Figure 2.

Proposed mechanisms of epithelial cell memory and trained immunity in type 2 CRS. The inflammatory memory of nasal epithelial cells and innate immune cells (such as macrophages and ILC2s) may perpetuate inflammation in the sinonasal mucosa, potentially contributing to the recurrence of type 2 CRS. Long-lasting memory of innate immune cells may be mediated by trained hematopoietic stem cells (central trained immunity). Trained immunity typically involves epigenetic and metabolic reprogramming of innate immune cells. This figure was created in Created with BioRender.