IL-2: A Cytokine with Immunostimulatory and Immunoregulatory Functions

Interleukin 2 (IL-2) is a pleiotropic cytokine central to the regulation of T-cell responses. In addition, IL-2 plays critical roles in a wide range of other immune modulatory actions.


IL-2 mediates its function by binding to IL-2 receptors (IL-2R). There are three subunits of IL-2 receptor, α chain (CD25), β chain (CD122), and γ chain (CD132). The β and γ chains are shared between IL-2 and IL-15 receptor complexes, while the γ chain is also used by IL-4, IL-7, IL-9, and IL-21. IL-2 binds to IL-2Rα alone with low affinity, to IL-2Rβ and IL-2Rγ heterodimer with intermediate affinity, and to IL-2α/β/γ heterotrimer with high affinity. Expression of IL-2R by different immune cell subsets determines the cellular sensitivity to IL-2. IL-2 signaling is then transduced via three different pathways: JAK-STAT, PI3K/Akt/mTOR, and MAPK/ERK.

Recent studies have recognized IL-2/IL-2R signaling pathway as an important target for the treatment of various diseases, including cancer, infectious diseases, and autoimmune diseases. New strategies are now being developed to improve the efficacy and lower toxic effects of IL-2 therapy. Sino Biological has developed a panel of recombinant IL-2 and IL-2R protein reagents to facilitate the study of the biology of IL-2.

Recombinant IL-2 Proteins

In addition to therapeutic usage, recombinant IL-2 protein also allows the culture of IL-2 dependent T-cell lines and NK cell lines, the proliferation of mitogen-activated T cells and NK cells, the establishment of thymocyte, splenocyte or peripheral blood lymphocyte derived T-cell lines, and the generation of lymphokine-activated killer (LAK) cells.

Sino Biological has developed high activity IL-2 proteins from various species. The activities of these proteins have been validated by cell proliferation assays using CTLL2 cells.

Human IL-2
IL-6 Neutralizing Antibody
Cell proliferation assay using CTLL2 cells.
The ED50 is typically 1-5 ng/mL.
Human IL-2
IL-6R Neutralizing Antibody
Cell proliferation assay using CTLL2 cells.
The ED50 is 0.35-1.4 ng/mL.

Recombinant IL-2 Receptor Proteins

IL-2 receptors with different subunits have been developed to accelerate the research of IL-2/IL-2R signaling.

Cat# Species Receptor Expressed Host Tag Activity Validated
10165-H02H Human IL-2Rα HEK293 hFc Bind to human IL-2
10165-H08H Human IL-2Rα HEK293 His Inhibit IL-2 induced proliferation
50292-M02H Mouse IL-2Rα HEK293 hFc  
80074-R08B Rat IL-2Rα Insect His  
90265-C02H Cynomolgus IL-2Rα HEK293 hFc  
90265-C27H-B Rhesus IL-2Rα HEK293 AVI & His  
10696-H05H Human IL-2Rβ HEK293 mFc Bind to human IL-2
50792-M08H Mouse IL-2Rβ HEK293 His  
70082-D02H Canine IL-2Rβ HEK293 hFc  
10555-H08H Human IL-2Rγ HEK293 His  
10555-H08B Human IL-2Rγ Insect His Bind to rat IL-2
50087-M03H Mouse IL-2Rγ HEK293 Fc & His  
80197-R02H Rat IL-2Rγ HEK293 hFc  

For full list, please kindly refer to

Cytokines Share the IL-2R γ Chain

The cytokines that share the common gamma-chain (γc) among their receptor subunits including interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21, play dominant roles in the regulation of immune responses.

Among members of γc family, IL-15 shares many biological activities to IL-2 as they bind common hematopoietic receptor (IL-2/15Rβ & γc) subunits and may compete for the same receptor. IL-15 induces the activation of JAK kinases, as well as the phosphorylation and activation of transcription activators, STAT3, STAT5, and STAT6.

By Molecule Initial