Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK, USA.
Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
Theranostics. 2022 Jan 1;12(2):639-656. doi: 10.7150/thno.65773. eCollection 2022.
B cells have emerged as key regulators in protective cancer immunity. However, the activation pathways induced in B cells during effective immunotherapy are not well understood. We used a novel localized ablative immunotherapy (LAIT), combining photothermal therapy (PTT) with intra-tumor delivery of the immunostimulant N-dihydrogalactochitosan (GC), to treat mice bearing mouse mammary tumor virus-polyoma middle tumor-antigen (MMTV-PyMT). We used single-cell RNA sequencing to compare the transcriptional changes induced by PTT, GC and PTT+GC in B cells within the tumor microenvironment (TME). LAIT significantly increased survival in the tumor-bearing mice, compared to the treatment by PTT and GC alone. We found that PTT, GC and PTT+GC increased the proportion of tumor-infiltrating B cells and induced gene expression signatures associated with B cell activation. Both GC and PTT+GC elevated gene expression associated with antigen presentation, whereas GC elevated transcripts that regulate B cell activation and GTPase function and PTT+GC induced interferon response genes. Trajectory analysis, where B cells were organized according to pseudotime progression, revealed that both GC and PTT+GC induced the differentiation of B cells from a resting state towards an effector phenotype. The analyses confirmed upregulated interferon signatures in the differentiated tumor-infiltrating B cells following treatment by PTT+GC but not by GC. We also observed that breast cancer patients had significantly longer survival time if they had elevated expression of genes in B cells that were induced by PTT+GC therapy in the mouse tumors. Our findings show that the combination of local ablation and local application of immunostimulant initiates the activation of interferon signatures and antigen-presentation in B cells which is associated with positive clinical outcomes for breast cancer. These findings broaden our understanding of LAIT's regulatory roles in remodeling TME and shed light on the potentials of B cell activation in clinical applications.
B 细胞已成为保护性癌症免疫中的关键调节因子。然而，在有效的免疫治疗中，B 细胞被激活的途径还不是很清楚。我们使用了一种新的局部消融免疫疗法（LAIT），将光热疗法（PTT）与免疫刺激剂 N-二氢半乳糖壳聚糖（GC）的肿瘤内递相结合，来治疗携带鼠乳腺肿瘤病毒-多瘤病毒中肿瘤抗原（MMTV-PyMT）的小鼠。我们使用单细胞 RNA 测序来比较 PTT、GC 和 PTT+GC 在肿瘤微环境（TME）中 B 细胞内诱导的转录变化。与单独使用 PTT 和 GC 治疗相比，LAIT 显著提高了荷瘤小鼠的存活率。我们发现，PTT、GC 和 PTT+GC 增加了肿瘤浸润 B 细胞的比例，并诱导了与 B 细胞激活相关的基因表达特征。GC 和 PTT+GC 均上调了与抗原呈递相关的基因表达，而 GC 上调了调节 B 细胞激活和 GTPase 功能的转录本，PTT+GC 诱导了干扰素反应基因。轨迹分析根据伪时间进展对 B 细胞进行了组织，结果表明，GC 和 PTT+GC 均诱导 B 细胞从静止状态向效应表型分化。分析结果证实，与单独使用 GC 治疗相比，PTT+GC 治疗后，肿瘤浸润 B 细胞中干扰素的特征明显上调。我们还观察到，如果小鼠肿瘤中 PTT+GC 治疗诱导的 B 细胞中基因的表达升高，乳腺癌患者的存活时间显著延长。我们的研究结果表明，局部消融与免疫刺激剂的局部应用相结合，可引发 B 细胞中干扰素和抗原呈递的激活，这与乳腺癌的积极临床结果相关。这些发现拓宽了我们对 LAIT 在重塑 TME 中的调节作用的理解，并揭示了 B 细胞激活在临床应用中的潜力。
