Special types of viruses, often found in nose streaming mucus, appear to offer a level of immune protection against pathogenic bacteria.
New research suggests that viruses called bacteriophages, or phages, attach onto mucus and then infect and kill invasive bacteria. This provides new information relating to the way that the body deals with pathogens.
Bacteriophages are viruses that break open bacteria, killing them. They have been used in several novel therapies over the past few decades. However, little is understood about their ‘natural’ role in the human body. Phages are coated in proteins that latch onto sugars called glycans, anchoring the viruses in the mucus.
Mucus is a slimy substance made by our noses, intestines and other organs also fights invaders with antimicrobial molecules. Until recently, it was not known that phages also play a role in the mucus defense barrier.
The study was based on an examination of samples of mucus collected from human gums, sea anemones, fish, corals and mouse intestines. The mucus layers had more phages and fewer bacteria than the surrounding environment, indicating that the viruses helped to limit the number of bacteria allowed into the mucus.
The findings have been published in Proceedings of the National Academy of Sciences by Forest Rohwer of San Diego State University.