Fig. 4

TLR7 RNA expression in mouse spleen and vagal ganglia after H1N1 infection. A Wild-type mice were weighed before (pre) and 4 days after (post) inoculation with H1N1 (H1N1-infected) or PBS vehicle (mock-infected). Body weights were significantly reduced in H1N1-infected mice. B H1N1 viral titers were quantified from lung tissue by real-time RT-PCR 4 days after inoculation. H1N1 viral RNA was present only in the mice inoculated with H1N1. N = 12–17. C Sections of the spleen were labeled with either the TLR7 or the housekeeping gene Ppib in situ hybridization probes (pink, representative images). Blue = hematoxylin nuclear stain. D TLR7 RNA was quantified and normalized to housekeeping RNA Ppib expression. H1N1 infection significantly increased the TLR7 RNA expression in mouse spleen. E Sections of the vagal ganglia were labeled with either TLR7 or the housekeeping gene Ppib in situ hybridization probes (pink, representative images). Blue = hematoxylin nuclear stain. F TLR7 RNA expression was quantified and normalized to the Ppib expression. H1N1 infection did not affect the TLR7 expression in mice vagal ganglia. G Similarly, in the contralateral ganglia, TLR7 RNA expression, quantified by real-time RT-PCR, was not affected by H1N1 infection. *p < 0.05