The development of an antibody to trimellitic anhydride

Acid anhydrides are a group of highly reactive chemicals used widely in the formulation of paints and plastics. Exposure to acid anhydrides causes several occupational lung diseases such as pneumonititis and asthma. Whilst anhydrides, specifically trimellitic anhydride (TMA), have been shown to bind to lung tissue in an animal model, further investigation has been hampered by the lack of a reagent which would enable the identification of primary target proteins for the binding of TMA. Our objective was to develop an antibody to TMA which would enable in vitro studies of TMA interactions with lung epithelial proteins. We developed a monoclonal antibody which binds solely to TMA. We have demonstrated that the antibody can be used to detect TMA bound to different human proteins with little non-specific binding to unconjugated proteins. We then exposed cells of the A549 lung epithelial cell line to TMA in vitro and have shown by western blotting that binding occurs in the 20-35 Kd weight range. We have developed a specific and sensitive reagent to detect TMA bound to proteins. We have used this to show that when TMA is incubated with a lung epithelial cell line, that the TMA binds to proteins with a restricted molecular weight range. These results suggest that the current paradigm for the detection of IgE to small molecular weight reactive chemicals, which presupposes that the chemical binds to serum albumin, may need further investigation.