Recombinant Human TGF-β sRII (soluble type II receptor) is used in research applications primarily as a potent inhibitor of TGF-β signaling, enabling precise modulation and study of TGF-β–mediated cellular processes.

Key reasons to use recombinant human TGF-β sRII in research:

• TGF-β Pathway Inhibition: TGF-β sRII acts as a decoy receptor, binding to TGF-β ligands and preventing their interaction with cell-surface TGF-β receptors, thereby blocking downstream signaling. This is crucial for dissecting the role of TGF-β in various biological contexts, such as immune regulation, fibrosis, cancer progression, and tissue regeneration.

• Cancer and Immunotherapy Research: In tumor models, blocking TGF-β signaling with sRII has been shown to render immune cells (e.g., T cells) resistant to TGF-β–induced immunosuppression, enhancing the efficacy of adoptive cell therapies and tumor regression studies. This allows researchers to evaluate the impact of TGF-β inhibition on tumor growth, immune cell function, and therapeutic outcomes.

• Functional Assays and Mechanistic Studies: Recombinant sRII is used to validate the specificity of TGF-β–dependent cellular responses by serving as a negative control or competitive inhibitor in signaling assays, cell differentiation protocols, and extracellular matrix studies.

• Tool for Screening and Drug Development: sRII can be employed in high-throughput screening assays to identify and characterize small molecules, antibodies, or biologics that modulate TGF-β activity, supporting drug discovery efforts targeting TGF-β–related pathways.

• Versatility Across Model Systems: The use of recombinant sRII is not limited to a single cell type or organism; it is applicable in vitro and in vivo, including studies involving primary cells, cell lines, organoids, and animal models.

Summary of Applications:

• Blocking TGF-β signaling in cell culture and animal models
• Enhancing immune cell function in cancer immunotherapy research
• Dissecting TGF-β’s role in fibrosis, wound healing, and tissue regeneration
• Serving as a control or inhibitor in mechanistic and screening assays

Scientific Rationale: TGF-β is a multifunctional cytokine involved in cell proliferation, differentiation, apoptosis, immune regulation, and extracellular matrix production. Its dysregulation is implicated in cancer, fibrosis, and autoimmune diseases. Recombinant sRII provides a targeted, reversible means to inhibit TGF-β activity, enabling detailed study of its biological functions and therapeutic targeting.

Note: Recombinant TGF-β sRII is for research use only and should be handled according to established laboratory protocols.

Using Recombinant Human TGF-β sRII as an ELISA Standard

Recombinant human TGF-β soluble receptor II (sRII) is not appropriate for use as a standard for quantifying TGF-β ligand in ELISA assays. Here's why:

Fundamental Difference in Assay Design

TGF-β sRII is a receptor protein, not the TGF-β ligand itself. ELISA standards must be the same molecular species you are attempting to quantify. If your objective is to measure TGF-β1, TGF-β2, or TGF-β3 concentrations, you require recombinant TGF-β ligand standards, not receptor standards.

Appropriate Standards for TGF-β Quantification

For sandwich ELISA assays measuring TGF-β ligands, the standard should be recombinant human TGF-β protein (the ligand itself). These standards are typically supplied as lyophilized recombinant proteins with defined molecular weights (approximately 25 kDa for mature TGF-β1) and are used in serial dilutions to generate standard curves.

For specialized applications measuring latent TGF-β1, the standard would be recombinant human latency-associated protein (LAP) homodimer, not the receptor.

Receptor-Based Assays

If you are developing an assay to measure TGF-β receptor II itself (rather than TGF-β ligand), then recombinant TGF-β RII would be the appropriate standard. However, this represents a fundamentally different assay measuring receptor abundance rather than ligand concentration.

Recommendation

Verify your assay objective: Are you quantifying TGF-β ligand or TGF-β receptor? Select your standard accordingly to ensure accurate calibration and reliable quantification results.

Recombinant Human TGF-β soluble Receptor II (sRII) has been validated in published research primarily as a TGF-β neutralizing agent and signaling inhibitor, with applications in cancer immunotherapy, immune modulation, and mechanistic studies of TGF-β signaling.

