Research Scientist The Jackson Laboratory for Genomic Medicine Farmington, Connecticut, United States
Disclosure(s):
Chun I. Yu, PhD: No financial relationships to disclose
Introduction/Rationale: Humanized mouse models were developed to bridge fundamental differences between murine and human immune systems and to overcome the limitations of in vitro models. However, existing humanized mice fail to fully recapitulate human mucosal immunity in the lung due to the absence of human airway epithelial cells within their native tissue architecture. Ths, we sought to develop a novel model with human immune cells alongside a human lung epithelium within the mouse lung, provides a physiologically relevant platform to investigate human epithelial–immune crosstalk in vivo.
Methods: NSGF6 mice, NSG‑based immunodeficient mice carrying a murine Flt3 knockout and human IL6 knock‑in, were engrafted with donor‑matched human bone marrow–derived CD34⁺ hematopoietic stem and progenitor cells and bronchial epithelial progenitor cells. Engraftments were performed at different time points to synchronize immune and epithelial development. Human immune cell and lung epithelial cell reconstitution were assessed by flow cytometry and immunofluorescence microscopy. Mice were infected intranasally with live influenza A virus to evaluate epithelial functionality and human immune responses.
Results: Following transplantation, human airway epithelial cells differentiated within their appropriate physiological niche in the murine lung and were permissive to human influenza A virus infection. Spatial analysis revealed a distinct compartmentalization, with human airway epithelial cells localized along the airway lining, whereas human immune cells were distributed throughout lung tissues, with sites of epithelial–immune interaction observed. In response to acute human influenza A virus infection, a significant increase in human CD14⁺CD16⁺ monocytes were detected in the lung.
Conclusion: Our model enables in situ reconstitution of human immune and airway epithelial compartments, providing a physiologically relevant platform to investigate human lung mucosal immunity, respiratory infection, and immune‑mediated lung disease.
