Anti-Mouse MAdCAM-1 (MECA-367) – Purified in vivo GOLD^TM Functional Grade

Clone MECA-367, a rat monoclonal antibody targeting mouse MAdCAM-1 (mucosal addressin cell adhesion molecule-1), is widely used in experimental mouse models to study lymphocyte trafficking and inflammatory conditions. This antibody functions by blocking the interaction between MAdCAM-1 and its receptors, particularly α4β7 integrin (LPAM-1), thereby preventing lymphocyte homing to mucosal tissues.

Primary In Vivo Applications

The MECA-367 antibody is primarily administered to neutralize MAdCAM-1, which prevents lymphocytes, particularly those expressing the β7 integrin, from migrating to gastrointestinal tissues. This blocking mechanism makes it a valuable tool for reducing T cell-mediated inflammation in mouse models of gastrointestinal diseases and inflammatory bowel disease.

When administered in vivo, MECA-367 produces a dose-dependent effect on circulating immune cell populations. Studies have shown that single doses ranging from 0.1 to 3 mg/kg administered intravenously induce a two- to threefold increase in circulating β7+ memory T-cells without affecting β7- populations. This increase reflects the successful blockade of lymphocyte homing to mucosal tissues, as these cells can no longer extravasate through MAdCAM-1-expressing endothelial venules in Peyer's patches, mesenteric lymph nodes, and gut lamina propria.

Experimental Design Considerations

The antibody demonstrates high binding affinity to mouse MAdCAM-1 with a Kd value of 5.1 pmol/L and effectively blocks the adhesion of α4β7+ leukocytes to MAdCAM-1. For experimental use, MECA-367 is typically administered via intravenous injection, with effects measurable at day 7 post-dosing. The antibody is formulated in pH 7.4 buffer without stabilizers or preservatives and maintains high purity (>95% by SDS-PAGE).

These applications make MECA-367 an essential research tool for investigating the role of mucosal lymphocyte trafficking in inflammatory conditions and for evaluating potential therapeutic strategies targeting the MAdCAM-1 pathway.

Commonly used antibodies or proteins associated with MECA-367 (anti-MAdCAM-1) studies include isotype controls such as rat IgG2a (e.g., R35–95), and other cell adhesion molecules like VCAM-1, integrins (particularly alpha4beta7/LPAM-1, VLA-4/alpha4beta1, and L-selectin/CD62L), and in some cases, other anti-MAdCAM-1 clones like PF-00547659.

Essential context:

• Isotype controls: The most frequently used isotype control in published studies is rat IgG2aκ, such as clone R35-95, to ensure specificity of MECA-367.
• Related adhesion molecules: When investigating cell migration, homing, or mucosal immunity, researchers often measure or block other key proteins:
  • VCAM-1 (Vascular Cell Adhesion Molecule-1)
  • ICAM-1 (Intercellular Adhesion Molecule-1)
  • LPAM-1 (alpha4beta7 integrin), VLA-4 (alpha4beta1 integrin), and CD62L (L-selectin), which are MAdCAM-1’s endothelial ligands
• Other monoclonal antibodies:
  • MECA-79: Another monoclonal antibody frequently used with MECA-367 to mark high endothelial venules (HEVs), alongside MECA-367 for additional specificity of localization in tissue sections.
  • PF-00547659: A humanized anti-MAdCAM-1 antibody used in translational and comparative studies alongside MECA-367.

In summary, MECA-367 is typically used in combination with:

• Rat IgG2a isotype controls (e.g., R35-95)
• VCAM-1 and ICAM-1 antibodies
• Integrin antibodies (alpha4beta7, VLA-4)
• MECA-79 antibody (for dual HEV/MAdCAM-1 studies)
• PF-00547659 (for human translational models)

If you require details on protocols or experimental combinations, most studies and antibody suppliers recommend consulting primary literature or product documentation for specific pairings.

