One for all? A class of antibodies targeting all types of coronavirus
Institutional Communication Service
15 July 2022
A study conducted by Federica Sallusto's Laboratory (IRB-USI, Bellinzona and ETH Zurich) and David Veesler's Laboratory (University of Washington, Seattle), recently published in Science, describes a new class of antibodies that bind to and neutralise most types of human and animal coronavirus, including all variants of SARS-CoV-2. These antibodies reveal a new target for the design of universal vaccines against coronaviruses.
Coronaviruses have been circulating in the human population for decades and cause seasonal common colds. However, recent zoonotic transmission (from animals) has led to the introduction of highly pathogenic SARS-CoV, MERS-CoV and SARS-CoV-2, which have caused epidemics and the current pandemic. In view of the global impact of the current pandemic and the likely occurrence of new zoonotic transmissions, there is an urgent need to develop a 'universal' vaccination strategy that can offer broad protection against all coronaviruses.
An important component of immunity is antibodies, 'Y'-shaped proteins produced by the B-cells of our immune system following infection or vaccination. Antibodies are able to bind to viruses, preventing infection of host cells, but are usually highly specific for a particular virus species. In this study, the team searched for a rare class of antibodies capable of recognising and neutralising all coronavirus species.
Using an innovative and responsive method, the team isolated a new class of antibodies from infected and vaccinated individuals that bind to and neutralise most human and animal coronaviruses, including all variants of SARS-CoV-2. These antibodies bind to a region of the coronavirus spike protein called the fusion peptide, which is essential for virus entry into the host cell and highly retained between different coronaviruses. Using structural and functional approaches, the team found that the fusion peptide is kept 'hidden' in the spike protein and is only exposed when the virus spike protein binds to the receptor on the host cell.
The discovery of the fusion peptide as a target for broadly neutralising antibodies paves the way for the design of next-generation vaccines capable of inducing such broadly protective antibodies.
This study was made possible thanks to the collaboration with Humabs BioMed (subsidiary of Vir Biotechnology), Swiss and Italian clinical institutions: Ente Ospedaliero Cantonale (EOC), Clinica Luganese Moncucco, INGM Milan and University of Leuven.
ACE2-binding exposes the SARS-CoV-2 fusion peptide to broadly neutralising coronavirus antibodies