Optimal human intestinal organoid model reveals interleukin-22-induced Paneth cell differentiation

Here, we developed an optimal system for culturing human small intestinal organoids (hSIOs) that recapitulate the structural and functional complexity of the intestinal crypt in vitro, including mature Paneth cells. With this model, we found that IL-22 is required for the differentiation of human Paneth cells. Rather than STAT3, the PI3K-mTORC1 axis, downstream of IL-22, mediates Paneth cell differentiation programs. CD-associated variants of the IL-22 receptor (IL10RB) were introduced in our system, resulting in the abolishment of Paneth cells in hSIOs. Moreover, our data demonstrated that long-term IL-22 exposure inhibited the growth of hSIOs, challenging the current perception of IL-22 in promoting intestinal regeneration, but rather in reducing cell viability. As a proof-of-principle, our study demonstrates that this optimal culture system for hSIOs has great potential for modelling human intestinal physiology and pathophysiology. Single-cell RNA-sequencing of human small intestinal organoids cultured in growth medium with or without the addition of IL22