Reporting in Nature, Santos et al. have used human organoids generated from individuals with coeliac disease to identify an unexpected role for IL-7 in the pathogenesis of this disease.

The authors used an air–liquid interface (ALI) system to generate organoids from human small intestinal biopsies. These organoids were embedded within a collagen matrix in an air-exposed transwell with access to medium with growth factors from an outer well via a permeable membrane. Organoids formed after three days of culture and could be expanded with epithelial proliferation for more than a year. Importantly, the organoids retained their diverse epithelial, mesenchymal and immune cell populations. Although the numbers of haematopoietic cells progressively declined during culture, these cells could be maintained for longer by supplementing the medium with cytokines.