Ultra-Low Doses of Inhaled Nanobodies Prevents and Treats Severe COVID-19 in Hamsters – SciTechDaily

Animals who received inhaled nanobodies have fewer coronavirus particles in their bronchioles (right panel, orange) and are less irritated (magenta). Credit: Nambulli et al., Science Advances
In a paper released today (May 26, 2021) in Science Advances, researchers from the University of Pittsburgh School of Medicine showed that inhalable nanobodies targeting the spike protein of the SARS-CoV-2 coronavirus can prevent and deal with serious COVID-19 in hamsters. This is the very first time the nanobodies– which are comparable to monoclonal antibodies however smaller in size, more steady, and cheaper to produce– were tested for inhalation treatment versus coronavirus infections in a pre-clinical model.
The scientists revealed that low doses of an aerosolized nanobody named Pittsburgh inhalable Nanobody-21 (PiN-21) secured hamsters from the dramatic weight loss generally related to severe SARS-CoV-2 infection and minimized the variety of contagious infection particles in the animals nasal cavities, throats and lungs by a million-fold, compared to placebo treatment with a nanobody that doesnt neutralize the infection.
” By using an inhalation therapy that can be straight administered to the infection website– the respiratory tract and lungs– we can make treatments more effective,” stated co-senior author Yi Shi, Ph.D., assistant teacher of cell biology at Pitt. “We are extremely ecstatic and encouraged by our data recommending that PiN-21 can be extremely protective versus severe illness and can possibly prevent human-to-human viral transmission.”

Yi Shi, Ph.D., assistant teacher of cell biology, University of Pittsburgh School of Medicine. Credit: Yi Shi
Formerly, Shi and coworkers found a big collection of over 8,000 high-affinity SARS-CoV-2 nanobodies. From this collection, the scientists picked an ultrapotent nanobody (Nb21) and bioengineered it into a trimeric form to more optimize its antiviral activity. The resulting PiN-21 is without a doubt the most powerful antiviral nanobody that has been determined, according to the scientists review of released studies.
The experiments showed that PiN-21 was protective when administered intranasally at the time of infection. Hamsters in the PiN-21 treatment group did not lose any body weight, unlike the placebo-treated animals who lost up to 16% of their preliminary body weight after a week of infection. For the typical adult human, the rate of the weight reduction would correspond to shedding roughly 20 pounds in a week.
Much more remarkably, inhalation of aerosolized nanobodies at an ultra-low dose reduced the number of transmittable virus particles in the lung tissue by 6-logs (or a million-fold). Animals who got aerosolized PiN-21 nanobodies had milder changes in the lung structure and a lower degree of swelling than those who got the placebo.
Doug Reed, Ph.D., associate professor of immunology, University of Pittsburgh School of Medicine. Credit: Doug Reed
To deliver therapeutics via aerosolization, the scientists had to conquer numerous technical difficulties– small particle aerosols need to reach deep into the lung, and treatment particles need to be little enough so that they do not clump together and strong enough to hold up against the extreme pressure required to suspend them in the air. PiN-21 nanobodies, which are approximately 4 times smaller than typical monoclonal antibodies with exceptionally high stability, are perfectly matched for the task. They likewise are more affordable to produce and can be generated rapidly to swiftly adapt to the shape-shifting virus.
” COVID-19 is now a preeminent disease of the 21st century,” said co-author Doug Reed, Ph.D., associate teacher of immunology at Pitt. “Delivering the treatment straight to the lungs can make a big distinction for our ability to treat it.”
Researchers mention that the vaccines and nanobodies are complementary and do not take on one another. Vaccines stay the very best tool to stop the virus from spreading out from person to person, however nanobodies will be beneficial to deal with people who currently are ill and those who cant get immunized for other medical reasons.
Appealing early preclinical data, integrated with the researchers substantial knowledge about quickly determining drug-quality nanobodies, recommend that this approach can offer a cost-efficient and practical restorative choice to control the coronavirus pandemic.
” This work is the result of professionals in nanobody production, infectious illness, and aerobiology working carefully together. At the University of Pittsburgh Center for Vaccine Research, we do not just talk about ideas, we really make them come to life,” stated co-senior author Paul Duprex, Ph.D., the centers director.
Recommendation: 24 May 2021, Science Advances.DOI: 10.1126/ sciadv.abh0319.
Other authors on the manuscript include Sham Nambulli, Ph.D., Natasha Tilston-Lunel, Ph.D., Linda J. Rennick, Ph.D., William Klimstra, Ph.D., all of the Pitt Center for Vaccine Research; Yufei Xiang, M.S., of Pitts Department of Cell Biology; Zhe Sang, M.S., of Pittsburgh-Carnegie Mellon University Program in Computational Biology; and Nicholas Crossland, Ph.D., of Boston University.
This work was supported by the National Institutes of Health (grant # 1R35GM137905-01), a University of Pittsburgh Clinical and Translational Science Institute pilot grant, the University of Pittsburgh, the Pitt Center for Vaccine Research, the Commonwealth of Pennsylvania Department of Community and Economic Development, the Richard King Mellon Foundation and the Henry L. Hillman Foundation.
Shi and Xiang are innovators on a pending patent associated to this work submitted by University of Pittsburgh (no. 63067567, filed on Aug. 28, 2020).

Previously, Shi and colleagues discovered a big repertoire of over 8,000 high-affinity SARS-CoV-2 nanobodies. From this repertoire, the researchers selected an ultrapotent nanobody (Nb21) and bioengineered it into a trimeric type to further optimize its antiviral activity. The resulting PiN-21 is by far the most powerful antiviral nanobody that has been recognized, according to the scientists evaluation of released research studies.
Hamsters in the PiN-21 treatment group did not lose any body weight, unlike the placebo-treated animals who lost up to 16% of their preliminary body weight after a week of infection. PiN-21 nanobodies, which are approximately four times smaller sized than typical monoclonal antibodies with remarkably high stability, are perfectly matched for the job.