IL-4 蛋白, Human

IL-4 Protein is an endogenous agonist of IL-4 receptor (IL-4R), which works through the JAK1/JAK3-STAT6 signaling pathway. It can cooperate with SCF to promote the proliferation of human intestinal mast cells (ED₅₀=100 pg/mL) and enhance the release of mediators such as histamine mediated by IgE receptor. IL-4 Protein can inhibit the production of IL-8 by human monocytes and regulate the secretion of endothelial cell factors. It is mainly used for IL-4R targeted therapy research of tumors (such as malignant pleural mesothelioma) and allergic diseases. IL-4 Protein, Human is a recombinant protein of human IL-4, expressed by E. coli, with tag free.

IL-4 Protein 是白细胞介素-4 家族的细胞因子，含α-螺旋结构的糖蛋白，是 IL-4 受体 (IL-4R) 的内源性激动剂，与 IL-4Rα 和 γc 链结合。IL-4 Protein 最初被称为 B 细胞生长因子 BSF1，在活化的 EL-4 胸腺瘤细胞的上清液中被描述为可以共刺激用致屈服浓度的抗 IgM。IL-4 Protein 通过 JAK1/JAK3-STAT6 信号通路发挥生物学活性，可协同干细胞因子 (SCF) 促进人肠道肥大细胞增殖 (ED₅₀=100 pg/mL)，增强 IgE 受体介导的组胺、白三烯 C₄ 及 IL-5 释放，同时抑制 LPS/TNF-α/IL-1β 刺激的人单核细胞 IL-8 mRNA 及蛋白分泌，并选择性增强人脐静脉内皮细胞 IL-6 分泌、抑制 IL-8。其作用机制涉及调控细胞膜受体表达和下游转录因子激活，主要用于过敏性疾病 (如哮喘)、肿瘤 (如恶性胸膜间皮瘤) 的免疫调节机制及靶向治疗研究，尤其是 IL-4R 靶向的细胞毒素融合蛋白 (如 IL-4-PE、cpIL-4-PE) 在肿瘤消融中的应用。IL-4 Protein 在调节炎症和免疫反应中发挥重要作用。IL-4 Protein 诱导幼稚辅助 T 细胞分化为 Th2 细胞。而 IL-4 Protein 与 IL-4 受体结合的同时，IL-4 受体还与另一种细胞因子 IL-13 结合，这可能解释了 IL-4 和 IL-13 的重叠功能^{[1][2][3][4][5]}。

人肠道肥大细胞 (MC) 实验：
IL-4 Protein (human；10 ng/mL；7-28 天) 与 SCF 协同促进 MC 增殖 (ED₅₀=100 pg/mL)，并增强 IgE 受体交联诱导的组胺、白三烯 C₄ 及 IL-5 释放，且效应可被IL-4受体拮抗剂完全阻断^[1]。
人单核细胞实验：
IL-4 Protein (human；10 ng/mL；20 h) 显著抑制 LPS/TNF-α/IL-1β 诱导的 IL-8 mRNA 及蛋白分泌，即使刺激后 2 小时添加仍有效^[2]。
人脐静脉内皮细胞 (HUVEC) 实验：
IL-4 Protein (human；10 ng/mL；20 h) 选择性增强 TNF-α/IL-1β/LPS 诱导的 IL-6 分泌，同时抑制 IL-8 产生；与 TGF-β1 (1 ng/mL) 联用可逆转 IL-6 增强效应，并协同抑制 IL-8^[3]。

IL-4-PE (human；200 μg/kg；瘤内注射；第 5、7、9 天注射) 在人胆道癌皮下移植裸鼠模型显著抑制肿瘤生长，使 40% 肿瘤完全消失^[1]。
IL-4-PE (human；100 μg/kg；腹腔注射；每天 2 次；第 5-9 天) 在人胆道癌腹膜播散裸鼠模型中显著延长裸鼠生存期^[1]。
cpIL-4-PE (human；250 μg/kg，750 μg/kg；瘤内注射；3 次；第 5、7、9 天注射) 在人恶性胸膜间皮瘤皮下移植裸鼠模型中，显著减小肿瘤体积，延长中位生存期^[2]。
cpIL-4-PE (human；300 μg/kg；腹腔注射；3 次；第 5、7、9 天注射) 在人恶性胸膜间皮瘤皮下移植裸鼠模型中无显著抗肿瘤效果^[2]。

The cell proliferation assay using TF-1 human erythroleukemic cells has an ED₅₀ value of ≤450 pg/mL.

• 
  Measured in a cell proliferation assay using TF-1 human erythroleukemic cells.The ED₅₀ for this effect is 0.2989 ng/mL.,corresponding to a specific activity is 3.35×10⁶ U/mg

Human

E. coli

Tag Free

P05112-1 (H25-S153)

3565  [NCBI]

Full Length of Isoform-1 Mature Protein

HKCDITLQEIIKTLNSLTEQKTLCTELTVTDIFAASKNTTEKETFCRAATVLRQFYSHHEKDTRCLGATAQQFHRHKQLIRFLKRLDRNLWGLAGLNSCPVKEANQSTLENFLERLKTIMREKYSKCSS

Approximately 13-15 kDa

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

无菌粉末.

Lyophilized from a 0.2 μm filtered solution of 20 mM Tris-HCL, 150 mM NaCl, pH 7.2 or 50 mM Tris-HCL, 300 mM NaCl, pH 8.0 or 50 mM Tris-HCL, 300 mM NaCl, pH 8.0, 5% trehalose or PBS, pH 7.4, 8% trehalose.

<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]. Bischoff SC, et al. IL-4 enhances proliferation and mediator release in mature human mast cells. Proc Natl Acad Sci U S A. 1999 Jul 6;96(14):8080-5.  [Content Brief]

  [2]. Standiford TJ, et al. IL-4 inhibits the expression of IL-8 from stimulated human monocytes. J Immunol. 1990 Sep 1;145(5):1435-9.  [Content Brief]

  [3]. Chen C C, et al. TGF-β1, IL-10 and IL-4 differentially modulate the cytokine-induced expression of IL-6 and IL-8 in human endothelial cells. cytokine, 1996, 8(1): 58-65.

  [4]. Ishige K, et al. Potent in vitro and in vivo antitumor activity of interleukin-4-conjugated Pseudomonas exotoxin against human biliary tract carcinoma. Int J Cancer. 2008 Dec 15;123(12):2915-22.  [Content Brief]

  [5]. Beseth BD, et al. Interleukin-4 receptor cytotoxin as therapy for human malignant pleural mesothelioma xenografts. Ann Thorac Surg. 2004 Aug;78(2):436-43; discussion 436-43.  [Content Brief]