Anti-Human/Mouse integrin β7 (Clone FIB21) – Purified in vivo GOLD™ Functional Grade

Clone FIB21 is a rat anti-mouse/human integrin β7 monoclonal antibody with several important in vivo applications in mice, primarily focused on studying immune cell trafficking and inflammatory processes in the gut and other tissues.

Blocking Integrin-Mediated Cell Adhesion

FIB21 functions as a blocking antibody that inhibits the interaction between integrin β7 and its ligands. Specifically, it blocks adhesion to MAdCAM-1 (mucosal addressin cell adhesion molecule-1) and E-cadherin, as well as α4β7 integrin binding to VCAM-1 and fibronectin. This blocking activity makes it particularly valuable for studying the role of these adhesion pathways in immune cell homing and tissue infiltration.

Gut Immunology and Inflammation Studies

The primary in vivo applications of FIB21 center on gut-associated immune responses. The integrin β7 forms two important heterodimers: α4β7, which is expressed on peripheral lymphocytes, thymocytes, and bone marrow progenitors, and αEβ7 (CD103/β7), which is expressed on intestinal intraepithelial lymphocytes (IELs), dendritic epidermal T cells, T regulatory cells, and CD8+ T cells in lymph nodes and lamina propria.

By blocking these integrins, researchers can investigate lymphocyte trafficking to gut-associated lymphoid tissues and the intestinal mucosa, making FIB21 a valuable tool for studying inflammatory bowel disease models, oral tolerance, and mucosal immunity.

Mechanistic Studies of Immune Cell Migration

FIB21 maps to amino acid residues 176-250 within the β7 integrin, a region that specifies MAdCAM-1 binding. This precise targeting allows researchers to dissect the specific molecular mechanisms governing immune cell recruitment to various tissues, particularly in the context of inflammation and autoimmune conditions.

The antibody is available in functional grade formulations specifically designed for in vivo use, with low or ultra-low endotoxin levels to minimize confounding inflammatory responses during experiments.

Commonly, antibodies or proteins used with FIB21 (an antibody targeting integrin β7) in the literature are those relevant to immune, cancer, and cell adhesion research. The most frequently co-utilized markers and reagents include:

• Integrin α4, as it forms the heterodimer α4β7 with integrin β7, and is central to studies of immune cell trafficking and gut homing because FIB21 detects β7.
• CD markers: commonly, CD4, CD8, and CD19 are stained alongside integrin β7 to phenotype T and B lymphocytes in flow cytometry or immunohistochemistry assays, particularly in immunology and gut homing research.
• Other integrins: antibodies against integrin β1 or αE may be used to distinguish between different integrin complexes present on leukocytes.
• Isotype controls: appropriate mouse or human IgG isotype controls are used to validate the specificity of FIB21 binding in flow or tissue assays.

In related experimental contexts, FIB21 is often combined with cytokine detection (such as IL-21, IL-15, or IL-2) or used in conjunction with the F8 antibody (which targets the EDA domain of fibronectin) for antibody-cytokine fusion protein development in cancer therapy research.

To summarize:

• Integrin α4 (to detect α4β7 heterodimer)
• CD markers (CD4, CD8, CD19) for immune cell phenotyping
• Other integrin antibodies (e.g., β1, αE)
• Isotype controls
• Antibodies to cytokines or other surface markers as dictated by study design
• F8 antibody platform in studies of antibody-cytokine fusions

The precise combination depends on the application, e.g., immunophenotyping, therapeutic fusion constructs, or functional assays.

Clone FIB21 is an antibody specifically targeting integrin β7 and is cited in scientific literature primarily in the context of research on integrin β7, a molecule important in immune cell trafficking and inflammation. The key findings from citations of FIB21 in scientific literature are as follows:

• Specificity: FIB21 is identified as a monoclonal antibody that recognizes human and mouse integrin β7, a 130 kDa protein.
• Research Usage: Its main use is for studying integrin β7 function, including experiments involving flow cytometry, cell sorting, and blocking assays to examine lymphocyte migration and immune responses.
• Applications:
  • It is commonly used to investigate the role of integrin β7 in gut-homing of lymphocytes, as this integrin is critical for leukocyte adhesion and migration into mucosal tissues.
  • Studies using FIB21 help clarify mechanisms of mucosal immunity and can support the development of immune-targeted therapies.

No evidence was found in the provided results linking clone FIB21 to fibroblast growth factor 21 (FGF21); clone FIB21 is an antibody tool, while FGF21 is a metabolic hormone.

In summary, FIB21 citations highlight its use as a research antibody for integrin β7, facilitating immunological studies, especially those focused on cell adhesion, migration, and mucosal immunity.

The dosing regimen of Clone FIB21, an anti-human/mouse integrin β7 antibody, can vary significantly across different mouse models, based on the disease model and study goals. However, specific dosing regimens are not detailed for Clone FIB21 across various mouse models in the provided search results. Generally, antibody dosing in mouse models can be quite variable, depending on the specific target, disease model, and study objectives.

For comparison, other substances like FGF21 have specific dosing regimens that depend on the model:

• FGF21 has been used at a dose of 4 mg/kg/day in some mouse models, such as those studying bovine viral diarrhea virus (BVDV) infection.
• Central infusion of FGF21 in mice has used a dose of 0.4 μg/day to avoid peripheral effects.
• In another context, a sc dose of 1.6 μg/day was administered to achieve a specific serum concentration.

For Clone FIB21, specific dosing regimens are often tailored to the study's objectives, such as lower doses for infectious models and higher doses for metabolic dysfunction. However, exact figures for Clone FIB21 are not provided in the search results. For precise dosing, it is advisable to consult the original research articles or study protocols related to Clone FIB21.