Synergistic activation of dendritic cells by Lycium barbarum polysaccharide and tumor endothelial progenitor cell lysate enhances anti-tumor responses

Dendritic cells (DCs) play a pivotal role in initiating robust T cell responses against tumors, yet effective strategies to enhance DC activation remain limited. This study explores the synergistic effects of Lycium barbarum polysaccharide (LBP) and the tumor cell lysate of endothelial progenitor cells (EPC-TCL) to boost DC activation and anti-tumor immunity. Using flow cytometry, the enzyme-linked immunosorbent assay, western blot analysis, and in vivo tumor models, we demonstrate that the combination treatment significantly enhanced expression of co-stimulatory molecules (CD40, CD80, CD86, and MHC-I) in DCs and elevated cytokine levels (IL-6 and IL-12). Co-culture experiments revealed that T cells primed with LBP and EPC-TCL-modified DCs increased proliferation and reduced exhaustion, characterized by upregulated CD69 and downregulated PD-1. Mechanistically, activation of the MAPK and STING signaling pathways was confirmed by phosphorylation of key proteins. Moreover, T cells activated by DCs treated with LBP and EPC-TCL exhibited potent anti-tumor effects, significantly reducing invasiveness of mouse lung carcinoma cells and impairing angiogenesis in vitro. In a mouse axillary tumor model, the combination treatment markedly suppressed tumor growth and induced apoptosis of tumor cells. These findings highlight the potential of LBP and EPC-TCL as novel immunotherapeutic agents targeting DCs to enhance anti-tumor immunity. Future studies will focus on clinical validation and integration into combination therapies for broader cancer applications.