TY - JOUR T1 - Immunosuppressive properties of human PD-1+ PDL-1+ dendritic cell from Lymph Nodes Aspirates of NSCLC patients JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2020.1656 VL - 56 IS - suppl 64 SP - 1656 AU - Iwona Kwiecień AU - Elżbieta Rutkowska AU - Rafał Sokołowski AU - Joanna Bednarek AU - Agata Raniszewska AU - Karina Jahnz-Różyk AU - Piotr Rzeepecki AU - Joanna Domagała-Kulawik Y1 - 2020/09/07 UR - http://erj.ersjournals.com/content/56/suppl_64/1656.abstract N2 - Dendritic cells DCs play a pivotal role in homeostasis of the immune system. The tumor microenviroment impairs the proper function of DCs. Despite the progress in anticancer immunotherapy, there are still many unresolved issues. Among them the immunomodulatory propeties of DCs in lung cancer are of interes.We investigated the differences of DCs subsets and with expression of immunomodulating and costimulatory molecules: PD-1, PD-L1 and CD80 in metastatic, non-metastatic LNs aspirates and peripheral blood PB.LNs aspirates were obtained during EBUS/TBNA procedure of 14 patients with primary NSCLC. The cells were analysed by flow cytometry.We reported the higher percentage of DCs in metastatic than in non-metastatic LNs and PB (0.324% vs 0.042% vs 0.036% p<0.05). The myeloid DCs was higher in metastatic LNs than in non- metastatic (49.2 vs 23.2 p<0.05). The proportions of PD-1 and PD-L1 DCs were higher in metastatic LNs than in non-metastatic (45.5% vs 13.3% and 52.7% vs 24.1% p<0.05). The proportion of DCs with CD80+ was higher in metastatic LNs than non-meatstatic (46.4% vs 11.0% p<0.05). Patients with metastatic disease have higher proportion of regulatory DCRegs (PD-1+ PDL-1+ CD80low) than patients with non-metastatic (respectively 6.7% vs 3.7%). Significantly lower expression of both PD-1+, PD-L2+ and CD80+ DCs was found in PB (2.2%, 2.2% and 3.2%).We report for the first time that DCs cells show increased expression of PD-1 and PD-L1 molecules that can interact with T lymphocytes in tumor suppressory microenvironment. It can be assumed that mature DCs infiltrating metastatic LNs can develop into DCRegs, which are involved in suppression of anti-tumor response.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 1656.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress 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 -