Anti-Mouse IFN-γ – Purified in vivo PLATINUM™ Functional Grade

In Vivo Applications of Clone R4-6A2 in Mice

Clone R4-6A2 is a well-characterized rat monoclonal antibody specific for mouse interferon-gamma (IFNγ). Its primary in vivo applications leverage its potent neutralizing activity against IFNγ, a key cytokine in immune regulation, inflammation, and host defense.

Core In Vivo Uses

• IFNγ Neutralization Studies: R4-6A2 is widely used to neutralize IFNγ bioactivity in mice, both in functional assays and therapeutic models. By blocking IFNγ signaling, researchers can dissect the cytokine’s role in immune responses, inflammation, and disease pathogenesis.
• In Vivo Cytokine Capture Assay (IVCCA): The antibody serves as a capture reagent in the IVCCA, a sensitive method to measure cytokine production in vivo by dramatically increasing the cytokine’s serum half-life. This technique amplifies detection sensitivity 30- to 1000-fold, enabling precise measurement of IFNγ during immune responses.
• Therapeutic Intervention in Disease Models: R4-6A2 has demonstrated therapeutic potential in preclinical models. For example, administration of R4-6A2 attenuated inflammation and improved survival in a mouse model of acute lung injury, highlighting its use in studying cytokine-driven pathologies.

Experimental Contexts

• Immune Response Modulation: By neutralizing IFNγ, R4-6A2 allows researchers to investigate the cytokine’s contributions to T cell, B cell, macrophage, and NK cell activation, as well as its effects on antigen presentation and antibody production.
• Disease Pathogenesis: The antibody is used to probe the role of IFNγ in infections, autoimmune diseases, and cancer, where IFNγ signaling may promote or suppress disease progression.
• Control for Specificity: In some experimental designs, R4-6A2 is employed as a specificity control in flow cytometry and other assays to confirm that observed effects are IFNγ-dependent.

Key Features Supporting In Vivo Use

• High Specificity and Neutralizing Capacity: R4-6A2 neutralizes both natural and recombinant mouse IFNγ, ensuring robust blockade of cytokine activity in vivo.
• Functional Grade Formulations: Commercially available preparations are often endotoxin-low and suitable for in vivo injection, reducing the risk of nonspecific immune activation.
• Established Protocols: Detailed methodologies, such as the IVCCA, are well-documented, facilitating reproducible application across laboratories.

Summary Table: Common In Vivo Applications

Clone R4-6A2 is a cornerstone tool for in vivo mouse studies focused on IFNγ biology, offering precise neutralization, sensitive detection, and therapeutic modulation in a range of experimental and disease contexts.

Scientific Significance of Clone R4-6A2 (Anti-Mouse IFN-γ Antibody)

Clone R4-6A2 is a widely cited rat-derived monoclonal antibody specific for mouse interferon-gamma (IFN-γ), a cytokine critical for immune regulation and inflammatory responses. The scientific literature highlights several key applications and findings related to this clone.

Key Applications

• Immunoassay Development: R4-6A2 is extensively used as a capture or detection reagent in ELISA, ELISPOT, and other immunoassays to quantify mouse IFN-γ in vitro, providing a robust tool for immunological research. In ELISPOT assays, it serves as a solid-phase capture antibody to detect IFN-γ production at the single-cell level.
• Antibody Pairing: It is commonly paired with another anti-IFN-γ antibody (clone XMG1.2) in sandwich immunoassays, with R4-6A2 typically as the capture antibody and biotin-conjugated XMG1.2 as the detection reagent. This pairing enables sensitive and specific quantification of IFN-γ in biological samples.
• Antibody Characterization: The R4-6A2 antibody (Rat IgG1) has been characterized in optimization studies for enzymatic fragmentation, highlighting its widespread use and reliability.

Functional Insights from In Vivo and In Vitro Studies

• Neutralizing Activity: R4-6A2 can neutralize mouse IFN-γ activity, as demonstrated in vivo by its administration to mice infected with invasive group A Streptococcus (GAS), where it directly impacted host responses by blocking IFN-γ function.
• Immune Response Analysis: The clone is used to assess IFN-γ production in mouse models of infection, vaccination, and autoimmune diseases. For example, after immunization, lymph node cells are often analyzed using ELISPOT with R4-6A2 to measure antigen-specific IFN-γ responses.
• Host–Pathogen Interactions: Studies using R4-6A2 have furthered understanding of the role of IFN-γ in host defense, immunopathology, and vaccine-induced immunity.

Model Systems and Research Impact

• Mouse Models: The antibody is essential in mouse models of cytokine release syndromes, hyperinflammation (e.g., hemophagocytic lymphohistiocytosis), and infectious diseases, where IFN-γ is a key mediator of pathology.
• Mechanistic Studies: By neutralizing IFN-γ, researchers have elucidated its role in driving other cytokines (e.g., IL-6, TNFα), tissue inflammation, and systemic manifestations of disease, such as splenomegaly, cytopenias, and hyperferritinemia.

Summary Table: Key Uses of Clone R4-6A2

Expert Perspective

Clone R4-6A2 has become a cornerstone reagent in mouse immunology, enabling precise measurement and functional manipulation of IFN-γ in diverse experimental contexts. Its reliability and specificity underpin a significant body of research on cytokine biology, infectious disease, autoimmunity, and vaccine responses.

Dosing regimens for the R4-6A2 antibody—a rat monoclonal targeting mouse interferon gamma (IFN-γ)—vary according to research aims, mouse strain, disease model, and administration route, but typical in vivo use in mice involves intraperitoneal injections at doses ranging from 100–500 μg per mouse, often repeated over several days or weeks.

In infectious disease models, R4-6A2 is administered intraperitoneally (i.p.) at 100–500 μg per mouse, timed to coincide with pathogen challenge or other immunologic stimuli. For example, one cited study used i.p. administration of R4-6A2 on the day of infection to neutralize IFN-γ activity in mouse models of severe invasive Group A Streptococcus infection.

In cancer and inflammation models, similar dosing regimens have been reported, generally falling within the 200–500 μg per mouse range, with doses repeated every 3–7 days depending on the experimental schedule and endpoint. Most suppliers typically recommend 100–500 μg per mouse per dose for effective neutralization, with the route being intraperitoneal injection.

An overview of reported regimens:

• Infection models: 100–500 μg/mouse i.p., usually as a single dose or repeated at key time points post-infection.
• Tumor and autoimmunity models: 200–500 μg/mouse i.p., given every 3–7 days for sustained neutralization of IFN-γ.
• Detection/ELISA applications: For in vitro use, recommended concentrations are much lower (0.5–2 μg/mL), but this does not apply to in vivo blocking or neutralization.

Important Notes:

• Most published studies use the intraperitoneal route for systemic neutralization.
• Dosing schedules may be adjusted based on the model, desired duration of IFN-γ blockade, mouse strain sensitivity, and other concurrent treatments.
• Regimens must be validated empirically, with pilot studies often run to identify optimal dosing, especially for sustained neutralization or in models with altered IFN-γ expression.

In summary, the most common dosing regimen of R4-6A2 in mouse models is 200–500 μg per mouse i.p., administered every 3–7 days, with adjustments made based on the disease model, severity, and targeted immunological effects.