Scientists found that a gut‑lining cell type called M cells has the ATP‑sensing P2X7 receptor, and that the antimicrobial peptide LL‑37 can activate this receptor to boost local immune activity. This is an early‑stage discovery showing a possible way the gut’s immune system can be tuned by molecules like LL‑37, but it doesn’t give dosing or practical tips yet.

Interactions between microbes and epithelial cells in the gastrointestinal tract are closely associated with regulation of intestinal mucosal immune responses. Recent studies have highlighted the modulation of mucosal immunity by microbe-derived molecules such as ATP and short-chain fatty acids. In this study, we undertook to characterize the expression of the ATP-gated P2X7 receptor (P2X7R) on M cells and its role in gastrointestinal mucosal immune regulation because it was poorly characterized in Peyer's patches, although purinergic signaling via P2X7R and luminal ATP have been considered to play an important role in the gastrointestinal tract. Here, we present the first report on the expression of P2X7R on M cells and characterize the role of P2X7R in immune enhancement by ATP or LL-37.