Figure 7.

Tg skin grafts on Wt recipients developed neutrophil-rich leukocytic infiltrates and edema within the papillary dermis that eventuated in clefting and/or blister formation within the epidermal BM at sites where in situ deposits of IgG and C3 were localized. a: Tg and Wt skin was grafted onto the opposite flanks of age and gender-matched Wt, Tg, and MHC II -/- recipients; biopsies were obtained between 6 and 25 days after grafting for light and IF microscopy studies. All specific alterations (i.e., those unrelated to wounds at the base and margins of grafts) developed in Tg grafts on Wt recipients (shown here). Such alterations were evident as early as 17 days after grafting and consisted of neutrophil-rich infiltrates within the papillary dermis. b: Alterations in Tg skin grafts on Wt recipients progressed to cleft and/or subepidermal blister formation within 20 to 25 days (top panels). Direct IF microscopy revealed in situ deposits of murine IgG and C3 in epidermal BMs of such grafts (arrows, bottom panels). Immunoreactants were not identified in the epidermal BMs of recipient skin adjacent to, or at distance from, Tg grafts, or in control grafts of Wt skin placed on the opposite flanks of Wt (insets, bottom panels, dotted white lines outline epidermal BM), Tg, or MHC II -/- recipients. Scale bars, ∼25 μm.