Identification and quantification of CD8+ t cells and Foxp3+ T cells in canine cutaneous mast cell tumors

• Grant number: 18/08895-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): October 01, 2018
• Effective date (End): May 31, 2020
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal researcher: Ricardo de Francisco Strefezzi
• Grantee: Bianca Sthefany Emerick
• Home Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

Cutaneous mast cell tumors are among the most common type of cutaneous neoplasms in dogs. Its etiology is unkown and the biological behavior of this tumor is variable, which makes it difficult to establish efficient therapies. Several prognostic indicators have been studied in attempt to predict the tumor behavior. Inflammation and the immune system are related to tumoral progression and therefore are considered important in predicting the diseases's course. The CD8+ T cells act by suppressing tumor growth by its cytotoxic mechanism, inducing apoptosis of neoplastic cells. In tumor microenvironment, T regulators cells cause the inactivation of effector T cells, facilitating the evasion of the antitumor immune response and, consequently, favoring tumor malignancy. Therefore, these immune cells are interesting for the evaluation of the mast cell tumor development, as they may help in prognosis and discovery of new treatments. This project aims to verify the presence of cytotoxic T lymphocytes and Treg lymphocytes in canine cutaneous mast cell tumors and its relation with the prognosis. Samples of canine cutaneous mast cell tumors will be analyzed by immunohistochemistry for detection and quantitation of T CD8+ and T FoxP3+ cells, and the results will be compared with histopathological grading, disease-related mortality and post-surgical survival.