Truncated EphA2 likely potentiates cell adhesion via integrins as well as infiltration and/or lodgment of a monocyte/macrophage cell line in the red pulp and marginal zone of the mouse spleen, where ephrin-A1 is prominently expressed in the vasculature
Truncated EphA2 likely potentiates cell adhesion via integrins as well as infiltration and/or lodgment of a monocyte/macrophage cell line in the red pulp and marginal zone of the mouse spleen, where ephrin-A1 is prominently expressed in the vasculature
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DOI：
10.1007/s00418-016-1494-8
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发表时间：
2017-03-01
影响因子：
2.3
通讯作者：
Ogawa, Kazushige
中科院分区：
文献类型：
--
作者：
Konda, Naoko;Saeki, Noritaka;Ogawa, Kazushige
我们之前建立了表达缺乏激酶结构域的截短EphA 2构建体的J774.1单核细胞/巨噬细胞亚系。我们证明，肝配蛋白-A1刺激后，内源性EphA 2通过与整合素和整合素配体如ICAM 1相互作用促进细胞粘附，并且截短的EphA 2增强粘附并与整合素/整合素配体复合物相关。基于这些发现，我们假设EphA/肝配蛋白-A系统，特别是EphA 2/肝配蛋白-A1，调节单核细胞/巨噬细胞的跨内皮迁移/组织浸润，因为肝配蛋白-A1被广泛认为在炎性血管中上调。为了评估这一假设是否适用于脾脏，我们筛选了EphA 2/肝配蛋白-A1表达，并重新检查了J774.1亚系的细胞特性。我们发现肝配蛋白-A1在边缘区和红髓的脉管系统中表达，并且其表达响应于吞噬细胞耗竭而上调;此外，CD 115、F4/80和CXCR 4在J774.1细胞中表达，其作为单核细胞/巨噬细胞的可用替代物。此外，肝配蛋白-A1刺激后，截短的EphA 2没有可检测地干扰内源性EphA 2的磷酸化，并且它可能通过调节整联蛋白亲合力来增强细胞粘附。因此，通过静脉内注射相同数量的J774.1和用不同荧光染料标记的亚系细胞的小鼠，我们确定截短的EphA 2显著增强了向红髓和边缘区的优先细胞浸润。因此，EphA 2信号传导的调节可能有助于组织特异性驻留巨噬细胞和/或单核细胞的有效移植。
We previously established a J774.1 monocyte/macrophage subline expressing a truncated EphA2 construct lacking the kinase domain. We demonstrated that following ephrin-A1 stimulation, endogenous EphA2 promotes cell adhesion through interaction with integrins and integrin ligands such as ICAM1 and that truncated EphA2 potentiates the adhesion and becomes associated with the integrin/integrin ligand complex. Based on these findings, we hypothesized that the EphA/ephrin-A system, particularly EphA2/ephrin-A1, regulates transendothelial migration/tissue infiltration of monocytes/macrophages, because ephrin-A1 is widely recognized to be upregulated in inflammatory vasculatures. To evaluate whether this hypothesis is applicable in the spleen, we screened for EphA2/ephrin-A1 expression and reexamined the cellular properties of the J774.1 subline. We found that ephrin-A1 was expressed in the vasculature of the marginal zone and the red pulp and that its expression was upregulated in response to phagocyte depletion; further, CD115, F4/80, and CXCR4 were expressed in J774.1 cells, which serve as a usable substitute for monocytes/macrophages. Moreover, following ephrin-A1 stimulation, truncated EphA2 did not detectably interfere with the phosphorylation of endogenous EphA2, and it potentiated cell adhesion possibly through modulation of integrin avidity. Accordingly, by intravenously injecting mice with equal numbers of J774.1 and the subline cells labeled with distinct fluorochromes, we determined that truncated EphA2 markedly potentiated preferential cell infiltration into the red pulp and the marginal zone. Thus, modulation of EphA2 signaling might contribute to effective transplantation of tissue-specific resident macrophages and/or monocytes.