title: Proliferative responses to canine thyroglobulin of peripheral blood mononuclear cells from hypothyroid dogs.
abstract: The immune responses of hypothyroid dogs to canine thyroglobulin (cTg) were evaluated for the proliferative ability of peripheral blood mononuclear cells (PBMC). PBMC from three hypothyroid dogs with high titers of thyroglobulin autoantibody (TgAA) and 3 clinically normal dogs were cultured with 5, 10, or 20 microg/ml of cTg for 72 hr. The proliferative responses of the cells were determined by the level of incorporated BrdU. The numbers of cells expressing Thy-1, CD4, CD8 and IgG in the PBMC were counted by the immunofluorescence method. Proliferative responses to cTg were observed in the cells from hypothyroid dogs. The number of cells expressing IgG and CD8 in the hypothyroid dogs tended to be high compared with the clinically normal dogs. The CD4+ cells in cultures from hypothyroid dogs increased depending upon the amount of cTg. There was a significant (P<0.05) positive correlation between the number of CD4+ cells and the concentration of cTg in the cultures from hypothyroid dogs. These findings suggest a possible relationship between canine hypothyroidism and cellular immunity. Loss of self tolerance to thyroid antigens in CD4+ T cells may play an important role in the development of canine hypothyroidism.
authors.affiliation: Department of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Sakai, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tani
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Nabetani
authors.forename: Kazumi
authors.initials: K
authors.lastname: Sasai
authors.forename: Eiichiroh
authors.initials: E
authors.lastname: Baba
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000276:immunology; D001973:Bromodeoxyuridine; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D004283:Dog Diseases / Q000276:immunology*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D007037:Hypothyroidism / Q000276:immunology*; D007074:Immunoglobulin G / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000378:metabolism*; D018800:Thy-1 Antigens / Q000378:metabolism; D013954:Thyroglobulin / Q000276:immunology / Q000494:pharmacology*
chemical_list: D001323:Autoantibodies; D015704:CD4 Antigens; D016827:CD8 Antigens; D007074:Immunoglobulin G; D018800:Thy-1 Antigens; D013954:Thyroglobulin; D001973:Bromodeoxyuridine