DataSheet_1_Flagellin From Pseudomonas aeruginosa Modulates SARS-CoV-2 Infectivity in Cystic Fibrosis Airway Epithelial Cells by Increasing TMPRSS2 Expression.docx

In the coronavirus disease 2019 (COVID-19) health crisis, one major challenge is to identify the susceptibility factors of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in order to adapt the recommendations for populations, as well as to reduce the risk of COVID-19 development in the most vulnerable people, especially patients with chronic respiratory diseases such as cystic fibrosis (CF). Airway epithelial cells (AECs) play a critical role in the modulation of both immune responses and COVID-19 severity. SARS-CoV-2 infects the airway through the receptor angiotensin-converting enzyme 2, and a host protease, transmembrane serine protease 2 (TMPRSS2), plays a major role in SARS-CoV-2 infectivity. Here, we show that Pseudomonas aeruginosa increases TMPRSS2 expression, notably in primary AECs with deficiency of the ion channel CF transmembrane conductance regulator (CFTR). Further, we show that the main component of P. aeruginosa flagella, the protein flagellin, increases TMPRSS2 expression in primary AECs and Calu-3 cells, through activation of Toll-like receptor-5 and p38 MAPK. This increase is particularly seen in Calu-3 cells deficient for CFTR and is associated with an intracellular increased level of SARS-CoV-2 infection, however, with no effect on the amount of virus particles released. Considering the urgency of the COVID-19 health crisis, this result may be of clinical significance for CF patients, who are frequently infected with and colonized by P. aeruginosa during the course of CF and might develop COVID-19.

在2019冠状病毒病（COVID-19）公共卫生危机中，一项重大挑战在于识别严重急性呼吸综合征冠状病毒-2（SARS-CoV-2）的易感因素，以便针对不同人群调整防控建议，并降低易感人群，尤其是患有囊性纤维化（CF）等慢性呼吸系统疾病患者的COVID-19发病风险。气道上皮细胞（AECs）在调节免疫反应和COVID-19病情严重程度方面发挥着至关重要的作用。SARS-CoV-2通过血管紧张素转换酶2受体和宿主蛋白酶跨膜丝氨酸蛋白酶2（TMPRSS2）感染气道。本研究发现，铜绿假单胞菌（Pseudomonas aeruginosa）能提高TMPRSS2的表达，尤其是在缺乏离子通道CF跨膜电导调节蛋白（CFTR）的原代AECs中。此外，我们观察到，铜绿假单胞菌鞭毛的主要成分——鞭毛蛋白flagellin，可通过激活Toll样受体5和p38 MAPK途径，在原代AECs和Calu-3细胞中提高TMPRSS2的表达。这一增加在缺乏CFTR的Calu-3细胞中尤为明显，并伴随SARS-CoV-2在细胞内感染水平的升高，然而，对病毒颗粒释放量并无影响。鉴于COVID-19公共卫生危机的紧迫性，这一结果对CF患者具有潜在的临床意义，CF患者在疾病过程中常被铜绿假单胞菌感染并定植，且可能发展为COVID-19。