Determination of the serum levels of soluble PD-1/PD-L1 and in small extracellular vesicles in dogs with mammary neoplasms and Mast Cell Tumors

Abstract

Cancer cells are dependent on the system immune evasion for their survival and evolution. T lymphocyte antitumoral activities can be suppressed through the PD-1/PD-L1 pathway. Antibodies blocking these proteins have been widely used in clinical trials to treat Cancer in humans, and their expressions have been analyzed as prognostic and predictive biomarkers. Canine neoplasms also express PD-1 and PD-L1, but the quantification of their soluble forms and in Small Extracellular Vesicles (SEVs) in blood serum have not been performed. The aim of the study is to verify the prognostic value of serum levels of soluble PD-1 and PD-L1 and in SEVs, in dogs with mast cell tumors and mammary gland tumors. Samples of 20 healthy dogs and 70 dogs bearing neoplasms (20 mast cell tumors and 50 mammary gland tumors) will be assessed. The expressions of PD-1 and PD-L1 in the blood serum, VEPs and in tumor tissue will be measured and compared with each other, the serum levels of IL-6, IL-8, IL-10 and IFN-gamma, post-surgical survival, and with mortality due to the disease. (AU)