Product Description

Interleukin-2 (IL-2) is a pleiotropic cytokine mainly produced by activated CD4⁺ T cells, playing central roles in the initiation, maintenance, and regulation of immune responses. IL-2 functions by binding to receptor complexes composed of α chain (CD25), β chain (CD122), and the common γ chain (CD132, also shared by several other cytokines), which form low-, intermediate-, and high-affinity receptors. This binding primarily activates downstream signaling pathways including JAK-STAT5, PI3K-Akt, and MAPK. The most classic functions of IL-2 are promoting T cell proliferation, differentiation, and survival, particularly for effector T cells and regulatory T cells (Tregs). For example, IL-2 is not only a key driver of T cell clonal expansion but also an essential cytokine for maintaining the immunosuppressive function of Treg cells. Additionally, IL-2 activates natural killer (NK) cells and B cells, thereby enhancing immune responses. Dysregulation of IL-2 signaling is frequently observed in various disease states: genetic mutations in IL-2 or its receptor can lead to severe combined immunodeficiency (SCID), whereas hyperactive IL-2 signaling is associated with autoimmune diseases such as type 1 diabetes and multiple sclerosis. In tumor immunology, IL-2 can enhance antitumor immunity, but high-dose IL-2 therapy is limited by severe toxicities. Consequently, recombinant IL-2 protein (e.g., aldesleukin) has been approved for the treatment of metastatic renal cell carcinoma and melanoma. Moreover, engineered IL-2 mutants (e.g., variants biased toward Tregs or effector T cells) and anti-IL-2 receptor monoclonal antibodies (e.g., basiliximab, daclizumab) used for transplant rejection prophylaxis underscore the critical role of IL-2 in normal immune homeostasis, autoimmunity, and cancer immunotherapy.

Screeningbio’s TR-FRET Human IL2 Detection Kit can be used to measure the levels of Human IL2 protein in supernatants. This kit is a sandwich immunoassay developed using TR-FRET technology, characterized by simplicity, rapidity, high specificity, high sensitivity, and good reproducibility.

The basic principle of this method is as follows: a pair of specific antibodies are separately conjugated to TR-FRET Solar Eu*1 (donor) and TR-FRET LA*2 (acceptor). When both antibodies bind to distinct epitopes of the Human IL2 protein, the TR-FRET donor and acceptor are brought into close proximity. Upon excitation by an external light source, fluorescence resonance energy transfer occurs between the donor and acceptor. The level of Human IL2 protein can then be determined by measuring the signal intensity at a specific wavelength (665 nm).