Anti-Mouse IL-12 p75 [Clone R2-9A5] — Purified in vivo PLATINUM™ Functional Grade

Clone R2-9A5 is a rat monoclonal antibody that specifically targets mouse IL-12 p75 (IL-12p70) and is primarily used for in vivo neutralization of IL-12 in mouse models. Its common applications include:

• Immune modulation in disease models: R2-9A5 is often administered to mice to block IL-12 activity, thereby inhibiting IL-12–mediated immune responses. This is critical in studies investigating the role of IL-12 in autoimmune diseases, infection, inflammation, and tumor immunology.

• Therapeutic intervention and mechanistic studies: R2-9A5 is used to determine how IL-12 contributes to immune cell activation, cytokine production, and disease progression. For example, it is applied to test the impact of IL-12 neutralization on the efficacy of immunotherapies, such as adoptive cell therapy and checkpoint blockade.

• Syngeneic and xenogeneic tumor models: Researchers use R2-9A5 to analyze how IL-12 blockade affects anti-tumor immunity in mice bearing tumors, including modulation of T cell and NK cell responses, as well as changes in the tumor microenvironment.

• Preclinical imaging and biodistribution: R2-9A5 can be conjugated to radioisotopes for immunoPET imaging to trace IL-12 distribution and inflammation sites in vivo, aiding in real-time visualization of immune processes.

• Gut microbiome research: It has been employed to study the interplay between gut microbiota and immune therapies, specifically assessing how IL-12 influences the outcome of immunotherapies in the presence of different microbial communities.

Implementation details:

• The antibody is administered via various routes (typically intraperitoneal) in dosing regimens designed to achieve sustained IL-12 neutralization.
• Its use is validated for effective blocking of IL-12–dependent biological effects in vivo without significant off-target toxicity or immunogenicity.

Summary of typical in vivo applications:

• Neutralization of IL-12 in autoimmune, infectious, and oncology models.
• Assessment of cytokine roles in immune regulation.
• Modulation of therapeutic responses and tumor growth.
• Imaging studies of inflammation and cytokine distribution.
• Microbiome–immunity interaction studies.

All cited applications involve blocking or tracking IL-12 as a mechanistic tool to elucidate immune pathways in mouse models.

R2-9A5 is a rat monoclonal antibody widely used to neutralize and detect mouse IL-12 p75 (heterodimer of p40 and p35) in immunological studies. In the literature, researchers commonly use R2-9A5 in combination with antibodies or proteins targeting related cytokines, cell surface markers, and signaling molecules involved in immune response or T cell functional analysis.

Common antibodies or proteins used alongside R2-9A5 include:

• Anti-IFN-γ antibodies (e.g., clone XMG1.2 or MAB485): Because IL-12 drives Th1 differentiation and IFN-γ production, anti-IFN-γ antibodies are often used to block, detect, or quantify IFN-γ for mechanistic or downstream readouts.
• Anti-IL-23 (p19 or p40) antibodies: IL-23 shares the p40 subunit with IL-12; thus, distinguishing their individual contributions frequently involves using antibodies against IL-23 or its unique p19 subunit, sometimes simultaneously with R2-9A5.
• Anti-IL-2 receptor antibodies: These are used to study T cell activation and proliferation, and their synergy or interaction with IL-12 blockade can be explored in immune modulation studies.
• Anti-IL-1β, anti-IFN-β (e.g., clone HDβ-4A7), and anti-IFNAR1 (e.g., clone MAR1-5A3): These antibodies are frequently used to dissect the contributions of other cytokines and interferon pathways in immune responses, often in conjunction with R2-9A5.
• T cell markers (such as anti-CD4, anti-CD8, and anti-CD62L antibodies): These are used for immunophenotyping by flow cytometry or in cell sorting when analyzing the effects of IL-12 on T cell subsets.
• Detection reagents and secondary antibodies: Such as anti-rat IgG antibodies for detecting R2-9A5 binding in tissue staining or flow cytometry.

