Anti-Mouse CD11a (Clone I21/7) – Purified in vivo GOLD™ Functional Grade

Common In Vivo Applications of Clone I21/7 in Mice:

Clone I21/7 is an anti-mouse CD11a antibody, which targets the LFA-1α subunit. This antibody is used in various in vivo applications related to immune cell studies in mice. The primary applications include:

• Immune Cell Depletion: Clone I21/7 is used to deplete CD11a-expressing cells such as thymocytes, blood lymphocytes, and certain macrophage-like cell lines. This helps in understanding the role of these cells in immune responses.

• Functional Studies: The antibody can block the interactions between LFA-1 and its ligands like ICAM-1 and ICAM-2, which are crucial for cell adhesion and immune synapse formation. This blocking ability is useful for studying the effects on immune cell functions and interactions.

• Blocking and Immunomodulation: By blocking LFA-1, researchers can modulate immune responses and study the effects on inflammation, immune tolerance, and disease models.

Overall, clone I21/7 is a valuable tool for immunologists studying immune cell interactions, immune responses, and potential therapeutic interventions in mice.

Commonly used antibodies or proteins employed with I21/7 (anti-mouse CD11a, LFA-1α) in the literature include antibodies targeting key leukocyte, T cell, and adhesion markers as well as functional cytokines for combinatorial immune modulation.

• Frequently used antibodies or proteins with I21/7:
  • Anti-CD3: A pan-T-cell marker often used alongside anti-CD11a to study T cell activation, adhesion, and signaling in both in vitro and in vivo settings.
  • Anti-CD8 and Anti-CD4: To delineate cytotoxic and helper T cell subsets in functional assays where anti-CD11a is used to block or measure LFA-1–mediated adhesion or trafficking.
  • Anti-CD18 (LFA-1β): Used to analyze the functional role of the full LFA-1 integrin complex, as CD11a must partner with CD18 for proper adhesion and signaling.
  • Anti-ICAM-1 (CD54): Since CD11a binds ICAM-1 as its principal ligand, anti-ICAM-1 antibodies are often used together with anti-CD11a to study cell–cell interactions, immune synapse formation, and migration events.
  • Cytokines and cytokine fusion proteins: Such as IL-21, IL-15, and IL-7, for combinatorial studies in cancer immunotherapy and T cell biology. These cytokines modulate T cell function in settings where LFA-1’s role in immune cell trafficking or memory is under investigation.
  • Other integrin antibodies: Such as anti-CD49d (VLA-4) or anti-CD29 (β1-integrin), sometimes used to study overlapping or distinct adhesion pathways with LFA-1/CD11a.
  • Fluorescent or biotinylated secondary antibodies: For flow cytometry or immunofluorescence applications to detect CD11a-labeled cell populations.

Context and rationale:

• I21/7 (anti-CD11a) is commonly used to block LFA-1 mediated interactions in models of T cell migration, adhesion, and immune synapse formation.
• Combination with lineage and activation markers like anti-CD3, anti-CD4, and anti-CD8 is routine to define cellular subsets and their responses when LFA-1 is blocked or detected.
• When investigating leukocyte trafficking or inflammation, anti-ICAM-1 and anti-CD18 are frequently paired to dissect the full receptor-ligand dynamics.
• In tumor immunology and cytokine biology, cytokine fusion proteins (like IL-21, IL-7, IL-15 linked to antibodies) are engineered and tested together, sometimes exploiting LFA-1 biology for targeted delivery or modulation.

Technical note: Selection of co-administered antibodies will vary based on application (in vivo depletion/blockade, flow cytometry, immunohistochemistry). When using I21/7 specifically, antibody panels often include isotype controls and may be tailored with additional markers (Gr-1, B220, CD25, NK1.1) for immune profiling in research settings.

Summary table of commonly co-used antibodies/proteins with I21/7 (anti-CD11a):

These combinations are broadly supported in immunology and oncology studies focusing on leukocyte trafficking, T cell biology, and immune modulation.

Based on the available information, there are no clear or direct key findings from scientific literature regarding clone I21/7 citations.

Clone I21/7 is an antibody that recognizes an epitope on mouse CD11a (also known as LFA-1α). This antibody is used as a research tool for studying CD11a, which is part of the LFA-1 integrin complex formed when CD11a combines with CD18.

What Clone I21/7 Targets

The antibody specifically recognizes CD11a, which plays important roles in immune function. LFA-1 (the complex formed by CD11a and CD18) serves as a receptor for several intercellular adhesion molecules including ICAM1, ICAM2, ICAM3, ICAM4, and F11R. This molecule participates in critical immune processes such as the immunological synapses between CD8+ T lymphocytes and antigen-presenting cells, leukocyte-endothelial cell interactions, cytotoxic T-cell mediated killing, and natural killer cell cytotoxicity.

The absence of functional LFA-1α or its β chain can lead to leukocyte adhesion deficiency (LAD). However, while the antibody clone I21/7 is commercially available as a research reagent for studying these processes, the search results indicate that specific published findings using this particular clone have not been documented or compiled in readily accessible scientific literature databases.

Dosing regimens of clone I21/7 (anti-mouse CD11a, LFA-1α) vary across mouse models primarily in dose amount and frequency, often tailored to the disease model and desired pharmacodynamic effect. In tumor models, daily regimens of 50 µg/dose and low-dose regimens as low as 12 µg/day show similar efficacy, while schedule and route of administration (e.g., subcutaneous or intraperitoneal) also differ by model.

Key variations by mouse model:

• Tumor model (e.g., B16 melanoma):

  • Dose: 50 µg/dose (standard)
  • Frequency: Daily administration
  • Route: Subcutaneous (SC) or intraperitoneal (IP)
  • Low-dose regimens: 12 µg/day, potentially reducing toxicity without efficacy loss.

• Renal cell carcinoma (RenCa) model:

  • Dose: 50 µg/dose (standard)
  • Frequency: 3 times per week
  • Low-dose regimens: 1–20 µg/dose, 3 times per week for 3 weeks, with dose-dependent efficacy observed
  • Alternative schedule: 30 µg/dose, once weekly.

• Fractionation strategies (general observation):

  • Splitting the daily 50 µg dose into twice-daily 25 µg doses decreased tumor mass further (suggesting benefit from fractionation).

• Route and timing: Some protocols start “early” post-tumor implantation; both SC and IP routes are used, depending on the model and study objective.

These regimens reflect efforts to balance efficacy, toxicity, and practical administration, and are based on empirical data as well as mathematical PK/PD modeling in each mouse strain and tumor context. Variations can be significant between models, emphasizing the need for regimen optimization in each context.