Changes in body temperature, such as those that occur during a fever, can prime the immune system to respond more effectively to infection, according to a new study from researchers at the University of California, Berkeley.
The study, published in the journal Nature Immunology, found that even a small increase in body temperature can lead to changes in the activity of immune cells, such as macrophages and dendritic cells, which play a critical role in the body's defense against infection.
"We found that a modest increase in temperature, similar to what you might experience during a low-grade fever, can prime the immune system to respond more quickly and effectively to infection," said study lead author Dr. Aurélie Kaplon, a postdoctoral fellow in the lab of Dr. Jennifer Y. Wang, a professor of molecular and cell biology at UC Berkeley.
The researchers believe that the body's response to temperature changes is an evolutionary adaptation that helps us fight off infection.
"When you're sick, your body temperature often goes up," said Wang. "This fever response is thought to be a way for the body to fight off infection. Our study suggests that one way fever does this is by priming the immune system to respond more effectively."
The researchers studied the effects of temperature changes on immune cell activity in both mice and human cells. They found that even a small increase in temperature, such as from 37 degrees Celsius (98.6 degrees Fahrenheit) to 38 degrees Celsius (100.4 degrees Fahrenheit), led to changes in the activity of immune cells.
For example, the researchers found that macrophages exposed to a slightly higher temperature were more likely to produce inflammatory cytokines, which are molecules that help coordinate the immune response. Dendritic cells exposed to a higher temperature were more likely to mature and migrate to lymph nodes, where they can present antigens to T cells, which are another critical component of the immune system.
The researchers also found that the effects of temperature changes on immune cell activity were reversible. When the temperature was lowered, the activity of immune cells returned to normal.
"Our findings suggest that temperature changes can have a significant impact on the immune system," said Kaplon. "This could have implications for the development of new vaccines and immunotherapies."
