PT - JOURNAL ARTICLE AU - Theodore Kapellos AU - Kevin Bassler AU - Wataru Fujii AU - Tal Pecht AU - Lorenzo Bonaguro AU - Izabela Galvao AU - Adem Saglam AU - Erica Dudkin AU - Amit Frishberg AU - Elena De Domenico AU - Arik Horne AU - Chantal Donovan AU - Richard Y. Kim AU - David Gallego-Ortega AU - Matthias Becker AU - Kristian Händler AU - Thomas Ulas AU - Jan Hasenauer AU - Carmen Pizarro AU - Phil M. Hansbro AU - Dirk Skowasch AU - Joachim L. Schultze TI - Inflammatory blood neutrophils in COPD stem from activated bone marrow progenitors AID - 10.1183/23120541.LSC-2022.210 DP - 2022 Mar 10 TA - ERJ Open Research PG - 210 VI - 8 IP - suppl 8 4099 - http://openres.ersjournals.com/content/8/suppl_8/210.short 4100 - http://openres.ersjournals.com/content/8/suppl_8/210.full SO - erjor2022 Mar 10; 8 AB - Systemic inflammation is an important hallmark of severe chronic obstructive pulmonary disease (COPD), a chronic respiratory condition that features small airway inflammation and damage. However, the molecular changes in blood leukocytes from COPD patients remain elusive. Especially, the population structure of neutrophils, major contributors to lung pathophysiology, is still undetermined. We aimed to appreciate the heterogeneity of human blood and bronchoalveolar neutrophils and study the molecular alterations and their developmental path in COPD. Blood and bronchoalveolar neutrophils from COPD patients were analyzed with scRNA-seq, and a murine COPD model of smoke exposure was used to unravel the phenotypical changes in bone marrow progenitors with CyTOF. Blood neutrophils from COPD patients consisted of distinct transcriptomic clusters that included a pre-neutrophil subset and an interferon response gene (ISG) state that correlated with patient exacerbation history. Moreover, we observed that bronchoalveolar neutrophil states exhibited a pro-inflammatory phenotype expressing CCL chemokines, ISGs and S100 proteins. Investigation into the origin of the described circulating neutrophils states was performed with a murine smoke-induced model of COPD where analysis of the bone marrow compartment found that myeloid progenitors undergo proliferation and induce hematopoiesis and migratory programs. Conclusively, peripheral blood and bronchoalveolar neutrophils are highly heterogeneous and express activation signatures in COPD patients. The source of the systemic neutrophil inflammatory responses can be found in bone marrow myeloid precursors which are proliferative and can egress into the circulation.FootnotesCite this article as ERJ Open Research 2022; 8: Suppl. 8, 210.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).