IL-2R alpha/CD25 Protein, Human (HEK293, Fc)

IL-2R alpha (CD25) is an essential component of high-affinity IL-2 receptors. IL-2R alpha enhances binding of IL-2 to its receptor complex so that regulates T cell growth and other lymphoid functions^[1][2]. IL-2R alpha/CD25 Protein, Human (HEK293, Fc) is a recombinant human IL-2R alpha protein with an hFc tag at the C-terminus and is expressed in HEK293 cells. It consists of 192 amino acids (E22-C213).

IL-2R alpha (CD25) is a type I membrane protein. IL-2R alpha is expressed in peripheral activated T and B cells, triple-negative thymocytes, and bone marrow pre-B cells. In high tumor regulatory T (Treg) cells, IL-2R alpha is highly expressed and is a potential target for Treg deletion. The expression of IL-2R alpha is undetectable on resting T cells^[1][2][3].
The sequence of amino acids in IL-2R alpha from different species is very different (less than 85% similarity among human, rat and mouse).
IL-2R alpha is an essential component of high-affinity IL-2 receptors and has no signal-transducing activity per se. IL-2R alpha functions through enhancing binding of IL-2 to its receptor complex and acts as a positive feedback regulator. IL-2 is a principal growth factor for T lymphocytes and plays an important role in T cell immune response. IL-2R alpha transcription is regulated by three positive regulatory regions (PRRs): PRRI, PRRII and PRRIII. PRRIII is an IL-2 response element^[1][2].
IL-2R alpha regulates T cell growth, augments lymphocyte activation and proliferation. IL-2R alpha is involved in preventing type 1 diabetes and cancers^[1][2][4].

1. 5 µg/mL (100 µL/well) of immoblized recombinant human IL-2 can bind human CD25/IL-2Rα-Fc with a linear range of 1.2-11 ng/mL.
2. Measured by its ability to inhibit the IL-2-dependent proliferation of MO7e. The ED₅₀ this effect is 0.1982 μg/mL in the presence of 30 ng/mL of recombinant human IL-2, corresponding to a specific activity is 5.05×10³ units/mg.
3.Immobilized Human IL-2RA-Fc at 5 μg/mL (100 μl/well) can bind Human IL-2-His.The ED₅₀ is 17.52 ng/mL.

• 
  Measured by its ability to inhibit the IL-2-dependent proliferation of MO7e. The ED₅₀ this effect is 0.1982 μg/mL in the presence of 30 ng/mL of recombinant human IL-2, corresponding to a specific activity is 5.05×10³ units/mg.

Human

HEK293

C-hFc

P01589 (E22-C213)

3559  [NCBI]

Partial

ELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGEMETSQFPGEEKPQASPEGRPESETSC

Approximately 60-80 kDa

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

Lyophilized powder

Lyophilized from a 0.2 μm filtered solution of PBS or 20 mM PB, 150 mM NaCl, 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]. H.Asao. Interleukin-2. Reference Module in Biomedical Sciences. 2014. ISBN 9780128012383.

  [2]. Kim HP, et al. The basis for IL-2-induced IL-2 receptor alpha chain gene regulation: importance of two widely separated IL-2 response elements. Immunity. 2001 Jul;15(1):159-72.  [Content Brief]

  [3]. Bell CJ, et al. Sustained in vivo signaling by long-lived IL-2 induces prolonged increases of regulatory T cells. J Autoimmun. 2015 Jan;56:66-80.  [Content Brief]

  [4]. Chistiakov DA, et al. The crucial role of IL-2/IL-2RA-mediated immune regulation in the pathogenesis of type 1 diabetes, an evidence coming from genetic and animal model studies. Immunol Lett. 2008 Jun 15;118(1):1-5.  [Content Brief]