Influence of the immune status on the malignancy of canine histiocytic sarcoma

2016 Fiscal Year Final Research Report

• Project/Area Number: 26450420
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Veterinary medical science
• Research Institution: Hokkaido University
• Principal Investigator: Takagi Satoshi 北海道大学, 獣医学研究科, 准教授 (50396305)
• Co-Investigator(Renkei-kenkyūsha): KONNAI Satoru 北海道大学, 大学院・獣医学研究科, 准教授 (40396304)
• Research Collaborator: TAGAWA Michihito 北海道大学, 大学院・獣医学研究科, 客員研究員 ; YOSHIDA Hiromitsu 北海道大学, 獣医学部, 学部学生 ; YOSHIMOTO Sho 北海道大学, 獣医学部, 学部学生
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 腫瘍 / 免疫 / 犬 / 組織球性肉腫 / 炎症 / 腫瘍微小環境

Outline of Final Research Achievements

Histiocytic sarcoma (HS) is a progressive neoplastic disease in dogs. It is unclear whether costimulatory molecules, including CD28, CTLA-4, PD-1 are expressed on peripheral blood lymphocytes (PBLs) of canine patients with HS. The expression of CTLA-4 on CD8+ lymphocytes was significantly higher and the expression of PD-1 on CD8+ lymphocytes was significantly higher in the HS group than in the control group.
On the other hand, we investigated the presence of tumor associated macrophages (TAMs) and fibroblasts (CAFs) in HS and other tumors. CAFs are rarely observed in HS tissues whereas relatively higher expressions were shown in epithelial tumors such as anal sac tumor and mammary gland tumor. CD204 positive TAMs were frequently observed in HS tissues which showed this tumor suppress host CTLs in situ. In conclusion, HS in dogs may have strong immunosuppressive ability and therapeutic agents such as anti-immune check point molecules can effective for the treatment of this tumor.

Free Research Field

獣医臨床腫瘍学