IL-3 protein belongs to the hematopoietic growth factor family and is a structurally stable small glycoprotein cytokine with a molecular weight of approximately 14-28 kDa. Its encoding gene is located on the long arm of human chromosome 5, and the gene sequence is highly conserved, ensuring the stability of IL-3 protein's biological functions. Compared to lineage-biased hematopoietic regulators like GM-CSF and G-CSF, IL-3 protein plays a central role in early hematopoietic initiation, immune-inflammatory responses, and stress repair due to its broad-spectrum and efficient hematopoietic regulatory activity, earning it the title of multi-colony stimulating factor. The secretion of IL-3 protein exhibits distinct immune cell bias, with CD4-positive helper T cells being the primary source. CD8-positive cytotoxic T cells, natural killer cells, mast cells, and activated macrophages can also participate in its synthesis and secretion under specific stimuli.
IL-3 protein secretion exhibits strong stress responsiveness. Under resting conditions, immune cells and hematopoietic stromal cells secrete only minimal levels of IL-3 protein, insufficient to trigger significant regulatory effects. When the body encounters stressors such as pathogen invasion, tissue damage, inflammatory stimulation, or chemoradiotherapy injury, relevant immune cells are rapidly activated, synthesizing and releasing large amounts of IL-3 protein in a short time to initiate hematopoietic and immune regulatory cascades. This characteristic underscores IL-3 protein's central role in emergency hematopoiesis, immune defense, and injury repair. The TR-FRET IL-3/IL-3R assay kit can be used to quantitatively detect the binding activity of IL-3 protein with its receptor, providing a technical tool for studying signal transduction following stress-responsive secretion.
Hematopoietic stem/progenitor cells (HSPCs) are the source of all blood cells in the body, and their stemness maintenance, proliferation, and differentiation regulation are core prerequisites for initiating hematopoiesis. IL-3 protein specifically binds to high-affinity receptors on the surface of HSPCs, precisely activating key intracellular signaling pathways such as JAK-STAT and PI3K-AKT, exerting dual regulatory effects. On one hand, it potently inhibits apoptosis of HSPCs, prolongs cell survival, maintains stemness, and prevents premature differentiation and exhaustion of hematopoietic stem cells, thereby preserving hematopoietic reserves. On the other hand, it strongly stimulates clonal proliferation of HSPCs, rapidly expanding the pool of early hematopoietic progenitor cells to provide sufficient cellular raw materials for subsequent multilineage blood cell differentiation. The TR-FRET IL-3/IL-3R assay kit can be used to detect the binding kinetics of IL-3 protein with receptors on HSPCs and evaluate dynamic changes in receptor-ligand interactions under different conditions.
The absence of lineage bias is the most prominent functional feature of IL-3 protein and the core reason it is termed a multi-colony stimulating factor. It simultaneously regulates the directional differentiation and maturation of myeloid, lymphoid, erythroid, and megakaryocytic lineage hematopoietic progenitor cells. Under the sole or synergistic action of IL-3 with other hematopoietic factors, myeloid progenitors can differentiate into core immune effector cells such as neutrophils and monocytes/macrophages; erythroid progenitors progressively develop into mature red blood cells, ensuring oxygen transport and gas exchange; megakaryocytic progenitors differentiate into mature megakaryocytes, ultimately generating platelets for coagulation and hemostasis. Additionally, IL-3 protein assists in regulating lymphoid progenitor differentiation, promoting T-cell and B-cell maturation to enhance adaptive immunity. TR-FRET technology can be applied to screen molecules that modulate IL-3-receptor binding, providing quantitative analysis for studying multilineage differentiation mechanisms.
IL-3 protein is not only a hematopoietic regulator but also a critical molecular bridge connecting the hematopoietic and immune systems. Its immunomodulatory functions are highly synergistic with hematopoietic effects, enabling precise adaptation of defense and repair mechanisms. During infections, inflammation, or tissue injury, IL-3 rapidly mobilizes bone marrow reserves, selectively expanding immune effector cells like granulocytes and macrophages to enhance pathogen clearance and accelerate inflammation resolution. Concurrently, it directly regulates mast cell development, activation, and degranulation, fine-tuning allergic and local inflammatory responses while boosting dendritic cell antigen presentation to bridge innate and adaptive immunity. The TR-FRET IL-3/IL-3R assay kit can detect IL-3 receptor expression levels on various immune cells, evaluating signal transduction properties in immune-inflammatory contexts.
Upon binding to its receptor, IL-3 activates multiple downstream signaling pathways. The JAK-STAT pathway serves as the core route, phosphorylating STAT transcription factors to regulate target gene expression and mediate cell proliferation/survival. The PI3K-AKT pathway primarily modulates cell metabolism and anti-apoptotic signaling. These interconnected pathways form a complex regulatory network. The α and β subunits of IL-3 receptor play distinct roles in ligand binding and signal transduction, with the β subunit shared by IL-3, IL-5, and GM-CSF, enabling signal cross-talk. TR-FRET technology can study IL-3 binding modes with receptor subunits and the impact of mutations on pathway activation.
Nanjing UA-BioTech Co., Ltd. independently developed the "UniOne® TR-FRET Human IL3/IL3R Binding Kit" (Cat. No.: UA086011), a high-performance analysis platform specifically designed for studying interleukin-3 (IL-3) interactions with its receptor. Utilizing time-resolved fluorescence resonance energy transfer (TR-FRET) technology, this kit accurately evaluates binding activity between human IL-3 and receptor complexes composed of IL-3Rα (CD123) and βc (CD131) subunits, providing standardized solutions for hematopoietic development research, allergic disease mechanisms, and drug screening.
| Core Advantages | Specifications / Functional Description |
|---|---|
| High Purity & Biological Activity | Key components include rigorously validated high-purity human IL-3 protein and receptor subunits (IL-3Rα/βc complex) with intact biological activity. All proteins maintain native conformation and full binding functionality, faithfully mimicking physiological high-affinity interactions to ensure data accuracy and reproducibility. |
| Exceptional Lot Consistency & Stability | Leveraging advanced protein expression platforms and standardized production with strict QC ensures outstanding long-term stability and inter-batch consistency, supporting continuous drug screening and mechanistic research. |
| Ready-to-Use Flexible Platform | The homogeneous TR-FRET-based kit features a simple "add-incubate-read" workflow without washing steps. Optimized for automation (96/384-well plates), it accommodates anti-IL-3 antibody/antagonist screening, receptor blocker evaluation, competition assays, affinity analysis, and biosimilar activity assessment. |
| Comprehensive Support | Includes validated protocols, standard dose-response curves, and detailed interpretation guides for rapid method establishment. UA-Bio's technical team provides end-to-end consultation for experimental design, optimization, and data analysis. |
Nanjing UA-BioTech remains committed to delivering cutting-edge reagents and tools for immunology, cell therapy, and drug discovery. For detailed specifications, validation data, or application inquiries regarding the "UniOne® TR-FRET Human IL3/IL3R Binding Kit" (Cat. No.: UA086011), please contact us.
