Hypoxia acts as an environmental cue for the human tissue-resident memory T cell differentiation program.

Farah Hasan,Junmei Wang,Yulun Chiu,Cassian Yee,Rebecca M Shaw

doi:10.1172/jci.insight.138970

Abstract

Tissue-resident memory T cells (TRM) provide frontline defense against infectious diseases and contribute to antitumor immunity; however, aside from the necessity of TGF-β, knowledge regarding TRM-inductive cues remains incomplete, particularly for human cells. Oxygen tension is an environmental cue that distinguishes peripheral tissues from the circulation, and here, we demonstrate that differentiation of human CD8+ T cells in the presence of hypoxia and TGF-β1 led to the development of a TRM phenotype, characterized by a greater than 5-fold increase in CD69+CD103+ cells expressing human TRM hallmarks and enrichment for endogenous human TRM gene signatures, including increased adhesion molecule expression and decreased expression of genes involved in recirculation. Hypoxia and TGF-β1 synergized to produce a significantly larger population of TRM phenotype cells than either condition alone, and comparison of these cells from the individual and combination conditions revealed distinct phenotypic and transcriptional profiles, indicating a programming response to milieu rather than a mere expansion. Our findings identify a likely previously unreported cue for the TRM differentiation program and can enable facile generation of human TRM phenotype cells in vitro for basic studies and translational applications such as adoptive cellular therapy.

Highlights

Tissue-resident memory T cells (TRM) are a recently defined subset of non-recirculating memory T cells that reside in peripheral tissues and are important in frontline defense against viral infections and associated with antitumor immunity
Studies using mouse splenocytes 4 to 5 days postactivation have shown that TNF-α and IL-33 synergize with TGF-β to induce an intestinal resident T cell phenotype (CD103+Ly6C−CD69+) as well as downregulation of the transcription factor Kruppel-like factor 2 (KLF2) and its target genes sphingosine-1 phosphate receptor 1 (S1PR1) and SELL (CD62L), which is required for TRM establishment [4, 10]
To determine whether hypoxia can contribute to induction of a TRM phenotype, we sorted naive (CD45RA+CCR7+) CD8+ T cells from human peripheral blood mononuclear cells (PBMCs), activated them for 4 days under hypoxia (2% O2) or normal cell culture conditions (~20% O2) to generate “early effectors,” and cultured an additional 2 days in the presence of TGF-β1 [25]

Summary

Introduction

Tissue-resident memory T cells (TRM) are a recently defined subset of non-recirculating memory T cells that reside in peripheral tissues and are important in frontline defense against viral infections and associated with antitumor immunity. Studies in mice have shown CD8+ TRM are seeded by early effector T cells that differentiate into resident memory in situ, likely in response to local cues [1, 2]. These cues are thought to differ by tissue but remain poorly defined. Studies using mouse splenocytes 4 to 5 days postactivation have shown that TNF-α and IL-33 synergize with TGF-β to induce an intestinal resident T cell phenotype (CD103+Ly6C−CD69+) as well as downregulation of the transcription factor Kruppel-like factor 2 (KLF2) and its target genes sphingosine-1 phosphate receptor 1 (S1PR1) and SELL (CD62L), which is required for TRM establishment [4, 10]

Methods

Results

Conclusion