title: T Lymphocytes in Histiocytic Sarcomas of Flat-Coated Retriever Dogs.
abstract: Flat-Coated Retriever dogs are predisposed to the development of histiocytic sarcoma (HS), a poorly differentiated, highly malignant neoplasm. The authors have previously documented a significant lymphocytic infiltrate in such tumors. The objective of this study was to examine the presence and expression of regulatory T cells in HS tumor samples. Forty tumors were included in this study. All tumors were immunolabeled for CD3, CD79a, CD25, CD45RA, and FOXP3. The proportion of positive cells was compared between tumors presenting as a localized primary soft tissue mass (soft tissue origin HS) and disseminated HS affecting viscera, especially the spleen (splenic origin HS). By immunohistochemistry, 95% of infiltrating T cells were positive for Foxp3 in all sections, suggesting the presence of regulatory T cells. The proportion of cells positive for FOXP3 was higher in the tumors arising in soft tissues, whereas the proportion of CD45RA-positive cells was higher in the splenic origin HS. Canine HS has an aggressive clinical behavior and is uniformly fatal. The difference in the proportion of tumor-infiltrating lymphocytes positive for these 2 markers in the 2 locations may represent differences in tumor microenvironment between the 2 sites.
authors.affiliation: 1 The Queen's Veterinary School Hospital, University of Cambridge, Cambridge, UK.
authors.forename: A
authors.initials: A
authors.lastname: Marcinowska
authors.affiliation: 1 The Queen's Veterinary School Hospital, University of Cambridge, Cambridge, UK.
authors.forename: F
authors.initials: F
authors.lastname: Constantino-Casas
authors.affiliation: 1 The Queen's Veterinary School Hospital, University of Cambridge, Cambridge, UK.
authors.forename: T
authors.initials: T
authors.lastname: Williams
authors.affiliation: 1 The Queen's Veterinary School Hospital, University of Cambridge, Cambridge, UK.
authors.forename: T
authors.initials: T
authors.lastname: Hoather
authors.affiliation: 1 The Queen's Veterinary School Hospital, University of Cambridge, Cambridge, UK.
authors.forename: B
authors.initials: B
authors.lastname: Blacklaws
authors.affiliation: 1 The Queen's Veterinary School Hospital, University of Cambridge, Cambridge, UK.
authors.forename: J
authors.initials: J
authors.lastname: Dobson
mesh_terms: D000818:Animals; D017252:CD3 Complex / Q000276:immunology; D051925:CD79 Antigens / Q000276:immunology; D004283:Dog Diseases / Q000276:immunology / Q000473:pathology*; D004285:Dogs; D005260:Female; D051858:Forkhead Transcription Factors / Q000276:immunology; D054747:Histiocytic Sarcoma / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D017493:Leukocyte Common Antigens / Q000276:immunology; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000473:pathology*; D059016:Tumor Microenvironment / Q000276:immunology
chemical_list: D017252:CD3 Complex; D051925:CD79 Antigens; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D017493:Leukocyte Common Antigens
keywords: Flat-Coated Retriever; cancer immunology; hematologic neoplasms; histiocytic sarcoma; regulatory T cells; tumor microenvironment; tumor-infiltrating lymphocytes