Unveiling an Important New Cell Type in the Lung: Microfold Cells

• Published in: American journal of respiratory cell and molecular biology Vol. 70; no. 4; pp. 235 - 236
• Main Author: Han, SeungHye
• Format: Journal Article
• Language: English
• Published: United States American Thoracic Society 01.04.2024
• Subjects: Antigens; Cells; Epithelial cells; Gene expression; Immunosurveillance; Intestine; Lung; Lung cancer; Lung diseases; Lungs; M Cells; Mucosal immunity; Respiratory tract
• ISSN: 1044-1549; 1535-4989; 1535-4989
• DOI: 10.1165/rcmb.2024-0002ED

Mammalian lungs have complex defense mechanisms to protect against environmental pathogens and toxins. Recent studies have identified a rare cell type in the respiratory tract that is distinct from other epithelial cells and shares gene expression patterns with intestinal microfold (M) cells. M cells are specialized epithelial cells that transport luminal antigens to immune cells for mucosal immune surveillance. While M cells are well-described in the gut and upper respiratory tract, their existence in the lung was unknown. Two independent studies used single-cell RNA sequencing to discover and characterize M cells in the lung. These cells were found in the trachea and lung airways, and they express genes characteristic of intestinal M cells. The studies provide new insights into the role of M cells in lung immunity, infection, and inflammation. However, many questions remain unanswered, such as the existence of M cells in the human lung and their ability to transport antigens. Further research is needed to fully understand the biology of M cells in the lung.