Scientists at the University of Tokyo came to the conclusion that global warming contributes to a decrease in immunity in animals and humans and makes them more vulnerable to various viral infections and other pathogens. The researchers' article was published in the journal Proceedings of the National Academy of Sciences.
During the experiment, scientists placed healthy female mice in chambers with cold air (4 degrees Celsius), air at room temperature (22 degrees) and hot air (36 degrees). On the eighth day in the chambers, the animals were infected with the influenza A / PR8 strain.
During a seven-day stay in high temperatures, the rodents ate little and lost 10 percent of their original body weight. In addition, it turned out that they significantly decreased the number of cytotoxic T-lymphocytes CD8 + T, specific to the virus, produced in the lungs, as well as the number of IgG antibodies.
High temperatures prevented the production of pro-inflammatory cytokine molecules and the activation of inflammasomes, protein complexes that trigger inflammatory reactions. On the seventh day of infection, the virus content in the lungs remained high. Also in mice exposed to hot air, there was an increase in autophagy in the lungs - the process of destroying unnecessary and damaged cell components.
In rodents kept at room temperature, artificial activation of autophagy reduced the ability to fight infection. However, injections of glucose and short-chain fatty acids restored the immune system's activity, which was disturbed by the high temperature.