Daniel Wrapp is in debt to a llama.
He's never met her, but the UT Austin grad student has his fingers crossed that one day he'll be able to personally thank the 4-year-old llama named Winter, an unlikely linchpin in the fight against COVID-19.
Wrapp co-authored a study out next week in the journal Cell with UT researcher Jason McLellan that suggests antibodies in llamas like Winter could prove a useful therapy to treat coronaviruses. They partnered with researchers at Ghent University, where Winter resides, along with the U.S. National Institutes of Health on the study, which started back in 2016.
The "corona" of any coronavirus, the spherical casing of each viral envelope, is studded with what are called spike proteins. These proteins are the point of attack for the viruses; the spike proteins glomb onto human cells, infect them and then replicate. To prevent that whole process (and any other infection), our body produces antibodies, which fight the infection.
Wrapp says, back in 2016, researchers hypothesized that Winter's antibodies could be useful in effectively treating diseases like SARS and MERS, which at the time were the most high-profile diseases caused by coronaviruses.
"Llamas produce a special class of antibodies called VHH's, and they're about half the size of a conventional antibody that you or I would produce," he said. "And because of that smaller size, they have some really interesting properties that make them potentially attractive therapeutic candidates."
So, they immunized Winter with spike proteins from the viruses that cause SARS and MERS, looking for a single antibody that would knock out all coronaviruses.
They didn't find that panacaea, but they did find two antibodies that were particularly effective at stunting the infection of the SARS and MERS viruses separately.
It was a promising result nonetheless. But, as researchers began writing up their findings, the pandemic happened.
With the global spotlight back on coronavirus research, Wrapp and the team of researchers thought COVID-19 could provide a real-time opportunity to re-test their findings.
"So, we tested our SARS antibody for reactivity against the new virus," Wrapp said, "and we found that it was cross-reactive, which means that it's capable of binding to both the SARS coronavirus and the virus that causes COVID-19."
For context, it's important to remember the lineage of the SARS virus and how it relates to COVID-19. The first virus that caused severe acute respiratory syndrome was identified in 2003. Between 2002 and 2003, it spread to 26 countries and affected 8,000 people.
The second strain of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) causes the disease COVID-19, which is an acronym for coronavirus disease-2019.
Wrapp says those antibodies found in that Belgian llama could be a breakthrough in treating both of those coronavirus strains.
"We're hopeful this antibody will be able to neutralize a broader swath of the SARS-family viruses," he said.
Researchers at Ghent University are moving forward with research to engineer the antibody into a drug that could be put in a nebulizer, a machine that turns medication from a liquid into a vapor patients can inhale, giving it a distinct advantage in combating the respiratory viruses. The Belgian-based researchers are also moving into animal trials.
As for Winter, Wrapp says he still owes her that debt, because none of this would've happened without her.
"Winter the llama is kind of the superstar of this story," he said.