单细胞测序揭示Ly6E分子对乳腺癌4T1细胞移植瘤微环境中DC浸润及功能的抑制作用OA北大核心CSTPCD

Objective:To preliminarily explore the potential mechanisms by which lymphocyte antigen 6 complex,locus E(Ly6E)regulates tumor immune microenvironment(TIME)in breast cancer 4T1 cells using single-cell RNA transcription sequencing technology(scRNA-seq).Methods:A mouse breast cancer 4T1 cell line with Ly6e gene knockout(Ly6E-KO)was constructed by CRISPR-Cas9 technology.The in vitro proliferation and in vivo growth capabilities of Ly6E-KO cells were compared to those of the wide type 4T1 cells(Ly6E-WT).CD45-positive cells from both types of tumor tissues were sorted by flow cytometry and analyzed using scRNA-seq.The sequencing results were first screened for differentially expressed gene profiles using the Seurat software package and annotated based on marker genes.Then,Cellchat and Monocle2 software were used to analyze the cell-to-cell interactions and the evolutionary trajectories of specific immune cells.Results:Compared with Ly6E-WT,Ly6E-KO cells showed no significant difference in in vitro proliferation capability but demonstrated significantly reduced in vivo growth capability(P<0.001).ScRNA-seq analysis showed that the proportion of infiltrated DCs in Ly6E-KO cell transplanted tumors was significantly higher than that in Ly6E-WT cell transplanted tumors,and the DCs were in a more active state of proliferation and division.Three DC subsets(pDC,cDC1 and cDC3)showed significant interactions with T cells.Additionally,genes related to T lymphocyte proliferation,activation and effector functions were more highly expressed in Ly6E-KO tumors,suggesting that Ly6E-KO offers stronger anti-tumor capabilities.Finally,scRNA-seq data from a human breast cancer cohort were analyzed,further confirming the above findings.Conclusion:Ly6e gene knockout in tumor cells can enhance the anti-tumor immune response by increasing DC activation and infiltration in TIME.