Anti-Human CD119 (IFN-γ Rα Chain) – Purified in vivo PLATINUM™ Functional Grade

Clone GIR-208 is a mouse monoclonal antibody that targets the human interferon-gamma receptor alpha (IFNγ Rα). In in vivo mouse studies, GIR-208 is often used as an isotype control rather than a specific therapeutic or diagnostic agent. This is because it does not interact with mouse interferon-gamma receptors but can serve as a control to assess the specificity of other treatments or antibodies in mouse models. It is also used in functional assays, such as flow cytometry, where it helps in staining cells to assess various cell surface markers. Additionally, GIR-208 can be used in research settings where understanding the effects of blocking or modulating specific immune pathways is necessary, although it specifically targets human receptors and is used in contexts where such specificity is needed.

Common Applications:

• Isotype Control: Used to verify the specificity of other antibodies or treatments in mouse models.
• Flow Cytometry: For staining cells to identify specific markers, although at low concentrations (≤ 0.5 μg per 10^6 cells).
• Functional Assays: Can be used in in vivo functional assays due to its purified form (e.g., GOLD™ Purified antibody) for assessing immune responses or receptor functions in mouse models.

However, since GIR-208 targets human receptors, its direct application in mouse models is limited to serving as a control or in studies involving humanized mice or specific research contexts where human receptor interactions are relevant.

Commonly Used Antibodies and Proteins with GIR-208 in the Literature

GIR-208 is a monoclonal antibody targeting the human interferon-gamma receptor alpha chain (IFN-γRα, CD119). It is widely used for flow cytometry, Western blotting, and functional studies involving IFN-γ signaling.

Companion Antibodies

• GIR-301: This is the most frequently mentioned companion antibody to GIR-208 in the literature. While details on GIR-301’s specific target are less clear from the provided sources, it is associated with components of the IFN-γ signaling pathway. GIR-208 and GIR-301 are often used together in studies investigating IFN-γ receptor biology.
• Isotype Control Antibodies: Common isotype controls used alongside GIR-208 include MOPC-21 (a mouse IgG1 isotype control), particularly for flow cytometry to distinguish specific from non-specific staining. BD Biosciences specifically mentions PE Mouse IgG1, κ Isotype Control (Cat. No. 554680) as the appropriate control for GIR-208 in flow cytometry applications.

Other Proteins in IFN-γ Signaling Pathways

• Interferon-gamma (IFN-γ): As the natural ligand for IFN-γRα (CD119), IFN-γ is routinely used in assays to validate the specificity and neutralizing activity of GIR-208. For example, excess recombinant human IFN-γ (≥200 ng/mL) can competitively inhibit GIR-208 binding to its receptor.
• IFN-γ Receptor Beta Chain (IFN-γRβ, CDw131): The functional IFN-γ receptor is a heterodimer of α (CD119) and β (CDw131) chains. Though GIR-208 targets the α chain, studies on IFN-γ signaling often assess both chains for receptor function and downstream signaling.
• Other IFN-γ Pathway Components: While not explicitly listed in the search results, other antibodies against downstream signaling molecules (e.g., STAT1, JAK1/2) are commonly used in the broader literature to study IFN-γ-mediated responses. However, these are not specifically mentioned as direct companions to GIR-208 in the provided sources.

Non-Interferon Proteins

• Recombinant Proteins: Recombinant forms of IFN-γRα (the target of GIR-208) and IFN-γ are commonly used for binding and inhibition assays to characterize receptor-antibody interactions.
• Cross-Reactivity Controls: Some studies use antibodies against unrelated receptors (e.g., IL-10 receptor beta) to demonstrate the specificity of GIR-208, as it does not cross-react with these proteins.

Summary Table

Additional Notes

• Species Specificity: GIR-208 is specific for human IFN-γRα and does not cross-react with mouse IFN-γR1 or other human cytokine receptors tested (e.g., IL-10Rβ).
• Functional Assays: GIR-208 is a neutralizing antibody, so it is often used in assays where blocking IFN-γ signaling is desired, such as inhibition of anti-viral responses.
• Alternative Antibodies: For detecting IFN-γRα expression without competition from endogenous IFN-γ, non-neutralizing antibodies (e.g., PE Mouse Anti-Human CD119, Cat. No. 558937) are recommended.

