sCD40L Mouse
Description
Definition and Biological Significance of sCD40L in Mice
Soluble CD40 Ligand (sCD40L) is an 18-kDa trimeric protein derived from the extracellular domain of CD40L (CD154), a member of the tumor necrosis factor (TNF) superfamily. In mice, sCD40L is primarily released by activated platelets and T-lymphocytes . It interacts with CD40 receptors on antigen-presenting cells (e.g., B cells, dendritic cells) and endothelial cells, modulating immune responses, thrombosis, and tumorigenesis .
Role in Colitis-Associated Colorectal Cancer (CAC)
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Elevated Serum sCD40L Correlates with CAC: Wild-type (WT) mice treated with azoxymethane/dextran sulfate sodium (AOM/DSS) developed CAC and exhibited significantly higher serum sCD40L levels compared to healthy controls (20.0 ng/ml vs. 5.0 ng/ml, p < 0.001) .
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TLR-4 Dependency: TLR-4 knockout (KO) mice were protected from CAC and showed no elevation in serum sCD40L, suggesting innate immunity (via TLR-4) drives sCD40L secretion .
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Tissue vs. Serum Levels: Tissue sCD40L remained unchanged across groups, highlighting serum sCD40L as a systemic biomarker for CAC progression .
Table 1: Serum sCD40L Levels in AOM/DSS-Treated Mice
| Group | Serum sCD40L (ng/ml) | Incidence of CAC |
|---|---|---|
| WT + AOM/DSS | 20.0 ± 2.1 | 100% |
| TLR-4 KO + AOM/DSS | 5.2 ± 0.8 | 0% |
| WT Control | 4.9 ± 0.6 | 0% |
| TLR-4 KO Control | 5.1 ± 0.7 | 0% |
| Data derived from Angelou et al. (2020) |
Thrombotic Effects and Platelet Activation
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Enhanced Thrombosis: Injection of sCD40L (0.25 mg/kg) in WT mice increased thrombus formation by 40% compared to controls (p < 0.01). CD40 KO mice showed no such effect, confirming CD40 dependency .
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Mechanism: sCD40L primes platelets via CD40-TRAF-2/Rac1/p38 MAPK signaling, amplifying agonist-induced αIIbβ3 activation and P-selectin expression .
Table 2: Platelet Activation Metrics Induced by sCD40L
| Parameter | WT Mice (+sCD40L) | CD40 KO Mice (+sCD40L) |
|---|---|---|
| Aggregation (% increase) | 65 ± 8 | 5 ± 3 |
| P-Selectin Expression | 85 ± 10 MFI | 15 ± 5 MFI |
| Leukocyte Infiltration | 2.5-fold ↑ | No change |
| MFI = Mean Fluorescence Intensity |
Immunosuppressive Properties
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Myeloid-Derived Suppressor Cells (MDSCs): Elevated sCD40L expands CD33⁺HLA-DR⁻ MDSCs, which suppress T-cell proliferation and IFN-γ production .
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Regulatory T Cells (Tregs): sCD40L increases CD4⁺CD25⁺Foxp3⁺ Tregs and IL-10 secretion, further dampening antitumor immunity .
ELISA Kits for Murine sCD40L
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BioVendor RAF094R: Sensitivity = 0.14 ng/ml; intra-assay CV = 6.5%; inter-assay CV = 11.1% .
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Thermo Fisher BMS6010: Detects natural and recombinant murine sCD40L in serum/cell culture .
Table 3: Performance of BioVendor RAF094R ELISA
Therapeutic Implications and Future Directions
Product Specs
The biological activity of sCD40 was assessed by its ability to induce MIP-1 alpha and TNF-alpha production in mouse splenocytes. The ED50, which represents the concentration at which 50% of the maximal response is observed, was determined to be 0.1 µg/ml. This corresponds to a Specific Activity of 10,000 IU/mg.
Product Science Overview
CD40 Ligand binds to its receptor, CD40, which is found on antigen-presenting cells, platelets, and endothelial and epithelial cells . This interaction is critical for several immune responses:
- B Cell Activation: CD40 Ligand stimulates B cell proliferation and the secretion of all immunoglobulin isotypes in the presence of cytokines .
- Cytokine Production: It induces the production of cytokines such as IFN-gamma, TNF-alpha, and IL-2, which are essential for immune regulation .
- Tumoricidal Activity: CD40 Ligand has been shown to induce tumoricidal activity in peripheral blood monocytes .
Recombinant soluble CD40 Ligand is widely used in research to study its effects on immune cells and its potential therapeutic applications. It is typically produced in E. coli and purified to high standards, with a purity of ≥ 98% by SDS-PAGE gel and HPLC analyses . The recombinant protein is used in functional assays to induce TNF-alpha and MIP-1alpha production by murine splenocytes .
