In findings recently published in the Proceedings of the National Academy of Sciences, a group of researchers led by Professor Stephen McSorley (interim director of the Center for Comparative Medicine) paved the way for the latest in the development of an effective Salmonella vaccine.
Though McSorley and his team performed the study on mice, he’s confident that the findings are a step in the right direction and will be able to help people -- particularly in rural areas of Africa where non-typhoidal Salmonella (NTS) has been known to kill large groups of people.
McSorley noted that oftentimes, the residents of these areas get infected, and what would normally cause gastroenteritis -- inflammation of the stomach and intestines -- becomes much more serious and can be deadly. It’s also important to note that while there are two Salmonella vaccines available, they only protect about half of immunized people and aren’t viable options.
“These forms of disease are really impactful for resource-poor communities in Asia and Africa where the vaccines are either nonexistent or terrible,” McSorley said in a press release. “They are diseases of poverty.
“The goal of our lab is to understand the mechanisms of protective immunity in mice to learn tricks of the immune system and then develop a vaccine that could replicate that use for kids and people who live in these areas,” he added.
McSorley and his team focused on two different kinds of T-cells: circulating and non-circulating memory T-cells. The researchers looked at how these T-cells worked in fighting off Salmonella.
“It’s a new cell population we haven’t looked at before and they’re very effective so we need to learn more about them,” McSorley said. “They may be part of the answer to developing vaccines against a variety of pathogens.”
To test the T-cells’ effectiveness in fighting off Salmonella, the researchers injected both circulating and non-circulating memory T-cells from previously injected mice into mice that had never been injected. Fluorescent markers were able to signify which of the cells were successful in staving off the infection.
The researchers found that the solution was a non-circulating population of liver memory cells that don’t travel throughout the body. Perhaps the greatest takeaway from the test was that these cells can aid scientists in developing future Salmonella vaccines.
“We found that you absolutely need these non-circulating T-cells to protect against Salmonella,” McSorley said in the press release. “That’s an important milestone, because if you’re going to make a vaccine, you have to know what you’re trying to induce with what vaccine. Now that we know these forms of T-cells exist and protect against Salmonella, the next goal is to try to develop synthetic ways to induce them to make a vaccine.”