I-TAC/CXCL11 蛋白, Human

CXCL11, also known as IFN-inducible T-cell α-chemoattractant (I-TAC), belongs to the ELR-negative CXC chemokine family. CXCL11 is produced by a variety of cells including leukocytes, fibroblasts, and endothelial cells upon stimulation with interferons (IFNs). CXCL11 signals through CXCR3. CXCL11 is associated with pleiotropic functions including chemotactic migration, regulation of cell proliferation and self-renewal, increasing cell adhesion, and modulation of angiostatic effects^[1][2]. I-TAC/CXCL11 Protein, Human consists of 73 amino acids (F22-F94) and is expressed in E. coli.

CXCL11主要在肺、胰腺、胸腺、外周血白细胞、脾脏和肝脏中表达，在肠道、胎盘和前列腺中表达量较低。CXCL11位于人类4号染色体上，主要由癌细胞、白细胞、单核细胞、树突状细胞、内皮细胞和成纤维细胞分泌。CXCL11 将活化的淋巴细胞和 NK 细胞吸引到发炎组织和肿瘤，并抑制肿瘤生长和组织修复所必需的新血管的生成^[1][2]。
CXCL11可以结合两种不同的趋化因子受体，CXCR3和CXCR7。CXCL11 的特征是 2 个 NH2 末端半胱氨酸之间存在 1 个氨基酸。CXCL11 在稳态条件下通常表达水平较低，但在癌症或传染病过程中表达上调。CXCL11主要受IFN-γ和IFN-β诱导，IFN-α诱导较弱。CXCL11 对 IL-2 激活的 T 细胞和表达 CXCR3 的转染细胞系具有有效的趋化活性，但对新鲜分离的 T 细胞、中性粒细胞或单核细胞没有作用。用 IFN-γ 和白介素-1β 或 TLR3 配体双链 RNA 同时刺激成纤维细胞或内皮细胞，导致 CXCL11 产量的协同增加。在白细胞中，细菌 LPS 和 PGN 甚至抑制干扰素诱导的 CXCL11 产生。CXCL11 吸引激活的辅助性 T 1 (Th1) 淋巴细胞和自然杀伤 (NK) 细胞。此外，CXCL11 可以与 CXCR7 结合，CXCR7 与侵袭性相关并减少肿瘤细胞的凋亡^[1][2]。
CXCL11 的多种功能包括抑制血管生成，影响不同细胞类型的增殖，在成纤维细胞定向癌侵袭中发挥作用，增加粘附特性，抑制 M2 巨噬细胞极化，并促进某些免疫细胞的迁移^{[1] [2]}。

Recombinant human CXCL11 (100 ng/mL) promotes proliferation and migration of IGROV-1 cells via CXCR3. Recombinant human CXCL11 (100 ng/mL; 5-60 min) increases the phosphorylated p44/42 and phosphorylated Akt in ovarian cancer cells^[3].

1. The ED₅₀ is <2.5 μg/mL as measured by the FLIPR assay using CHO cells transfected with Human CXCR3, the receptor of human CXCL11, corresponding to a specific activity of >400 units/mg.
2. The biological activity determined by a chemotaxis bioassay using activated human T-lymphocytes. The ED₅₀ for this effect is 1.98 ng/mL in the presence of 1 ng/mL human IL-2, corresponding to a specific activity is 5.05×10^5 U/mg.

• 
  The biological activity determined by a chemotaxis bioassay using activated human T-lymphocytes. The ED₅₀ for this effect is 1.98 ng/mL in the presence of 1 ng/mL human IL-2, corresponding to a specific activity is 5.05×10⁵ U/mg.

Human

E. coli

Tag Free

O14625 (F22-F94)

6373  [NCBI]

FPMFKRGRCLCIGPGVKAVKVADIEKASIMYPSNNCDKIEVIITLKENKGQRCLNPKSKQARLIIKKVERKNF

Approximately 10.71 kDa

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

无菌粉末.

Lyophilized from a 0.2 μm filtered solution of PBS or 20 mM PB, 150 mM NaCl, pH 7.4.

<0.2 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. 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]. Proost P, et al. Proteolytic processing of CXCL11 by CD13/aminopeptidase N impairs CXCR3 and CXCR7 binding and signaling and reduces lymphocyte and endothelial cell migration. Blood. 2007 Jul 1;110(1):37-44.  [Content Brief]

  [2]. Proost P, et al. Proteolytic processing of CXCL11 by CD13/aminopeptidase N impairs CXCR3 and CXCR7 binding and signaling and reduces lymphocyte and endothelial cell migration. Blood. 2007 Jul 1;110(1):37-44.  [Content Brief]

  [3]. Qun Gao, et al. CXCL11 Signaling in the Tumor Microenvironment. Adv Exp Med Biol. 2021;1302:41-50.  [Content Brief]

  [4]. Tat-San Lau, et al. Cancer cell-derived lymphotoxin mediates reciprocal tumour-stromal interactions in human ovarian cancer by inducing CXCL11 in fibroblasts. J Pathol. 2014 Jan;232(1):43-56.  [Content Brief]