After contact of the spike protein S of the SARS-Cov-2 virus with the ACE2 receptor of the host cell, a membrane fusion occurs, which enables the virus to enter the host cell. In addition, however, a fusion of infected and uninfected host cells occurs, which leads to the death of these cells and thus to tissue damage.

An interdisciplinary research team at the Paul Ehrlich Institute (PEI) led by Prof. Christian Buchholz, head of the "Molecular Biotechnology and Gene Therapy" research group, has investigated the extent to which the spike protein-mediated cell fusion takes place. For this purpose, the team developed assays that can be used to measure these fusions.

The scientists observed in cell culture that even the tiniest, barely detectable amounts of the spike protein on the cell surface are sufficient to initiate cell fusion and thus cell death. In this context, neutralizing antibodies and sera from covid-19 convalescents were able to inhibit particle-cell fusion with high efficiency, but cell-cell fusion only moderately.

Original paper:
Theuerkauf, S. A., Michels, A., Riechert, V. et al. (2021). Quantitative Assays Reveal Cell Fusion at Minimal Levels of SARS-CoV-2 Spike Protein and Fusion-from-Without. iScience 24, 102170, March 19, 2021. https://www.sciencedirect.com/science/article/pii/S2589004221001383

Source:
https://www.bionity.com/de/news/1169949/gewebeschaeden-durch-zellfusion-in-covid-19-und-die-rolle-des-spikeproteins.html