Anti-Mouse/Human CD44 [Clone IM7] — Purified in vivo PLATINUM™ Functional Grade

Clone IM7 is a rat anti-mouse CD44 monoclonal antibody that has been widely used in various in vivo applications in mice. Some of the common applications include:

• Inhibition of Delayed-Type Hypersensitivity Response: Clone IM7 has been used to inhibit delayed-type hypersensitivity responses in mice, which is a form of immune response mediated by T cells.
• Modulation of Immune Responses: It has been effective in modulating immune responses, particularly in reducing joint swelling and affecting leukocyte-endothelium interactions in arthritic models.
• Neutralization of CD44: Clone IM7 has been shown to neutralize CD44 in vivo, which is crucial for studying its role in cell adhesion, lymphocyte activation, and lymph node homing.
• In Vivo Inhibition of Leukocyte Rolling and Adhesion: This antibody disrupts leukocyte rolling and adhesion, which are important processes in inflammation and immune responses.

These applications highlight the utility of Clone IM7 in understanding the biological functions of CD44 and its role in immune responses and inflammatory processes in mice.

Commonly Used Antibodies and Proteins with IM7

In the literature, IM7 most commonly refers to a monoclonal antibody that recognizes an epitope common to all isoforms of CD44, a cell surface glycoprotein involved in adhesion, migration, and lymphocyte activation. When discussing IM7 in the context of immunology and cell biology, researchers often use it in combination with other antibodies or proteins, especially in flow cytometry, immunohistochemistry, and functional assays.

Commonly Paired Antibodies and Proteins with IM7 (for CD44 studies)

Applications and Context

• Cell Depletion and Adhesion Studies: IM7 is frequently used with antibodies to Gr-1 (a granulocyte marker) and PSGL-1 to profile or deplete specific immune cell populations, particularly in inflammation or adhesion experiments.
• Inflammation and Functional Assays: The pairing with anti-IgG is standard for secondary detection and validation. Heparin and platelets are used in functional assays to study IM7’s role in cell-matrix and cell-cell interactions.
• Flow Cytometry and Immunohistochemistry: IM7 is a staple in panels for immunophenotyping mouse and human leukocytes, often alongside other lineage-specific antibodies (e.g., CD3, CD19, CD11b) depending on the research focus, though these are not explicitly listed in the provided sources.

A Note on Confusion with Im7 Protein

The search results also mention Im7 (lowercase “m”), which is a completely different entity: a small, stable protein from E. coli that binds tightly to the DNase domain of colicin E7 and is used as a scaffold in protein engineering. This Im7 protein is not an antibody and is not typically used with the IM7 monoclonal antibody in immunology. In protein engineering, Im7 is used with its cognate partner, the DNase domain of colicin E7, and has been engineered for novel binding, but this is unrelated to the CD44-targeting IM7 antibody.

Summary Table: IM7 (CD44 mAb) vs. Im7 (Protein Scaffold)

Conclusion

In the immunology literature, IM7 (the CD44 monoclonal antibody) is most commonly used with antibodies to Gr-1 and PSGL-1, as well as anti-IgG, heparin, and platelets in functional and adhesion assays. These pairings are standard for cell depletion, inflammation, and adhesion studies. Im7 (the bacterial protein) is unrelated and used in protein engineering with the colicin E7 DNase domain. Always clarify whether “IM7” refers to the antibody or the protein scaffold, as they belong to entirely different scientific contexts.

Clone IM7, primarily known for its role as an anti-mouse/human CD44 monoclonal antibody, has been extensively studied in scientific literature. Here are some key findings:

Role in Immunological Research

• CD44 Recognition: Clone IM7 recognizes an epitope common to all isoforms of CD44, located between amino acids 145 and 186. This epitope is crucial for CD44's role in cell-cell and cell-matrix interactions.
• Effects on Leukocyte Rolling: IM7 binding to CD44 on leukocytes disrupts rolling interactions with endothelial cells, but not when bound to endothelial CD44. This suggests a specific role in modulating immune responses.

Applications in Research and Therapy

• Immunohistochemistry and Immunoprecipitation: IM7 is used in various applications including immunohistochemistry, immunoprecipitation, and complement-mediated cytotoxicity.
• Potential in Cancer Treatment: IM7 has shown efficacy in treating conditions like ovarian cancer; however, its toxicity must be considered.

Mechanistic Insights

• Cross-Linking Requirement: IM7-mediated effects require CD44 cross-linking, highlighting the importance of protein interactions in modulating immune responses.
• Chimeric Models: Studies using chimeric mice have demonstrated that IM7's effects are primarily through binding to leukocytic CD44.

These findings underscore the utility of the IM7 antibody in both understanding CD44 function and exploring therapeutic applications.

Dosing regimens for clone IM7 (anti-CD44) in mouse models commonly utilize 200 μg per mouse administered intravenously or intraperitoneally, but the exact regimen can vary depending on the experimental context and disease model.

Key details include:

• In arthritis and leukocyte trafficking studies, IM7 is often given as a single 200 μg intravenous dose, resulting in rapid effects on leukocyte-endothelial interactions within minutes and lasting suppression (e.g., reduced cellular adhesion/rolling for up to 24 hours).
• In cancer metastasis models (e.g., osteosarcoma lung metastasis), a 200 μg intraperitoneal dose of IM7 (specifically, IM7.8.1, a functionally similar clone) is reported.
• The route of administration—either intravenous or intraperitoneal—is chosen based on study design, tissue targeting, and desired onset of action.
• Repeat dosing schedules are less commonly reported for IM7 compared to some checkpoint blockade antibodies, as its effects in many models are acute and short term.

*Some commercial guides recommend starting at 100–200 μg/mouse IP as a general guideline.

Summary:
Most mouse studies using clone IM7 use a single 200 μg dose by either IV or IP injection, but researchers may adapt the regimen based on model, experimental endpoints, and mouse strain/species. Repeated dosing, where used, should be justified by pharmacodynamics and disease kinetics, as repeated high-dose anti-CD44 can have systemic immunomodulatory effects.

There is no evidence for substantial inter-strain or inter-model adjustment of IM7 dosing beyond these standard values in the surveyed literature, but precise schedules should always be calibrated based on pilot data and study objectives.