Conclusion
We show that human mucosal organoids exhibit proper immune functions and successfully mimic an immunocompetent tissue microenvironment able to host patient-derived immune cells. Our experimental set-up provides a novel tool to tackle the complexity of immune responses in mucosal tissues which can be tailored to different human pathologies.
Methods
We developed human 3D lung and intestinal organoids differentiated from induced pluripotent stem cells to model mucosal tissues. We then compared their response to a panel of microbial ligands and investigated their ability to attract and host human primary monocytes.
Results
Mature lung and intestinal organoids comprised epithelial (EpCAM+) and mesenchymal (CD73+) cells which responded to Toll-like receptor stimulation by releasing pro-inflammatory cytokines and expressing tissue inflammatory markers including MMP9, COX2 and CRP. When added to the organoid culture, primary human monocytes migrated towards the organoids and began to differentiate to an 'intermediate-like' phenotype characterised by increased levels of CD14 and CD16.