Fig 1.
The cDC1 subset is required for priming of CD8 T-cells in the MLN and lungs following SARS-CoV-2 infection.
hACE2/Batf3KO (red) and hACE2 (blue) mice were infected i.n with 50pfu of SARS-CoV-2. Results obtained with naïve, non-infected mice, are also depicted (black). At day 8 post infection SARS-CoV-2-specific CD8 T-cells were quantified by tetramer staining in the MLN (A-representative FACS analysis from each group and B-histograms incorporating the individual sets of results obtained for each animal) and the lung (C and D, see explanation for A and B above). Frequencies of effector cells were evaluated by CD62L staining (E and F, see explanation for A and B above). Bars indicate means ± SEM from 3–6 animals per group. Gating strategies for A-B and C-E appear in S5 and S6 Figs, respectively. P values: *P < 0.05, **P < 0.01.
Fig 2.
The cDC1 subset is required for induction of CD8 memory T-cells following SARS-CoV-2 infection.
hACE2/Batf3KO (red) and hACE2 (blue) mice were infected i.n with 50pfu of SARS-CoV-2. Results obtained with naïve non-infected mice are also depicted (black). 7 weeks post infection the frequencies of mucosal imprinted CD103+ memory CD8 T-cells was evaluated (A-representative FACS analysis from each group and B- histograms incorporating the individual sets of results obtained for each animal). Memory CD8 T-cells specific for SARS-CoV-2 in the lung were quantified by tetramer staining (C and D, as above). ELIspot assays were performed using splenocytes from infected animals stimulated with the S539 (E) and S915 (F) peptides. SARS-CoV-2 specific CD4 T-cells were quantified on splenocytes from infected animals using ORF3 peptide (G). Neutralizing antibody titers were determined by pseudovirus neutralization assay (H). Bars indicate means ± SEM from 4–6 animals per group. Gating strategy for A-D appear in S7 Fig. P values: *P < 0.05, **P < 0.01, ***P < 0.001, and ns, not significant.
Fig 3.
cDC1 cells contribute to SARS-CoV-2 clearance from infected lungs.
hACE2/Batf3KO (red) and hACE2 (blue) mice were infected i.n with 50pfu of SARS-CoV-2. At different time points post infection viral loads in the lungs were determined by plaque assay (A). Viral loads in the lungs of hACE2 or hACE2/Batf3KO mice at day 8 post infection following depletion of CD4 T-cells (B). Bars indicate means ± SEM from 4–8 animals per group. P values: *P < 0.05, **P < 0.01, ***P < 0.001, and ns, not significant.
Fig 4.
Confirmation of the cDC1 subset requirement in activation of CD8 T-cells using a mouse-adapted SARS-CoV-2.
Batf3-/- (red) and C57BL/6 (blue) mice were infected i.n with 105pfu of mouse-adapted SARS-CoV-2 (MA10). Morbidity (weight loss) of infected animals was monitored for 14 days (A). At different time points post infection viral loads in the lungs were determined by plaque assay (B). Five weeks post infection, animals were sacrificed and analyzed for the presence of SARS-CoV-2-specific CD8 T cells by tetramer staining (C and D). ELIspot assays were performed using splenocytes from infected animals stimulated with the S539 peptide (E). Neutralizing antibody titers were determined by pseudovirus neutralization assay (F). Bars indicate means ± SEM from 4–6 animals per group. P values: *P < 0.05, **P < 0.01, ***P < 0.001, and ns, not significant.