TY - JOUR T1 - Late Breaking Abstract - The innate immune collectin surfactant protein SP-D binds to SARS-CoV-2 spike-protein JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2020.1055 VL - 56 IS - suppl 64 SP - 1055 AU - Raquel Arroyo AU - Shawn N Grant AU - Paul S Kingma Y1 - 2020/09/07 UR - http://erj.ersjournals.com/content/56/suppl_64/1055.abstract N2 - Severe cases of coronavirus 2019 (COVID-19) are characterized by inflammation, thick mucous secretions, extensive lung damage and in some cases respiratory failure and death. Viral infection of host cells is driven by binding of the SARS-CoV-2 glycosylated spike-(S)-protein to lung type 2 pneumocytes, followed by virus replication. Surfactant protein SP-D, an immune collectin protein that participates in the innate defense, has critical roles in clearing viral and bacterial pathogens from the lung. The present work aims to demonstrate the interaction of SP-D with the spike protein of SARS-CoV-2 and subsequent viral aggregation in vitro, as the first molecular actions of SP-D that would lead to viral clearance from the lungs. Binding and competition assays have been performed by ELISA and the result of aggregation assays have been observed by electrophoresis followed by silver staining. We have found that recombinant human rhSP-D binds the SARS-CoV-2 glycosylated spike-(S)-protein, which is the first step of SP‑D mediated inhibition of viral pathogenesis. Binding induces the formation of protein bridges to initiate viral aggregation, and it is not inhibited by the presence of ACE2 receptor. Therefore, recombinant human rhSP-D could be a promising therapeutic option for COVID-19 that should be explored with further studies.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 1055.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 -