TY - JOUR T1 - Tissue resident memory T cells are increased in the lungs of COPD patients JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.LSC-2022.247 VL - 8 IS - suppl 8 SP - 247 AU - Bradley Richmond AU - Ana Serezani AU - Jacob Schaff AU - Timothy Blackwell Y1 - 2022/03/10 UR - http://openres.ersjournals.com/content/8/suppl_8/247.abstract N2 - Background: Adaptive immune activation is common in the lungs of chronic obstructive pulmonary disease (COPD) patients, but it is unclear whether tissue resident memory T cells (TRMs) are increased as part of this response.Aims: To determine if TRMs are increased in the lungs of COPD patients and identify their location in COPD lungs.Methods: TRMs (defined as CD4+CD103+ or CD8+CD103+) were quantified by mass cytometry in explanted lungs of 12 COPD patients who underwent lung transplantation and 6 deceased organ donors without chronic respiratory disease (e.g. controls) whose lungs were rejected for transplantation. The location of TRMs in COPD lungs was assessed by immunostaining for CD3+CD103+ cells in 5 micrometer lung sections.Results: COPD patients were older than controls and exclusively former smokers while controls were often current smokers. The percentage of CD4+ TRMs among CD45+ immune/inflammatory cells was increased in COPD lungs compared to controls (2.6% vs. 0.1%, p < 0.05) as was the percentage of CD8+ TRMs among CD45+ immune/inflammatory cells (5.8% vs. 0.9%, p < 0.05). Interestingly, both CD4+ and CD8+ TRMs expressed high levels of PD1. CD3+/CD103+ cells were present in or around 43/110 (39%) airways examined from 10 patients with COPD. Among airways with TRMs present, the median number of cells was 3 and the range was 0-15. In many cases, TRMs were found within small airway walls.Discussion: In this cohort of COPD patients and controls without chronic respiratory disease, TRMs were increased and often localized within small airway walls. Future studies will be needed to replicate these findings in an age-matched control cohort and assess the functional properties of TRMs in COPD.FootnotesCite this article as ERJ Open Research 2022; 8: Suppl. 8, 247.This article was presented at the 2022 ERS Lung Science Conference, in session “Poster Session 2”.This is an ERS Lung Science Conference abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -