Immunohistochemical studies of basement membrane proteins and proliferation and apoptosis markers in sulfur mustard induced cutaneous lesions in weanling pigs.

Sulfur mustard (2,2-dichlorodiethyl sulfide, HD) is a chemical warfare agent that is a threat to both troops and civilians. The focus of HD research has been on intracellular adduct formation leading to apoptosis and/or necrosis in cutaneous lesions. However, there is work which suggests that HD may have a more direct effect on the basement membrane zone. Immunohistochemical staining to desmosomal proteins, cellular fibronectin, laminin 1, laminin 5, collagen IV, collagen VII, p53, Bcl-2, and PCNA was performed on weanling pig skin exposed to vesicating doses of HD, GB3, an antibody to laminin 5, showed a progressive decrease with loss of expression during the time period of clinical vesiculation. The other basement membrane proteins showed no change or inconsistent changes. PCNA, and p53 staining increased in the overlying epidermis in areas of vesiculation without significant necrosis. Bcl-2 positive cells were decreased or absent after exposure. This study implicates laminin 5 as the main basement membrane protein affected acutely by HD exposure. The patterns of staining of PCNA, Bcl-2, and p53 within the epidermis suggest that apoptosis and cellular necrosis both may play a role in cell death secondary to HD.