[Mucocutaneous diseases and murine models with death of keratinocytes induced by lichenoid tissue reaction/interface dermatitis].

A set of histopathological elements with death of epidermal basal cell layer keratinocytes along with inflammatory cell infiltration distinguishes lichenoid tissue reaction (LTR)/interface dermatitis (IFD) from other inflammatory mucocutaneous diseases. The LTR/IFD can be seen in skin disorders like as lichen planus, acute graft-versus-host disease, lupus erythematosus, dermatomyositis, and toxic epidermal necrolysis/Stevesn-Johnson syndrome. Clinical and basic researches suggested that cytotoxic CD8 T cells producing interferon-γ and FasL are final effector cells to cause apoptosis of keratinocyte. Some murine models of LTR/IFD have been established, for example, LTR/IFD reactions of keratinocyte-specific ovalbumin (OVA)-transgenic mice after OVA-specific T-cell-receptor(+)CD8 T cells. By analysis of the murine model, a new class of immunosuppressant, a JAK inhibitor, has been suggested as a new candidate for treatment of LTR/IFD.