Anti-Mouse IL-2 [Clone JES6-1A12] – Purified in vivo GOLD™ Functional Grade

The clone JES6-1A12 is a monoclonal antibody used in in vivo mouse studies for several purposes, primarily focusing on interleukin-2 (IL-2) biology. Here's how it is commonly used:

Applications of JES6-1A12 in In Vivo Mouse Studies

1. IL-2 Neutralization:

   • Role: The JES6-1A12 antibody is used to neutralize IL-2 activity in vivo. IL-2 is crucial for T-cell proliferation and differentiation, playing roles in immune regulation and autoimmune disease prevention.
   • Mechanism: By binding to IL-2, the antibody prevents IL-2 from interacting with its receptors on T cells and other immune cells, thereby inhibiting its functional activity.

2. Complex Formation with IL-2:

   • Role: The JES6-1A12 antibody can form complexes with IL-2, which are used to enhance IL-2 signaling. These complexes prolong the half-life of IL-2 in the circulation, making them more effective in expanding IL-2-dependent cells such as T regulatory cells or effector T cells.
   • Effects: Such complexes have been shown to increase sensitivity to lipopolysaccharide (LPS), expand myeloid cell populations, and modulate immune responses.

3. Autoimmune Disease Treatment:

   • Role: The IL-2/JES6-1A12 complexes have potential applications in treating autoimmune diseases by promoting regulatory T cell differentiation and function, which can help suppress pathogenic immune responses.

Overall, JES6-1A12 is a versatile tool in immunology research, allowing for manipulation of IL-2 activity and thus influencing various immune cell populations and responses in vivo.

Storage Temperature Guidelines

The correct storage temperature for the sterile packaged clone JES6-1A12 varies depending on the manufacturer, formulation, and whether the product is reconstituted or supplied dry:

• Supplied dry (unreconstituted): Store at –20 to –70°C until use. The product from R&D Systems can be stored this way for up to 12 months from the date of receipt.
• After reconstitution (sterile): Store at either 2–8°C (refrigerated) for 1 month or at –20 to –70°C (frozen) for up to 6 months.
• BioLegend Ultra-LEAF™ Purified (liquid, sterile): Store undiluted at 2–8°C (refrigerated). Do not freeze, and handlingshould be aseptic.
• BioLegend regular purified (azide-containing): Store undiluted at 2–8°C.
• BD Biosciences Unlabeled (liquid): Store undiluted at 4°C.

Key Recommendations

• Check the product datasheet for lot-specific instructions, as recommendations can differ by manufacturer and formulation.
• For sterile, azide-free (Ultra-LEAF) preparations intended for sensitive applications like in vivo studies, strictly refrigerate and avoid freezing.
• For lyophilized or dried antibodies, long-term storage at –20 to –70°C is safe and standard.
• After reconstitution, options include short-term (1 month) refrigeration or longer-term (six months) freezing, always under sterile conditions.
• Avoid repeated freeze-thaw cycles, especially after reconstitution or if the product is in liquid form.

Summary Table

Always refer to the product datasheet for the most accurate, lot-specific instructions.

The most commonly used antibodies or proteins with JES6-1A12—a monoclonal antibody targeting mouse IL-2—are S4B6 and JES6-5H4, which are often employed in combination for ELISA, ELISPOT, and related assays to detect or quantify mouse IL-2.

Essential details and typical pairings:

• Sandwich ELISA/ELISPOT Assays often pair JES6-1A12 as the capture antibody with biotinylated JES6-5H4 as the detection antibody.
• S4B6 is used in studies alongside JES6-1A12 for competition, binding, and functional assays. S4B6 is known as an "immunoenhancing" anti-IL-2 antibody, binding a different epitope than JES6-1A12, and is functionally distinct from it.
• Recombinant mouse IL-2 protein is typically used as a standard in quantification assays with JES6-1A12.

