TY - JOUR T1 - CD15<sup>+</sup> Bone Marrow-derived Cells Are Regulators of Immune Response in ARG1-producing Colorectal Cancer Cells JF - Anticancer Research JO - Anticancer Res SP - 459 LP - 470 DO - 10.21873/anticanres.15504 VL - 42 IS - 1 AU - KENTA MIYOSHI AU - EIICHI SATO AU - KENJI KATSUMATA AU - GENTARO FUKUSHIMA AU - RYUTARO UDO AU - EMI NISHIMURA AU - TOMOYA TAGO AU - KENTA KASAHARA AU - JUNICHI MAZAKI AU - MASANOBU ENOMOTO AU - TETSUO ISHIZAKI AU - YUICHI NAGAKAWA AU - AKIHIKO TSUCHIDA Y1 - 2022/01/01 UR - http://ar.iiarjournals.org/content/42/1/459.abstract N2 - Background/Aim: Bone marrow-derived cells regulate the antitumor functions of tumor infiltrating lymphocytes (TILs) through arginase 1 (ARG1)-dependent metabolism. This study examines which ARG1-producing lineage is responsible for the inhibitory function of TILs. Materials and Methods: Multiplexed immunohistochemistry was performed for CD11b, CD163, CD68, and CD15, together with ARG1 expression and CD3+ TIL infiltration estimation in human colorectal cancer specimens. Results: Stratified survival analyses demonstrated that a large number of CD3+ TILs is a favorable prognostic factor in subgroups with a high level of ARG1+ infiltration and in the subgroup with a low level of ARG1– CD15+ infiltration. Calculation of the ARG1+/ARG1– ratio demonstrated that CD3+ TIL infiltration was prognostic in the subgroup with a low ARG1+/ARG1– ratio for CD15+ cells, contrary to other lineages. Conclusion: Tumor infiltrating CD15+ cells, the majority of which show polymorphonuclear features, are responsible for the ARG1-dependent T-cell dysfunction in human colorectal cancer. ER -