Anti-PD-L1 Antibody Enhances T Cell Immune Responses and Reduces Resistance of Breast Cancer Cells to Radiotherapy

Autor: Lei-Ming Guo, Gao-Feng Ding, Wen-Cai Xu, Hong Ge, Yue Jiang, Yu-Fei Lu
Rok vydání: 2022
Předmět:
Zdroj: Oxidative Medicine and Cellular Longevity. 2022:1-16
ISSN: 1942-0994
1942-0900
Popis: Immune escape is a frequent occurrence, which limits the duration of antitumor immune responses to radiotherapy. Here, we aimed to ascertain the roles and underlying mechanisms of programmed death ligand 1 (PD-L1) in tolerance of breast cancer (BC) to radiotherapy. We first quantified microRNA-21 (miR-21) and PD-L1 expression in BC tissues and cells, followed by identification of the interactions between miR-21, PD-L1, and programmed cell death protein 4 (PDCD4). miR-21 knock-in mice were used to construct tumor-bearing models, which were then treated with anti-PD-L1 antibody and irradiation, followed by measurement of tumor growth and tumor immune escape. Finally, we evaluated the synergistic effects of radiotherapy and anti-PD-L1 antibody in vivo. The results showed increased miR-21 expression in BC tissues and cells, which was positively correlated with PD-L1 expression. The treatment with radiotherapy or anti-PD-L1 antibody in the miR-21 knock-in mice diminished tumor weight and volume, along with decreased CD3+CD8+ positive cells, serum IL-2 and IFN-γ levels, and lower PD-L1 expression, but augmented apoptosis of T and BC cells. Moreover, miR-21 significantly augmented PD-L1 expression via PI3K/Akt pathway activation by targeting PDCD4 in BC cells. Thus, radiotherapy and anti-PD-L1 antibody synergistically accelerated the therapeutic effect against BC in mice, thereby implicating a close interplay between radiotherapy, T cells, and the miR-21/PDCD4/PI3K/Akt/PD-L1 axis.
Databáze: OpenAIRE
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