NeoCoV, a coronavirus strain related to MERS-CoV found in bats (NeoCoV is not a new variant of SARS-CoV-2, the human coronavirus strain responsible for COVID-19 pandemic) has been reported to be the first case of a MERS-CoV variant using ACE2. NeoCoV has potential of human emergence with both high fatality and transmission rate.
NeoCoV este o tulpină înrudită cu MERS-CoV care utilizează lilieci ACE 2 receptori pentru intrarea și infectarea acestuia în celulele de lilieci. Cu toate acestea, tulpinile de MERS folosește receptorii DPP4 pentru intrarea celulară. Este important de reținut că NeoCoV nu este o variantă nouă a SARS-2 care a provocat pandemia la nivel mondial de la apariția ei în noiembrie 2019.
This article shows that NeoCoV and its close relative PDF-2180-CoV is able to efficiently bind to ACE 2 receptors in bat, but bind less favourably to human ACE 2 receptors. Studies using cryo-electron microscopy revealed a distinct virus-ACE 2 binding surface in case of binding of NeoCoV and PDF-2180-CoV to ACE 2 receptors. A molecular determinant implicates Asp 338 residue, that prevents NeoCoV from binding to human ACE 2 receptor. In addition, a T510F mutation in the receptor binding motif of NeoCoV causes it to efficiently bind human ACE 2 receptor.
Given the high fatality rate of 35% associated with MERS-CoV related viruși derived from Beta CoV lineage, the NeoCoV could pose a potential threat to emergence of a high transmissible strain of NeoCoV and PDF-2180-CoV (upon gaining the T510F mutation due to antigenic drift) that can cause infection and mortality in humans, far worse than the current pandemic. Antigenic drift refers to random genetic mutații care a provocat schimbări în proteină structura, modificând astfel capacitatea proteinei de a se lega de un anumit receptor. În plus, infecția cauzată de mutația T510F a NeoCoV nu a putut fi neutralizată încrucișat de anticorpi care vizează SARS-CoV-2 sau MERS-CoV.
The entire global community hopes that the mutation in NeoCoV and PDF-2180-CoV that causes it to efficiently bind to human ACE 2 receptor, remains a laboratory study to understand the virulence of these viruși, and it doesn’t become a case of zoonotic transmission from bats to humans, creating another worldwide chaos.
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Sursa:
Yan H., et al 2022. Rudele apropiate ale MERS-CoV la lilieci folosesc ACE2 ca receptori funcționali. Preprint bioRxiv. Postat pe 25 ianuarie 2022. DOI: https://doi.org/10.1101/2022.01.24.477490
