TLR7 deficient mice show impaired CD4⁺ T cell response.

<p>WT or TLR7^-/- mice were infected with 50PFU of PR8 and CD86 expression on migratory DC present in the mediastinal lymph node were analyzed by flow cytometry on day 2 and 4 post infection. (A) Representative histograms showing upregulation of CD86 in CD103⁺ DC (upper panel) and CD11b⁺ DC (lower panel) in MLN on day 4 post infection. (B) Quantification of MFI of CD86 upregulation on lymph node DC in infected mice with relative to naïve control. (C) Bar graphs showing the frequencies of single or polyfunctional CD4⁺T cells on day 7 post infection with PR8. (D) Absolute number of IFNγ+ CD4+T cells in lungs on day 7 post infection with PR8. (E-F) Quantification of the frequencies of IFNγ and IFNγ, GrB, TNFα secreting CD4⁺ T cells in ex vivo stimulation with class-II restricted NP peptide on day 7 post infection. (G) Absolute number of IFNγ⁺ CD8⁺T cells in lungs on day 7 post infection with PR8 (H) Viral titers in the lungs on day 4 and 8 post-infection. The limit of detection for plaque assay was 10 PFU/ml. Data shown is a presentative of two independent experiments (n = 7–11 mice/group). The values are expressed as mean ± SEM, * denotes statistical significance at p<0.05 and ** denotes statistical significance at p<0.01.