ACE2 Protein Landscape in the Head and Neck Region: The Conundrum of SARS-CoV-2 Infection
Géraldine Descamps,
Laurine Verset,
Anne Trelcat,
Claire Hopkins,
Jérome R. Lechien,
Fabrice Journe,
Sven Saussez
Affiliations
Géraldine Descamps
Department of Human Anatomy and Experimental Oncology, Faculty of Medicine and Pharmacy, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMONS), Avenue du Champ de Mars 6, 7000 Mons, Belgium
Laurine Verset
Department of Pathology, Institute Jules Bordet, Université Libre de Bruxelles, Rue Héger-Bordet 1, 1000 Brussels, Belgium
Anne Trelcat
Department of Human Anatomy and Experimental Oncology, Faculty of Medicine and Pharmacy, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMONS), Avenue du Champ de Mars 6, 7000 Mons, Belgium
Claire Hopkins
Guy’s and St Thomas’ Hospitals, Westminster Bridge Road, London SE1 9RT, UK
Jérome R. Lechien
Department of Human Anatomy and Experimental Oncology, Faculty of Medicine and Pharmacy, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMONS), Avenue du Champ de Mars 6, 7000 Mons, Belgium
Fabrice Journe
Department of Human Anatomy and Experimental Oncology, Faculty of Medicine and Pharmacy, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMONS), Avenue du Champ de Mars 6, 7000 Mons, Belgium
Sven Saussez
Department of Human Anatomy and Experimental Oncology, Faculty of Medicine and Pharmacy, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMONS), Avenue du Champ de Mars 6, 7000 Mons, Belgium
The coronavirus pandemic raging worldwide since December 2019 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which invades human cells via the angiotensin-converting enzyme 2 (ACE2) receptor. Although it has already been identified in many organs, ACE2 expression remains largely unknown in the head and neck (HN) sphere. Thus, this study aims to investigate its protein expression in several sites of the upper aerodigestive tract in order to highlight potential routes of infection. We compared ACE2 immunohistochemical expression between 70 paraffin-embedded specimens with two different antibodies and reported the quantified expression in each histological location. Surprisingly, we obtained different results depending on the antibody, an absence of labeling having been observed with a monoclonal antibody raised against the extracellular domain, whereas the polyclonal, against the cytoplasmic part of the protein, revealed enriched ACE2 expression, particularly in sinuses, vocal cords, salivary glands and oral cavity epithelial cells. The interpretation of these discordant results has brought several exciting lines of reflection. In conclusion, this study provides possible routes of entry for the SARS-CoV-2 in HN region and, above all, has led us to encourage caution when studying the ACE2 expression which is currently at the center of all attention.
