BCA-1/CXCL13 蛋白, Human

CXCL13, known as BCA-1 (B cell-attracting chemokine 1) or BLC (B-lymphocyte chemoattractant), is an efficacious attractant selective for B lymphocytes through binding to the BLR1/CXCR5 receptor^[1]. CXCL13 is a homeostatic chemokine, and is constitutively secreted by stromal cells in B-cell areas of secondary lymphoid tissues (follicles), such as spleen, lymph nodes, tonsils, and Peyer's patches^[2]. BCA-1/CXCL13 Protein, Human is produced in E. coli, and consists of 87 amino acids (V23-P109).

CXCL13，也称为 B 淋巴细胞趋化剂，最初在 B 细胞滤泡的基质细胞中被鉴定为调节 B 细胞和 T 细胞亚群的归巢。CXCL13 在协调次级淋巴器官空间不同区域内的细胞迁移中发挥着关键作用。它强烈吸引 B 淋巴细胞，同时促进少量 T 细胞和巨噬细胞的迁移。CXCL13 及其受体 CXCR5 在炎症、感染、癌症和免疫反应中发挥重要作用^[1][2][3]。
人CXCL13蛋白的氨基酸序列与小鼠CXCL13蛋白的同源性较低。
CXCL13通过其受体CXCR5发挥其功能。CXCR5 在成熟的再循环 B 淋巴细胞（滤泡辅助 T 细胞 (TFH) 和皮肤来源的迁移树突细胞 (DC) 的亚群）上高表达，并控制它们向 CXCL13 梯度迁移到次级淋巴器官。由于 BLR1/CXCR5 受体的丧失足以破坏脾脏和派尔氏集结中的滤泡组织，因此 BCA-1 可能充当 B 细胞归巢趋化因子。人 BCA-1 与放射性标记的 IFN-γ 诱导蛋白 10 (IP-10) 竞争与 Ba/F3 和 293EBNA 细胞系中表达的人 CXCR3 受体的结合。此外，人 BCA-1 对于人 CXCR3 转染细胞来说是有效的引诱剂。BCA-1 不会诱导 B 淋巴细胞中钙的释放。此外，人 BCA-1 是刺激 GTP gamma S 结合的激动剂。人 BCA-1 是人 CXCR3 受体的特异性、功能性 G 蛋白连接趋化配体。CXCL13 广泛涉及多种自身免疫性疾病和炎症以及淋巴增殖性疾病的发病机制。此外，CXCL13:CXCR5 轴协调细胞间相互作用，调节肿瘤微环境中的淋巴细胞浸润^[1][2][3]。
影响 B 细胞和 TFH 细胞功能的 CXCL13:CXCR5 轴失调是自身免疫性疾病的主要参与者，并可能作为疾病进展和治疗反应的生物标志物。此外，CXCR5和CXCL13的表达在HIV感染中表现出失调，使得CXCR5+B细胞的数量随着HIV感染的进展而减少，同时CXCL13的血浆水平增加。CXCL13/CXCR5 信号传导调节癌细胞生长、增殖、侵袭和转移的能力。CXCL13 通过 CXCR5 驱动脊髓星形胶质细胞激活和神经性疼痛^[1][2][3][4] 。

Recombinant human CXCL13 (0-15 ng/mL; for 0-6 h) dose dependently induces CXCR5 expression in SAKA-T and MC3T3-E1 cells. Also, CXCL13 (15 ng/mL; 0-60 min) significantly increases p-ERK1/2 in SAKA-T and MC3T3-E1 cells^[5].

1.Full biological activity determined by a chemotaxis bioassay using human B cells is in a concentration range of 1.0-10 ng/mL.
2.Measured in a cell proliferation assay using PC-3 cells. The ED₅₀ for this effect is typically 4.604 ng/mL, corresponding to a specific activity is 2.17×10⁵ units/mg.

• 
  Measured in a cell proliferation assay using PC-3 cells. The ED₅₀ for this effect is typically 4.604 ng/mL, corresponding to a specific activity is 2.17×10⁵ units/mg.

Human

E. coli

Tag Free

O43927 (V23-P109)

10563  [NCBI]

VLEVYYTSLRCRCVQESSVFIPRRFIDRIQILPRGNGCPRKEIIVWKKNKSIVCVDPQAEWIQRMMEVLRKRSSSTLPVPVFKRKIP

Approximately 10.3 kDa

• 
  Greater than 95% as determined by reducing SDS-PAGE.

无菌粉末.

Lyophilized after extensive dialysis against 20 mM PB, pH 7.4, 100 mM NaCl or PBS, pH 7.4.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years from date of receipt. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. Jenh CH, et al. Human B cell-attracting chemokine 1 (BCA-1; CXCL13) is an agonist for the human CXCR3 receptor. Cytokine. 2001 Aug 7;15(3):113-21.  [Content Brief]

  [2]. Muzammal Hussain, et al. CXCL13/CXCR5 signaling axis in cancer. Life Sci. 2019 Jun 15;227:175-186.  [Content Brief]

  [3]. Marcelo G Kazanietz, et al. CXCL13 and Its Receptor CXCR5 in Cancer: Inflammation, Immune Response, and Beyond. Front Endocrinol (Lausanne). 2019 Jul 12;10:471.  [Content Brief]

  [4]. Bao-Chun Jiang, et al. CXCL13 drives spinal astrocyte activation and neuropathic pain via CXCR5. J Clin Invest. 2016 Feb;126(2):745-61.  [Content Brief]

  [5]. Y Sambandam, et al. CXCL13 activation of c-Myc induces RANK ligand expression in stromal/preosteoblast cells in the oral squamous cell carcinoma tumor-bone microenvironment. Oncogene. 2013 Jan 3;32(1):97-105.  [Content Brief]