Comprehensive immunophenotyping reveals distinct tumor microenvironment alterations in anti-PD-1 sensitive and resistant syngeneic mouse model

Abstract The advent of immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway has revolutionized cancer treatment, resulting in improved clinical outcomes. However, resistance remains a critical challenge. This study aimed to comparatively elucidate immunophenotypic changes in syngeneic mouse...

Full description

Saved in:
Bibliographic Details
Main Authors: Hiroyuki Inoue, Takayuki Hamasaki, Kazuhiko Inoue, Akira Nakao, Noriyuki Ebi, Hirofumi Minomo, Ichiro Nagata, Masaki Fujita, Naoto Horai
Format: Article
Language:English
Published: Nature Portfolio 2025-03-01
Series:Scientific Reports
Subjects:
Online Access:https://doi.org/10.1038/s41598-025-91979-w
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract The advent of immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway has revolutionized cancer treatment, resulting in improved clinical outcomes. However, resistance remains a critical challenge. This study aimed to comparatively elucidate immunophenotypic changes in syngeneic mouse models sensitive (MC-38) or resistant (LLC1) to anti-PD-1 monoclonal antibody (mAb) treatment. In the sensitive MC-38 model, anti-PD-1 therapy increased dendritic cells (DCs) and macrophages, while decreasing myeloid-derived suppressor cells (MDSCs) within the tumor microenvironment. Enhanced expression of antigen presentation molecules (MHC I/II) and costimulatory molecules (CD80/CD86) was observed on tumor-associated DCs and macrophages. Tumor-infiltrating CD4+T, CD8+T, regulatory T, NK, and NKT cells also significantly increased. Importantly, treatment boosted lymphocyte cytotoxic potential, with perforin identified as a key marker of efficacy. Notably, perforin expression in CD4+T and NKT cells strongly negatively correlated with tumor volume. In contrast, the resistant LLC1 model exhibited minimal immunophenotypic changes upon treatment. These findings highlight critical immune modifications induced by anti-PD-1 therapy, particularly the role of perforin, and the DC/MDSC ratio in predicting therapeutic outcomes. This research offers valuable insights into potential predictive biomarkers and informs strategies to overcome resistance, emphasizing the complex interplay between anti-PD-1 treatment and the tumor microenvironment, ultimately aiming to improve immunotherapy response rates.
ISSN:2045-2322