Researchers study antibodies against coronavirus
As laboratories across the country rush to find answers for the novel coronavirus, UT Health San Antonio is bringing a unique combination of expertise to bear on the crisis. The goal is a precise and effective vaccine to prevent infection, said Robert Hromas, M.D., professor and dean of the university’s Long School of Medicine.
UT Health San Antonio is supporting multiple research projects in vaccine development. “We are working very fast to attack this problem because until we have a vaccine and a therapy, this virus represents a huge threat to humanity,” Dr. Hromas said.
UT Health San Antonio has repurposed strategic teams in its research enterprise to focus on the problem, he said.
For example, a team from the Long School of Medicine is on a quest to isolate antibodies that neutralize the novel coronavirus.
“People who had the infection and recovered from it make specific antibodies,” said researcher Evelien Bunnik, Ph.D., assistant professor in the Department of Microbiology, Immunology & Molecular Genetics. “We will obtain samples from these individuals and study the antibodies.”
Goal is to lock cells against viral spread
The novel coronavirus, which in some individuals with weaker immune systems gives rise to the respiratory syndrome COVID-19, features spike proteins on its coat. The virus uses the spikes to force its way into surrounding cells.
“You can sort of see it as a lock and a key,” Dr. Bunnik said. “The spike protein is the key that needs to bind to the lock on the host cell. If you can prevent the key from going into the lock, you can prevent infection. That is what a neutralizing antibody does.”
The researchers are studying the antibodies’ chemical footprints – where the antibodies bind on the spike proteins – to learn which antibodies inhibit the virus and which do not.
“Once we know the footprints of the antibodies that give the best inhibitory effect, we can take that footprint, essentially, and make it into a vaccine,” Dr. Bunnik said.
UT Health San Antonio researchers are working with colleagues at the Texas Biomedical Research Institute, where biosafety level 3 and 4 labs enable scientists to work with live viruses.
“We will test our vaccine candidates at Texas Biomed to see if they actually block the virus from infecting cells,” Dr. Hromas said.
“This is another example of the outstanding partnership between our institutions,” said Larry Schlesinger, M.D., president and CEO of Texas Biomed.
Unique mice will aid the cause
UT Health San Antonio collaborators include Paolo Casali, M.D., professor in the Department of Microbiology, Immunology & Molecular Genetics. Dr. Casali has created mice that have a full human immune system (H-Mice). He will immunize H-Mice mice with the COVID-19 virus spike protein and analyze what kind of antibodies the mice produce. The goal is to compare the antibodies that are observed in the humanized mice after infection with antibodies from the novel coronavirus survivors.
“We will test the immune response of the humanized mice to identify vaccine candidates,” Dr. Hromas said.
“Many people around the country are looking for vaccines, but they’re not doing it quite the way we are,” Dr. Hromas said. “Our niche is that we can track infection in our humanized H-Mice and compare it to the immune response in humans. Then we can go back and test what we find in humans in the humanized mouse. No one else has that capability.”
The team’s expertise runs the gamut from basic scientists looking at single amino acids of the spike proteins of the coronavirus to clinicians who are experts in running clinical trials in humans, Dr. Hromas said.
The UT Health San Antonio portion of the team includes immunologists such as Dr. Casali, cell biologists such as Dr. Bunnik, structural biologists such as Yogesh Gupta, Ph.D., and clinical trialists including Dr. Hromas, Jan Evans Patterson, M.D., and Thomas Patterson, M.D. The Texas Biomed portion of the group will be led by Luis Martinez-Sobrido, Ph.D., a virologist and assisted by a team of 30 COVID-19 investigators and staff.