Researchers find key protein involved in creating targeted immune responses

We are not born a blank slate, according to a new animal study from Washington State University. New research shows your innate immune system possesses targeted responses when encountering certain germs and microbes.

The body has two immune systems: the innate and adaptive immune system. The innate immune system is the first line of defense against dangerous pathogens and is what babies mainly rely on in the first few months of life. As babies develop, so does your second immune system called the adaptive immune system. This next line of defense prepares your body for a future encounter with a pathogen and helps build long-lasting immunity.

Scientists previously believed recognizing and targeting specific pathogens was a function of the adaptive immune system and only developed after exposure to disease and illness. But the new study suggests a neuronal protein known NMUR-1 works with the brain to drive away infection.

“Clinical studies have shown that stimulating impaired neural circuits—either electrically or pharmacologically—can cure or alleviate many innate immune diseases,” says Jingru Sun, associate professor in the WSU Elson S. Floyd College of Medicine and co-senior author on the study in a statement. “Knowing how the innate immune system generates a specific response to a particular pathogen enables us to manipulate neural circuits to adjust the intensity of the immune response as needed.”

While the research was based on animals, understanding the critical role of NMUR-1 protein in immunity may help with treating conditions with dysfunctional innate immune systems such as sepsis, arthritis, and inflammatory bowel disease. Further, Dr. Sun says the findings could help in mounting an immune response in a “post-antibiotic era” where antibiotics are not effective against drug-resistant superbugs.

The researchers studied a species of worm called Caenorhabditis elegans (C. elegans), a trusted model to study the brain. C. elegans have only 302 neurons in their brain, making them easier to study than the 82 billion neurons in the human brain. The tiny worm also has a transparent body, making it easier to see how different genes are expressed. Most importantly, C. elegans does not have an adaptive immune system making it easier to study the innate immune response.

When worms did not have the NMUR-1 protein, the innate immunity of C. elegans changed when exposed to different bacterial species. NMUR-1 also showed specific responses to certain pathogens. When researchers exposed worms to two types of bacteria , one increased the lifespan while the other decreased it. The findings suggest NMUR-1 is needed to created targeted responses to pathogens. in the innate immunity system 

“What we found is that NMUR-1 controls transcription factors, which in turn control the transcription of distinct innate immune genes in response to different pathogens,” says Yiyong Liu, an assistant professor in the WSU Elson S. Floyd College of Medicine and director of the university’s Genomics Service Center and co-senior author of the study.

The study is available to read in the journal Cell Reports.

Leave a Comment