In summary, the most commonly cited companion reagents for GIR-208 are GIR-301, isotype controls like MOPC-21, recombinant IFN-γ, and antibodies targeting the IFN-γRβ chain, reflecting its central role in IFN-γ receptor biology studies.

Clone GIR-208 is a monoclonal antibody widely used in scientific literature to target human IFNγ receptor 1 (CD119, IFNγ Rα) in immunological research, particularly for studying interferon gamma (IFNγ) signaling pathways and related functional assays. The key findings from its citations are summarized as follows:

• Specificity and Application: GIR-208 specifically binds to an epitope on the alpha chain of the human IFNγ receptor (IFNγ R1), which is involved in IFNγ signal transduction through association with JAK1, JAK2, and Stat1. It is used in various assays including flow cytometry, immunoprecipitation, and functional studies of IFNγ signaling.

• Functional Studies: GIR-208 is employed to functionally block IFNγ R1, allowing investigation of IFNγ-dependent cellular responses. For example, in cell signaling studies, GIR-208 enables examination of STAT1 activation and IFNγ-induced gene transcription.

• Role in Disease Research: Citations indicate its use in studying genetic defects of IFNGR1 that cause susceptibility to infections (e.g., mycobacterial disease) and conditions associated with immune privilege or dysregulation. GIR-208 enables evaluation of the pathogenic mechanisms involving IFNγ signaling in these diseases.

• Experimental Controls: GIR-208 is frequently used as an isotype control antibody, which is critical for ensuring the specificity of immunological assays, thus improving the reliability of experimental data.

• Neutralization and Blocking: The literature describes GIR-208's effectiveness as a neutralizing antibody that can block extracellular IFNγR1, evidenced by its ability to prevent IFNγ from binding the receptor in both in vitro and in vivo assays. This blockade is essential to dissect IFNγ-dependent effects on immune cells.

• Cancer Immunology: Recent studies cite GIR-208 in experiments analyzing immune responses in the tumor microenvironment, showing its utility in characterizing IFNγ receptor expression and function in cancer immunology research.

• Experimental Techniques: Its application has been validated for flow cytometric analysis of human peripheral blood cells, with recommended concentrations and titration for optimal staining and assay performance. Immunoprecipitation studies use GIR-208 to detect IFNγR1 in varying genotypes and experimental conditions.

In summary, scientific citations of clone GIR-208 consistently highlight its reliability and versatility in targeting human IFNγ receptor 1, enabling mechanistic studies of IFNγ signaling, disease susceptibility related to IFNγR1, and immune cell profiling in both basic and translational immunology.

Dosing regimens for clone GIR-208 in mouse models are highly standardized; published studies and commercial antibody providers report the use of a single 2 mg intraperitoneal (i.p.) dose per mouse, most often administered one day prior to experimental intervention. There is no documented variation in dose, frequency, or route of administration across different mouse strains or disease models within the available literature.

Supporting Details:

• Major suppliers and technical datasheets (e.g., Leinco) and literature reviews confirm that the “2 mg i.p. per mouse, single dose” approach is used uniformly for GIR-208 in wild-type and genetically altered mice (e.g., C57BL/6J, Ifnar1^−/−^).
• Studies specifically note that “this regimen does not vary substantially between different mouse models or experiments in the reviewed literature”.
• Earlier work documents rare use of a lower dose (0.2 mg per mouse), but such regimens are not the norm and are typically replaced in current practice by the 2 mg dose for functional in vivo studies.

Additional Information:

• GIR-208 is primarily utilized as a control isotype antibody against human IFNγ receptor rather than a function-blocking antibody in mouse models, which may further explain dosing uniformity.
• For flow cytometry and in vitro applications, much lower concentrations (≤0.5 µg per 10^6 cells) are recommended, and titration is advised for optimal performance.
• If specialized applications or unique mouse models require deviation from this regimen, such details should be explicitly described in individual study protocols, but there is no general evidence of routine adjustments.

Comparison to Other Antibodies:

• By contrast, function-blocking or depleting antibodies targeting mouse proteins (e.g., anti-PD-1, anti-CD4) often show variable dosing, frequency, and routes tailored to disease model, experimental aims, and pharmacokinetics. GIR-208 is notable for its lack of such variation in published sources.