title: The relationship between epithelial Ia expression and the inflammatory cell infiltrate during experimental oral carcinogenesis.
abstract: The development of oral epithelial expression of Ia antigens and its relationship to the presence of IL-2r+ (CD25+) cells was investigated in rats treated with the water soluble carcinogen 4-nitroquinoline-N-oxide (4NQO). Acetone fixed frozen sections of the palate and tongue were stained using an indirect immunoperoxidase technique and monoclonal antibodies to rat Ia (I-A & I-E) and IL-2 receptor. After 4 weeks 4NQO treatment all rats expressed oral epithelial Ia but thereafter (2-9 months) expression was present in only 20-40% of animals. Epithelial expression of Ia by histologically normal, dysplastic and neoplastic epithelium was always associated with the presence of an underlying inflammatory cell infiltrate containing CD25+ cells. Overall there were significantly more CD25+ cells in tissue specimens containing Ia+ epithelium compared with Ia- epithelium. Furthermore, during the first 4 weeks of carcinogen treatment, a significant positive correlation was found between the CD25+ cell density and occurrence of focal epithelial Ia expression. These results, together with analysis of the T cell, NK cell, macrophage and B cell content of the infiltrates induced by 4NQO, suggest that the CD25+ cells represent activated T cells. Thus, our results in this experimental model are consistent with the idea that epithelial expression of Ia is the result of production of IFN-gamma by locally activated T cells.
mesh_terms: D015112:4-Nitroquinoline-1-oxide; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000276:immunology* / Q000473:pathology; D004195:Disease Models, Animal; D004848:Epithelium / Q000276:immunology / Q000473:pathology; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis*; D007150:Immunohistochemistry; D008297:Male; D009061:Mouth Mucosa / Q000276:immunology* / Q000473:pathology; D009062:Mouth Neoplasms / Q000276:immunology* / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000949:Histocompatibility Antigens Class II; D015112:4-Nitroquinoline-1-oxide