Scientists who work at UNSW in Sydney have found that a specific transposable element, or jumping gene, in the genome of mice have the ability to fight any virus infection. Here's what they discovered.
The finding teaches us more about the immune system and how it works in mice and potentially humans. The gene suggests the possibility of treating virus infections by causing an overactive immune response. "It shows very clearly that a transposable element can control the immune system to favor host survival following virus infection and it's probably been selected to remain in the genome for this very reason," explained the senior author of the paper, Dr. Cecile King, Associate Professor from UNSW Science's School of Biotechnology & Biomolecular Sciences.
Roughly 2/3rds of a mammal's genome is acquired from transposable elements. It's still not known whether or not these transposable elements have a good or bad effect on gene transcription, and researchers are still not aware what kind of effects jumping genes have - nor what they do. To recognize their function, scientists must analyze what occurs when jumping genes are removed, explained Dr. King.
"That has been difficult because transposable elements are repetitive, and their ability to multiply across the genome has been one reason why they're so prominent in terms of the content of our genome," she said. "When you're trying to knock one out, you often actually target a whole group of them across the genome on different chromosomes, so it's been a little bit tricky to do." In the findings, which were published in Nature, the researchers removed the transposable elements called Lx9c11 from mice. They then infected the animals with Coxsackievirus B4, a virus that largely negatively impacts the pancreas and other tissues. The mice who lacked the Lx9c11 element died, showing that it's important to fight off infections. "We found that they had increased damage to the pancreas; infiltration of cells into the lung; activation of immune cell subsets; dysregulated blood glucose levels; weight loss and lethality. And the data indicated that the lethality was host induced," Dr. King said. Stay tuned for updates.