An immunochromatographic assay to detect reduced level of laminin-5 gamma2 in sulfur mustard-exposed normal human epidermal keratinocytes

Abstract

The need for reliable methods to detect the nature and extent of poisoning with chemical warfare agents is evident from the recent threat of use of these agents in warfare and terrorist attacks. Sulfur mustard (SM; 2,2'-dichlorodiethyl sulfide) is an alkylating vesicant agent, which has been used as a chemical weapon in various conflicts during the 20th century. The injuries resulting from SM-exposure are mainly characterized by epithelial damage of the tissues through which it is absorbed, i.e. skin, eye and the respiratory tract. Proteins in the skin mostly affected by SM-exposure are laminin-5 and integrin alpha6beta4. Laminin-5 constitutes the anchoring filaments and binds the transmembrane protein integrin alpha6beta4. Recent studies have shown that SM alkylation causes a significant reduction of laminin-5, disruption of alpha6beta4 integrin and decreases the expression of integrin alpha6 and beta4 subunits, therefore, leads to destabilization of dermal-epidermal attachments and potentiates vesication. This study established a unique immunochromatographic detection method (strip assay) to detect the degradation of laminin-5 in SM-exposed NHEK (normal human epidermal keratinocytes) extract. This method may serve as a rapid SM-exposure diagnostic/screening procedure that could be applied directly to skin extracts of individuals who have supposedly been exposed to SM.