Blog admin completely agree with the following author’s opinion about alternative host receptors for SARS-CoV-2 to ACE2.
A review paper from a group of Shandong University of Traditional Chinese Medicine, China,
https://www.sciencedirect.com/science/article/pii/S2211383521001726?via%3Dihub
Although the role of ACE2 as a receptor for SARS-CoV-2 is clear, extensive studies have demonstrated that the expression of ACE2 is tissue- and cell-type specific and SARS-CoV-2 appears to infect tissues that are negative for ACE2. For example, ACE2 expression in human lung and respiratory tract is extremely low and limited in the epithelium, however, it’s well studied that SARS-CoV-2 preferentially infects cells of the respiratory tract, and SARS-CoV-2 can successfully infect human H522 lung adenocarcinoma cells despite complete absence of ACE2. The existence of alternative host receptors for SARS-CoV-2 entry was therefore speculated. Interestingly, Wang et al. recently identified the tyrosine-protein kinase receptor UFO (AXL) as a candidate receptor that promoting SARS-CoV-2 infection of the human respiratory system. Based on their study, the NTD rather than RBD of SARS-CoV-2 Spike is responsible for AXL recognition, highlighting the importance of NTD during SARS-CoV-2 infection. Meanwhile, Amraei et al. demonstrated thatCD209L/L-SIGN and CD209/DC-SIGN may also serve as alternative receptors for SARS-CoV-2 in disease-relevant cell types, including the vascular system.
The following papers are cited in this review paper regarding AXL and L-SIGN/DC-SIGN.
Regarding AXL by Wang et al.
Regarding L-SIGN/DC-SIGN by Amraei et al.
