Study of the Expression of Angiotensin-converting Enzyme 2 (ACE2), a Cell Membrane Receptor for SARS-CoV-2 and the TMPRSS2 Serine Protease in Tonsils and Adenoids of Children and Adults

The entry point for SARS-CoV-2 into the body is the nasal and pharyngeal mucosa. Angiotensin-converting enzyme 2 (ACE 2) was quickly identified as the functional receptor for SARS-CoV-2. Furthermore, the TMPRSS2 serine protease is required for the anchoring of the S protein in cell lines. In addition, the most commonly used screening test is a test for viral RNA by RT-PCR on a nasopharyngeal sample because the viral load is high.

The tonsils and adenoids could be a target organ of the virus. In order to study this hypothesis, the expression of ACE 2 and the serine protease TMPRSS2 will be sought in these tissues.

In addition, children, generally at high risk of severe viral respiratory infections (RSV, influenza), have milder symptoms than older patients with SARS-CoV-2 infection. The reason for this difference remains elusive. But one of the hypotheses formulated is that the level of expression of ACE 2 and / or TMPRSS2 may differ between adults and children, the viral load seeming to be correlated with the severity of the attack. In order to study this hypothesis, we will therefore compare the level of expression of ACE 2 in the tonsil tissue of children and adults.