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

Clone 7G7B6 is a monoclonal antibody specific for human CD25 (IL-2Rα), and its common in vivo applications in mice are primarily in studies involving humanized mice—that is, mice engrafted with human immune cells expressing human CD25. Its chief use is the depletion of regulatory T cells (Tregs), which constitutively express high levels of CD25.

Key in vivo applications include:

• Regulatory T cell (Treg) depletion: Clone 7G7B6 is widely used to deplete human Tregs in humanized mouse models to study immune regulation, tumor immunity, and autoimmunity. This mirrors the function of other anti-CD25 antibodies, such as daclizumab, but with a murine epitope specificity useful in xenografted systems.
• Preclinical cancer immunotherapy studies: 7G7B6 has been used in mice, often in a radiolabeled form, for radioimmunotherapy targeting human CD25-expressing lymphomas engrafted into mice, demonstrating specific binding and therapeutic potential.
• Functional studies of IL-2 signaling: Since CD25 is the high-affinity IL-2 receptor component, antibodies like 7G7B6 are employed in blocking or depletion experiments to dissect IL-2/IL-2R signaling's role in immune responses.
• Mechanistic studies of immune modulation: Research into the effects of regulatory T cell removal or alteration of IL-2 signaling on immune-mediated diseases, infections, or graft-versus-host disease (GVHD) frequently relies on 7G7B6 in appropriate xenograft models.

Restrictions and suitability:

• 7G7B6 does not cross-react with mouse CD25 and is therefore not effective in wild-type mice lacking human CD25 expression. For depletion of mouse Tregs, other clones such as PC61 are required.
• Its use in vivo is limited to “humanized” mice or xenograft models where human immune cells or tumors express the target antigen.

Summary Table:
| Application | Context | Model system ||---------------------------|-------------------------------------------------------------|------------------------------------|| Treg depletion | Studying human Treg function, anti-tumor immunity, autoimmunity | Humanized mice || Radioimmunotherapy | Targeting human CD25+ tumors | Human lymphoma xenografts in mice || IL-2 signaling blockade | Analyzing effects on human lymphocyte proliferation | Humanized or chimeric mice || Flow cytometry/ELISA | Detection of human CD25+ cells | Human cells in mouse tissues |

In summary, clone 7G7B6 is a tool for in vivo experiments involving human immune components in mice, especially for Treg functional studies and preclinical immunotherapy evaluation in xenograft or human immune system-reconstituted mouse models.

The 7G7B6 antibody is commonly used in research as a monoclonal antibody targeting human CD25 (the IL-2 receptor alpha subunit). In the scientific literature, several other antibodies or proteins are often used alongside 7G7B6 for complementary or comparative purposes, especially in studies involving CD25-expressing cells such as activated T cells or regulatory T cells.

Key examples include:

• Daclizumab: This is another monoclonal antibody that targets a different epitope on human CD25 than 7G7B6. Studies often use both 7G7B6 and daclizumab in combination or for comparison. Daclizumab can be used at receptor-saturating doses to block IL-2 signaling and deplete CD25+ cells, while 7G7B6 may be used as a radioimmunotherapeutic agent. The two do not compete for the same binding site, enabling their combined use in some experimental or therapeutic protocols.

• Anti-human IgG secondary antibodies: For detection purposes, especially in flow cytometry or immunofluorescence, secondary antibodies (such as FITC-labeled anti-human IgG) are commonly used in conjunction with 7G7B6 to visualize its binding to CD25+ cells.

• Other anti-CD25 antibodies: Additional anti-CD25 clones used in the literature may include MA251 and 7D4 (the latter is more common for mouse CD25 rather than human). These are sometimes used for comparative binding studies, functional blocking, or in parallel experiments to define cross-reactivity or specificity.

• Isotype controls: Mouse IgG isotype controls are regularly used to ensure the specificity of labeling by 7G7B6 in flow cytometry or immunoprecipitation experiments.

• Markers for T cell phenotyping: In immunological studies, CD4, CD8, CD122 (IL-2Rβ), and CD132 (IL-2Rγ) antibodies are used alongside 7G7B6 to distinguish T cell subpopulations and to provide a complete analysis of IL-2 receptor composition.

• IL-2 protein: Recombinant human IL-2 is sometimes included in functional assays to study signaling or receptor internalization in the presence of CD25-targeting antibodies.

These protein and antibody combinations enhance the specificity, detection, and analysis of CD25-related biological processes and are standard in both therapeutic and mechanistic investigations.

Summary Table

This reflects the most common combinations and experimental uses of 7G7B6 with other proteins and antibodies described in the literature.

Clone 7G7B6 is a well-characterized monoclonal antibody against human CD25 (IL-2Rα) and has been widely cited in scientific literature for its specificity, utility in functional studies, and relevance in immune cell characterization and therapeutics.

