Fig. 1.
Demonstration of ongoing oxidative and nitrative stress is tissue biopsies of AIDS-KS lesions. Immunohistochemistry was conducted to identify presence and cellular localization of MnSOD, inducible NOS 2 and 3-nitrotyrosine. While MnSOD staining is predominantly found in surface epithelium and infiltrating phagocytes in healthy mucosa (A), AIDS-KS lesional cells, which are contained within the connective tissue stroma, contain abundant MnSOD protein (B). Both aggregates of AIDS-KS tumor cells (C) and individual AIDS-KS spindle cells (D) show intense lesional cell NOS 2 expression. AIDS-KS tumor islands also showed positive staining indicative of tyrosine nitration (E), while the anti-nitrotyrosine negative control (F) shows an absence of staining. (A and B = 100× image scale, C = 40× image scale, D, E and F = 200× image scale.)