Colon identified as a seat of immune cell learning
HEY! T-cells! Leave them bugs alone! Some immune cells need an education to avoid attacking gut bacteria that help digest food – and their classroom is your colon.
One seat of immune cell learning – the thymus – is already known. Chyi-Song Hsieh at Washington University School of Medicine in St Louis, Missouri, says the colon is another. His team found that receptors on regulatory T-cells in the colon of mice match those on the gut bacteria, meaning the T-cells have been "taught" to avoid the bugs. As these bacteria are found only in the gut, Hsieh says the T-cells received their education there.
When Hsieh’s team transferred T-cells between mice with different gut flora, the mice displayed symptoms of colitis – an inflamed gut (Nature, DOI: 10.1038/nature10434). That suggests colitis may be down to poor education of the T-cells.