Anti-Mouse IL-12 [Clone R1-5D9] — Purified in vivo GOLD™ Functional Grade

Recombinant Mouse IL-12 p70

This monoclonal antibody is aseptically packaged and formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 6.0 with no carrier protein, potassium, calcium or preservatives added. Due to inherent biochemical properties of antibodies, certain products may be prone to precipitation over time. Precipitation may be removed by aseptic centrifugation and/or filtration.

Liquid

Functional grade preclinical antibodies are manufactured in an animal free facility using only in vitro protein free cell culture techniques and are purified by a multi-step process including the use of protein A or G to assure extremely low levels of endotoxins, leachable protein A or aggregates.

Functional grade preclinical antibodies may be stored sterile as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at ≤ -70°C. Avoid Repeated Freeze Thaw Cycles.

Research Use Only

2 – 8° C Wet Ice

ELISA, FC, IHC, in vivo Neutralization

Applications reported in the literature for Preclinical In Vivo Models:
Because dysregulated IL-12 expression is heavily implicated in chronic inflammatory cascades and the pathogenesis of severe autoimmune conditions, Anti-Mouse IL-12 (Clone R1-5D9) is an invaluable tool for in vivo blockade and neutralization studies. It is widely cited in animal research models investigating:
- Infectious Diseases: Studying host immune responses and disease progression during intracellular parasitic and microbial infections, such as Leishmania or Cryptosporidium.
- Autoimmune & Inflammatory Pathology: Modeling conditions like skin inflammation, multiple sclerosis (via central nervous system p40 overexpression pathways), and septic immunosuppression.
- Tumor Microenvironments: Dissecting the role of IL-12-driven cellular immunity in tumor rejection or progression.

Activity is directed against the p40 subunit of mouse Interleukin-12 (IL-12). Clone R1-5D9 specifically recognizes an epitope on the p40 subunit, which is shared by both the bioactive IL-12 p70 heterodimer (p35/p40) and the IL-23 heterodimer (p19/p40), as well as the p40 homodimer and monomer^1,2.

IL-12 is a critical disulfide-linked heterodimeric cytokine (p70) that bridges innate and adaptive immunity by promoting Th1 cell differentiation and inducing Interferon-gamma (IFN-gamma) production by T cells and NK cells^2,4. The regulation of IL-12 is complex; in addition to the bioactive p70 form, cells often secrete an excess of the p40 subunit as a monomer or an antagonistic homodimer p40 that competes for receptor binding^1,2. Hochrein et al. (2000) utilized clone R1-5D9 as a biotinylated detection antibody in high-sensitivity ELISAs to characterize the regulatory mechanisms governing IL-12 secretion by dendritic cells². Their research revealed that IL-4, the primary Th2-driving cytokine, paradoxically serves as a major regulator that enhances the production of bioactive IL-12 p70 while selectively suppressing the secretion of the antagonistic p40 homodimer². This discovery highlighted a novel negative feedback loop where IL-4 enables DCs to produce the very cytokine (IL-12) required for Th1 polarization, thereby maintaining immunological balance during the initiation of an immune response^2,4. Because it binds a monomorphic framework epitope on the p40 subunit, R1-5D9 is a standard reagent for quantifying IL-12/p40 levels in various genetic backgrounds and for investigating the IL-12/IL-23 axis in chronic inflammation and autoimmunity^1,2,5. Beyond its use as a detection tool, R1-5D9 is highly effective for both in vivo and in vitro neutralization of IL-12 bioactivity, facilitating the study of cytokine-dependent resistance to pathogens such as Leishmania^3,5.

Mechanism of Action for Clone R1-5D9
The monoclonal antibody Clone R1-5D9 is a rat IgG2a that reacts specifically with mouse IL-12. Generated using recombinant mouse IL-12 p75 as the immunogen, Clone R1-5D9 binds to the bioactive cytokine and effectively neutralizes its downstream biological functions. By blocking the interaction of IL-12 with its receptor complex, this antibody inhibits:
- Th1 Polarization: Prevents the differentiation of naive CD4+ T lymphocytes into pathogenic T helper 1 (Th1) cells.
- IFN-γ Production: Strongly suppresses the secretion of Interferon-gamma (IFN-γ) from T cells and Natural Killer (NK) cells.
- NK Cell Cytotoxicity: Attenuates the functional activation and cytolytic activity of NK cells.

IL-12 is primarily produced by activated professional antigen-presenting cells (APCs), including dendritic cells (DCs), macrophages, and monocytes, in response to microbial or inflammatory stimuli^2,4.

IL-12R-beta Receptor Subunit

1. Wilkinson VL, et al. Characterization of anti-mouse IL-12 monoclonal antibodies and measurement of mouse IL-12 by ELISA. J Immunol Methods. 189(1):15-24. 1996.
2. Hochrein H, et al. Interleukin (Il)-4 Is a Major Regulatory Cytokine Governing Bioactive IL-12 Production by Mouse and Human Dendritic Cells. J Exp Med. 192(6):823-834. 2000.
3. Presky DH, et al. A functional interleukin 12 receptor complex is composed of two membrane-bound proteins. Proc Natl Acad Sci U S A. 93(24):14002-14007. 1996.
4. Trinchieri G. Interleukin-12 and the regulation of innate resistance and adaptive immunity. Nat Rev Immunol. 3(2):133-146. 2003.
5. Gimblet C, et al. Cutaneous Leishmaniasis Induces a Transmissible Dysbiotic Skin Microbiota that Promotes Skin Inflammation. Cell Host Microbe. 22(1):13-24. 2017.