IL-15R alpha Protein, Human (Biotinylated, HEK293, His-Avi)

IL-15R alpha is a high affinity receptor for IL-15 (K_d: 100 pM)^[1]. IL-15R alpha binds IL-15 and thereby activating the antitumor functions of NK cells and CD8+ T cells^[2]. IL-15R alpha plays an important role in memory CD8+ T cell homeostasis and lymphocyte development^[3]. IL-15R alpha Protein, Human (Biotinylated, HEK293, His-Avi) is a biotinylated recombinant human extracellular region of IL-15R alpha (I31-T205) with a C-Terminal His-Avi tag, which is produced in HEK293 cells.

IL-15R alpha is expressed on various cell types, including lymphocytes, myeloid cells, nonlymphoid and nonhematopoietic cells^[4]. IL-15R alpha is down-regulated in Epstein-Barr virus associated gastric cancer (EBVaGC) via promoter hypermethylation^[5].
The sequence of amino acids in IL-15R alpha differs in different species. Human IL-15R alpha shares <55% aa sequence identity with mouse.
IL-15R alpha is required for transporting of IL-15 from the endoplasmic reticulum to the cell surface to bind with β (CD122) and γ (CD132) chains on responding lymphocytes^[4][6]. When binding with IL-15, the complex increases the in vivo half-life of IL-15 and enhances binding affinity of IL-15 with IL-15Rβ/γ in NK cells and CD8+ T cells. Thus, the signal transmission improves proliferation and antitumor activities of NK cells and CD8+ T cells^[2]. Moreover, IL-15R alpha on the cancer cell surface induces the malignant phenotype, such as augmented cancer cell growth, migration and invasion, and decreased apoptosis^[5].
IL-15R alpha binds with IL-15 and activates the antitumor functions of NK cells and CD8+ T cells, and is also important in memory CD8 T cell homeostasis and lymphocyte development^[2][3].

IL-15R alpha (mouse) exhibits a high level of IL-15 binding with high affinity when transfected to 32D-01 cells^[7].

Immobilized Human IL-15 at 0.5 μg/mL (100μL/Well) on the plate. Dose response curve for Biotinylated Human IL-15RA His with the EC₅₀ of 18-20 ng/mL determined by ELISA.

Human

HEK293

C-Avi;C-His

Q13261 (I31-T205)

3601  [NCBI]

50-70 kDa

Greater than 95% as determined by Tris-Bis PAGE.

Lyophilized powder.

Lyophilized from a 0.22 μm filtered solution of PBS, pH 7.4. Normally 5% trehalose is added as protectant before lyophilization.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

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]. Yin Guo, et al. Immunobiology of the IL-15/IL-15Rα complex as an antitumor and antiviral agent. Cytokine Growth Factor Rev. 2017 Dec;38:10-21.  [Content Brief]

  [2]. Johan Mj Van den Bergh, et al. IL-15 receptor alpha as the magic wand to boost the success of IL-15 antitumor therapies: The upswing of IL-15 transpresentation. Pharmacol Ther. 2017 Feb;170:73-79.  [Content Brief]

  [3]. Spencer W Stonier, et al. Trans-presentation: a novel mechanism regulating IL-15 delivery and responses. Immunol Lett. 2010 Jan 4;127(2):85-92.  [Content Brief]

  [4]. Patrick R Burkett, et al. IL-15R alpha expression on CD8+ T cells is dispensable for T cell memory. Proc Natl Acad Sci U S A. 2003 Apr 15;100(8):4724-9.  [Content Brief]

  [5]. Jing Wei, et al. Tumor cell-expressed IL-15Rα drives antagonistic effects on the progression and immune control of gastric cancer and is epigenetically regulated in EBV-positive gastric cancer. Cell Oncol (Dordr). 2020 Dec;43(6):1085-1097.  [Content Brief]

  [6]. Emanuela Romano, et al. Human Langerhans cells use an IL-15R-α/IL-15/pSTAT5-dependent mechanism to break T-cell tolerance against the self-differentiation tumor antigen WT1. Blood. 2012 May 31;119(22):5182-90.  [Content Brief]

  [7]. J G Giri, et al. Identification and cloning of a novel IL-15 binding protein that is structurally related to the alpha chain of the IL-2 receptor.  [Content Brief]