Fig 5. In vivo transfection of hACE2 mRNA permits the detection and functional mapping of SARS-CoV-2 specific CD4⁺ T cell responses.

(A) As potential “well” hits were identified, the peptides contained in each well were deconvoluted and used individually to stimulate splenocytes from hACE2 transfected, SARS-CoV-2 infected mice. 6 potential epitopes were identified (marked with red arrows) as defined by the frequency of IFN-γ⁺ CD4⁺ T cells being at least 2-fold above background (stimulated with vehicle) in at least 3 of the 4 mice screened. (B) Representative flow cytometry plots displaying IFN-γ and TNFα expression in CD4⁺ T cells for each putative epitope in comparison to a vehicle control.