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

Area of Science:

• Immunology
• Cell Biology
• T cell differentiation

Background:

• Tissue-resident memory T cells (TRM) are crucial for immunity but factors driving their development, especially in humans, are not fully understood.
• Transforming growth factor-beta (TGF-β) is known to be necessary, but other environmental cues are less clear.

Purpose of the Study:

• To investigate the role of oxygen tension (hypoxia) as an environmental cue in human TRM cell differentiation.
• To explore the synergistic effects of hypoxia and TGF-β1 on TRM development.

Main Methods:

• Human CD8+ T cells were differentiated under varying conditions: normoxia, hypoxia, TGF-β1 alone, and combined hypoxia and TGF-β1.
• Phenotypic analysis using markers like CD69 and CD103, and transcriptional profiling were performed.

Main Results:

• Co-culture of human CD8+ T cells with hypoxia and TGF-β1 significantly increased the generation of cells with a TRM phenotype (CD69+CD103+).
• This combination synergistically enhanced TRM cell development compared to either factor alone, revealing distinct transcriptional profiles.
• The study identified enriched gene signatures characteristic of TRM cells, including adhesion molecules and reduced recirculation genes.

Conclusions:

• Hypoxia, in conjunction with TGF-β1, acts as a potent inductive cue for human TRM cell differentiation.
• This finding offers a novel method for generating human TRM phenotype cells in vitro.
• These findings have implications for basic immunology research and translational applications like adoptive cellular therapy.