In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2, no specific and effective drugs for treating this disease have been reported until today. Angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2, mediates the virus infection by binding to spike protein. Although ACE2 is expressed in the lung, kidney, and intestine, its expressing levels are rather low, especially in the lung. Considering the great infectivity of COVID-19, we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection. Here, we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein. The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody, Meplazumab, inhibits SARS-CoV-2 amplification. Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells, which can be neutralized by CD147 extracellular fragment. Viral loads are detectable in the lungs of human CD147 (hCD147) mice infected with SARS-CoV-2, but not in those of virus-infected wild type mice. Interestingly, virions are observed in lymphocytes of lung tissue from a COVID-19 patient. Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dose-dependent manner, which is specifically inhibited by Meplazumab. Furthermore, CD147 mediates virus entering host cells by endocytosis. Together, our study reveals a novel virus entry route, CD147-spike protein, which provides an important target for developing specific and effective drug against COVID-19.

Currently, COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been widely spread around the world; nevertheless, so far there exist no specific antiviral drugs for treatment of the disease, which poses great challenge to control and contain the virus. Here, we reported a research finding that SARS-CoV-2 invaded host cells via a novel route of CD147-spike protein (SP). SP bound to CD147, a receptor on the host cells, thereby mediating the viral invasion.Our further research confirmed this finding. First, in vitro antiviral tests indicated Meplazumab, an anti-CD147 humanized antibody, significantly inhibited the viruses from invading host cells, with an EC 50 of 24.86 μg/mL and IC 50 of 15.16 μg/mL. Second, we validated the interaction between CD147 and SP, with an affinity constant of 1.85×10 -7 M. Co-Immunoprecipitation and ELISA also confirmed the binding of the two proteins. Finally, the localization of CD147 and SP was observed in SARS-CoV-2 infected Vero E6 cells by immuno-electron microscope. Therefore, the discovery of the new route CD147-SP for SARS-CoV-2 invading host cells provides a critical target for development of specific antiviral drugs.

Background: The COVID-19 pandemic has become a great threat to public health, which has greatly impacted the study and life of undergraduate students in China. This study aims to perform a survey of their knowledge, attitude and practice (KAP) associated with COVID-19. Methods: A cross-sectional survey was designed to gather information regarding the COVID-19 related KAP among undergraduates during the home isolation in the outbreak. Subjects were recruited from 10 universities in Shaanxi Province, China. Enrollees voluntarily submitted their answers to a pre-designed questionnaire online. Results: A total of 872 subjects (female, 534; male, 338) were enrolled with ages from 17 to 25 years old. This cohort included 430 medical and 442 non-medical students, 580 freshmen and 292 higher school year students. There were 453 from public schools and 442 from private school, residing in 28 regions and provinces at the time of study. Results showed that appropriate knowledge was acquired by 82.34% subjects; the levels were significantly higher in undergraduates from public universities and medical majors than those from private schools and nonmedical majors (p<0.05). 73.81% subjects reported positive attitudes; females showed significantly higher levels of positive attitudes than males (p<0.05). Proactive practice was found in 87.94% subjects. Using a common scoring method, the overall scores for Knowledge, Attitude and Practice were 4.12 ± 0.749 (range: 0~5), 8.54 ± 1.201 (range: 0~10), and 8.91 ± 1.431 (range: 0~10), respectively. There was a positive correlation between attitude and practice (r = 0.319, p < 0.05) in the whole study group. Total KAP score was 21.57 ± 2.291 (range: 0~25), which was significantly different between gender groups and major groups. Conclusions: Most undergraduates acquired necessary knowledge, positive attitude and proactive practice in response to COVID-19 outbreak; but their KAP scores significantly varied by gender, major and school types.