Figure 5.

CD103⁺ cDC1s support the LN egression of IAV-specific CD8⁺ T cells. (A) Total number of NP_366−374-specific CD8⁺ T cells (left) and bulk CD8⁺ T cells (right) in the mLN of wild type and Clec9A-DTR mice on day 3, 6, 10, and 15 of infection. (B) Representative picture of posterior mLN harvested from uninfected mice and infected Clec9A-DTR and wild type mice after 10 days of infection. (C) Representative H&E histology images of posterior mLN harvested from day 10-infected Clec9A-DTR and wild type mice. (D) Representative flow cytometry profiles of CD8 and CD43 stained cells obtained from mLN harvested on day 6, 10, and 15 of infection. (E) Frequency of CD43⁺/CD43⁻ CD8⁺ T cells in the mLN (left). Total number of CD43⁺ CD8⁺ T cells in the mLN (right) on day 6, 10, and 15 of infection. (F) Flow cytometry profiles of OT1⁺CD8⁺ T cells co-cultured with sorted DCs for 3 days with or without exogenous SIINFEKL peptide. Cells are gated on Ly5.1⁺, CD8⁺, and CD3⁺. (G) MFI of S1PR by OT1⁺CD8⁺ T cells that were co-cultured without DC (gray filled), with migratory CD103⁺ cDC1s (blue), or with migratory CD11b⁺ cDC2s (red) in the absence of exogenous SIINFEKL peptide. (H) MFI of S1PR by OT1⁺CD8⁺ T cells that were co-cultured without DC (gray filled), with migratory CD103⁺ cDC1s (blue), or with migratory CD11b⁺ cDC2s (red) in the presence of exogenous SIINFEKL peptide. (I) CFSE dilution profiles of donor OT1-CD8⁺ T cells in the mLN. Wild type and Clec9A-DTR recipients were infected with recombinant OVA-PR8 virus 3 h before donor OT1-CD8⁺ T cells transfer (2 × 10⁶), and mLNs were harvested 4 days after infection. (J) MFI of S1PR expression by donor OT1-CD8⁺ T cells in each cell division. Data are shown as mean ± SEM. ^*p < 0.05. ^**p < 0.01. ^***p < 0.001. Data represent two (A,E,G–J) (n = 3–5) independent experiments.