FRO3 Antibody

Introduction to FPR3 Antibody

FPR3 (Formyl Peptide Receptor 3) is a G-protein-coupled receptor involved in immune responses, particularly neutrophil activation and chemotaxis. The FPR3 antibody is a recombinant monoclonal antibody (clone EPR11865) developed for detecting human FPR3 in research applications . It binds to FPR3's extracellular or intracellular epitopes, enabling studies on receptor expression, localization, and function.

Antibody Structure

• Isotype: Rabbit IgG .

• Specificity: Recognizes human FPR3 with no reported cross-reactivity to other FPR family members (e.g., FPR1 or FPR2) .

• Epitope: Linear or conformational, depending on fixation methods (e.g., works in frozen and formalin-fixed tissues under optimized conditions) .

Target Biology

• FPR3 interacts with N-formyl-methionyl peptides (e.g., bacterial byproducts) and humanin (a mitochondrial-derived peptide), modulating neutrophil degranulation and inflammatory responses .

• It activates phosphatidylinositol-calcium signaling pathways, influencing immune cell migration and cytokine release .

Key Techniques

Performance Notes

• Fixation Sensitivity: Staining intensity varies with fixation protocols. Methanol or acetone fixation improves epitope accessibility compared to formalin .

• Freeze-Thaw Stability: Repeated freeze-thaw cycles (up to 16×) do not significantly affect antibody reactivity in ELISA or WB .

Specificity and Sensitivity

• Western Blot: A single band at 40 kDa in human thymus lysates .

• Flow Cytometry: Clear separation of FPR3⁺ and FPR3⁻ populations in NCI-H460 cells .

• Cross-Reactivity: No binding to FPR1 or FPR2, as confirmed via protein arrays .

Comparative Studies

• Clone EPR11865 outperforms other anti-FPR3 antibodies (e.g., 259D/C7, 236A/E7) in signal-to-noise ratio when paired with high-affinity fluorophores like Alexa647 .

• In IMC (Imaging Mass Cytometry), FPR3 antibodies require overnight incubation at 4°C for optimal staining .

Limitations and Future Directions

• Species Restriction: Validated only in humans; reactivity in other species (e.g., mouse) is untested .

• Functional Assays: Limited data on FPR3 antibody utility in blocking or neutralizing receptor activity .