Langat Daudi L, Wheaton David A, Platt Jeralyn Sue, Sifers Travis, Hunt Joan S
Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160-7400, USA.
Am J Pathol. 2008 May;172(5):1303-11. doi: 10.2353/ajpath.2008.071139. Epub 2008 Apr 10.
The tumor necrosis superfamily (TNFSF) contains two soluble ligands that are involved in B lymphocyte development, BAFF (B cell activating factor, BlyS, TALL-1, CD257, TNFSF13B) and APRIL (a proliferation inducing ligand, CD256, TNFSF13). These two ligands signal through three receptors: the exclusive BAFF receptor (BAFF-R, CD268, TNFRSF17) and two receptors that recognize both BAFF and APRIL, TACI (transmembrane-activator-1 and calcium-modulator- and cyclophilin ligand-interactor CD267, TNFRSF13B) and BCMA (B cell maturation antigen, CD269, TNFRSF13C). All but BAFF-R are known to be synthesized in term placentas. In this study, expression of the ligands and receptors were distinguished in two embryologically discrete subpopulations of placental cells, villous cytotrophoblast (vCTB) cells and mesenchymal cells (MCs). Real-Time PCR showed that vCTB cells contain low levels of BAFF and APRIL transcripts whereas MCs contain high levels. Both Real-Time PCR and immunohistochemistry identified BAFF-R and BCMA mRNA and proteins in vCTB cells but essentially no TACI. By contrast, MCs contained readily detectable levels of all three receptors. These results illustrating potential autocrine and paracrine pathways for BAFF and APRIL signaling in human placentas suggest that lineage-specific regulation of placental cell viability, differentiation and/or other activities may be novel functions of these proteins.
肿瘤坏死超家族（TNFSF）包含两种参与B淋巴细胞发育的可溶性配体，即BAFF（B细胞活化因子、BlyS、TALL-1、CD257、TNFSF13B）和APRIL（增殖诱导配体、CD256、TNFSF13）。这两种配体通过三种受体发出信号：唯一的BAFF受体（BAFF-R、CD268、TNFRSF17）以及两种既能识别BAFF又能识别APRIL的受体，即TACI（跨膜激活剂-1和钙调节剂及亲环素配体相互作用分子CD267、TNFRSF13B）和BCMA（B细胞成熟抗原、CD269、TNFRSF13C）。已知除BAFF-R外，其他受体均在足月胎盘中合成。在本研究中，在胎盘细胞的两个胚胎学上不同的亚群，即绒毛细胞滋养层（vCTB）细胞和间充质细胞（MCs）中区分了配体和受体的表达。实时定量PCR显示，vCTB细胞中BAFF和APRIL转录本水平较低，而MCs中含量较高。实时定量PCR和免疫组织化学均在vCTB细胞中鉴定出BAFF-R和BCMA的mRNA及蛋白，但基本未检测到TACI。相比之下，MCs中所有三种受体的水平都易于检测到。这些结果说明了人胎盘中BAFF和APRIL信号传导的潜在自分泌和旁分泌途径，表明胎盘细胞活力、分化和/或其他活动的谱系特异性调节可能是这些蛋白质的新功能。
