title: CD40 expression in epidermal tumors.
abstract: CD40 antigen, expressed on many cell types is involved in cell-cell interactions, with activated T cells expressing the CD40 ligand. In the skin, keratinocytes express CD40 which may play a role in amplifying inflammatory responses. We investigated the expression of this antigen in a series of epidermal tumors in correlation with T cell infiltrates. Our results indicate a-down-regulation or a drastic loss of CD40 antigen by tumor cells from basal cell carcinoma and squamous cell carcinoma and a moderate to discrete CD40 reactivity of keratinocyte from proliferative layers of benign viral-induced lesions. Endothelial cells, most infiltrating cells and a subpopulation of intraepidermal dendritic cells strongly expressed CD40, mainly in benign lesions, in which T cell-keratinocyte interactions may be observed, and were restricted to epithelial cells expressing CD40. The lack of CD40 expression by tumor cells might account for tumor escape mechanism from activated T cells expressing the CD40 ligand.
authors.affiliation: INSERM U346 and Clinique Dermatologique, Hôpital E. Herriot, Lyon, France.
authors.forename: J
authors.initials: J
authors.lastname: Viac
authors.forename: D
authors.initials: D
authors.lastname: Schmitt
authors.forename: A
authors.initials: A
authors.lastname: Claudy
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis*; D019013:CD40 Antigens / Q000032:analysis*; D002280:Basal Cell Carcinoma / Q000276:immunology*; D002294:Carcinoma, Squamous Cell / Q000276:immunology*; D003218:Condylomata Acuminata / Q000276:immunology*; D006801:Humans; D012878:Skin Neoplasms / Q000276:immunology*; D014860:Warts / Q000276:immunology*
chemical_list: D000951:Antigens, Neoplasm; D019013:CD40 Antigens