NIH scientists have shown that COVID-19 infection can be prevented by isolating nanobodies from saliva. Infection occurs when the SARS-Cavi-2 virus spike protein (yellow) licks the ACE2 receptors (blue) on the outside of the cell. NIH nanobodies (gray) can prevent infection by covering the spike protein, which binds to the ACE2 receptor. Credit: Courtesy Brody Lab, NIH / NINDS
Preliminary results suggest that anti-Covid 19 nanobodies may be effective in preventing and diagnosing infections.
National health research institutes have isolated a set of promising, small antibodies or “nanobodies”. SARS-CoV-2 Were created by a lama named Karmak. Publish preliminary results in Scientific reports Suggests that at least one of these nanobodies, called NIH-CovinB-112, can detect virus particles by capturing the SARS-Covin-2 spike protein. In addition, the nanobody appeared to work equally well in liquid or aerosol form, suggesting that it may remain effective after inhalation. SARS-CoV-2 is the virus that causes it COVID-19.
NIH scientists differentiate small antibodies, or nanobodies, from a saliva called corvid against COVID-19. Credit: Courtesy Triple J Farms, Bellingham, WA.
The study was led by Thomas J. “TJ” Esperza, BS, and David L. Brody, MD, Ph.D. Was performed by a pair of, working in the brain imaging labs of NIH’s National Institute for Neurological Disorders and Stroke. (NINDS).
“For years TJ and I have been testing how to use nanobodies to improve brain imaging. When the epidemic broke out, we thought that once in a lifetime, together they were in a deck situation and engaged in a fight, ”said Dr. Br. Brody, who is a professor and senior at the Uniform Services University for Health Sciences, said. Author of the study. “We hope that these anti-Covid-19 nanobodies can be very effective and versatile in combating coronavirus epidemics.”
Nanobody is a special type of antibody that naturally consists of lunts, llamas and alpacas, produced by the immune system of a group of animals. On average, this protein is about one-tenth the weight of most human antibodies. This is because the nanobodies isolated in the lab are essentially free-floating versions of the heavy chain protein weapon tips, forming the backbone of the typical Y-shaped human IgG antibody. These tips play a crucial role in protecting the immune system by recognizing proteins from viruses, bacteria and other invaders, also known as antigens.
Because nanobodies are more stable, less expensive to produce, and easier to engineer than typical antibodies, a growing body of researchers, including Mr. Essarza and Dr. Brody, are using them for medical research. For example, several years ago, scientists showed that humanized nanobodies could be more effective in treating autoimmune thyroid thrombocytopenic purpura, a rare blood disorder than current treatments.
Since the epidemic broke out, many researchers have built lalama nanobodies against the SARS-Co-2 spike protein that may be effective in preventing infection. In the present study, researchers have used slightly different strategies than others to detect nanobodies that may work particularly well.
“The SARS-CoV-2 spike acts like a protein key. It opens the door to infection when it binds to a protein called angiotensin converting enzyme 2 (ACE2) receptor, which is found on the surface of some cells, ”said Estarza. “We developed a method that would isolate nanobodies that block the infection by covering the teeth with a spike protein that binds and unlocks the ACE2 receptor.”
To do this, the researchers vaccinated Corm Cor five times in 28 days with a pure version of the SARS-Covy-2 Spike protein. After testing hundreds of nanobodies, they found that Karmak produced 13 nanobodies that could be strong candidates.
NIH scientists have shown that Lalama’s anti-covid-19 nanobodies can be an effective tool in the fight against the colloid-19 virus. Credit: Courtesy of Brody Lab NIH / NIDS
Preliminary experiments suggest that a candidate named NIH-CoVnb-112 may work very well. Test tube studies show that these nanobodies bind to the ACE2 receptor, 2 to 10 times stronger than nanobodies produced by other labs. Other experiments suggest that the ACE2 receptor binding portion of the NIH nanobody spike protein hangs directly.
The team then showed that the NIH-CoVNB-112 nanobody could be effective in preventing coronavirus infection. To mimic the SARS-Cavi-2 virus, researchers genetically modified a harmless “pseudovirus” so that it could use the spike protein to infect cells with human AC2 receptors. The researchers found that relatively low levels of NIH-CoVnb-112 nanobodies prevented pseudoviruses from infecting these cells in petri dishes.
Importantly, the researchers showed that the nanobody was equally effective in preventing infections in petri dishes when it was sprayed with a nebulizer or inhaler, often used to treat asthma patients.
“The amazing thing about nanobodies is that, unlike most regular antibodies, they can be aerated and inhaled to coat the lungs and airways,” said Dr. Brody.
The team has applied for a patent on the NIH-CoVnB-112 nanobody.
“Nevertheless, although we have a lot of work ahead, these results represent a promising first step,” Mr Essarza said. “With the support of NIH, we are rapidly moving forward to test whether these nanobodies can be a safe and effective preventive treatment for Covid-19. Collaborators are also working to find out if they can be used for cheap and accurate testing. “
Reference: “High Efficiency Nanobodies SARS-CoV-2 Spike Receptor Binding Domain Interaction Asparza, TJ et al., 22 December 2020 inhibits binding domain interaction with human angiotensin converting enzyme. Scientific reports.
DOI: 10.1038 / s41598-020-79036-0
The study was supported by the National Institute for Neurological Disorders and Stroke (NINDS) and the NIH Intramural Research Programs of the National Institute of Environmental Health Sciences (NIAHS); Dr. Brody is an employee of the Uniform Services University of Health Sciences. The views expressed herein do not represent the Department of Defense.
