A colorized scanning electron micrograph of a cultured T cell with a large number of exosomes budding from its surface.
Artificial Intelligence

Nasal Passage

How our airways fight bacteria

Given that bacteria are in just about every breath we take, how is it that our airways remain largely free of infection? Research by HMS scientists at Massachusetts Eye and Ear has provided an answer. According to their study, when cells at the front of the nose detect bacteria, they trigger TLR4, a receptor that stimulates the release of tiny fluid-filled sacs called exosomes. The exosomes not only contain an antimicrobial molecule that attacks the bacteria, but they also shuttle the protective antimicrobials from the front of the nose to the back of the airway, protecting other cells along the way.

Nocera AL, et al., Journal of Allergy and Clinical Immunology, November 2018

Image: Steve Gschmeissner/Science Source