Dendritic cells and skin sensitisation hazard assessment.

Allergic contact dermatitis is an important occupational and environmental health disease. There is a need, therefore, to identify skin sensitisation hazard, and to assess accurately likely risks to human health. During the past 15 years very significant advances have been made in our understanding of the cellular and molecular mechanisms that serve to initiate and regulate cutaneous immune responses, including the acquisition of skin sensitisation. This has facilitated parallel advances in the identification and characterisation of skin sensitising chemicals and the development of more robust approaches to risk assessment. It is relevant to consider whether advances in immunobiology provide opportunities also for the design of alternative approaches to the toxicological evaluation of skin sensitisation, including the development of in vitro methods. Here we review the potential use of strategies based on analysis of responses induced in Langerhans cells and dendritic cells; professional antigen processing and presenting cells that are known to play pivotal roles during the induction phase of adaptive immune responses.