In silico prediction of immune-escaping hot spots for future COVID-19
vaccine design
Abstract
The COVID-19 pandemic has had a widespread impact on a global scale, and
the evolution of considerable dominants has already taken place. Some
variants contained certain key mutations located on the receptor binding
domain (RBD) of spike protein, such as E484K and N501Y. It is
increasingly worrying that these variants could impair the efficacy of
current vaccines or therapies. Therefore, how to design future vaccines
to prevent the different variants remains urgent. In this work, we
proposed an in silico approach, in which we combined binding free energy
measured by computational mutagenesis of spike-antibody complexes and
mutation frequency calculated from viral genome sequencing data, to
estimate an immune-escaping score ( IES) and predict
immune-escaping hot spots. We identified 23 immune-escaping mutations on
the RBD, nine of which occurred in omicron variants (R346K, K417N,
N440K, L452Q, L452R, S477N, T478K, F490S, and N501Y), despite our
dataset being curated before the omicron first appeared. The highest
immune-escaping score ( IES=1) was found for E484K, which agrees
with recent studies stating that the mutation significantly reduced the
efficacy of neutralization antibodies. Furthermore, our predicted
binding free energy and IES show a high correlation with
high-throughput deep mutational scanning (Pearson’s r = 0.70) and
experimentally measured neutralization titers data (mean Pearson’s
r = -0.80). In summary, our work provides valuable insights and
will help design future COVID-19 vaccines.