Publication highlights

Scientists from Imperial College London and the Francis Crick Institute have uncovered genetic variants which help to explain why some children with mild COVID-19 go on to develop a severe inflammatory condition weeks after their infection. Throughout the COVID-19 pandemic, severe SARS-CoV-2 infections in children and infants were rare. But an estimated 1 in 10,000 children went on to develop multisystem inflammatory syndrome in children (MIS-C), presenting with a range of symptoms including rash, swelling and nausea and vomiting. In an analysis including more than 150 cases of MIS-C from Europe and the United States, the researchers in this study found that rare variations of a gene which helps regulate the lining of the gut made children four-times more likely to develop systemic inflammation and an array of symptoms. Understanding the genetic basis of MIS-C provides new insights into how the condition develops, who is at risk, and how patients and those with related conditions might be better treated.

Researchers at the Francis Crick Institute, King’s College London and Guy’s and St Thomas’ NHS Foundation Trust have characterised a specialised type of immune cell, which plays a key role in protecting and repairing the cells in the healthy human gut. The researchers investigated tissue from over 150 patients at Guy’s and St Thomas’ NHS Foundation Trust, dissecting a major population of T cells called gamma delta (γδ) T cells in the colons of people with healthy guts and people with IBD. In healthy guts, there was a unique specialised subset of gamma delta cells, termed V-gamma-4 (V4) cells, that intriguingly were significantly altered and often conspicuously depleted in inflamed IBD samples.

The researchers also observed that, in people whose inflammation had improved, those with restored V4 T cell function were less likely to relapse than those who did not. This suggests that assessing the status of V4 T cells could be a useful biomarker for disease progression.

Researchers at the Francis Crick Institute and UCL have identified stem cells in the human thymus for the first time. These cells represent a potential new target to understand immune diseases and cancer and how to boost the immune system. The researchers found that these stem cells, named Polykeratin cells, express a variety of genes allowing them to give rise to many cell types not previously considered to have a common origin. They can develop into epithelial as well as muscle and neuroendocrine cells, highlighting the importance of the thymus in hormonal regulation. The researchers isolated Polykeratin stem cells in a dish and were able to show that thymus stem cells can be extensively expanded. They demonstrated that all the complex cells in the thymus epithelium could be produced from a single stem cell, highlighting a remarkable and yet untapped regenerative potential.