Swaying immune system to pave way for better vaccines

A team of researchers has opened a door to influencing the immune system, which would be useful to boost the effectiveness of vaccines or to counter autoimmune diseases such as lupus and rheumatoid arthritis.

The Scripps Research Institute (TSRI) research focused on a molecule called microRNA-155 (miR-155), a key player in the immune system's production of disease-fighting antibodies.

"It's very exciting to see exactly how this molecule works in the body," said co-leader Changchun Xiao.

Our cells rely on molecules called microRNAs (miRNAs) as a sort of "dimmer switches" to carefully regulate protein levels and combat disease.

"People know miRNAs are involved in immune response, but they don't know which miRNAs and how exactly," explained co-first author Zhe Huang.

In the study, the researchers focused on the roles of miRNAs during the critical period when the immune system first detects "invaders" such as viruses or bacteria. At this time, cells called T follicular helpers proliferate and migrate to a different area of the lymph organs to interact with B cells.

"They do a sort of tango," said Xiao.

This interaction prompts B cells to mature and produce effective antibodies, eventually offering long-term protection against infection.

"The next time you encounter that virus, for example, the body can respond quickly," said Xiao.

Using a technique called deep sequencing, the team identified miR-155 as a potential part of this process. Studies in mouse models suggested that miR-155 works by repressing a protein called Peli1. This leaves a molecule called c-Rel free to jump in and promote normal T cell proliferation.

This finding could help scientists improve current vaccines. While vaccines are life-saving, some vaccines wear off after a decade or only cover around 80 percent of those vaccinated.

The study is published in The Journal of Experimental Medicine.