Technology developed by TGen researchers could help fine-tune future vaccines
PHOENIX, Ariz. — July 5, 2022 — Could the SARS-CoV-2 vaccine reawaken previous antibody responses and point the way to a universal coronavirus vaccine? A new analysis of the antibody response to a COVID-19 vaccine suggests the immune system’s past history with other coronaviruses, including those behind the common cold, shapes the patients response, according to a study published today in Cell Reports.
Led by scientists at the Translational Genomics Research Institute (TGen), part of City of Hope, and Northern Arizona University (NAU), a research team found that the vaccine generates antibodies that target regions of the SARS-CoV-2 spike protein that are unique to the new virus, while also targeting regions of the protein that are shared or conserved among many coronaviruses.
What’s more, the antibody response to these different coronaviruses appears to follow different paths. Over the course of 140 days following vaccination, the response to common cold coronaviruses started early but diminished over time. The response to SARS-CoV-2 continued to get stronger and stronger over time.
“The findings could help fine-tune the design of future vaccines or new monoclonal antibody treatments, perhaps leading to a universal coronavirus vaccine,” said John Altin, Ph.D., senior author and Assistant Professor in TGen’s Pathogen Genomics and Integrated Cancer Genomics Divisions.
“Even if the response to the conserved regions is just a small part of the vaccine’s overall protection, it may be a response that could be leveraged in future vaccines against future variants of the COVID-19 virus,” he added.
Altin and colleagues are now looking more closely at the antibodies that target the two conserved regions they identified in their study to determine whether these are broadly-neutralizing antibodies that generate immunity extending to new variants of the virus.
Using a technology called PepSeq developed by Altin and co-author Jason Ladner, Ph.D., an Assistant Professor at NAU’s Pathogen and Microbiome Institute, allowed the researchers to carefully map antibody responses and track them serially over 140 days in 21 people who received the Moderna SARS-CoV-2 vaccine. The technology matches individual peptides (the building blocks of proteins) with unique DNA tags. The tags allow scientists to pinpoint which peptides are being targeted by antibodies.
Before technologies like PepSeq, researchers had to measure the response of antibodies against one protein target at a time.
“PepSeq allows us to perform up to hundreds of thousands of measurements of antibodies against different parts of virus proteins all at the same time from the same sample,” said Ladner.
PepSeq also helps scientists precisely map the antibody response to specific regions of a protein. This allowed Ladner, Altin and their colleagues to track the differences in antibody response between divergent and conserved regions of the SARS-CoV-2 Spike protein.
“Our theory is that there is actually memory from previous common cold coronavirus encounters, and when you get the vaccine for SARS-CoV-2, the vaccine reawakens some of those memories … then you see this early response which is basically just a rapid memory response to what you’ve already seen,” Altin explained. “Then with time the immune system can reshape those responses more in the direction of the pandemic virus.”
Before COVID-19, Ladner and Altin were using PepSeq to get a closer look at the full range of viruses that infect humans. The powerful technology offers a way to “understand something about the viruses that a person has been exposed to in the past and the immune response to those infections,” said Ladner.
For instance, Ladner and his colleagues are looking at whether some chronic diseases, such as type 1 diabetes and celiac disease, might have some of their roots in different viral exposures. They also use the technology to look for different rates of infection between different populations, to see how this exposure history might be related to health disparities between those populations.
Research funding support came from the NIAID (U24AI152172, U24AI152172-01S1, U24AI152172-IOF); the California Institute for Regenerative Medicine (CLIN2COVID19-11775); the State of Arizona Technology and Research Initiative Fund (TRIF, administered by the Arizona Board of Regents, through Northern Arizona University); the Flinn Foundation; and The Cowden Endowment for Microbiology.
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About TGen, part of City of Hope
Translational Genomics Research Institute (TGen) is a Phoenix, Arizona-based nonprofit organization dedicated to conducting groundbreaking research with life-changing results. TGen is part of City of Hope, a world-renowned independent research and treatment center for cancer, diabetes and other life-threatening diseases. This precision medicine affiliation enables both institutes to complement each other in research and patient care, with City of Hope providing a significant clinical setting to advance scientific discoveries made by TGen. TGen is focused on helping patients with neurological disorders, cancer, diabetes and infectious diseases through cutting-edge translational research (the process of rapidly moving research toward patient benefit). TGen physicians and scientists work to unravel the genetic components of both common and complex rare diseases in adults and children. Working with collaborators in the scientific and medical communities worldwide, TGen makes a substantial contribution to help patients through efficiency and effectiveness of the translational process. Follow TGen on Facebook, LinkedIn and Twitter @TGen.
About Northern Arizona University
Founded in 1899, Northern Arizona University is a high-research institution providing exceptional educational opportunities and outcomes in Arizona and beyond. NAU delivers a student-centered experience to its nearly 30,000 students in Flagstaff, statewide and online through rigorous academic programs in a supportive, inclusive and diverse environment. As a community-engaged engine of opportunity, NAU powers social impact and economic mobility for the students and communities it serves. The university’s longstanding history of educating and partnering with diverse students and communities throughout Arizona is enhanced by its recent designation as a Hispanic-Serving Institution (HSI). Dedicated, world-renowned faculty and staff help ensure students achieve academic excellence, experience personal growth, have meaningful research and experiential learning opportunities and are positioned for personal and professional success. Located on the Colorado Plateau, in one of the highest-ranked college towns in the country, the NAU Flagstaff Mountain Campus is truly a jewel of the Southwest.