Fms-like Tyrosine Kinase 3 Ligand (Flt3 Ligand)
Quick Facts
| Feature | Information |
|---|---|
| Full Name | Fms-like Tyrosine Kinase 3 Ligand |
| Abbreviation | Flt3 Ligand (FLT3L) |
| Alternative Name | FLT3L |
| Molecule Type | Recombinant Cytokine |
| Family | Hematopoietic Growth Factor |
| Molecular Weight | ~17-20 kDa (monomer, glycosylation dependent) |
| Primary Receptor | Flt3 (CD135) |
| Typical Working Concentration | 10-100 ng/mL |
| Common Stock Concentration | 10-100 μg/mL |
Overview
Fms-like Tyrosine Kinase 3 Ligand (Flt3 Ligand or FLT3L) is a hematopoietic cytokine that promotes the survival, proliferation, and differentiation of early hematopoietic progenitor cells. It plays a central role in dendritic cell development and is widely used in hematopoietic stem cell expansion and immune cell differentiation protocols.
Unlike lineage-specific cytokines such as M-CSF or G-CSF, Flt3 Ligand acts primarily on early progenitor populations, maintaining multipotency and supporting the development of multiple hematopoietic lineages, particularly dendritic cells.
Biological Function
Flt3 Ligand regulates several key processes in hematopoiesis, including:
- Promotes hematopoietic progenitor survival
- Supports stem and progenitor cell expansion
- Stimulates dendritic cell development
- Enhances lymphoid progenitor proliferation
- Maintains early hematopoietic precursors
- Supports immune system development
- Promotes hematopoietic recovery following myelosuppression
Mechanism of Action
Flt3 Ligand binds to the Flt3 receptor (CD135) expressed on hematopoietic stem cells and early progenitor cells.
Ligand binding induces receptor dimerization and activation of downstream signaling pathways, including:
- PI3K-AKT pathway
- MAPK/ERK pathway
- JAK-STAT pathway
- SRC family kinase pathways
These pathways regulate stem cell survival, proliferation, differentiation, and hematopoietic lineage commitment.
Common Applications
Flt3 Ligand is widely used for:
- Hematopoietic stem cell culture
- Dendritic cell differentiation
- Expansion of hematopoietic progenitors
- Bone marrow cell culture
- Immune cell development studies
- Cancer immunology research
- Vaccine development
- Hematopoietic regeneration studies
Cell Types Commonly Supplemented with Flt3 Ligand
| Cell Type | Typical Application |
|---|---|
| Hematopoietic Stem Cells (HSCs) | Expansion |
| CD34⁺ Progenitor Cells | Maintenance and proliferation |
| Bone Marrow Cells | Stem cell culture |
| Cord Blood Cells | Stem cell expansion |
| Common Lymphoid Progenitors | Differentiation studies |
| Dendritic Cell Precursors | Dendritic cell generation |
| Human iPSCs | Hematopoietic differentiation |
| Human ESCs | Hematopoietic lineage specification |
Flt3 Ligand is frequently combined with additional cytokines to enhance stem cell expansion and lineage-specific differentiation.
Typical Working Concentrations
| Application | Typical Concentration |
|---|---|
| Hematopoietic Stem Cell Culture | 25-100 ng/mL |
| CD34⁺ Cell Expansion | 50-100 ng/mL |
| Dendritic Cell Differentiation | 50-100 ng/mL |
| Bone Marrow Culture | 10-50 ng/mL |
Advantages
- Supports early hematopoietic progenitors
- Essential for dendritic cell generation
- Enhances stem cell expansion
- Well-characterized signaling pathway
- Frequently used in immunology and stem cell research
- Compatible with serum-free and defined media
Limitations
- Activity depends on Flt3 receptor expression
- Does not support mature immune cell proliferation
- Sensitive to repeated freeze-thaw cycles
- Usually requires combination with other cytokines
- Differentiation outcomes depend on cytokine combinations
Related Cytokines
Frequently combined with:
- Stem Cell Factor (SCF)
- Thrombopoietin (TPO)
- Interleukin-3 (IL-3)
- Interleukin-6 (IL-6)
- Granulocyte Colony-Stimulating Factor (G-CSF)
- Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF)
- Macrophage Colony-Stimulating Factor (M-CSF)
See Also
- Hematopoietic Stem Cell Culture
- CD34⁺ Cell Expansion
- Dendritic Cell Differentiation
- Bone Marrow Cell Culture
- Growth Factor Handling and Storage Guide
- Cytokines in Hematopoiesis
Key Takeaways
- Flt3 Ligand (FLT3L) is a key cytokine regulating early hematopoietic stem and progenitor cells.
- It signals through the Flt3 receptor (CD135) to activate PI3K-AKT, MAPK/ERK, JAK-STAT, and SRC signaling pathways.
- Flt3 Ligand is widely used for hematopoietic stem cell expansion, dendritic cell differentiation, and immune cell development.
- It is commonly combined with SCF, TPO, IL-3, IL-6, GM-CSF, and G-CSF in hematopoietic culture systems.
- Typical working concentrations range from 10-100 ng/mL, with 50-100 ng/mL commonly used for stem cell expansion and dendritic cell generation.
References
- McKenna HJ et al. Blood (2000).
- Sitnicka E, Bryder D. Experimental Hematology (2002).
- Freshney RI. Culture of Animal Cells: A Manual of Basic Technique and Specialized Applications.
- Thermo Fisher Scientific. Recombinant Human Flt3 Ligand Product Information.
- PeproTech. Recombinant Human Flt3 Ligand Product Datasheet.