Anti-PD-1 antibody decreases tumour-infiltrating regulatory T cells

• DOI: 10.21203/rs.2.12812/v4
• Publication Date: 2019-12-20T18:37:22Z
• Authors: Kazushige Yoshida; Masanori Okamoto; Jun Sasaki; Chika Kuroda; Haruka Ishida; Katsuya Ueda; Hirokazu Ideta; Takayuki Kamanaka; Atsushi Sobajima; Takashi Takizawa; Manabu Tanaka; Kaoru Aoki; Takeshi Uemura; Hiroyuki Kato; Hisao Haniu; Naoto Saito
• Keywords: Immune checkpoint

Abstract Background: There are many types of therapies for cancer. In these days, immunotherapies, especially immune checkpoint inhibitors, focused on. Though inhibitors there, the difference effect and its mechanism unclear. Some reports suggest response rate anti-PD-1 antibody is superior to that anti-PD-L1 could potentially produce different mechanisms action. On other hand, Treg also express PD-1; however, their relationship remains Methods: this study, we used osteosarcoma cell lines in vitro mouse model vivo. vitro, analyzed IFNγ expression PD-L1 on surface by flowcytometry. vivo, murine line LM8 was subcutaneously transplanted into dorsum mice. Mouse intraperitoneally administered. analysed survival proportion T cells tumour Results: We discovered increased lines. assessing between Treg, administration suppresses increases volume prolongs overall time. microenvironment, found decreased within tumour-infiltrating lymphocytes. Conclusions: Here clarify first time an additional anti-tumour effect—as exerted decreasing Treg— anticipate our findings will lead development new methods cancer treatment.