30 Dec 2020
Systemic immune responses can hamper local infection immune responses
Doherty Institute researchers have found that if the immune system is mounting a systemic response throughout the whole body, it’s unlikely to respond effectively to localised infections.
The findings could have detrimental impact on the effectiveness of vaccines in people with chronic disease, or who are experience systemic infections causing severe inflammation
University of Melbourne Professor Scott Mueller, Laboratory Head at the Doherty Institute and his team, wanted to find out how the immune system balances local and systemic immune responses if they occur at the same time.
Published today in Cell Reports, using mouse models, the team discovered that in response to systemic inflammation white blood cells are drawn away from the local lymph glands and towards the systemic response, suppressing the response to the local infection.
“Interestingly, the killer T-cell response, the cells that kill virus-infected cells, was fine. But it was the antibody response that was mostly suppressed,” Professor Mueller explained.
“We also explored this in vaccination. Most vaccines are given in a locally, such as in the arm, eliciting an antibody response that will than protect you from future infection. But what happens if you have a local vaccine, but are experiencing a systemic response like a chronic disease or an acute virus causing inflammation in your body? We found that the vaccine was not as effective.”
One of the main signals the research team found that was critical in inflammation around the body hampering the local response was the body’s defense proteins, interferons.
“These are exciting findings; we have been able to reveal that systemic infection results in an inflammation-induced suppression of local immunity. This could have significant repercussions for the ability to fight infections or for vaccine effectiveness in individuals experiencing a systemic infection or inflammatory diseases.”
Next steps for this research are potentially exploring the detrimental effects to vaccination on the different conditions or diseases being experienced by the person at the same time.