Researchers from Cornell University have discovered a new molecule called N-0385 that could be used to develop the first COVID-19 nose spray, a medication taken intranasally.
In collaboration with researchers from Université de Sherbrooke and University of British Columbia in Canada, the team published their study in Nature journal on Mar. 28, claiming N-0385 could potentially be utilized both for prevention and early treatment against COVID-19.
Prof. Hector Aguilar-Carreno, microbiology and immunology, a senior author of the paper, said the study began in his lab in 2020. “We moved to working with coronaviruses, specifically SARS-Cov 2, because we felt that we needed to do something about the pandemic,” Aguilar-Carreno said.
The Aguilar-Carreno lab started preparing biosafety and animal training for its researchers, and after a few months, it became the first lab at Cornell to conduct mouse and hamster experiments with SARS-CoV-2. This led to collaboration with Prof. Gary Whittaker, virology, along with Prof. Richard Letuc, pharmacology, from the Université de Sherbrooke and Prof. François Jean, microbiology and immunology, from the University of British Columbia.
The team’s focus was to test certain molecules that can combat SARS-CoV-2 infection using animal experiments. Specifically, they wanted to observe the compound effects on repressing SARS-CoV-2 TMPRSS22 activity. TMPRSS22 is a transmembrane serine protease, an enzyme embedded within the virus’ membrane that breaks down proteins.
TMPRSS22 performs an important function in cleaving and exposing the SARS-CoV-2 spike protein by binding to its target attachment site, composed of a specific four amino acid sequence. The spike protein becomes capable of binding to the host organism’s surface cell receptors and fusing the viral membrane with the cell membrane. As a result, the virus can enter the host cell and produce thousands of copies of itself, spreading the infection to neighboring cells and ultimately throughout the body.
According to Aguilar-Carreno, the researchers identified candidate molecules by determining if they could block the attachment site between TMPRSS22 and the spike protein, inhibiting TMPRSS22 activity and thus, preventing COVID-19 infection.
Mice experiments were conducted to test the candidate molecules. Because mice typically cannot get infected with COVID-19, they were engineered with human cell surface receptors that bind to the SARS-CoV-2 spike protein in order to contract COVID-19. Factors such as weight loss, temperature, inflammation and presence of SARS-CoV-2 were carefully observed and compared between treated and untreated groups before, during and after COVID-19 infection.
These experiments allowed the researchers to determine that N-0385, a molecule developed by investigators from the Letuc Lab of Université de Sherbrooke, was most effective in COVID-19 prevention and treatment.
N-0385 is composed of the same four amino acid sequences as the TMPRSS22 attachment site as well as a “warhead” that aids in the chemistry of binding. Due to its basic structure and the abundant availability of amino acids, the molecule could be easily and cheaply mass-produced as a drug.
The study concluded that N-0385 protected the mice from COVID-19 infection before exposure and effectively treated COVID-19 illness 12 hours after exposure. Aguilar-Carreno also explained that the possibility of side effects with the molecule is much lower.
In fact, cytotoxicity in cells was only noted when N-0385 was given in significantly high concentrations. Given that N-0385 only needs to be administered in low concentrations to be effective, this showed even greater potential for the molecule to be used against COVID-19.
During the experiments, N-0385 was given intranasally to further increase efficacy against the virus, as SARS-CoV-2 enters the body mainly through the nose and into the respiratory tract. Besides respiratory cells, SARS-CoV-2 also primarily goes to the brain, as well as the heart and spleen.
N-0385 has been observed to be effective in reducing inflammation in the brain caused by the virus. “We don’t fully understand the mechanism of how the drug is helping the brain,” Aguilar-Carreno said. “But we would expect that the component would inhibit entry of the virus into any cell that uses serum proteases to get in.”
N-0385 was also tested against different COVID-19 strains and was found to be effective against all variants in cell cultures. In mice experiments, N-0385 has been found effective against the Alpha and Delta variants. The lab plans to start testing the Omicron strain on mice but remains hopeful for the continued success of N-0385.
The Aguilar-Carreno lab plans to continue testing the timing of when N-0385 can be administered against COVID-19 infection, other routes of molecule administration and effects of N-0385 in combination with other drugs and antivirals. The lab additionally plans to test the molecule on other viruses that use serine proteases for entry, such as MERS and human parainfluenza virus.
EBVIA Therapeutics, a California-based biotechnology company, has also recently taken up the lab’s research. They have begun raising funds to expand testing of the molecule to human trials, as well as drug development and mass production.
“I’m sure [N-0385] can still be improved,” Aguilar-Carreno said. “[But] so far, this [molecule] is the best.”