[摘 要] 目的：利用单细胞RNA测序（scRNA-seq）解析结直肠癌（CRC）肿瘤微环境（TME）中B细胞的异质性特征，为基于B 细胞的预后评估与免疫治疗提供理论依据。方法：采集原发CRC患者的新鲜手术切除样本（n = 36），进行scRNA-seq。采用 Seurat（v5.0）进行细胞分群，Monocle3（v1.3）和scVelo（v0.3.0）分析细胞分化轨迹，GSEA识别功能通路，pySCENIC（v0.11.2）构建 基因调控网络。结果：识别B细胞（24 652个）和浆细胞（49 138个）共11个功能亚型。拟时序分析显示B细胞从初始态向组织驻 留态分化。应激适应性B细胞在肿瘤中富集（10.39%），其NOD样受体信号和抗原提呈通路显著激活。组织驻留性B细胞在肿 瘤中占9.09%，其C型凝集素信号和内吞作用增强。迁移性B细胞在TNM Ⅱ期组织中比例最低（16.42%），氧化磷酸化等代谢通 路显著富集。浆细胞呈终末分化状态，肿瘤中以IgG型为主（20.68%）。结论：应激适应性和组织驻留性B细胞可能促进肿瘤免 疫逃逸，迁移性B细胞或具抗肿瘤潜力；同时，IgG型浆细胞可能与免疫抑制有关。

[Abstract] Objective: To characterize the heterogeneity of B cells in the colorectal cancer (CRC) tumor microenvironment (TME) through single-cell RNA sequencing (scRNA-seq), thereby providing a theoretical foundation for B cell-based prognostic assessment and immunotherapy. Methods: Fresh surgical specimens from patients with primary colorectal cancer (n = 36) were collected and subjected to scRNA-seq. Cell clustering was performed using Seurat (v5.0). Cell differentiation trajectories were analyzed with Monocle3 (v1.3) and scVelo (v0.3.0). Gene Set Enrichment Analysis (GSEA) was employed to identify relevant functional pathways, and the gene regulatory network was constructed using pySCENIC (v0.11.2). Results: 11 functional subtypes were identified from 24 652 B cells and 49 138 plasma cells. Pseudotime analysis revealed a differentiation trajectory of B cells from a naive to a tissue resident state. Stress-adapted B cells were enriched in tumor tissues (10.39%), exhibiting significant activation of the NOD-like receptor signaling pathway and antigen processing and presentation. Tissue-resident B cells accounted for 9.09% of tumor-infiltrating B cells and showed enhanced C-type lectin receptor signaling and endocytosis. Migratory B cells were least abundant in stage Ⅱ tumors (16.42%), with significant enrichment of metabolic pathways such as oxidative phosphorylation. Plasma cells were terminally differentiated, with IgG-type cells predominating in tumor tissues (20.68%). Conclusion: Stress-adapted and tissue-resident B cells may promote immune escape, while migratory B cells potentially exert anti-tumor effects. IgG-type plasma cells appear to be associated with immunosuppression.