Effects of tofacitinib on the functions of HMBPP-specific γδT cells

Abstract

Objective To investigate the inhibitory effects of Tofacitinib on 4-hydroxy-3-methyl-but-enyl pyrophosphate(HMBPP)-specific γδT cells. Method We used HMBPP as an antigen to stimulate γδT cells, in order to study the inhibitory effects of tofacitinib on the production of cytokines, activation, proliferation and phosphorylation of STATs in HMBPP-specific γδT cells. Results Stimulation with HMBPP could induce the production of interferon(IFN)-γ and tumor necrosis factor(TNF)-α in γδT cells.The production of IFN-γ showed a dose-dependent trend, while TNF-α reached a peak at 12 hours after culture.After the addition of Tofacitinib into the culture system, the expression of IFN-γ and TNF-α in γδT cells was significantly reduced.Flow cytometry analysis showed that the cytokine-expressing cells in PBMCs cells after stimulation with HMBPP were Vδ2+ γδT cells, and this subpopulation of cells could produce IFN-γ and TNF-α.Upon further investigations, we found that Tofacitinib inhibited the activation of Vδ2+ γδT cells induced by HMBPP, and mainly suppressed the expression of CD25 from 3.85% and 5.37% to 1.66% and 1.70% at the first and the third day respectly, but not CD69 molecular.Furthermore, CFSE-labeled cell culture showed that tofacitinib inhibited HMBPP-induced proliferation of Vδ2+ γδT cells from 16.1% to 8.06%.The results from flow cytometry showed that tofacitinib inhibited HMBPP-induced phosphorylation of signal transducers and activators of transcriptions (STATs)in Vδ2+ γδT cells, which might be the main mechanism of the inhibition effects by tofacitinib in γδT cells. Conclusions Tofacitinib could inhibit the production of cytokines, activation, proliferation and phosphorylation of STATs in HMBPP-specific γδT cells.Our results showed that tofacitinib could inhibit the functions of γδT cells, except inhibition on Th1 cells, which provided a theoretical basis for clinical applications. Key words: Tofacitinib; γδT cells; Cytokines; Immunosuppression