Recombinant Rat IL-9

Recombinant Rat IL-9 is a valuable tool for research applications due to its well-characterized biological functions and its ability to modulate immune responses in a variety of experimental settings. Here are several reasons why you should consider using Recombinant Rat IL-9 in your research:

1. Immune Cell Regulation

Recombinant Rat IL-9 plays a critical role in the development, expansion, and activation of several immune cell types, including:

• Mast cells and eosinophils: IL-9 enhances their expansion and recruitment, which is important for studies on allergic inflammation, asthma, and parasite clearance.
• T helper (Th) cells: IL-9 supports the growth of IL-2 and IL-4 independent helper T cells, making it useful for studies on T cell differentiation and function.
• Regulatory T cells (Tregs): IL-9 can act as an autocrine growth and activation factor for Tregs, which are important in immune suppression and tolerance.

2. Inflammation and Autoimmunity Studies

IL-9 is involved in both pro-inflammatory and anti-inflammatory processes:

• It contributes to allergic inflammation and autoimmunity-induced inflammation, making it relevant for studies on asthma, arthritis, and other inflammatory diseases.
• IL-9 can also promote the resolution of chronic inflammation, as seen in models of rheumatoid arthritis, where it activates Treg cells and reduces tissue damage.

3. Cancer Research

IL-9 has dual roles in cancer:

• In solid tumors (e.g., melanoma, gastric cancer), IL-9 can promote anti-tumor immune responses by enhancing the activity of CD8+ T cells and improving the efficacy of immunotherapies.
• In hematologic malignancies (e.g., T-cell acute lymphoblastic leukemia), IL-9 can support the growth and survival of leukemic cells, making it useful for studying tumor-promoting environments.

4. Parasite Clearance and Infection Models

IL-9 is essential for the clearance of parasites from the gastrointestinal tract by promoting the recruitment and proliferation of mast cells. It also helps in conferring resistance to infections by modulating the production of inflammatory and anti-inflammatory cytokines.

5. Signal Transduction Studies

IL-9 functions through the IL-9 receptor, which activates various signal transducer and activator (STAT) proteins. This makes Recombinant Rat IL-9 a useful tool for studying cytokine signaling pathways and their downstream effects.

6. High Purity and Bioactivity

Recombinant Rat IL-9 is typically produced in mammalian expression systems (e.g., CHO cells, NS0 cells) to ensure proper folding and post-translational modifications. This results in a highly pure and bioactive protein that is suitable for a wide range of applications, including cell culture, animal models, and biochemical assays.

7. Versatility in Experimental Models

Recombinant Rat IL-9 can be used in various experimental models, including:

• In vitro cell culture studies
• In vivo animal models of inflammation, cancer, and infection
• Functional assays to study cytokine signaling and immune cell activation

8. Standardization and Reproducibility

Using a recombinant protein ensures consistency and reproducibility across experiments, which is crucial for generating reliable and comparable data.

In summary, Recombinant Rat IL-9 is a versatile and well-characterized cytokine that can be used to study a wide range of biological processes, from immune regulation and inflammation to cancer and infection. Its high purity and bioactivity make it an excellent choice for both basic and applied research applications.

You can use recombinant rat IL-9 as a standard for quantification or calibration in your ELISA assays, provided that the recombinant protein is well-characterized, of high purity, and compatible with the antibodies used in your specific ELISA system.

Key considerations:

• Recombinant proteins are commonly used as standards in ELISA kits for quantifying cytokines like IL-9. The standard curve is generated using known concentrations of recombinant IL-9, and sample concentrations are interpolated from this curve.
• The recombinant IL-9 standard should match the native protein as closely as possible in terms of sequence, folding, and post-translational modifications, as differences can affect antibody recognition and quantification accuracy.
• Expression system matters: Recombinant IL-9 expressed in E. coli may lack post-translational modifications present in mammalian-expressed IL-9, which can sometimes affect antibody binding and assay performance. If your ELISA kit was validated with a mammalian-expressed standard, using a bacterial-expressed standard may introduce quantification errors.
• Kit compatibility: Some ELISA kits are optimized for their own supplied standards and may not guarantee accurate quantification with third-party or differently produced recombinant proteins. Always check the kit manual for recommendations or restrictions regarding external standards.
• Validation: If you use a recombinant IL-9 standard not supplied with your ELISA kit, you should validate its performance by generating a standard curve and confirming parallelism with the kit’s standard curve, if available. This ensures that the recombinant standard is recognized equivalently by the capture and detection antibodies.

