产品名：重组人白介素21（IL-21）

产品号：LT-0134

产品信息：

白介素21属于I类细胞因子，与IL-2、IL-4和IL-5等有较高的同源性，他们与IL-7、IL-9共用Yc受体亚单位和细胞因子特异性受体α亚单位。体内IL-21由活化的CD4⁺ T细胞产生，具有多种生物学效应：刺激CD4⁺和CD8⁺ T细胞增殖；增强CD8⁺ T细胞和NK细胞毒性而不触发激活诱导的细胞死亡等。虽然IL-2在Th1/Th2分化中的作用机制尚未清楚，IL-21在体液免疫和天然免疫与获得性免疫之间的转换起到重要的调节作用。

白介素21与白介素2相比一个显著的优势是白介素21可优先扩增CD27⁺CD28⁺的CD8⁺ T细胞，通常认为这一类细胞群是年轻的T细胞，具有更强的细胞毒作用。同时IL-21不会引起Treg的扩增。由于IL21体外刺激抗原特异性T细胞产生和提高对抗原亲和力的卓越效果，在免疫细胞治疗中起着越来越重要的作用。

别名：Interleukin-21, Za11

英文描述：

IL-21 is a pleiotropic cytokine produced by CD4+ T cells in response to antigenic stimulation. Its action generally enhances antigen-specific responses of immune cells. The biological effects of IL-21 include: inducing the differentiation of T-cell-stimulated B-cells into plasma cells and memory B-cells; the stimulation of IgG production in conjunction with IL-4; and the induction of apoptotic effects in na茂ve B-cells and stimulated B-cells in the absence of T-cell signaling. Additionally, IL-21 promotes the anti-tumor activity of CD8+ T-cells and NK cells. IL-21 exerts its effect through binding to a specific type I cytokine receptor, IL-21R, which also contains the 纬 chain (纬c) found in other cytokine receptors, including IL-2, IL-4, IL-7, IL-9 and IL-15. The IL-21/IL-21R interaction triggers a cascade of events, which includes activation of the tyrosine kinases JAK1 and JAK3, followed by activation of the transcription factors STAT1 and STAT3. Recombinant Human IL-21 is a 15.4 kDa protein consisting of 132 amino acid residues.

氨基酸序列:

MQDRHMIRMR QLIDIVDQLK NYVNDLVPEF LPAPEDVETN CEWSAFSCFQ KAQLKSANTG NNERIINVSI KKLKRKPPST NAGRRQKHRL TCPSCDSYEK KPPKEFLERF KSLLQKMIHQ HLSSRTHGSE DS

表达宿主来源:

E.coli

保存条件：

4℃保存6个月，-20℃保存一年或者-80℃长期保存。

纯度&内毒素: 

Greater than 95% by SDS-PAGE gel and HPLC analyses.

Endotoxin level <0.5EU/ug

The purity of rhIL-21 was determined by SDS-PAGE of reduced rhIL-21 and staining overnight with Coomassie Blue.