Additional context:

• JES6-5H4 shares similar epitope recognition with S4B6 but differs in affinity and neutralizing capacity; JES6-1A12 binds a separate IL-2 region and does not compete with S4B6/JES6-5H4.
• These antibodies may also be conjugated or used with reporter-labeled antibodies (such as anti-M13 for phage display detection).
• Biotinylation of detection antibodies (e.g., JES6-5H4) is recommended for streptavidin-based detection methods.

Summary table:

These combinations are prevalent in literature for immune quantification, neutralization, and mechanistic studies of IL-2 biology.

Key Findings from Clone JES6-1A12 Citations

Clone JES6-1A12 is a monoclonal antibody (mAb) specific for mouse interleukin-2 (IL-2) that has been widely used in immunological research. Its unique functional properties and the biological effects of IL-2/JES6-1A12 complexes have yielded several important scientific insights.

Epitope Specificity and Functional Impact

• Epitope Localization: JES6-1A12 recognizes a conformational epitope on mouse IL-2 formed by residues E37–P51, confirmed by grafting experiments that reconstructed this epitope on human IL-2. This segment is critical for antibody binding, and substitutions within this region, especially at solvent-exposed residues, can abrogate recognition.
• Mechanism of Action: JES6-1A12 does not simply neutralize IL-2 but converts it into a weak agonist by simultaneously blocking interactions with both the ? (CD25) and ?/? (CD122/CD132) chains of the IL-2 receptor. This dual blockade drastically reduces IL-2 signaling in cells that express the intermediate-affinity IL-2 receptor (??), such as effector T cells, while still allowing some signaling in cells expressing the high-affinity (???) receptor, notably regulatory T cells (Tregs).
• Selective Treg Stimulation: This differential inhibition results in preferential stimulation of Tregs over effector T cells, both in vitro and in vivo, reinforcing Treg expansion and function while dampening effector responses.

Cellular and Immunological Effects

• Treg Expansion: IL-2 complexed with JES6-1A12 (IL-2/JES6-1A12) delivers strong, sustained IL-2 signals selectively to CD25+ cells—primarily Tregs—leading to robust Treg expansion.
• Myeloid Cell Expansion: Treatment with IL-2/JES6-1A12 expands not only Tregs but also myeloid cells, including granulocytes, eosinophils, dendritic cells, monocytes, and macrophages. This is reflected by increased counts of CD11b+CD14+ cells in the spleen and blood.
• Enhanced Myeloid Function: IL-2/JES6-1A12 increases MHC class II expression on monocytes and macrophages and enhances their proliferation, as confirmed by BrdU incorporation. These cells become more responsive to lipopolysaccharide (LPS), producing more TNF-? and displaying increased CD25 expression, which further enables them to utilize IL-2/JES6-1A12 complexes for proliferation and activation.
• Inflammation and Immune Modulation: The expansion and activation of myeloid cells by IL-2/JES6-1A12 may have broader implications for inflammation and immune regulation, given their dual roles in promoting both regulatory and potentially pro-inflammatory pathways.

Translational Relevance

• Autoimmunity and Transplantation: The selective immunomodulatory effects of JES6-1A12 (promoting Tregs and inhibiting effector T cells) have been explored in models of autoimmune disease therapy, transplantation, and tolerance induction.
• Myeloid Immunotherapy: The unexpected expansion of myeloid cells by IL-2/JES6-1A12 complexes suggests new potential therapeutic applications in diseases where myeloid activation or suppression is desired.

Summary Table: Major Biological Effects of IL-2/JES6-1A12 Complexes

Conclusion

JES6-1A12 is unique among IL-2 antibodies due to its ability to convert IL-2 into a selective agonist for CD25+ cells—especially Tregs—while inhibiting effector responses. This has made it a valuable tool for investigating immune regulation and has uncovered broader effects on myeloid cells, suggesting complex roles in both tolerance and inflammation. The dual capacity to modulate adaptive and innate immunity highlights its potential as a research tool and possibly as a therapeutic agent in immune-mediated diseases.