A team of researchers from Trinity College Dublin found a new way to fight MRSA, according to a study published in the scientific journal JCI Insight. The authors showed that targeting a key molecule called IL-10 during vaccine delivery improves the vaccine’s ability to protect against infection.
Staphylococcus aureus is one of the leading causes of infections spread in hospitals and causes over one million deaths worldwide each year. The problem is that current antibiotics are becoming less effective. The antibiotic-resistant form of MRSA is responsible for the highest number of deaths in high-income countries that are caused by antimicrobial-resistant bacterial infections.
As a result, many researchers want to find a solution to fight S. aureus-related infections. An obvious option is a vaccine but, while there has been some progress in recent years, a number of major problems remain. One of these issues is how S. aureus can dampen the immune response by activating a natural break in the immune system, an important immune-suppressive molecule known as Interleukin-10 (IL-10), which naturally acts to reduce inflammation in the body.
The exciting thing about S. aureus is that certain forms of this bacteria live in our bodies without causing harm. However, even during these harmless interactions, the bacterium still controls the immune system, and any vaccine would struggle to respond appropriately.
Using an animal model, the team showed that using a vaccine that primed the immune system while antibodies neutralised IL-10, the immune response improved significantly and reduced bacterial load.
“Taken in combination, our results offer significant promise for what would be a novel strategy for improving the efficacy of vaccines developed with the aim of suppressing S. aureus infection,” said Rachel McLoughlin, Professor in Immunology at Trinity College Dublin’s School of Biochemistry and Immunology. “Our work also strongly suggests that prior exposures to this bacterium may create a situation whereby our immune system no longer sees it as a threat and thus does not respond appropriately to a vaccine due to the creation of this immune-suppressed state. Again, this underlines why immunisation delivered with something that helps neutralise IL-10 offers renewed hope for effective vaccines against S. aureus.”
Kelly AM, McCarthy KN, Claxton TJ, Carlile SR, O’Brien EC, Vozza EG, Mills KH, McLoughlin RM. IL-10 inhibition during immunization improves vaccine-induced protection against Staphylococcus aureus infection. JCI Insight. 2024 May 28;9(13):e178216. doi: 10.1172/jci.insight.178216.