Key Findings from Clone MECA-367 Literature

Blockade of MAdCAM-1 Function and Lymphocyte Homing

• MECA-367 is a rat monoclonal antibody that specifically targets murine mucosal addressin cell adhesion molecule-1 (MAdCAM-1) and blocks its interaction with its main counter-receptor, the leukocyte integrin α₄β₇ (LPAM-1). This blockade occurs both in vitro and in vivo, effectively inhibiting the adhesion of α₄β₇⁺ leukocytes to MAdCAM-1-bearing endothelial cells.
• The antibody prevents lymphocyte homing to gut-associated lymphoid tissues, such as Peyer’s patches, a key mechanism in the recruitment of immune cells to mucosal sites. Administration of MECA-367 has been shown to almost completely inhibit lymphocyte migration to Peyer’s patches and block the adhesion of relevant leukocyte subsets in functional assays.
• MECA-367 binds with high affinity to mouse MAdCAM-1 (K_d ≈ 5.1 pmol/L) and, in preclinical models, induces a dose-dependent increase in circulating β₇⁺ memory T-cells, reflecting displacement of these cells from tissue sites due to MAdCAM-1 blockade.

Role in Disease Models and Therapeutic Insights

• MECA-367 has been instrumental in elucidating the pathophysiological role of MAdCAM-1 in lymphocyte trafficking and in the development of inflammatory diseases. In multiple preclinical colitis models, MAdCAM-1/α₄β₇ blockade (using MECA-367) reduced lymphocyte recruitment, mucosal destruction, and clinical signs of disease, suggesting that targeting this axis could be beneficial in inflammatory bowel disease (IBD).
• In the context of diabetes, MECA-367 administration significantly reduced disease development in a neonatal mouse model, highlighting the broader relevance of MAdCAM-1 in immune-mediated pathologies.
• The antibody has also served as a critical tool for validating the mechanism of action of clinical-stage anti-MAdCAM-1 therapeutics (e.g., PF-00547659) in humans, despite its limited cross-reactivity to human MAdCAM-1.

Technical and Experimental Applications

• MECA-367 is widely used in flow cytometry, immunohistochemistry, Western blot, and immunoprecipitation to detect and study MAdCAM-1 expression and function in murine systems.
• The antibody reacts with a 50–66 kDa glycoprotein, a member of the immunoglobulin superfamily, that is expressed on endothelial cells in mucosal and inflamed tissues.
• Recommended usage includes titration for optimal performance in different assays, with typical concentrations of ≤1 µg per test in flow cytometry.

Summary Table: Major Effects of MECA-367

Conclusion

MECA-367 is a foundational tool in immunology research, enabling the dissection of MAdCAM-1’s role in lymphocyte trafficking, mucosal immunity, and inflammatory diseases. Its blockade of MAdCAM-1 not only elucidates basic mechanisms of immune cell homing but also provides preclinical validation for therapeutic strategies targeting this pathway in human disease.

Dosing regimens of clone MECA-367 (anti-MAdCAM-1 antibody) in mouse models commonly involve single intravenous injections at doses typically ranging from 0.1 to 3 mg/kg.

The most detailed published regimen specifies:

• FVB mice were administered single increasing doses of MECA-367 (0.1, 0.3, 1, and 3 mg/kg) via intravenous tail vein injection in a saline vehicle (20 µL per mouse).
• Efficacy and biomarker response (circulating LPAM⁺ CD4⁺ memory T cells) were measured at day 7 post-injection.

Key points on regimen variation:

• The maximal pharmacodynamic effect (increased circulating LPAM⁺ memory T cells) was observed at 1 mg/kg, with higher doses (up to 3 mg/kg) not providing substantially greater benefit for this biomarker.
• Dosing adjustments (including dose and frequency) may be tailored to the specific experimental aim, mouse strain, or disease model, but most studies utilize the above range of single intravenous doses.
• Other suppliers and reviews confirm this typical dose range and intravenous administration route. However, specific variations across mouse strains/models (e.g., FVB, C57BL/6, BALB/c, or disease versus healthy) are not explicitly detailed in the cited search results.

Summary Table: Typical Dosing in Mouse Models

*While use in other mouse strains is reported, explicit published dosing variations are not detailed in the search results.

Conclusion:
MECA-367 is most often dosed as a single IV injection at 0.1–3 mg/kg in various mouse models, with FVB mice as the specific example. Dose selection may depend on the measured endpoint, but higher doses (above 1 mg/kg) may not proportionally increase target biomarker effects. Detailed model-specific regimen adjustments (beyond this general range) are not reported in the sources found.