A T7 Bacteriophage

We’ve had a previously undescribed immune system right under our noses, and we never noticed. Or rather, in our our noses and any place else we have mucus membranes. And not just humans – all animals that have mucosal surfaces, from sea anemones to humans to, presumably, gnus and geckos.

Bacteriophage are viruses that infect and destroy bacteria, and most bacteriophage are specifically attuned to just a couple of bacterial strains.

A promising new study out this month in the Proceedings of the National Academy of Sciences found that bacteriophage on mucosal surfaces – often the entry way for infectious bacteria into a host – provide an effective and powerful barrier against those bacteria. The bacteriophage form bonds with the sugars in mucus, causing them to adhere to the surface when they might otherwise have moved on. Experiments introduced bacteria and complementary phage into host tissue samples both with and without mucosal surfaces – the rate of cell death among the host tissue without mucus was three times that of the mucosal surfaces with phage protection.

Bacteriophage Adherence to Mucus (BAM) model, where bacteriophage adheres to mucus layers and provides immunity against invading bacteria.
Credit: Jeremy Barr via: MedicalExpress.com

The study, carried out by a San Diego State University research team led by biology post-doctoral fellow Jeremy Barr, proposes Bacteriophage Adherence to Mucus—or BAM—as a new model of immunity.

The role of bacteriophage in fighting bacterial infection has been known and researched since the early 20th century. In Russia, ‘phage’ therapy became widespread while the West focused on the

Electron micrograph of bacteriophages attacking a bacterial cell
Image: Dr. Graham Beard via Wikipedia

development of antibiotic treatment, following the first human use of penicillin in the 1940s. Who knows how much more quickly this would have progressed without the Iron Curtain of the Cold War blocking the open exchange of scientific research? This could be another entry in my posts about What We Talk About When We Talk About War, but I’ll leave it at that.