Key validated applications include:

• Cancer Immunotherapy:
  Recombinant TGF-β sRII has been used as a "TGF-β trap" to sequester and neutralize TGF-β ligands in the tumor microenvironment. For example, fusion proteins containing the extracellular domain of TGF-β RII (sRII) have been validated in preclinical and clinical studies to block TGF-β-mediated immune evasion and enhance the efficacy of immune checkpoint inhibitors (e.g., Bintrafusp alfa, a fusion of TGF-β sRII and anti-PD-L1 antibody). These studies demonstrate its use in reversing immunosuppression, reducing regulatory T cell infiltration, and promoting antitumor immune responses.

• Immune Modulation:
  TGF-β sRII has been employed to study and inhibit TGF-β-driven differentiation of regulatory T cells (Tregs), as well as to investigate its role in autoimmune diseases and inflammatory responses. By blocking TGF-β signaling, sRII enables researchers to dissect the cytokine’s effects on immune cell populations and their functional outcomes.

• Mechanistic Studies of TGF-β Signaling:
  Recombinant TGF-β sRII is used in vitro to specifically inhibit TGF-β signaling pathways, allowing for the analysis of downstream effects on cell proliferation, differentiation, migration, and apoptosis in various cell types. This includes studies on epithelial cell growth inhibition and tumor suppressor functions.

• Development of Therapeutic Fusion Proteins:
  sRII has been incorporated into bifunctional fusion proteins for therapeutic purposes, validated in both preclinical models and early-phase clinical trials for solid tumors. These fusion proteins combine TGF-β neutralization with other immunomodulatory functions.

Summary Table: Validated Applications of Recombinant Human TGF-β sRII

Additional Notes:

• Most published validations are in the context of preclinical models (mouse, human cell lines) and early-phase clinical trials for cancer and immune-related diseases.
• sRII is not typically used for direct tissue regeneration or wound healing studies; those applications more commonly use recombinant TGF-β ligands rather than the soluble receptor.

If you require protocols or specific experimental setups for any of these applications, please specify the context (e.g., cell type, disease model, assay type).

To reconstitute and prepare Recombinant Human TGF-β sRII (soluble Receptor III) for cell culture experiments, follow these general guidelines based on standard protocols for recombinant soluble receptors and related TGF-β family proteins:

Reconstitution Protocol

1. Centrifuge the Vial
   Briefly centrifuge the lyophilized protein vial in a microcentrifuge (20–30 seconds) before opening to ensure all powder is at the bottom.

2. Reconstitution Buffer
   Reconstitute the protein using sterile phosphate-buffered saline (PBS) containing at least 0.1% human serum albumin (HSA) or bovine serum albumin (BSA). This helps stabilize the protein and prevent adsorption to surfaces.

3. Concentration
   Prepare a stock solution of no less than 20 µg/mL. For most applications, a concentration between 20–100 µg/mL is suitable for initial reconstitution.

4. Mixing
   Gently swirl or tap the vial to dissolve the protein. Do not vortex or pipette vigorously, as this may denature the protein.

5. Storage

   • Store the reconstituted protein at 2°C to 8°C for up to one month.
   • For longer-term storage, aliquot and store at –20°C (avoid repeated freeze-thaw cycles).

Preparation for Cell Culture

• Dilution
  Dilute the reconstituted TGF-β sRII stock in cell culture medium or PBS containing 0.1% BSA/HSA to the desired working concentration. Typical working concentrations for soluble receptors range from 1–10 µg/mL, depending on the experimental design and cell type.

• Carrier Protein
  Always include a carrier protein (e.g., 0.1% BSA/HSA) in dilution buffers to minimize protein loss due to adsorption.

• Sterility
  Ensure all buffers and dilutions are sterile if used directly in cell culture.

Additional Notes

• Solubility
  TGF-β sRII is a soluble receptor and generally dissolves well in PBS with carrier protein. If solubility issues arise, ensure the protein is fully warmed to room temperature before reconstitution.

• Functional Assays
  For functional blocking experiments, pre-incubate TGF-β sRII with TGF-β ligand (if applicable) before adding to cells, or add directly to culture medium.

Summary

• Reconstitute: Sterile PBS + 0.1% HSA/BSA, ≥20 µg/mL
• Mix: Gently, no vortex
• Store: 2–8°C (short-term), –20°C (long-term, aliquoted)
• Dilute: In culture medium or PBS + 0.1% BSA/HSA
• Use: 1–10 µg/mL (optimize for your assay)

Always refer to the specific Certificate of Analysis (COA) or product datasheet for any manufacturer-specific instructions.