Abstract

Conventional dendritic cells (cDCs) are pivotal sentinels of the immune system, playing a critical role in initiating and regulating immune responses in the respiratory tract. The conducting airway mucosa, a primary site of pathogen and allergen entry, is continuously surveyed by these cells. However, a precise characterization of the distinct conventional dendritic cell subpopulations, specifically cDC1 and cDC2, within this mucosal environment remains essential for understanding local immune homeostasis and disease pathogenesis. This study aimed to identify and quantify the cDC1 and cDC2 subsets in the conducting airway mucosa. Using a whole-mount immunohistochemistry approach on mouse airway tissue, we employed specific markers: XCR1 for cDC1 and CD172 (SIRPα) for cDC2. Our findings reveal the presence of both XCR1+ cDC1 and CD172+ cDC2 subpopulations, strategically positioned within the mucosal layer. The cDC2 subset was found to be the predominant population, suggesting a primary role in antigen presentation and T-helper 2 (Th2) polarization, which is highly relevant to allergic airway inflammation. The identification and spatial mapping of these cDC subsets provide a foundational understanding of the cellular landscape governing immune surveillance in the conducting airways, offering potential targets for therapeutic intervention in respiratory diseases such as asthma and chronic obstructive pulmonary disease.