在临床情况下,外周血可及的CD3+CD4+CXCR5+T滤泡辅助细胞(TFH)可能必须作为组织中生发中心反应失调的替代指标.为了确定外周血与扁桃体中TFH细胞的异质性,分选两种来源的CD3+CD4+CD45RA-CXCR5+细胞。转录组,通过单细胞RNA测序分析TCR库和细胞表面蛋白表达,流式细胞术和免疫组织化学。令人放心的是,所有血液循环中的CD3+CD4+CXCR5+T细胞亚群也出现在扁桃体中,有一些补充的TFH特征,而外周血来源的TFH细胞显示增殖和迁移的标志物。另外三个TFH细胞亚群,然而,具有真正的T-滤泡基因表达模式,只在扁桃体中发现。一个额外的,独特的和寡克隆的CD4+CXCR5+亚群具有明显的细胞毒性。这些“杀手TFH(TFK)细胞”可以在外周血以及扁桃体细胞中发现,但主要位于生发中心之外。它们表现为终末分化,可以通过NKG7(TIA-1)的表达与所有其他TFH亚群区分,Granzymes,穿孔素,CCL5,CCR5,EOMES,CRTAM和CX3CR1。总而言之,本研究为临床可用血样的CD4+CXCR5+T细胞评估提供了详细的数据,并为其扁桃体对应物的外推可能性提供了数据.
In clinical situations, peripheral blood accessible CD3+CD4+CXCR5+ T-follicular helper (TFH) cells may have to serve as a surrogate indicator for dysregulated germinal center responses in tissues. To determine the heterogeneity of TFH cells in peripheral blood versus tonsils, CD3+CD4+CD45RA-CXCR5+ cells of both origins were sorted. Transcriptomes, TCR repertoires and cell-surface protein expression were analysed by single-cell RNA sequencing, flow cytometry and immunohistochemistry. Reassuringly, all blood-circulating CD3+CD4+CXCR5+ T-cell subpopulations also appear in tonsils, there with some supplementary TFH characteristics, while peripheral blood-derived TFH cells display markers of proliferation and migration. Three further subsets of TFH cells, however, with bona fide T-follicular gene expression patterns, are exclusively found in tonsils. One additional, distinct and oligoclonal CD4+CXCR5+ subpopulation presents pronounced cytotoxic properties. Those \'killer TFH (TFK) cells\' can be discovered in peripheral blood as well as among tonsillar cells but are located predominantly outside of germinal centers. They appear terminally differentiated and can be distinguished from all other TFH subsets by expression of NKG7 (TIA-1), granzymes, perforin, CCL5, CCR5, EOMES, CRTAM and CX3CR1. All in all, this study provides data for detailed CD4+CXCR5+ T-cell assessment of clinically available blood samples and extrapolation possibilities to their tonsil counterparts.