Correspondence:
Prof. Dr. Xicheng Song. Department of Otolaryngology, Head and Neck Surgery. Yantai Yuhuangding Hospital, Qingdao University, Yantai 264000, China. Tel: +86535 6691999; Fax: +86535 6240341; E-mail: drxchsong@163.com
Prof. Dr. Yu Zhang. Department of Otolaryngology, Head and Neck Surgery. Yantai Yuhuangding Hospital, Qingdao University, Yantai 264000, China. Tel: +86535 6691999; Fax: +86535 6240341; E-mail: superzhang013@163.com
Potential conflict of interest: The authors declare no conflict of interest.
Funding sources for the study: The research was supported by the National Key Research and Development Program of China (2022YFC2504104), the National Natural Science Foundation of China (82271146 and 82271147) and the Major Scientific and Technological Innovation Project of Shandong Province (2020CXGC011302 and 2022CXGC020506).
Acknowledgement: The authors thank all the staff from Department of Otolaryngology, Head and Neck Surgery.

Abstract

Single-cell sequencing (SCS), including genomic, transcriptomic, epigenomic, proteomic, and metabolomic sequencing, is a powerful tool for revealing cellular and molecular landscapes at the level of single-cell resolution. The use of SCS in upper and lower airway diseases has revealed numerous intrinsic biological characteristics and dynamics of airway inflammation, cancer, viral infection, and other lesions, and has also constructed an immune landscape of health and disease states. In this report, we review how advances in SCS technology have increased our understanding of upper and lower airway diseases, including chronic rhinosinusitis, allergic rhinitis, asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, and other inflammatory diseases, as well as the landscape of airway immune cells in healthy and pathological conditions. We also discuss the potential mechanisms of tumor heterogeneity, circulating tumor cells, and tumor biological behavior. The rapid development of single-cell technology will further increase our understanding of the biological characteristics of upper and lower airway diseases and provide precise treatment targets for patients.
Key words: Upper and lower airway; Single-cell sequencing; Single cell map of the airway; Immune microenvironment; Tumor circulating cells.