Characterization of a novel Fc gamma receptor-defined, IgG-containing organelle in human placental endothelial cells

人胎盘内皮细胞中新型 Fc γ 受体定义的含 IgG 细胞器的表征

• 批准号: 16390479
• 负责人: TAKIZAWA Toshihiro
• 金额: $ 6.4万
• 依托单位: Nippon Medical School
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390479/
• 关键词: human placenta; IgG; endothelial cells; Fc gamma receptor IIb; intracellular trafficking; Proteomics; immunohistochemistry; Fc受容体; カベオラ; 免疫細胞化学

Human placental transfer of IgG from maternal circulation to that of the fetus is crucial for fetal and newborn immunity. This process requires that IgG broach two cellular layers of the placenta. IgG transport across the first layer, the syncytiotrophoblast, is mediated by the MHC-related Fc receptor for IgG, FcRn. The second layer, the villus endothelium, was until recently thought to allow IgG movement nonspecifically by constitutive transcytosis in caveolae. Recently, it has been shown that the villus endothelium expresses a separate Fc receptor for IgG, the inhibitory motif-bearing FcγRIIb seen on macrophages and B cells. We characterized the FcγRIIb-containing compartment in human fetal endothelial cells by ultrahigh-resolution immunofluorescence and immunoelectron microcopies. About half of these FcγRIIb organelles contain IgG; the remainder lack IgG. The majority fraction (~80%) of IgG containing organelles is associated with FcγRIIb. No IgG-containing organelles are associated … More with caveolin. These findings are compatible with FcγRIIb-mediated transfer of IgG across the fetal endothelial cells, independently of caveolae. Next, we verified the expression of FcγRIIb in the placental endothelial cells and use reverse transcriptase-polymerase chain reaction and sequencing analyses to define the expressed FCGR2B mRNA transcript variant. The mRNA sequence of FCGR2B expressed specifically in the endothelial cells is that of transcript variant 2. In addition, proteomics and microarray analyses of the villus endothelium discovered candidate proteins that were probably associated with FcγRIIb-vesicles. Further functional characterization of these proteins in the IgG-transcytosis pathway remains to be elucidated. In addition, a proteomics screen of human placental microvillous syncytiotrophoblast revealed the expression of dysferlin, a plasma membrane repair protein related with certain muscular dystrophies. We found a novel FcγRIIb-defined, IgG-containing organelle in the villus endothelium, unassociated with caveolae. This organelle is likely a key structure for the transcytosis of IgG in the human placenta. Less

IgG从母体循环到胎儿循环的人胎盘转移对于胎儿和新生儿免疫至关重要。这个过程需要IgG刺穿胎盘的两个细胞层。IgG穿过第一层（合体滋养层）的转运由IgG的MHC相关Fc受体FcRn介导。直到最近，人们才认为第二层（绒毛内皮）通过小窝中的组成性转胞吞作用允许IgG非特异性移动。最近，研究表明绒毛内皮表达IgG的单独Fc受体，即在巨噬细胞和B细胞上观察到的带有抑制基序的FcγRIIb。我们通过超高分辨率免疫荧光和免疫电镜对人胎儿内皮细胞中含有Fcγ RIIb的区室进行了表征。这些FcγRIIb细胞器中约有一半含有IgG;其余缺乏IgG。含IgG的细胞器的大部分（约80%）与FcγRIIb相关。无含IgG的细胞器相关 ...更多信息 与Caveolin这些发现与Fcγ RIIb介导的IgG跨胎内皮细胞转移一致，与小窝无关。接下来，我们验证了FcγRIIb在胎盘内皮细胞中的表达，并使用逆转录酶-聚合酶链反应和测序分析来确定表达的FCGR 2B mRNA转录变体。在内皮细胞中特异性表达的FCGR 2B的mRNA序列是转录变体2的序列。此外，绒毛内皮的蛋白质组学和微阵列分析发现了可能与Fcγ RIIb囊泡相关的候选蛋白质。这些蛋白在IgG转胞吞途径中的进一步功能表征仍有待阐明。此外，人胎盘微绒毛合胞体滋养层的蛋白质组学筛选揭示了dysferlin的表达，dysferlin是一种与某些肌营养不良症相关的质膜修复蛋白。我们在绒毛内皮中发现了一种新的Fcγ RIIb定义的含IgG的细胞器，与小窝无关。这种细胞器可能是人胎盘中IgG转胞吞作用的关键结构。少

项目成果

Histochemistry for placenta research : theory and application

胎盘研究的组织化学：理论与应用

• 发表时间: 2007
• 期刊: J Nippon Med Sch 74(4)
• 作者: Toshihiro Takizawa;Hidetaka Eguchi;Shigeki Namimatsu;Udo Jeschke;Renate Fuchs;John M. Robinson
• 通讯作者: John M. Robinson

Expression of heat shock proteins and stress fiber formation within the arterial vascular tree of adult rats under normal physiological conditions

正常生理条件下成年大鼠动脉血管树内热休克蛋白的表达和应激纤维的形成

• 发表时间: 2007
• 期刊: J Nippon Med Sch 74(4)
• 作者: Shan-Shun Luo;Keiji Sugimoto;Sachiko Fujii;Song-Bin Fu;Kazuo Yamashita;Toshihiro Takizawa
• 通讯作者: Toshihiro Takizawa

Correlative microscopy of ultrathin cryosections in placental research. In : Methods in Molecular Medicine, Vol 121 : Placenta and Trophoblast : Methods and Protocols, Vol 1,eds. Soares MJ, Hunt JS

胎盘研究中超薄冷冻切片的相关显微镜。

• 发表时间: 2005
• 作者: Toshihiro Takizawa;John M. Robinson;瀧澤 俊広;Toshihiro Takizawa;Toshihiro Takizawa
• 通讯作者: Toshihiro Takizawa

Leukocyte migration through the basement membrane : ultrastructural-cytochemical observation of the human fetal membrane in women with chorio-amnionitis-related preterm delivery.

白细胞通过基底膜的迁移：绒毛膜羊膜炎相关早产妇女人胎膜的超微结构细胞化学观察。

• 发表时间: 2005
• 期刊: Acta Histochem Cytochem 38
• 作者: Watanabe T;et al.;井上 善仁;Takyama T.;Mori M.;Mishima T.;Hirashima C.;Okuchi A.;Watanabe T.;Takayama T;Matsubara S
• 通讯作者: Matsubara S

Role ofheat shock protein 70 in induction of stress fiber formation in rat artenail endothelial cells in response to stretch stress

热休克蛋白70在大鼠动脉内皮细胞响应拉伸应力诱导应力纤维形成中的作用

• 发表时间: 2007
• 期刊: Acta Histochem Cytochem 40・1
• 作者: Teruo Sugawara;Nobuhiko Hoshi;Kenji Fujieda;John M. Robinson;瀧澤 俊広;Dale D. Vandre;Toshihiro Takizawa;Miki Mori;Takuya Mishima;Katsuya Mine;Shan-Shun Lua
• 通讯作者: Shan-Shun Lua