In a study at The University of Alabama, aging fruit flies died faster than younger flies from a viral infection because of different genetic responses, lowering the older flies’ tolerance to the infection.

The findings published recently in G3: Genes, Genomes, Genetics add to the understanding of innate immunity, the first line of defense against infections, which is not fully understood in humans, and prove the fruit fly, Drosophila, is a good candidate for aging immunity studies that could lead to advancements in treating viral infections in older humans.

“We are living in times where there is a substantial increase in aging populations, and we know there is a decline of immune function in humans as we age,” said Dr. Stanislava Chtarbanova, UA assistant professor of biological sciences whose lab led the study. “This is the first study to use the fly for investigating age-dependent, anti-viral responses. Our lab can leverage this genetic model to study the molecular mechanisms underlying aging immunity.”

Mitochondria are the energy suppliers of our body cells. These tiny cell components have their own genetic material, which triggers an inflammatory response when released into the interior of the cell. The reasons for the release are not yet known, but some cardiac and neurodegenerative diseases as well as the aging process are linked to the mitochondrial genome. Researchers at the Max Planck Institute for Biology of Aging and the CECAD Cluster of Excellence in Aging research have investigated the reasons for the release of mitochondrial genetic material and found a direct link to cellular metabolism: when the cell’s DNA building blocks are in short supply, mitochondria release their genetic material and trigger inflammation. The researchers hope to find new therapeutic approaches by influencing this metabolic pathway.

Our body needs energy—for every metabolic process, every movement and for breathing. This energy is produced in tiny components of our body cells, the so-called mitochondria. Unlike other cell components, mitochondria have their own genetic material, mitochondrial DNA. However, in certain situations, mitochondria release their DNA into the interior of the cell, causing a reaction from the cell’s own immune system and being associated with various diseases as well as the aging process. The reasons for the release of mitochondrial DNA are not yet known.