A cell-based, spike protein binding assay highlights differences in antibody neutralising capacity for SARS-CoV-2 variants (preprint)

The engagement of the SARS-CoV-2 spike protein with ACE2 is a critical step for viral entry to human cells and accordingly blocking this interaction is a major determinant of the efficacy of monoclonal antibody therapeutics and vaccine-elicited serum antibodies. The emergence of SARS-CoV-2 variants necessitates the development of adaptable assays that can be applied to assess the effectiveness of therapeutics. Through testing of a range of recombinant spike proteins, we have developed a cell based, ACE2/spike protein binding assay that characterises monoclonal anti-spike protein antibodies and neutralising antibodies in donor serum. The assay uses high-content imaging to quantify cell bound spike protein fluorescence. Using spike proteins from the original "Wuhan" SARS-CoV-2 virus, as well as the delta and omicron variants, we identify differential blocking activity of three monoclonal antibodies directed against the spike receptor binding domain. Importantly, biological activity in the spike binding assay translated to efficacy in a SARS-CoV-2 infection assay. Hence, the spike binding assay has utility to monitor anti-spike antibodies against the major known SARS-CoV-2 variants and is readily adaptable to quantify impact of antibodies against new and emerging SARS-CoV-2 variants.

Sustainable urban development observatory of Thessaloniki - lessons learnt from the first year of operation

Sustainable Urban Development Observatory of Thessaloniki (SUDOTh) started operating in the first semester of 2020 with the objective to promote territorial evidence in policy making in urban governance. SUDOTh was developed as part of the Sustainable Urban Development Strategy 2016-2023 of Thessaloniki Metropolitan Area to address the need to obtain, observe and monitor how complex urban functions interact, at a territorial level, with product development (or lagging) effects. In the first year of operation, the Observatory had to set, test and evaluate the system of indicators and indexes it uses. Initially the system was formed in 4 basic sections: 1. Territorial Development and Urban renewal, 2. Urban Mobility, 3. Environmental Conditions and 4. Social Conditions. An extra set of indicators for Urban Governance was also developed. The process of data collection, test and evaluation of indicators was eventually coincided with the COVID-19 pandemic. This situation influenced deeply several urban functions as well as the data collection methodology. The first results and conclusions from the first year of the operation of SUDOTh are presented and discussed further in this paper.