ABSTRACT

This study aimed to document the functional microbiome affecting immune homeostasis in long-term post-liver transplantation (LT) patients. We compared the frequency of regulatory T (Treg) and T helper 17 (Th17) cells in the blood and fecal microbiome of 27 LT patients to matched healthy controls (n = 20) using flow cytometry and 16S rRNA sequencing. Among the 27 LT patients, 22 patients ingested immunosuppressants (long-term post-LT group) and five were tolerant patients. The changes in Treg and Th17 cell proportion after treatment with distinct microbiomes in the long-term post-LT group were also examined in vitro . Changes in the identified functional microbiome and Treg cells in tolerant patients were evaluated. The mean time after LT of the included patients was 13.2 y. The gut microbiome of the long-term post-LT group showed lower alpha-diversity (P < .05) with distinct overall microbial composition (P = .001) compared to healthy controls. Among the 11 distinct bacterial genera in abundance, Faecalibacterium was the most decreased in the long-term post-LT group. The long-term post-LT group also demonstrated a decrease in Treg with an increase in Th17 cells, recovered by administration of F. prausnitzii and butyric acid in in vitro analysis. In tolerant patients, Faecalibacterium was marginally increased, coupled with an increase in Treg cells, compared to the long-term post-LT group. In conclusion, the long-term post-LT patients showed a decrease in functional microbiomes represented as Faecalibacterium . These findings provide potential biomarkers for assessing immune status and targets for improving immune homeostasis in LT patients.

Abbreviations

LT, liver transplantation; HCC, hepatocellular carcinoma; IS, immunosuppressants; DC, dendritic cells; Treg, regulatory T; Th17, T helper 17; AST, aspartate transaminase; ALT, alanine transaminase; OUT, operational taxonomic unit; LEfSe, linear discriminant analysis effect size; LDA, linear discriminant analysis; IL, interleukin; TGF, transforming growth factor; GM-CSF, granulocyte-macrophage colony-stimulating factor; IFN, interferon; TNF-α, tumor necrosis factor-α; MIP-1α, macrophage inflammatory protein-1α; IP-10, interferon γ-induced protein; MCP-1, monocyte chemoattractant protein-1; ACR, acute cellular rejection; NF-κB, nuclear factor κB; PT INR, prothrombin time; QC, quality check; PBMC, peripheral blood mononuclear cells; PBS, phosphate-buffered saline; ELISA, enzyme-linked immunosorbent assay

中文翻译：

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以粪杆菌为代表的功能性微生物组减少会影响长期稳定肝移植患者的免疫稳态

摘要

本研究旨在记录影响长期肝移植后 (LT) 患者免疫稳态的功能性微生物组。我们使用流式细胞术和 16S rRNA 测序比较了 27 名 LT 患者的血液和粪便微生物组中调节性 T (Treg) 和 T 辅助细胞 17 (Th17) 与匹配的健康对照 (n = 20) 的频率。在 27 名 LT 患者中，22 名患者摄入了免疫抑制剂（长期 LT 后组），5 名患者耐受。还在体外检查了长期 LT 后组中不同微生物组治疗后 Treg 和 Th17 细胞比例的变化. 评估了耐受患者中已识别的功能性微生物组和 Treg 细胞的变化。纳入患者的 LT 后平均时间为 13.2 年。与健康对照组相比，长期 LT 后组的肠道微生物组表现出较低的 α 多样性 ( P < .05)，具有明显的整体微生物组成 ( P = .001)。在丰富的 11 个不同的细菌属中，粪杆菌属在长期 LT 后组中减少最多。长期 LT 后组还显示 Treg 减少，Th17 细胞增加，在体外分析中通过施用F. prausnitzii和丁酸恢复。在耐受患者中，粪杆菌与长期 LT 后组相比，Treg 细胞略有增加，同时 Treg 细胞增加。总之，长期 LT 后患者表现出以粪杆菌为代表的功能性微生物组减少。这些发现为评估免疫状态和改善 LT 患者免疫稳态的目标提供了潜在的生物标志物。

缩写

LT，肝移植；HCC，肝细胞癌；IS，免疫抑制剂；DC，树突状细胞；Treg，调节 T；Th17，T 助手 17；AST，天冬氨酸转氨酶；ALT，丙氨酸转氨酶；OUT，操作分类单元；LEfSe，线性判别分析效应大小；LDA，线性判别分析；IL，白细胞介素；TGF，转化生长因子；GM-CSF，粒细胞-巨噬细胞集落刺激因子；干扰素，干扰素；TNF-α，肿瘤坏死因子-α；MIP-1α，巨噬细胞炎症蛋白-1α；IP-10，干扰素γ诱导蛋白；MCP-1，单核细胞趋化蛋白-1；ACR，急性细胞排斥反应；NF-κB，核因子 κB；PT INR，凝血酶原时间；QC，质量检查；PBMC，外周血单个核细胞；PBS，磷酸盐缓冲盐水；ELISA，酶联免疫吸附测定