title: Immunohistochemical and immunoelectron study of major histocompatibility complex class-II antigen in canine cutaneous histiocytoma: its relation to tumor regression.
abstract: In order to investigate the immune mechanisms involved in regression of canine cutaneous histicytoma (CCH), major histocompatibility complex (MHC) class-II immuno-expression and the number of T- and B-lymphocytes and macrophages were analyzed in 93 cases of CCH. MHC class-II was also studied in 16 cases of CCH by immunoelectron microscopy. All tumors expressed MHC class-II, and two major staining patterns were identified: focal juxtanuclear cytoplasmic staining and rim-like staining along the cell periphery. The MHC class-II labelling pattern and T- and B-lymphocyte infiltrates were associated with tumor regression. In regressing lesions, MHC class-II molecules shift to the cell surface and an increase of both T- and B-lymphocytes were noted. The increasing expression of MHC class-II molecules on the cell surface could be a significant factor for the onset and progression of tumour regression.
authors: CECAV, Department of Veterinary Sciences. University of Trás-os-Montes and Alto Douro, 5000-911 Vila Real, Portugal. ipires@utad.pt
authors: Isabel
authors: I
authors: Pires
authors: Paula
authors: P
authors: Rodrigues
authors: Anabela
authors: A
authors: Alves
authors: Felisbina Luisa
authors: FL
authors: Queiroga
authors: Filipe
authors: F
authors: Silva
authors: Carlos
authors: C
authors: Lopes
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D004283:Dog Diseases / Q000276:immunology*; D004285:Dogs; D018219:Histiocytoma, Benign Fibrous / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D000949:Histocompatibility Antigens Class II / Q000276:immunology* / Q000378:metabolism; D016253:Microscopy, Immunoelectron / Q000662:veterinary; D009365:Neoplasm Regression, Spontaneous / Q000276:immunology* / Q000473:pathology; D012878:Skin Neoplasms / Q000276:immunology / Q000473:pathology / Q000662:veterinary*
chemical_list: D000949:Histocompatibility Antigens Class II