title: Epithelial dendritic cells and connective tissue macrophages in oral carcinogenesis and the effects of systemic Corynebacterium parvum.
abstract: Epithelial dendritic cells (EDC) and connective tissue macrophages were examined during the induction and growth of oral squamous cell carcinomas in Sprague-Dawley rats treated with the carcinogen 4-nitroquinoline N-oxide (4NQO) and the immune potentiator Corynebacterium parvum. Splenomegaly was induced in all animals receiving C. parvum. Acetone-fixed frozen sections of the palate and tongue were stained using an indirect immunoperoxidase technique and monoclonal antibodies to rat Ia (MRC OX-6) and macrophage subpopulations (ED1, ED2, ED3). EDC were predominantly Ia+, ED1-, ED2- and ED3-. The lamina propria contained Ia+, ED1+ and ED2+ cells; ED3-reactive cells were rare. ED2+ cells predominated in the interstitial connective tissue of deeper muscle. In the non-invasive tissues, the number of positive cells (Ia+EDC and connective tissue Ia+, ED1+ and ED3+ cells) increased significantly throughout the experimental period (0-9 months), were significantly more prevalent in the test tissues (4NQO, 4NQO + C.parvum, C.parvum) compared to untreated controls and, at 9 months, the carcinogen-treated rats (4NQO, 4NQO + C.parvum) had significantly more Ia+ EDC and connective tissue Ia+ cells than C.parvum controls. Irrespective of the marker under study, there were no significant differences between rats treated with 4NQO or 4NQO + C.parvum at any time during the experimental period. Similarly, intra-epithelial Ia+ and ED1+ cells increased significantly throughout the experimental period in all test groups compared to untreated controls, but no significant differences were evident between carcinogen-treated animals (4NQO, 4NQO + C.parvum) and C.parvum controls. Significant positive correlations between connective tissue Ia+ and ED1+ cells and also intra-epithelial Ia+ and ED1+ cells were present in all experimental groups; connective tissue ED2+ and ED3+ cell numbers did not correlate with any of the other phenotypes and intra-epithelial ED2+ and ED3+ cells were rare/absent. Palatal and/or lingual tumours developed in 80% of carcinogen-treated rats by 9 months and the tumour incidence was similar in rats treated with either 4NQO or 4NQO + C.parvum. There were no significant differences in the number of Ia+ EDC between the infiltrating and the non-invasive overlying epithelium of the lingual carcinomas and the non-invasive lingual epithelium treated with either 4NQO or 4NQO + C.parvum.(ABSTRACT TRUNCATED AT 400 WORDS)
authors.affiliation: University Department of Oral Medicine, Surgery and Pathology, University of Bristol, UK.
authors.forename: A
authors.initials: A
authors.lastname: Pitigala-Arachchi
authors.forename: J B
authors.initials: JB
authors.lastname: Matthews
authors.forename: C
authors.initials: C
authors.lastname: Scully
authors.forename: S S
authors.initials: SS
authors.lastname: Prime
mesh_terms: D015112:4-Nitroquinoline-1-oxide; D000818:Animals; D000911:Antibodies, Monoclonal; D003238:Connective Tissue / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D004817:Epidermis / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D008264:Macrophages / Q000276:immunology*; D008297:Male; D009061:Mouth Mucosa / Q000276:immunology; D009062:Mouth Neoplasms / Q000276:immunology* / Q000473:pathology; D011425:Propionibacterium acnes / Q000276:immunology*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II; D015112:4-Nitroquinoline-1-oxide