Australian scientists published a paper in the latest issue of American Public Library of Science Biology, saying that they found a protein LRRC15 in the human lung. This new receptor can bind with COVID-19 to block its infection, and form a natural protective screen in the human body. This discovery provides a new way for scientists to develop new drugs to prevent COVID-19 infection or respond to pulmonary fibrosis. This study is one of three independent papers, which revealed the interaction between leucine rich repeat protein 15 (LRRC15) and COVID-19. Greg Neely, the co-author of the research paper and a scientist at the University of Sydney, said: "Together with two other teams, we found that LRRC15 can reduce infection by combining with COVID-19 and isolating the virus. We can use this new receptor to design broad-spectrum drugs, thus blocking viral infection, and even inhibiting pulmonary fibrosis." COVID-19 attaches to the specific receptor angiotensin converting enzyme 2 (ACE2) on human cells through spike protein, As a result, human beings are infected, and there are high levels of ACE2 receptors in lung cells, which is also the reason why the lungs of patients with COVID-19 are prone to severe disease. Like ACE2, LRRC15 is also a coronavirus receptor, which means it can bind to virus. But unlike ACE2, LRRC5 does not support infection, so it can combine with the virus and fix it to prevent other susceptible cells from being infected in the process. LRRC15 exists in many parts of the human body, such as lung, skin, tongue, fibroblasts, placenta and lymph nodes. However, researchers found that more LRRC15 would "surface" after lung infection with COVID-19. The research team said that LRRC15 may be part of the natural response of the human body to fight infection, which will form a barrier to physically isolate the virus from the most sensitive lung cells. This discovery can help scientists develop new antiviral and anti-fibrosis drugs. They are using LRRC15 to develop two strategies to combat COVID-19: one is preventive treatment for nose; The other is the treatment for the lungs of severe patients. (Xinhua News Agency)