The Immunoregulatory Architecture of the Adult Oral Cavity

Abstract

The oral cavity is a critical barrier with immunosurveillance capabilities. A detailed understanding of its cellular, molecular, and spatial architecture is essential for advancing precision medicine across aerodigestive tissues. Here, we present the first integrated atlas of human adult oral and craniofacial tissues, derived from single-cell RNA sequencing of ~250,000 cells from 70 samples across 13 niches, including salivary glands and oral mucosae. Complementary spatial atlases using a 40-plex protein and 300-plex transcriptomics panels were developed, covering >2 million cells. Using our new AstroSuite package, we identified 8 tissue cellular neighborhoods (TCNs) and 17 multicellular interaction modules (MCIMs) across gland and mucosae in health. Diverse fibrovascular TCNs emerged as centralized hubs, coordinating immune cell migration and activation. Mucosal hubs within stroma displayed higher immune cell density, diversity, and activation than glands, underscoring differences in functional architecture. In keratinized and nonkeratinized mucosae, common fibrovascular hubs, and MCIMs revealed a specialized biogeography of immunoregulation. Under chronic inflammation, mucosal TCNs were fragmented, and MCIMs involving fibroblasts and immune cells were reorganized and expanded. Focused analysis of tertiary lymphoid structures (TLS) and fibroblasts identified TLS-associated MCIMs and drug candidates targeting these spatial interactions, offering a foundational framework for broadly dissecting mucosal immunity to guide precision medicine approaches.