Thioredoxin-1 improves the immunometabolic phenotype of antitumor T cells

Paramita Chakraborty,Elizabeth G Hill,Krishnamurthy Thyagarajan,Hung Nguyen,Michael I Nishimura,Shilpak Chatterjee,Shikhar Mehrotra,Mark P Rubinstein,Nancy Klauber-Demore,Xue-Zhong Yu,Gary Hardiman,Supinya Iamsawat,Pravin Kesarwani,Patrick Nasarre,Nilanjana Maulik,Gina Scurti,Vamsi K Gangaraju ,Lauren E Ball ,Shanmugam Panneer Selvam ,Besim Öğretmen ,Annika V Dalheim

doi:10.1074/jbc.ra118.006753

Abstract

Adoptive transfer of tumor epitope-reactive T cells has emerged as a promising strategy to control tumor growth. However, chronically-stimulated T cells expanded for adoptive cell transfer are susceptible to cell death in an oxidative tumor microenvironment. Because oxidation of cell-surface thiols also alters protein functionality, we hypothesized that increasing the levels of thioredoxin (Trx), an antioxidant molecule facilitating reduction of proteins through cysteine thiol-disulfide exchange, in T cells will promote their sustained antitumor function. Using pre-melanosome protein (Pmel)-Trx1 transgenic mouse-derived splenic T cells, flow cytometry, and gene expression analysis, we observed here that higher Trx expression inversely correlated with reactive oxygen species and susceptibility to T-cell receptor restimulation or oxidation-mediated cell death. These Trx1-overexpressing T cells exhibited a cluster of differentiation 62Lhi (CD62Lhi) central memory-like phenotype with reduced glucose uptake (2-NBDGlo) and decreased effector function (interferon γlo). Furthermore, culturing tumor-reactive T cells in the presence of recombinant Trx increased the dependence of T cells on mitochondrial metabolism and improved tumor control. We conclude that strategies for increasing the antioxidant capacity of antitumor T cells modulate their immunometabolic phenotype leading to improved immunotherapeutic control of established tumors.

Highlights

Adoptive transfer of tumor epitope–reactive T cells has emerged as a promising strategy to control tumor growth
We recently bred melanoma epitope gp100-reactive TCRbearing transgenic mouse Pmel with a thioredoxin1 (Trx1)transgenic mouse, in which human Trx1 is systemically overexpressed under the control of the ␤-actin promoter [11], to obtain Pmel–Trx mouse
The increased antioxidant thiol levels were inversely correlated to the reactive oxygen species (ROS) levels in the activated T cells as measured by DCFDA (Fig. 1C), and less cell death was mediated by oxidant injury using H2O2 (Fig. 1D) or activation-induced cell death induced upon TCR restimulation (Fig. 1E)

Summary

Introduction

Adoptive transfer of tumor epitope–reactive T cells has emerged as a promising strategy to control tumor growth. Using pre-melanosome protein (Pmel)–Trx transgenic mouse-derived splenic T cells, flow cytometry, and gene expression analysis, we observed here that higher Trx expression inversely correlated with reactive oxygen species and susceptibility to T-cell receptor restimulation or oxidation-mediated cell death. These Trx1-overexpressing T cells exhibited a cluster of differentiation 62Lhi (CD62Lhi) central memory-like phenotype with reduced glucose uptake (2-NBDGlo) and decreased effector function (interferon ␥lo). We conclude that strategies for increasing the antioxidant capacity of antitumor T cells modulate their immunometabolic phenotype leading to improved immunotherapeutic control of established tumors. Array data have been deposited in the EBI ArrayExpress Database accession number E-MTAB-7571. 1 These authors contributed to this work. 2 To whom correspondence should be addressed: Dept. of Surgery, Hollings

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Conclusion