New insights into tissue-localized immunity in lung transplants
/Generation and persistence of human tissue-resident memory T cells in lung transplantation
Tissue-resident memory T cells (TRM) maintain immunity in diverse sites as determined in mouse models, whereas their establishment and role in human tissues have been difficult to assess. By studying donor and recipient T cells in transplanted lungs, Snyder et al. have provided a rare glimpse into the generation and maintenance of human TRM. Whereas donor T cells were barely detectable in blood within 10 weeks after transplantation, donor TRM were abundant and persisted in transplanted lungs for more than a year. Recipient T cells infiltrating the lung gradually acquired TRM profiles over time as determined by analyses of T cells from bronchoalveolar lavages. In this 20-patient cohort, persistence of donor lung TRM correlated with improved clinical outcome, although further studies are needed to understand their role in graft retention.