SARS-CoV-2 mutations affect antigen processing by the proteasome to alter CD8+ T cell responses

Mutations within viral epitopes can result in escape from T cells, but the contribution of mutations in flanking regions of epitopes in SARS-CoV-2 has not been investigated. Focusing on two SARS-CoV-2 nucleoprotein CD8+ epitopes, we investigated the contribution of these flanking mutations to protea...

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Bibliographic Details
Main Authors: Wellington, D, Yin, Z, Yu, Z, Heilig, R, Davis, S, Fischer, R, Felce, SL, Antoun, E, Hublitz, P, Beveridge, R, Dong, D, Liu, G, Yao, X, Peng, Y, Kessler, B, Dong, T
Format: Journal article
Language:English
Published: Elsevier 2023
Description
Summary:Mutations within viral epitopes can result in escape from T cells, but the contribution of mutations in flanking regions of epitopes in SARS-CoV-2 has not been investigated. Focusing on two SARS-CoV-2 nucleoprotein CD8+ epitopes, we investigated the contribution of these flanking mutations to proteasomal processing and T cell activation. We found decreased NP9-17-B*27:05 CD8+ T cell responses to the NP-Q7K mutation, likely due to a lack of efficient epitope production by the proteasome, suggesting immune escape caused by this mutation. In contrast, NP-P6L and NP-D103 N/Y mutations flanking the NP9-17-B*27:05 and NP105-113-B*07:02 epitopes, respectively, increased CD8+ T cell responses associated with enhanced epitope production by the proteasome. Our results provide evidence that SARS-CoV-2 mutations outside the epitope could have a significant impact on proteasomal processing, either contributing to T cell escape or enhancement that may be exploited for future vaccine design.