Anti-Human CD25 (IL-2Rα) [Clone 7G7B6] — Purified in vivo GOLD™ Functional Grade

Clone 7G7B6 is a mouse monoclonal antibody specific for human CD25 (IL-2 receptor alpha), and its most common in vivo application in mice is the depletion or modulation of regulatory T cells (Tregs) in humanized mouse models.

Key details:

• Depletion of Tregs: 7G7B6 is used to target and deplete human CD25-expressing regulatory T cells in humanized mice, which helps researchers study immune responses, tumor immunology, and therapeutic interventions in a model with human immune system components.
• Functional studies: This application is particularly relevant in cancer immunotherapy research, autoimmunity models, and tolerance investigations, as Treg depletion can alter disease outcomes or enhance the efficacy of immunomodulatory agents.
• Radioimmunotherapy: Preclinical studies have also used 7G7B6, conjugated with radionuclides, for targeted radioimmunotherapy against CD25-expressing lymphomas in xenograft models, demonstrating its potential for delivering cytotoxic radiation to tumors expressing human CD25.

Additional supporting uses:

• Flow cytometry detection: While not strictly in vivo, 7G7B6 can be administered in mouse models followed by analysis of human CD25+ cells through flow cytometric detection (often after depletion studies).
• In vivo imaging and tracking: Labeled versions (e.g., with radioactive isotopes) have been used for biodistribution and tumor targeting assays in xenograft-bearing mice.

Important limitations:

• Species specificity: 7G7B6 does not cross-react with mouse CD25, so its use is restricted to mice engrafted with human cells, notably humanized models or xenografts.
• Low endotoxin/functional grade: As provided by commercial sources, in vivo-grade 7G7B6 is purified and suitable for animal administration, reducing the risk of off-target inflammation.

In summary, clone 7G7B6 is primarily employed for in vivo depletion or modulation of human Tregs and as a therapeutic or imaging tool in humanized mouse models for immunological and oncological research.

In the literature, 7G7B6 (an anti-human CD25 monoclonal antibody) is most frequently used in conjunction with other antibodies targeting different epitopes of CD25—notably anti-Tac (daclizumab)—as well as antibodies for various immune cell markers and isotype controls.

Key antibodies and proteins commonly used with 7G7B6 include:

• Anti-Tac (daclizumab): Recognizes a different, non-overlapping epitope on the IL-2 receptor alpha (CD25). Used to distinguish binding sites, competition, and functional effects in mechanistic or therapeutic studies.

• Isotype controls: Mouse IgG2a isotype controls are routinely paired with 7G7B6 to ensure specificity and for proper gating in flow cytometry.

• Antibodies for other IL-2R subunits: CD122 (IL-2Rβ) and CD132 (IL-2Rγ) antibodies may be included when studying IL-2 receptor complex formation and expression. While not always cited by clone, these are common in IL-2 pathway studies.

• Other anti-CD25 clones: When comparing epitope mapping or function, additional anti-CD25 antibodies such as anti-Tac (daclizumab, mouse/rat clones), 7D4 (anti-mouse CD25), and MA251 (anti-human CD25) are sometimes used in parallel to 7G7B6 for cross-blocking or competitive binding studies.

• Phenotypic markers: Panels may include antibodies against CD3, CD4, CD8, CD19, CD45, and other lymphocyte markers to define T and B cell populations that express CD25.

• Detection antibodies: Secondary antibodies—such as FITC-labeled anti-human IgG—are used for flow cytometry detection of 7G7B6 or for immunoprecipitation experiments.

Summary Table: Common Combinations with 7G7B6

In summary, the most frequent partners for 7G7B6 are anti-Tac/daclizumab, other anti-CD25 clones (for competition), isotype controls, and lineage-defining antibodies for immune cell subset analysis.

Clone 7G7B6 is a monoclonal antibody specific for human CD25 (IL-2Rα), the alpha chain of the interleukin-2 receptor, and is widely cited for its use in both basic and preclinical immunology research.

Key findings from scientific literature include:

• Validation and Specificity: 7G7B6 selectively binds to human CD25, which is expressed on activated T cells, activated B cells, certain thymocytes, and regulatory T cells (Tregs). Binding studies show that radiolabeled and unlabeled forms of 7G7B6 maintain high specificity and affinity for CD25-positive cells.

• Functional Application: The antibody is primarily used in flow cytometry (FACS) to detect or sort CD25-expressing cells in research applications. It is also noted for potential use in radioimmunotherapy when conjugated with radioisotopes, demonstrating CD25-specific cytotoxicity in preclinical lymphoma models.