Best practices:

• Use a recombinant rat IL-9 standard that is as similar as possible to the native protein and, ideally, validated for use in ELISA.
• Prepare the standard curve in the same buffer and matrix as your samples to minimize matrix effects.
• If switching standards, run both the kit standard and your recombinant standard in parallel to confirm comparable results.

Summary:
Recombinant rat IL-9 is suitable as a standard for ELISA quantification if it is compatible with your assay’s antibodies and validated for this use. Always confirm compatibility and performance through appropriate controls and validation experiments.

Validated Applications of Recombinant Rat IL-9

Recombinant Rat IL-9 has been validated for several key research applications across molecular biology and immunological studies.

Functional and Biochemical Assays

The protein has been validated for use in functional assays, ELISA, and Western blot applications. Bioactivity has been confirmed through cell proliferation assays using MC/9-2 mouse mast cells, with an ED₅₀ ranging from 8.02-32.1 ng/mL. These functional validations demonstrate the protein's biological activity and suitability for quantitative research applications.

Immunological Research Applications

IL-9 recombinant proteins have been extensively utilized in studies examining immune cell responses. Research has demonstrated IL-9's role in modulating CD8+ T cell cytotoxicity and antitumor immunity, with studies showing that IL-9 neutralizing antibodies reduce granzyme B, TNFα, IFNγ, and CD107a expression in tumor-specific CD8+ T cells. The protein has also been validated for investigating effects on type 2 innate lymphoid cells (ILC2), mast cells, macrophages, and keratinocytes.

Disease Model Studies

Published research has validated recombinant IL-9 for investigating its role in various pathological conditions. Studies have employed the protein in models of allergic asthma, where anti-IL-9 treatment provided protection against airway reactivity. Additionally, IL-9 has been studied in the context of helminth infections, mastocytosis, eosinophilia, and B cell-related disorders.

Therapeutic Development

The protein serves as a critical reagent in therapeutic development programs, including studies examining IL-9 receptor antagonism for targeting malignant cells such as Hodgkin's lymphoma, non-Hodgkin lymphoma, and acute myeloid leukemia.

Reconstitution Protocol

Initial Preparation

Begin by centrifuging the lyophilized vial at 6000-10000 rpm for 30 seconds before opening to ensure complete recovery of the protein product. This step is critical to prevent loss of material that may adhere to the vial walls during shipping and storage.

Reconstitution Conditions

Reconstitute the lyophilized protein to a concentration of 0.1-0.5 mg/mL in sterile distilled water or sterile 18 MΩ·cm H₂O. The recommended minimum reconstitution concentration is 100 µg/mL to ensure adequate protein stability. During reconstitution, avoid vortexing or vigorous pipetting, as these actions can denature the protein and reduce bioactivity. Instead, use gentle mixing techniques to dissolve the lyophilized powder completely.

Storage and Stabilization

Short-term Storage

After reconstitution, the protein solution remains stable at 2-8°C for up to one week. For immediate use in cell culture experiments, this timeframe is typically sufficient for most applications.

Long-term Storage

For extended storage beyond one week, maintain the reconstituted protein at -20°C or below, where it remains stable for approximately 3 months. To maximize stability during long-term storage, add a carrier protein or stabilizer to the reconstituted solution before aliquoting:

• 0.1% bovine serum albumin (BSA)
• 5% human serum albumin (HSA)
• 10% fetal bovine serum (FBS)
• 5% trehalose

Minimize freeze-thaw cycles by dividing the reconstituted protein into smaller aliquots rather than repeatedly thawing a single large volume.

Bioactivity Considerations

Recombinant Rat IL-9 demonstrates bioactivity in cell proliferation assays using MC/9-2 mouse mast cells, with an ED₅₀ (effective dose for 50% response) of 8.02-32.1 ng/mL. This potency range should inform your experimental design and dilution strategies for cell culture applications. The protein typically contains 127 amino acids with a molecular mass of 14.3 kDa and maintains full cysteine residue conservation between species.