Hartmann Wiebke, Blankenhaus Birte, Brunn Marie-Luise, Meiners Jana, Breloer Minka
Helminth Immunology Group, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
Instituto de Medicina Molecular João Lobo Antunes, Lisbon, Portugal.
Sci Rep. 2021 Jan 15;11(1):1536. doi: 10.1038/s41598-020-79477-7.
Helminths are large multicellular parasites that infect one quarter of the human population. To prolong their survival, helminths suppress the immune responses of their hosts. Strongyloides ratti delays its expulsion from the gut by induction of regulatory circuits in a mouse strain-specific manner: depletion of Foxp3 regulatory T cells (Treg) improves the anti-S. ratti immunity in BALB/c but not in C57BL/6 mice. In the current study we compare the hierarchy of immunoregulatory pathways in BALB/c, C57BL/6 mice and their F1 progeny (BALB/c × C57BL/6). Using multicolor flow cytometry, we show that S. ratti induces a distinct pattern of inhibitory checkpoint receptors by Foxp3 Treg and Foxp3 T cells. Intensity of expression was highest in C57BL/6 and lowest in BALB/c mice, while the F1 cross had an intermediate phenotype or resembled BALB/c mice. Treg subsets expanded during infection in all three mouse strains. Similar to BALB/c mice, depletion of Treg reduced intestinal parasite burden and increased mucosal mast cell activation in S. ratti-infected F1 mice. Our data indicate that Treg dominate the regulation of immune responses in BALB/c and F1 mice, while multiple regulatory layers exist in C57BL/6 mice that may compensate for the absence of Treg.
蠕虫是大型多细胞寄生虫,感染着四分之一的人类。为了延长自身存活时间,蠕虫会抑制宿主的免疫反应。鼠类圆线虫通过以小鼠品系特异性方式诱导调节回路来延缓其从肠道的排出:耗竭Foxp3调节性T细胞(Treg)可增强BALB/c小鼠而非C57BL/6小鼠对鼠类圆线虫的免疫力。在本研究中,我们比较了BALB/c、C57BL/6小鼠及其F1代(BALB/c×C57BL/6)免疫调节途径的层级关系。使用多色流式细胞术,我们发现鼠类圆线虫可通过Foxp3 Treg和Foxp3 T细胞诱导出不同模式的抑制性检查点受体。C57BL/6小鼠中该受体的表达强度最高,BALB/c小鼠中最低,而F1代杂交小鼠表现出中间型表型或类似BALB/c小鼠。在所有三种小鼠品系感染期间,Treg亚群均会扩增。与BALB/c小鼠类似,在感染鼠类圆线虫的F1代小鼠中,Treg的耗竭降低了肠道寄生虫负荷并增加了黏膜肥大细胞的活化。我们的数据表明,Treg在BALB/c和F1代小鼠的免疫反应调节中起主导作用,而C57BL/6小鼠中存在多个调节层,可能会弥补Treg缺失的影响。