Anti-Human/Mouse Integrin β7 – Purified in vivo PLATINUM™ Functional Grade

Clone FIB504 is primarily used in in vivo mouse studies to block ?7 integrin-mediated cell adhesion, which impacts the migration and homing of immune cells—especially in the context of inflammation and immune regulation.

In detail:

• FIB504 is a monoclonal antibody that specifically targets mouse (and human) integrin ?7, a protein that forms part of the integrins ?4?7 (involved in lymphocyte adhesion to endothelial cells via VCAM-1 and MAdCAM-1) and ?E?7 (binding E-cadherin), both playing essential roles in leukocyte trafficking to tissues such as the gut and lymph nodes during immune responses.
• In in vivo experiments, FIB504 is administered to mice to interfere with integrin ?7 function, thereby inhibiting the adhesion and transmigration of select immune cell populations across the endothelium. This is frequently used to study:
  • The role of ?7 integrin in inflammatory processes, such as colitis or other gut-associated immune conditions.
  • The migration of lymphocytes, particularly in models that assess the contribution of ?7 to mucosal immunity and tissue-specific homing of T cells.

The antibody is often used in blocking protocols, where it is injected into mice at dosages and intervals determined by the experimental design to disrupt integrin ?7-dependent cellular processes in vivo. This allows researchers to delineate the biological significance of ?7 integrin in disease, inflammation, or immune regulation.

Key applications of FIB504 in mouse in vivo studies:

• Blocking cell adhesion and migration (especially in gut-associated lymphoid tissues or sites of inflammation).
• Functional studies of immune cell homing and trafficking by disrupting ?7-mediated interactions between lymphocytes and endothelial ligands like MAdCAM-1.
• Understanding disease mechanisms in models of inflammatory bowel disease and mucosal immunity.

In summary: FIB504 is used in vivo to functionally block ?7 integrin, providing a tool to analyze lymphocyte adhesion, trafficking, and the immune response in mouse models.

The correct storage temperature for sterile packaged clone FIB504 is 2–8°C (refrigerated) for short-term storage, protected from light and without freezing. For long-term storage, aliquot the antibody and keep it at –20°C or –80°C; avoid repeated freeze-thaw cycles.

• For short-term storage (up to 1 month), keep at 2–8°C (do not freeze).
• For long-term storage (beyond a month), store aliquoted samples at –20°C or –70/–80°C.
• Do not freeze if storing at 2–8°C; freezing is only recommended for long-term storage, and repeated freeze-thaw cycles should be avoided to maintain antibody activity.
• Always protect the antibody from prolonged exposure to light.

These recommendations are consistent across multiple reputable antibody suppliers.

Commonly used antibodies and proteins employed together with FIB504 in the literature include those targeting CD3, V2 domain antibodies (such as 1027, 1088, 6E10), and secondary antibodies for detection. These reagents are typically used for flow cytometry, immunocytochemistry, or competitive binding assays.

Essential context and details:

• Anti-CD3 antibodies (e.g., Alexa Fluor® 647-conjugated anti-CD3) are frequently used in conjunction with FIB504 for the immunophenotyping of T cell subsets by flow cytometry, enabling gating on lymphocyte populations and distinguishing T cell subsets with integrin ?7 expression.
• Secondary antibodies (e.g., goat anti-rat IgG conjugated to Alexa Fluor® 488 for detecting the rat FIB504 antibody) are standard when the primary antibody (like FIB504) is not directly labeled.
• Other anti-V2 domain antibodies: In HIV research, FIB504 (which binds integrin ?4?7) is used together with monoclonal antibodies targeting distinct epitopes within the V2 region of HIV-1 gp120 (notably 1027, 1088, and 6E10). These studies assess competition or blockade of V2-gp120 interaction with ?4?7, as well as epitope mapping and neutralization.
• Streptavidin conjugates: When FIB504 is used in a biotinylated format, streptavidin conjugated to fluorophores (e.g., Alexa Fluor 647 or PE) is commonly used for detection in flow cytometry or microscopy.

Additional frequently co-used reagents:

• Isotype controls (e.g., rat IgG2a) to verify the specificity of FIB504 staining.
• In functional studies, recombinant or purified forms of gp120 (the HIV-1 envelope protein) are also frequently included when assessing binding to ?4?7 and inhibition by antibodies.

In summary, the most commonly co-used antibodies or proteins with FIB504 are:

• Anti-CD3 (for T cell identification)
• Secondary or detection reagents (e.g., Alexa Fluor®-conjugated secondary antibodies, streptavidin-PE)
• Isotype controls
• Other anti-V2 domain monoclonal antibodies (notably 1027, 1088, 6E10)
• HIV-1 gp120 (for binding/blocking studies)

Key findings from scientific literature on clone FIB504 center on its specificity for the integrin ?7, its applications in immunological assays and imaging, and insights into the biology of ?7 integrin:

• Clone FIB504 targets the ?7 integrin and is widely used to detect ?7 expression on lymphocytes in various experimental and clinical contexts.

• Origin and engineering: FIB504 is a rat anti-mouse/human monoclonal antibody against ?7 integrin. Humanization of this clone, resulting in rhuMAb Beta7, required targeted modifications for optimal antigen binding after complementarity-determining region (CDR) grafting.

• Immunological research: The clone is used in flow cytometry panels to quantify ?7 expression on T cells from blood and mucosal tissues, and to study lymphocyte trafficking, particularly in the gut and in context of mucosal inflammation. This has clarified the role of ?7 in recruiting T cells to mucosal sites and its distribution alongside other integrins (e.g., ?4?7, ?E?7, ?4?1).

• Animal model findings: In a mouse model of experimental autoimmune encephalomyelitis (EAE), anti-?7 (using muFIB504, a chimeric derivative for murine studies) showed no impact on disease severity or central nervous system inflammation, unlike anti-?4 therapy, which was highly effective. Survival rates in anti-?7-treated mice did not differ significantly from controls.

• Imaging of inflammation: Radiolabeled FIB504 (^64Cu-conjugated) was shown to selectively accumulate in inflamed gut tissue in a mouse colitis model. MicroPET imaging revealed substantially higher uptake in animals with colitis compared to healthy or isotype control-antibody-treated animals, indicating that ?7-targeted antibodies such as FIB504 can function as specific diagnostic agents for intestinal inflammation.

• Methodological applications: FIB504 is established as a gold-standard reagent for detecting ?7 integrin via flow cytometry and has been adapted for in vivo imaging and for evaluating therapeutic antibody engineering.

In summary, clone FIB504 is critical for advancing understanding of lymphocyte migration to mucosal tissues and for developing diagnostic and therapeutic antibodies targeting ?7 integrin, especially in inflammatory bowel diseases and related conditions.