Deriving Human Intestinal Organoids with Functional Tissue-Resident Macrophages All From Pluripotent Stem Cells.

Area of Science:

• Gastroenterology
• Immunology
• Stem Cell Biology

Background:

• Gastrointestinal organs host tissue-resident immune cells vital for development, homeostasis, and disease.
• Current human organoid models, like human intestinal organoids (HIOs), often lack these immune cells, limiting their utility as disease models.
• The absence of immune cells in HIOs restricts their potential as accurate avatars for studying diseases.

Purpose of the Study:

• To engineer a human intestinal organoid (HIO) model incorporating functional tissue-resident macrophages.
• To create a more comprehensive organoid system for studying gastrointestinal diseases.

Main Methods:

• Human pluripotent stem cells were differentiated to generate HIOs and macrophages separately.
• HIOs and macrophages were co-cultured in vitro for 2 weeks.
• Organoids were analyzed via transcriptional profiling, macrophage functional assays, or in vivo maturation in immunocompromised mice for 10-12 weeks.

Main Results:

• Macrophages successfully integrated into HIOs, persisting in vitro for 2 weeks and in vivo for at least 12 weeks.
• Co-cultured macrophages exhibited transcriptional profiles similar to human fetal intestinal macrophages, indicating acquisition of tissue-resident characteristics.
• HIO macrophages demonstrated functional capabilities, including bacterial phagocytosis and cytokine production in response to inflammatory stimuli, with modulation by interleukin-10.

Conclusions:

• A novel HIO system with functional, long-term tissue-resident macrophages has been successfully generated.
• This advanced organoid model provides a valuable platform for investigating the complex molecular mechanisms underlying inflammatory bowel disease.