Researchers at the Trudeau Institute have found a method to deliver more effective vaccines in order to protect against chronic parasitic worm infections.
Dr. Markus Mohrs and his team focus much of their studies on cytokines, messengers used by cells of the immune system to communicate with one another.
Cytokines help determine both the size and the quality of our immune system's response to an infection.
How well they perform their job can decide whether it's the person or the pathogen that wins the battle for survival.
Despite their obvious importance, however, very little is known about how far or for how long cytokines can operate during an infection.
But now Mohrs' team has revealed when and where cytokine signals are received in the body.
Dr. Mohrs reports that cytokines not only signal locally to neighbouring cells, as previously thought, but they also spread throughout the affected lymph node influencing even those cells not actively involved in fighting the current infection.
The indiscriminate action of the cytokines means that these bystander cells may respond inappropriately when the immune system encounters a different infection and it becomes their turn to react.
The findings provide a potential explanation for the ability of chronic infections to alter immune responses to subsequent infections or vaccination procedures.
This is particularly important for the design of vaccines in the developing world, where chronic parasitic infections can derail vaccination programs that are effective in healthy individuals.
Because only bystander cells in the same lymph node as those responding to the parasite infection are affected by active cytokines, this study suggests that people infected with gastrointestinal worms may respond better to vaccines injected under the skin than those given by mouth.
This is critical information for the development of globally-effective vaccination strategies.
The study has appeared in the current issue of the journal Nature Immunology.