ABSTRACT
This chapter provides a brief summary of the current thinking on the special relationship that exists between the skin and the immune system and also provides a short overview of immune-mediated cutaneous diseases. It then focuses on a disease with well-documented, although somewhat controversial, links to the immune system, psoriasis. The chapter describes some studies performed on antigen-presenting cells isolated from human psoriatic skin, and then explores the possibility that epidermal antigen-presenting cells isolated from flaky skin mutant mice may be useful in answering questions relative to the immunopathology of psoriasis. Tissue damage can be due either to specific immune mechanisms, where the immune system is targeting an antigen (pathogen, tumor, or self-antigen) expressed in the skin, or as a result of nonspecific inflammation, often termed the “innocent bystander” phenomenon. The flaky skin autosomal recessive mouse mutation causes pathologic changes in the skin which resemble psoriasis.
