Inhibition of SARS‐CoV‐2‐mediated thromboinflammation by CLEC2.Fc

Abstract

AbstractThromboinflammation is the major cause of morbidity and mortality in COVID‐19 patients, and post‐mortem examination demonstrates the presence of platelet‐rich thrombi and microangiopathy in visceral organs. Moreover, persistent microclots were detected in both acute COVID‐19 and long COVID plasma samples. However, the molecular mechanism of SARS‐CoV‐2‐induced thromboinflammation is still unclear. We found that the spleen tyrosine kinase (Syk)‐coupled C‐type lectin member 2 (CLEC2), which was highly expressed in platelets and alveolar macrophages, interacted with the receptor‐binding domain (RBD) of SARS‐CoV‐2 spike protein (SARS‐CoV‐2 RBD) directly. Unlike the thread‐like NETs, SARS‐CoV‐2‐induced aggregated NET formation in the presence of wild‐type (WT), but not CLEC2‐deficient platelets. Furthermore, SARS‐CoV‐2 spike pseudotyped lentivirus was able to induce NET formation via CLEC2, indicating SARS‐CoV‐2 RBD engaged CLEC2 to activate platelets to enhance NET formation. Administration of CLEC2.Fc inhibited SARS‐CoV‐2‐induced NET formation and thromboinflammation in AAV‐ACE2‐infected mice. Thus, CLEC2 is a novel pattern recognition receptor for SARS‐CoV‐2, and CLEC2.Fc and may become a promising therapeutic agent to inhibit SARS‐CoV‐2‐induced thromboinflammation and reduced the risk of post‐acute sequelae of COVID‐19 (PASC) in the future.