Gerasimčik Natalija, He Minghui, Baptista Marisa A P, Severinson Eva, Westerberg Lisa S
Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
Front Immunol. 2017 May 1;8:491. doi: 10.3389/fimmu.2017.00491. eCollection 2017.
We sought to identify genes necessary to induce cytoskeletal change in B cells. Using gene expression microarray, we compared B cells stimulated with interleukin-4 (IL-4) and anti-CD40 antibodies that induce B cell spreading, cell motility, tight aggregates, and extensive microvilli with B cells stimulated with lipopolysaccharide that lack these cytoskeletal changes. We identified 84 genes with 10-fold or greater expression in anti-CD40 + IL-4 stimulated B cells, one of these encoded the guanine nucleotide exchange factor (GEF) dedicator of cytokinesis 10 (Dock10). IL-4 selectively induced Dock10 expression in B cells. Using lacZ expression to monitor Dock10 promoter activity, we found that Dock10 was expressed at all stages during B cell development. However, specific deletion of Dock10 in B cells was associated with a mild phenotype with normal B cell development and normal B cell spreading, polarization, motility, chemotaxis, aggregation, and Ig class switching. Dock10-deficient B cells showed lower proliferation in response to anti-CD40 and IL-4 stimulation. Moreover, the IgG response to soluble antigen was lower when Dock10 was specifically deleted in B cells. Together, we found that most B cell responses were intact in the absence of Dock10. However, specific deletion of Dock10 in B cells was associated with a mild reduction in B cell activation and .
我们试图鉴定诱导B细胞细胞骨架变化所必需的基因。利用基因表达微阵列，我们将用白细胞介素-4（IL-4）和抗CD40抗体刺激的B细胞（这些刺激可诱导B细胞铺展、细胞运动、紧密聚集和广泛微绒毛形成）与用脂多糖刺激的B细胞（缺乏这些细胞骨架变化）进行了比较。我们鉴定出在抗CD40 + IL-4刺激的B细胞中表达上调10倍或更高的84个基因，其中一个编码鸟嘌呤核苷酸交换因子（GEF）胞质分裂 dedicator 10（Dock10）。IL-4选择性地诱导B细胞中Dock10的表达。利用lacZ表达监测Dock10启动子活性，我们发现Dock10在B细胞发育的所有阶段均有表达。然而，B细胞中Dock10的特异性缺失与一种轻度表型相关，B细胞发育正常，B细胞铺展、极化、运动、趋化性、聚集和Ig类别转换也正常。Dock10缺陷的B细胞在抗CD40和IL-4刺激下增殖较低。此外，当B细胞中Dock10被特异性缺失时，对可溶性抗原的IgG反应较低。总之，我们发现没有Dock10时大多数B细胞反应是完整的。然而，B细胞中Dock10的特异性缺失与B细胞活化的轻度降低相关。
