On the interactions of the receptor-binding domain of SARS-CoV-1 and SARS-CoV-2 spike proteins with monoclonal antibodies and the receptor ACE2

Carolina Corrêa Giron; Aatto Laaksonen; Fernando L. Barroso da Silva

The SARS-CoV-2, virus recently found in Wuhan, Hubei province, China and officially named by the World Health Organization (WHO), 1 has already spread through China from all continents (more than 168 countries), with 1,133,758 confirmed cases globally and 62,784 deaths (data as reported by Central European Time 5 April 2020). Due to the pandemic, the disease is not only affecting the health services, but also the economy in a global scale, interfering in the widespread displacement of people, tourism, local and even international markets. Once China's economy is a worldwide reference, its disruption leads to a global impact in the supply chains and the production itself. [1] [2] [3] The Coronaviridae family, to which SARS-CoV-2 belongs, includes a large variability of viruses and became recognized in the spring of 2003, when a human coronavirus caused severe acute respiratory syndrome (SARS). [4] [5] [6] [7] Based on phylogenetic analysis, the SARS-CoV-2 is classified as a lineage B betacoronavirus 8 and belongs to the same group as SARS-CoV-1 and HKU9-1, the bat coronavirus, demonstrating wide similarity with both genetically 9 (96,2% of sequence identity with HKU9-1). 10 The transmission was confirmed to be human-to-human once several medical care personnel and relatives got infected, 8, 9 but it is believed that it all started with an animal host, may it be a bat or another intermediate host. 7, 9, 11, 12 Even though the virus usually does not cause severe damage to the body, as will be explained below, the major concern is its high infectivity and pathogenicity. 8, 12, 13 The COVID-19 disease, caused by SARS-CoV-2 virus, 14 generally causes mild upper respiratory tract infections, resulting in fever and cough, yet it can also affect the lower effective neutralizing Abs which is relevant for the future prevention and treatment of this now widespread illness that should be immediately controlled. At the end, a new designed mAb candidate is proposed based on our present in silico findings.