes de GITR stimulent l'activité antitumorale des Th9 [14].…”