No abstract

By the end of 2019, the World Health Organization (WHO) was informed about an outbreak of pneumonia of unknown etiology in Wuhan, China. Some patients were linked to a seafood market, suggesting animal-to-human transmission, but, soon, human-tohuman transmission was confirmed. The pathogen was promptly identified as a novel coronavirus belonging to lineage B betacoronaviruses that also include severe acute respiratory syndrome coronavirus (SARS-CoV), which caused a pandemic in China in 2002/2003, and bat SARS-like coronaviruses. 1 Since 2012, the outbreak of Middle East respiratory syndrome coronavirus infection starting from Saudi Arabia has resulted in 2494 confirmed cases and 858 deaths in 27 countries, posing ongoing threat to global public health (https://www.who.int/ emergencies/mers-cov/en). As of 1 February 2020, there were 12,024 confirmed cases with Wuhan pneumonia and 259 deaths, of which 11,860 cases were found in Mainland China and 164 in 26 other countries and territories. The estimated case fatality rate is about 2%, which is much lower than that of SARS (9.6%), while its transmission rate (R0) is 2-3% (https://www.worldometers.info/coronavirus), similar to that of SARS (3%). Like SARS-CoV-infected individuals, patients infected with this novel betacoronavirus showed abnormal findings on chest computed tomography, along with common symptoms that include fever, cough, and myalgia, or fatigue, at the onset of illness. Still, all indications suggest that the acute respiratory syndrome of SARS is, so far, more severe than that manifested by the present pneumonia outbreak. 2 The novel coronavirus was denoted as "2019-nCoV" by WHO (https://www.who.int/emergencies/diseases/novel-coronavirus-2019) and the Wuhan pneumonia was named as "novel coronavirus-infected pneumonia (NCIP)" by Chinese scientists. 3 However, it will seem illogical if coronavirus is listed after NCIP, i.e., "novel coronavirus-infected pneumonia coronavirus (NCIP-CoV)". Therefore, we suggest renaming NCIP as "pneumonia-associated respiratory syndrome (PARS)" and 2019-nCoV as "PARS coronavirus (PARS-CoV)", similar to SARS-CoV, to retain equivalent terminology.

Background:The Fc region of an antibody is a homodimer of two CH2-CH3 chains. Results: Monomeric IgG1 Fcs (mFcs) were generated by using a novel panning/screening procedure. Conclusion: The mFcs are highly soluble and retain binding to human FcRn comparable with that of Fc. Significance: The mFcs are promising for the development of novel therapeutic antibodies of small size and long half-lives.

The newly identified 2019 novel coronavirus (2019-nCoV) has caused more than 800 laboratory-confirmed human infections, including 25 deaths, posing a serious threat to human health. Currently, however, there is no specific antiviral treatment or vaccine. Considering the relatively high identity of receptor binding domain (RBD) in 2019-nCoV and SARS-CoV, it is urgent to assess the cross-reactivity of anti-SARS-CoV antibodies with 2019-nCoV spike protein, which could have important implications for rapid development of vaccines and therapeutic antibodies against 2019-nCoV. Here, we report for the first time that a SARS-CoV-specific human monoclonal antibody, CR3022, could bind potently with 2019-nCoV RBD (KD of 6.3 nM). The epitope of CR3022 does not overlap with the ACE2 binding site within 2019-nCoV RBD. Therefore, CR3022 has the potential to be developed as candidate therapeutics, alone or in combination with other neutralizing antibodies, for the prevention and treatment of 2019-nCoV infections. Interestingly, some of the most potent SARS-CoV-specific neutralizing antibodies (e.g., m396, CR3014) that target the ACE2 binding site of SARS-CoV failed to bind 2019-nCoV spike protein, indicating that the difference in the RBD of SARS-CoV and 2019-nCoV has a critical impact for the cross-reactivity of neutralizing antibodies, and that it is still necessary to develop novel monoclonal antibodies that could bind specifically to 2019-nCoV RBD.