Recent research has identified a novel class of small antibodies that demonstrate significant protective capabilities against various strains of SARS coronaviruses, including SARS-CoV-1 and multiple variants of SARS-CoV-2. Published in Nature Communications, the study reveals that these antibodies target a highly conserved site at the base of the virus's spike protein, effectively preventing the virus from infecting host cells.
The ongoing evolution of SARS-CoV-2 presents challenges for current antibody therapies, as many traditional antibodies are designed to target regions that frequently mutate. This mutability allows the virus to escape detection and neutralization by the immune system. To address this issue, a research team led by Prof. Xavier Saelens and Dr. Bert Schepens at the VIB-UGent Center for Medical Biotechnology explored the S2 subunit of the spike protein, which is less prone to mutation and critical for viral entry into cells.
The researchers utilized single-domain antibodies, or nanobodies, derived from llamas, particularly one llama named Winter. These nanobodies exhibit a unique mechanism by acting as a molecular clamp, binding to a stable region of the spike protein and preventing it from unfolding, a necessary step for viral infection. Laboratory studies indicated that these antibodies provide strong protection against the virus, even at low concentrations, and the virus displayed difficulty in developing resistance.
The findings suggest a promising pathway for the development of broad-spectrum antiviral treatments that could remain effective against emerging viral variants. With their high potency and stability, these antibodies may serve as a foundation for next-generation therapies aimed at addressing current and future coronavirus threats. The research received support from various organizations, including the Research Foundation - Flanders and EU Horizon 2021.