R2-9A5 is most commonly used with antibodies detecting cytokines involved in the Th1/Th17 axis, T cell lineage markers, and secondary detection reagents for in vivo neutralization and immunoassays (ELISA, flow cytometry, IHC). In studies dissecting cytokine networks or immune modulation, multiplexing with these antibodies provides complementary functional information.

Clone R2-9A5 is a widely used rat monoclonal antibody that specifically targets the IL-12 p75 subunit (IL-12p70, also known as IL-12p40/IL-12p35 heterodimer) and functions as a neutralizing antibody for IL-12 in mouse models. The following key findings have emerged from scientific literature citing clone R2-9A5:

• Neutralization of IL-12 Function: R2-9A5 is consistently utilized to block IL-12 signaling in vivo and in vitro, allowing investigators to dissect the specific roles of IL-12 in immune responses.

• Role in T-helper 1 (Th1) Polarization:

  • Blockade of IL-12 with R2-9A5 inhibits Th1 polarization and reduces IgG2a antibody responses after DNA vaccination or protein immunization, confirming IL-12’s critical role in promoting rapid Th1 cell differentiation and class-switch recombination toward IgG2a.
  • Early administration (days 1 and 2 post-immunization) of R2-9A5 significantly suppresses Th1-type responses, but delayed blockade (days 6 and 7) does not, illustrating that IL-12's influence is time-sensitive during early immune priming.

• Antitumor and Inflammatory Models:

  • R2-9A5 is used in studies to probe how modulation of IL-12 signaling impacts the effectiveness of adoptive cell therapy, the tumor microenvironment, and inflammatory conditions, indicating a broader utility in immuno-oncology and autoimmune research.

• Research Applications and Specificity:

  • The antibody is typically sourced from Bio X Cell (catalog #BE0233) and validated as a rat IgG2b, κ isotype used for both neutralization and mechanistic immunology studies in mice.
  • Experiments frequently include isotype control antibodies to confirm specificity and to distinguish IL-12-dependent effects from non-specific antibody interactions.

• Mechanistic Insights:

  • Use of R2-9A5 has revealed that IL-12 is indispensable for early Th1 cell development and for directing antibody class switch recombination, but is less crucial for later immune processes once these programs have been established.
  • The antibody has also been pivotal in delineating the interplay between dendritic cells, T-cell help, and cytokine milieus in vaccines and inflammation studies.

In summary, clone R2-9A5 is an established tool for IL-12 neutralization in mouse immunological research, and its use has demonstrated that IL-12 is required for the early induction of Th1 immunity and IgG2a antibody responses, particularly during the initial phase of immune activation.

Dosing regimens for the anti-mouse IL-12p75 antibody clone R2-9A5 vary by experimental design and mouse model, but published studies and commercial sources indicate common patterns for in vivo use.

• Typical Dose: The most frequently reported dose is 1 mg per mouse per injection, administered intraperitoneally.
• Dosing Frequency: In one widely cited protocol, R2-9A5 was given once per week for 3 weeks (total 3 injections).
• Mouse Models: This regimen has been used in various immunological and inflammatory disease models, including those investigating T cell responses and tumor immunity.

Additional context:

• The route of administration is almost always intraperitoneal, which is standard for mouse antibody treatments.
• Commercial suppliers, such as Bio X Cell, recommend in vivo use at doses that fall within the 0.5–1 mg range per mouse per injection but encourage referencing primary literature for disease model specifics.
• Different mouse models and disease settings (e.g., chronic vs. acute inflammation, infectious vs. autoimmune models) may justify alterations in dose, frequency, or total number of doses, but most published studies use the regimen above.

There is no evidence in recent literature or on manufacturer datasheets that R2-9A5 dosing requires dramatic adjustment for genetic mouse backgrounds or disease settings, as antibody pharmacokinetics and bioavailability are generally similar across common laboratory strains unless the experimental context specifically warrants modification.

In summary, 1 mg per mouse, intraperitoneally, weekly for 3 weeks is a standard regimen for R2-9A5 across diverse mouse models, with frequency or total dose adapted as needed for specific research questions.