• Preclinical Therapeutics: In a notable study, a radiolabeled version (^90Y-7G7B6) showed high immunoreactivity and robust binding to CD25-positive lymphoma cells, similar to other established radiolabeled antibodies[^111In-7G7B6]. The findings support the feasibility of using 7G7B6 for targeted therapy against CD25-expressing malignancies.

• Comparative Performance: The affinity and off-rate (Koff) of 7G7B6 are frequently used as a benchmark in patents and development of new anti-CD25 antibodies, sometimes highlighting engineered clones that may have improved binding characteristics over 7G7B6, daclizumab, and basiliximab.

• Immunological Relevance: The literature underscores that CD25 is critical in immune regulation, especially for Treg cell survival and immune homeostasis, and that 7G7B6 is a tool for dissecting these mechanisms in human cells. The functional role of CD25 can differ between human and mouse, and 7G7B6 is specific for the human protein.

• Product and Purity Standards: Commercially available 7G7B6 antibody products are noted to be of high purity (≥95–98% monomer), with low endotoxin levels, making them suitable for sensitive immunological assays.

In summary, clone 7G7B6 is a well-validated tool antibody for human CD25 research, cited for its specificity, utility in flow cytometry and preclinical therapeutics, and used as a comparator in novel antibody development.

Dosing regimens of clone 7G7B6 (anti-human CD25 antibody) in mouse models have primarily been studied in the context of radioimmunotherapy and pharmacokinetic analyses, particularly in immune-deficient or lymphoma-bearing mice. The regimen can vary based on the study objective, mouse strain, tumor burden, and whether the antibody is radiolabeled.

Key findings from published studies:

• In SUDHL-1 lymphoma-bearing mice, 7G7B6 was administered intravenously in the form of ^90Y-labeled 7G7B6 at 75 μCi (low dose) or 150 μCi (high dose) per mouse per single administration.
  • Low-dose (75 μCi/mouse): Substantial inhibition of tumor growth; 30% of mice became tumor-free.
  • High-dose (150 μCi/mouse): Tumor shrinkage and 75% of mice became tumor-free.
• In biodistribution studies (for pharmacokinetics), mice received 10 μg of ^111In-7G7B6 intravenously.
• When defining the maximum tolerated dose (MTD), healthy nude mice (without tumors) received increasing doses (100, 150, 200, 300 μCi ^90Y-7G7B6/mouse) to assess safety and toxicity, all with a coinjection of 400 μg UPC10 to block nonspecific Fc-mediated binding in the liver and spleen of nude mice.

The protocols and mouse models:

• Mouse strain: Most studies use nude mice (immunodeficient) to allow human tumor engraftment and minimize immune rejection of human-targeted antibodies.
• Usage context: Dosing regimens may shift with:
  • Mouse immune status (immunodeficient vs. immunocompetent)
  • Tumor type and tumor burden
  • Use of radiolabeled vs. unconjugated antibody
  • Administration route (intravenous in cited results)

General considerations for regimen variation:

• Model-specific factors: No direct evidence was found regarding dosing in other mouse models (e.g., different immunocompetent strains, non-tumor-bearing mice) for 7G7B6 specifically.
• Empirical titration: As with other monoclonal antibodies, dosing in new mouse models may require empirical adjustment to match differences in size, metabolism, immune context, or antibody clearance characteristics.
• Lack of broad comparative studies: No comprehensive data compare 7G7B6 regimens across many mouse strains or disease models.

Summary dosing from key data:| Regimen context | Dose per mouse | Route | Notes ||-------------------------|---------------------|----------------|----------------------------------------------------------------------------|| Tumor therapy (lymphoma) | 75–150 μCi ^90Y-7G7B6 | Intravenous | Single dose, with/without replacement control antibody || Biodistribution study | 10 μg ^111In-7G7B6 | Intravenous | With 400 μg UPC10 to block nonspecific binding in nude mice || MTD determination | 100–300 μCi ^90Y-7G7B6 | Intravenous | Four escalating doses; toxicity monitoring with coadministered UPC10 |

No published data was found detailing:

• Dosing frequency (repeat vs. single-dose studies)
• Direct comparison between mouse strains (e.g., BALB/c vs. C57BL/6)
• Regimens in immunocompetent or autoimmune models

For other antibodies (and potentially for 7G7B6 in extended research), dosing and frequency are typically titrated for efficacy and tolerability in the selected mouse model, as regimens may need to be adjusted for immune status, body weight, or disease context.

In the absence of a broader dataset, standard dosing for 7G7B6 in mouse models remains largely based on single-dose, radioimmunotherapy protocols in immunodeficient mice, with empirical adjustments in other settings likely necessary but not published.