ACE2 receptor protein ＂nanobubbles＂ can prevent and treat COVID-19.

　　Science and Technology Daily, Beijing, January 23rd (Intern reporter Zhang Jiaxin) According to a paper published in the journal Nature Communication on the 20th, scientists from Northwestern University School of Medicine and the University of Texas, The University of Texas MD Anderson Cancer Center, found in preclinical research that there are natural nano-sized bubbles containing angiotensin converting enzyme 2 protein in the blood of COVID-19 patients, and found that it can prevent a wide range of Covid-19 strains from being infected, including many current Covid-19 variants and possible coronaviruses in the future. Once developed into a therapeutic product, it can be used as the least toxic biotherapy method to benefit mankind.

　　EvACE2 protein is a tiny lipid (fat) vesicle with the size of nanoparticles, which expresses ACE2 protein (the receptor of Covid-19). Scientists say that these bubbles can be used as bait in the body to "lure" Covid-19 away from the ACE2 protein on the cell.

　　Covid-19 spike protein "grabs" the "handle" of evACE2, but not the intracellular ACE2, which can prevent the virus from entering human cells. Once caught, the virus will either float around harmlessly, or it will be cleared by macrophage immune cells, and it will never cause infection again.

　　Dr Lagu Karuri, co-senior author of the study and chairman of The University of Texas MD Anderson Cancer Center Cancer Biology, said that the key of this study is to identify the naturally occurring extracellular vesicles in the body, and these vesicles express ACE2 receptors on their surfaces, which is part of the normal adaptive defense against Covid-19. On this basis, they found a new potential therapy to use this natural defense against Covid-19.

　　This study shows for the first time that evACE2 protein can block the original strain with the same or better effect against the new Covid-19 variety. The researchers found that these evACE2 nanobubbles exist in human blood, which is a natural antiviral reaction. The more serious the disease is, the higher the level of evACE2 detected in the patient’s blood.

　　"Whenever new Covid-19 variants proliferate, the initial vaccines and therapeutic antibodies may lose resistance to Alpha, Beta, Delta and the latest Omicron variants." Dr. Liu Huiping, associate professor of pharmacology and medicine at feinberg Medical College of Northwest University, said, "However, the beauty of evACE2 lies in its super ability to prevent a wide range of coronavirus strains, including the current Omicron, and even the future coronavirus from infecting humans."

　　Studies on mice show that when Covid-19 spreads to the airway through droplets, evACE2 has therapeutic potential to prevent or block infection.

　　One of the biggest challenges in fighting the COVID-19 epidemic is the moving target of the virus, which constantly evolves into a new virus strain (variant) with mutation. There are various changes in the spike protein of these new virus strains, which may lead to an increase in infection rate and breakthrough infection.

　　At present, the team is applying for a patent on evACE2, with the goal of cooperating with industry partners to develop evACE2 as a biotherapy product (nasal spray or injection therapy) to prevent and treat COVID-19.