tetano
Editor, Senior Moderator
Infect Genet Evol
. 2021 Sep 9;105075.
doi: 10.1016/j.meegid.2021.105075. Online ahead of print.
Pre-existing T cell-mediated cross-reactivity to SARS-CoV-2 cannot solely be explained by prior exposure to endemic human coronaviruses
Cedric C S Tan[SUP] 1 [/SUP], Christopher J Owen[SUP] 2 [/SUP], Christine Y L Tham[SUP] 3 [/SUP], Antonio Bertoletti[SUP] 3 [/SUP], Lucy van Dorp[SUP] 2 [/SUP], Francois Balloux[SUP] 2 [/SUP]
Affiliations
Abstract
T-cell-mediated immunity to SARS-CoV-2-derived peptides in individuals unexposed to SARS-CoV-2 has been previously reported. This pre-existing immunity was suggested to largely derive from prior exposure to 'common cold' endemic human coronaviruses (HCoVs). To test this, we characterised the sequence homology of SARS-CoV-2-derived T-cell epitopes reported in the literature across the full proteome of the Coronaviridae family. 54.8% of these epitopes had no homology to any of the HCoVs. Further, the proportion of SARS-CoV-2-derived epitopes with any level of sequence homology to the proteins encoded by any of the coronaviruses tested is well-predicted by their alignment-free phylogenetic distance to SARS-CoV-2 (Pearson's r = -0.958). No coronavirus in our dataset showed a significant excess of T-cell epitope homology relative to the proportion of expected random matches, given their genetic similarity to SARS-CoV-2. Our findings suggest that prior exposure to human or animal-associated coronaviruses cannot completely explain the T-cell repertoire in unexposed individuals that recognise SARS-CoV-2 cross-reactive epitopes.
. 2021 Sep 9;105075.
doi: 10.1016/j.meegid.2021.105075. Online ahead of print.
Pre-existing T cell-mediated cross-reactivity to SARS-CoV-2 cannot solely be explained by prior exposure to endemic human coronaviruses
Cedric C S Tan[SUP] 1 [/SUP], Christopher J Owen[SUP] 2 [/SUP], Christine Y L Tham[SUP] 3 [/SUP], Antonio Bertoletti[SUP] 3 [/SUP], Lucy van Dorp[SUP] 2 [/SUP], Francois Balloux[SUP] 2 [/SUP]
Affiliations
- PMID: 34509646
- DOI: 10.1016/j.meegid.2021.105075
Abstract
T-cell-mediated immunity to SARS-CoV-2-derived peptides in individuals unexposed to SARS-CoV-2 has been previously reported. This pre-existing immunity was suggested to largely derive from prior exposure to 'common cold' endemic human coronaviruses (HCoVs). To test this, we characterised the sequence homology of SARS-CoV-2-derived T-cell epitopes reported in the literature across the full proteome of the Coronaviridae family. 54.8% of these epitopes had no homology to any of the HCoVs. Further, the proportion of SARS-CoV-2-derived epitopes with any level of sequence homology to the proteins encoded by any of the coronaviruses tested is well-predicted by their alignment-free phylogenetic distance to SARS-CoV-2 (Pearson's r = -0.958). No coronavirus in our dataset showed a significant excess of T-cell epitope homology relative to the proportion of expected random matches, given their genetic similarity to SARS-CoV-2. Our findings suggest that prior exposure to human or animal-associated coronaviruses cannot completely explain the T-cell repertoire in unexposed individuals that recognise SARS-CoV-2 cross-reactive epitopes.