目的 分析日本血吸虫感染后小鼠脾脏中B细胞的转录组学特征，筛选并验证差异表达基因（DEG），为揭示日本血吸虫感染B细胞的调控机制提供依据。方法 将BALB/C小鼠随机分为对照组（NC组）、感染4周组（Sj_4W组）和感染6周组（Sj_6W组），Sj_4W组和Sj_6W组小鼠使用贴片法经皮肤感染（25 ± 1）尾日本血吸虫尾蚴，感染第4、6周分别剖杀对应组小鼠，收集小鼠脾组织，通过磁珠富集分选获得脾B细胞。提取脾B细胞总RNA，构建转录组文库，基于Illumina平台进行RNA转录组测序，利用limma和edgeR软件包进行差异表达分析，筛选DEG，对DEG进行京都基因与基因组百科全书（KEGG）代谢通路富集分析和基因本体（GO）功能富集分类。筛选出3个高表达基因进行逆转录实时荧光定量PCR（RT-qPCR）验证。结果 聚类分析发现，Sj_6W组和NC组间共鉴定出6 443个DEG，其中上调基因4 421个、下调基因2 022个；Sj_6W组和Sj_4W组间共鉴定出6 757个DEG，其中上调基因4 754个、下调基因2 003个。GO功能富集分析结果显示，下调基因主要涉及淋巴细胞分化、免疫应答调节信号通路、淋巴细胞增殖等条目，上调基因主要富集在淋巴细胞介导的免疫、免疫应答分子介质的产生、B细胞介导的免疫与体液免疫等条目；KEGG代谢通路富集分析结果显示，下调基因主要富集在丝裂原活化蛋白激酶信号通路、Th1与Th2细胞分化、Th17细胞分化等条目，上调基因主要富集细胞因子-细胞因子受体相互作用、细胞外基质-受体相互作用、磷脂酰肌醇3-激酶/蛋白激酶B信号通路等条目。RT-qPCR验证结果显示，Sj_6W组小鼠脾B细胞中白细胞介素27（IL-27）、基质金属蛋白酶-8（MMP-8）和嗜酸粒细胞蛋白X（EPX）的mRNA相对转录水平分别为2.14 ± 1.18、21.86 ± 14.06、324.40 ± 252.40，高于Sj_4W组的0.31 ± 0.18、0.03 ± 0.02、0.44 ± 0.72（Mann-Whitney U检验，P < 0.01），亦高于NC组的1.04 ± 0.29、1.20 ± 0.72、1.17 ± 0.69（Mann-Whitney U检验，P < 0.05）。结论 感染日本血吸虫后，小鼠脾B细胞发生了转录重编程，IL-27、EPX和MMP-8等基因表达均上调，淋巴细胞分化与增殖、Th1/Th2及Th17细胞分化、免疫应答分子介质的产生、B细胞介导的免疫及体液免疫调节、细胞因子-细胞因子受体相互作用、细胞外基质-受体相互作用等通路发生改变。

Objective To analyze the transcriptomic characteristics of splenic B cells in mice infected with Schistosoma japonicum, screen and validate differentially expressed genes (DEGs), and provide a basis for elucidating the regulatory mechanisms of B cells during S. japonicum infection. Methods Balb/C mice were randomly divided into the control group (NC group), the 4-week post-infection group (Sj_4W group), and the 6-week post-infection group (Sj_6W group). Mice in the Sj_4W and Sj_6W groups were infected percutaneously using the patch method with (25 ± 1) S. japonicum cercariae. Mice were sacrificed at week 4 and 6 post-infection and spleen tissues were collected, respectively. Splenic B cells were isolated and enriched by magnetic bead sorting. Total RNA was extracted from splenic B cells, and transcriptome libraries were constructed. RNA sequencing was performed on the Illumina platform. Differential expression analysis was conducted using the limma and edgeR packages to screen for DEGs. Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis and gene ontology (GO) functional enrichment classification were performed on the DEGs. Three highly expressed genes were selected for validation by reverse transcription quantitative Real-time PCR (RT-qPCR). Results Cluster analysis revealed that a total of 6 443 DEGs were identified between the Sj_6W and NC groups, including 4 421 up-regulated genes and 2 022 down-regulated genes. A total of 6 757 DEGs were identified between the Sj_6W and Sj_4W groups, including 4 754 up-regulated genes and 2 003 down-regulated genes. GO functional enrichment analysis showed that downregulated genes were primarily involved in lymphocyte differentiation, immune response regulatory signaling pathways, and lymphocyte proliferation, whereas upregulated genes were mainly enriched in lymphocyte-mediated immunity, production of immune response molecular mediators, B cell-mediated immunity, and humoral immunity. KEGG pathway enrichment analysis revealed that downregulated genes were mainly enriched in the mitogen-activated protein kinase (MAPK) signaling pathway, Th1 and Th2 cell differentiation, and Th17 cell differentiation, whereas upregulated genes were mainly enriched in cytokine-cytokine receptor interaction, extracellular matrix-receptor interaction, and the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. RT-qPCR validation confirmed that the relative mRNA expression levels of interleukin-27 (IL-27), matrix metalloproteinase-8 (MMP-8), and eosinophil protein X (EPX) in splenic B cells of the Sj_6W group were 2.14 ± 1.18, 21.86 ± 14.06, and 324.40 ± 252.40, respectively, which were significantly higher than those in the Sj_4W group (0.31 ± 0.18, 0.03 ± 0.02, and 0.44 ± 0.72; Mann-Whitney U test, P < 0.01) and also higher than those in the NC group (1.04 ± 0.29, 1.20 ± 0.72, and 1.17 ± 0.69; Mann-Whitney U test, P < 0.05). Conclusion Following S. japonicum infection, splenic B cells in mice underwent transcriptional reprogramming, with upregulated expression of IL-27, EPX, and MMP-8, accompanied by alterations in pathways related to lymphocyte differentiation and proliferation, Th1/Th2 and Th17 cell differentiation, production of immune response molecular mediators, B cell-mediated immunity and humoral immune regulation, cytokine-cytokine receptor interaction, and extracellular matrix-receptor interaction.