Slime-forming proteins called mucins are tethered to the surfaces of your body to block bacteria that would happily chomp their way into your organs and tissues. To understand more about these front-line defenders, cells from the cornea – the surface of the eye – were genetically modified and grown in the lab, each deficient in a particular type of mucin. Scientists discovered that the lack of a mucin called MUC16 weakened the surface barrier and, surprisingly, disrupted the ability of the cells beneath to form the tight junctions between neighbours (here stained light green) that are normally free of gaps to stop anything slipping through. The absence of another mucin, MUC1, didn't reduce the barrier function, suggesting that different types of mucin work together to create the barrier. Understanding more about our natural defences could help us develop new anti-infective drugs as existing antibiotics become less effective.
Written by Mick Warwicker
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