Immunohistochemical analyses of TLR3 expression in dermal fibrosis. Immunohistochemical analyses were performed using rabbit polyclonal antibodies against TLR3 (histograms a, b, d-f, g-i, k-m) or isotype control (histograms c and j). (A) Skin biopsies from mice injected with bleomycin, but not saline, demonstrated expression of TLR3 in the dermis (panel d), which localized to fibroblast-like cells (histogram e) and inflammatory cells (histogram f). n = 3 saline, n = 3 bleomycin. (B) Skin biopsies from control skin (n = 4) and SSc skin (n = 4) demonstrated TLR3 expression in the dermis of SSc skin (histogram k), which localized to fibroblast-like cells and inflammatory cells (histogram l) as well as to endothelial cells (histogram m) in SSc but no control skin.