Assessment of SARS-CoV-2 specific CD4(+) and CD8 (+) T cell responses using MHC class I and II tetramers

The success of SARS-CoV-2 (CoV-2) vaccines is measured by their ability to mount immune memory responses that are long-lasting. To achieve this goal, it is important to identify surrogates of immune protection, namely, CoV-2 MHC Class I and II immunodominant pieces/epitopes and methodologies to measure them. Here, we present results of flow cytometry-based MHC Class I and II QuickSwitchTM platforms for assessing SARS-CoV-2 peptide binding affinities to various human alleles as well as the H-2 Kb mouse allele. Multiple SARS-CoV-2 potential MHC binders were screened and validated by QuickSwitch testing. The screen included 31 MHC Class I and 19 MHC Class II peptides predicted to be good binders by the IEDB web resource provided by NIAID. While several predicted peptides with acceptable theoretical Kd showed poor MHC occupancies, fourteen MHC class II and three MHC class I peptides showed promiscuity in that they bind to multiple MHC molecule types. In addition to providing important data towards the study of the SARS-CoV-2 virus and its presented antigenic epitopes, the peptides identified in this study can be used in the QuickSwitch platform to generate MHC tetramers. With those tetramers, scientists can assess CD4 + and CD8 + immune responses to these different MHC/peptide complexes. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study focuses on evaluating the binding affinities of SARS-CoV-2 peptides to different MHC alleles using the QuickSwitchTM platform, identifying multiple MHC binders with high promiscuity. These results provide important data for further research on the SARS-CoV-2 virus and its antigenic epitopes.