A new approach to contact allergenicity screening

A new approach to contact allergenicity screening is proposed. As a first step, an immunogen-Langerhans cell (IC) binding assay (a) is suggested. LC's are isolated from trypsinized epidermis by fluorescence activated cell sorting using monoclonal antibody anti-T6. The chemical or drug under study (pre-incubated in homogenized skin as it may be allergenic only after binding to protein or upon metabolic interaction) is tested for LC binding by a radiometric assay. When binding is not established, the drug is probably inert. When binding occurs its possible effect on LC activity is studied by a LC activation/migration assay (b). When negative, this assay indicates passive binding and the drug or chemical may be expected to be inert. When migration does occur, the activated LC's may be co-cultured with autologous lymphocytes in a lymphocyte blastogenicity assay (c). A positive result in this assay will indicate the drug or chemical's allergenicity. The proposed three-step procedure for contact allergenicity screening is expected to have a high profitability.