Research Paper|Volume 16, Issue 2|pp 1845—1859

Activation of Notch-1 signaling pathway in macrophages to secrete PD-L1 and regulate cytotoxicity of CAR-T cells in diffuse large B-cell lymphoma

Weijing Li¹, Lili Wu¹, Chen Huang¹, Hongqing Ma², Lianjing Wang¹, Wei Liu¹, Lihong Liu¹

¹Department of Hematology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, China
²Department of General Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, China

Received: May 12, 2023Accepted: December 12, 2023Published: January 22, 2024

https://doi.org/10.18632/aging.205463

Copyright: © 2024 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Objective: To investigate the mechanism of action of the Notch-1/IRE1/XBP1s signaling pathway in diffuse large B-cell lymphoma (DLBCL).

Methods: The expressions of relevant proteins were detected by Western blotting. The effect of myeloid-specific knockout of Notch-1 on lymphoma progression was observed by mouse tumor transplantation and imaging. The apoptosis of chimeric antigen receptor T-cell therapy (CAR-T) cells were detected by flow cytometry, and the proliferation of CAR-T cells was detected by wound healing assay and cell counting kit-8 (CCK8) assay.

Results: Lymphoma cells mediated the Notch-1 signaling pathway in bone marrow-derived macrophages and promoted the activation of STAT3 and STAT6 in bone marrow-derived macrophages. Myeloid-specific knockout of Notch-1 could inhibit the progression of lymphoma. Lymphoma cells enhanced the expression of p-PERK, p-IRE1α, ATF6, IL-6, IL-4, p-AKT, CD9, CD63 and PD-L1 in bone marrow-derived macrophages by mediating the Notch-1 signaling pathway. Knockout of Notch-1 in macrophages alleviated, to some extent, the suppression of killing activity of CAR-T cells, while activation of Notch-1 in macrophages inhibited proliferation and promoted apoptosis of CAR-T cells. The PD-L1 antibody significantly restored the cytotoxicity and proliferation of CAR-T cells, and inhibited their apoptosis.

Conclusion: Activation of the Notch-1/IRE1/XBP1s signaling pathway in myeloid macrophages promotes the secretion of IL-6 and IL-4 as well as PD-L1, thereby inhibiting the activity and proliferation of CAR-T cells and promoting their apoptosis.