Immune memory cells become sirens, sending alarm signals to neighboring cells upon reinfection according to a report published in Nature Immunology.
Immune responses occur faster and stronger upon reencounter with viruses or other pathogens. This speed of response forms the basis for vaccination strategies. Looking at immune responses in mouse female reproductive tract, David Masopust shows that tissue-resident immune cells called CD8+ effector memory T cells act as local sensors and deliver alarm signals to neighboring cells. This signaling leads to the release of chemical attractants that recruit more memory cells to the site of reinfection. This siren alarm allows immune cells to respond more rapidly to combat recurrent infections at the site of re-entry.
These findings suggest vaccination to establish memory T cells in local tissues, such as the mucosa, might be beneficial to combat future infections.