Research Service, Veteran Administration Greater Los Angeles Healthcare System, Los Angeles, CA, United States.
Division of Rheumatology, Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.
Front Immunol. 2021 May 19;12:662901. doi: 10.3389/fimmu.2021.662901. eCollection 2021.
The regulation of autoimmunity and the molecular mechanisms by which different immune cells, including T cells, polymorphonuclear leukocytes (PMN-granulocytes), and B cells suppress autoimmune diseases is complex. We have shown previously that BWF1 lupus mice are protected from autoimmunity after injection or oral administration of tolerogenic doses of pCons, an artificial synthetic peptide based on sequences containing MHC class I and MHC class II determinants in the VH region of a J558-encoded BWF1 anti-DNA Ab. Several T cell subsets can transfer this tolerance. In this study, we determined the potential roles of granulocytes, B cells and regulatory T cells altered by pCons treatment in the BWF1 (NZB/NZW) mouse model of lupus. Immunophenotyping studies indicated that pCons treatment of BWF1 mice significantly increased CD4FoxP3 T cells, reduced the percent of B cells expressing CD19CD5 but increased the percent of CD19CD1d regulatory B cells and increased the ability of the whole B cell population to suppress IgG anti-DNA production . pCons treatment significantly decreased the expression of CTLA-4 (cytotoxic T-lymphocyte-associated protein-4) in CD8 T cells. In addition, peptide administration modified granulocytes so they became suppressive. We co-cultured sorted naïve B cells from mice making anti-DNA Ab (supported by addition of sorted naive CD4 and CD8 T cells from young auto-antibody-negative BWF1 mice) with sorted B cells or granulocytes from tolerized mice. Both tolerized granulocytes and tolerized B cells significantly suppressed the production of anti-DNA . In granulocytes from tolerized mice compared to saline-treated littermate controls, real-time PCR analysis indicated that expression of increased more than 2-fold while and mRNA were up-regulated more than 10-fold. In contrast, expression of these genes was significantly down-regulated in tolerized B cells. Further, another IFN-induced protein, Bcl2, was reduced in tolerized B cells as determined by Western blot analyses. In contrast, expression of FoxP3 was significantly increased in tolerized B cells. Together, these data suggest that B cells and granulocytes are altered toward suppressive functions by tolerization of BWF1 mice with pCons and it is possible these cell types participate in the clinical benefits seen .
自身免疫的调节以及不同免疫细胞（包括 T 细胞、多形核白细胞（PMN-粒细胞）和 B 细胞）抑制自身免疫性疾病的分子机制非常复杂。我们之前已经表明，BWF1 狼疮小鼠在接受基于 J558 编码的 BWF1 抗-DNA Ab VH 区中包含 MHC Ⅰ类和 MHC Ⅱ类决定簇的人工合成肽 pCons 的耐受剂量的注射或口服后，可免受自身免疫的侵害。几种 T 细胞亚群可以传递这种耐受。在这项研究中，我们确定了 pCons 处理后改变的粒细胞、B 细胞和调节性 T 细胞在 BWF1（NZB/NZW）狼疮小鼠模型中的潜在作用。免疫表型研究表明，pCons 处理 BWF1 小鼠可显著增加 CD4FoxP3 T 细胞，降低表达 CD19CD5 的 B 细胞的比例，但增加表达 CD19CD1d 的调节性 B 细胞的比例，并增加整个 B 细胞群体抑制 IgG 抗-DNA 产生的能力。pCons 处理显著降低了 CD8 T 细胞中 CTLA-4（细胞毒性 T 淋巴细胞相关蛋白-4）的表达。此外，肽给药修饰了粒细胞，使其具有抑制作用。我们将从小鼠中分离出的幼稚 B 细胞（通过从小鼠中分离出的幼稚 CD4 和 CD8 T 细胞来支持抗-DNA Ab 的产生）与来自耐受小鼠的幼稚 B 细胞或粒细胞共培养。与来自盐水处理的同窝对照相比，来自耐受小鼠的耐受粒细胞和耐受 B 细胞均显著抑制抗-DNA 的产生。在来自耐受小鼠的粒细胞中，与实时 PCR 分析相比，增加了超过 2 倍，而和 mRNA 则上调了超过 10 倍。相比之下，在耐受 B 细胞中这些基因的表达显著下调。此外，Western blot 分析表明，另一种 IFN 诱导蛋白 Bcl2 在耐受 B 细胞中也减少。相反，FoxP3 在耐受 B 细胞中的表达显著增加。总之，这些数据表明，B 细胞和粒细胞通过 BWF1 小鼠用 pCons 进行耐受而向抑制功能转变，并且这些细胞类型可能参与了所观察到的临床益处。
