The effect of eosinophil subtypes on ASM cells proliferation and viability in asthma

Abstract

Introduction: Eosinophilic inflammation is one of the main asthma features. Recently two eosinophil subtypes were identified: lung-resident eosinophils (rEOS) and inflammatory eosinophils (iEOS). However, their role in asthma pathogenesis is not entirely clear Aim: To investigate the effect of rEOS and iEOS on airway smooth muscle (ASM) cells proliferation and viability in asthma Methods: We involved 16 severe non-allergic eosinophilic asthma (SNEA) patients with a high dose of inhaled steroids, 8 steroid-free non-severe allergic asthma (AA) patients and 9 healthy subjects (HS). Total blood EOS were isolated by high-density centrifugation and magnetic separation, phenotyping - with antibodies against CD62L. An individual combined cell culture between EOS and immortalized ASM cells was prepared. ASM cells proliferation was measured by Alamar Blue assay; viability – by annexin V FITC and propidium iodide staining Results: Both EOS subtypes significantly increased proliferation of ASM cells, and the effect of rEOS was stronger compared with iEOS in all investigated groups: 42.6±12.5% vs. 21.6±7% in SNEA, 29.1±4.2% vs. 15.6±2.8% in AA, 11.8±3.0% vs. 3.9±1.8% in HS groups, p Conclusions: rEOS stronger enhanced proliferation of ASM cells and prolonged their viability, compared with the effect of iEOS in asthma