Key findings from scientific literature and referenced citations include:

• Specific Reactivity and Binding: 7G7B6 is highly specific for human CD25, the alpha chain of the IL-2 receptor, recognizing activated T cells, activated B cells, certain thymocytes, myeloid precursors, and oligodendrocytes. It binds to CD25 with high immunoreactivity, as demonstrated in radiolabeling and cell-binding assays. The binding is specific and can be competitively inhibited by excess unlabeled 7G7B6.

• Functional Applications: The antibody is validated for flow cytometry (FACS), used extensively to characterize immune populations, especially regulatory T cells (Tregs), which constitutively express CD25. It is also employed in internalization and modulation studies, revealing its utility in tracking receptor dynamics and potential immune modulation.

• Therapeutic Potential: In radioimmunotherapy studies, radiolabeled 7G7B6 (e.g., with ^90Y) retained high specificity and binding, and showed potential as a radioimmunotherapeutic agent for CD25-expressing lymphomas. The antibody’s labeling does not compromise its specificity or efficacy in vitro.

• Biophysical and Biochemical Characterization: 7G7B6 is a mouse IgG2a kappa antibody, typically purified by protein G chromatography, and is available in functional grades with high purity and low endotoxin levels suitable for preclinical applications.

• Comparative Performance: 7G7B6 is noted in patent literature alongside other antibodies like daclizumab and basiliximab. Some engineered CD25 antibody clones reportedly have superior affinity and kinetic properties compared to 7G7B6. Additionally, unlike some Fc-optimized anti-CD25 antibodies designed for selective cell depletion, 7G7B6 allows IL-2 binding to CD25 and is distinct from function-blocking clones like daclizumab.

• Role in Immunology Research: CD25, and thus 7G7B6, plays an important role in studies of immune regulation, especially with Tregs and effector T cells, as CD25 expression is critical for Treg survival and immune homeostasis in humans.

• Storage and Usage: The antibody is stable for several months refrigerated, and longer at –20°C, with standard concentration recommendations for FACS (0.5–1 µg/10⁶ cells).

Summary Table: Key Properties and Uses of 7G7B6

These properties and findings have established 7G7B6 as a cornerstone antibody in CD25-related immunology and therapeutic research.

Dosing regimens of the anti-human CD25 monoclonal antibody clone 7G7B6 in mouse models vary according to the purpose (e.g., biodistribution, toxicity, or therapeutic effect), disease context, and sometimes mouse strain, but available preclinical data provide specific examples primarily in lymphoma xenograft models.

Key findings from published regimens:

• In a preclinical SUDHL-1 lymphoma model (using nude mice), radioimmunotherapy with 7G7B6 conjugated to ^90Yttrium (^90Y-7G7/B6) was administered intravenously (i.v.) at:

  • 75 μCi per mouse (low dose) and 150 μCi per mouse (high dose), with treatment leading to tumor inhibition or eradication depending on the dose.
  • The maximum tolerated dose (MTD) was determined in healthy nude mice prior to therapeutic studies, using single injections of 100, 150, 200, and 300 μCi per mouse.
  • All mice received a coinjection of 400 μg of UPC10 to block nonspecific Fc receptor binding in the liver and spleen of nude mice.

• For biodistribution studies, a fixed amount of 10 μg of radiolabeled 7G7/B6 (using ^111Indium) was administered i.v. per mouse, and all mice again received 400 μg UPC10.

Variation by Model and Context:

• Data on specific differences in regimen across other mouse models, such as those with different immunodeficient backgrounds or with non-lymphoma disease indications, are limited.
• No direct evidence was found showing regimen changes between different genetic backgrounds (such as BALB/c vs. C57BL/6), immunodeficient strains, or disease models for 7G7B6; most published protocols use nude or NOD/SCID mice due to the need for human tumor xenografts.
• Adjustments to dose and frequency in other disease settings or immune-competent models are not explicitly documented in the search results, although general principles indicate regimen optimization based on toxicity, antibody clearance, and disease biology would be standard practice.

General context for antibody dosing in mouse models:

• Dosing of monoclonal antibodies in mice typically ranges from 10–300 μg per mouse per injection for in vivo functional studies, administered i.v. or intraperitoneally, with the frequency and duration depending on antibody pharmacokinetics and experimental aims.
• For radioimmunotherapy, dosing is expressed as radioactivity per mouse (μCi) because therapeutic effect and toxicity are driven by both the antibody and radioisotope load.

Summary Table: 7G7B6 Dosing Regimens in Nude Mice

• No explicit evidence of dosing adjustment across different mouse strains or for other disease models was identified in these results.
• Regimen optimization for other models (e.g., non-tumor, immunocompetent) would logically follow general in vivo antibody dosing and toxicity assessment principles but requires empirical validation.

References:

• Therapeutic and dosing regimens in SUDHL-1 lymphoma-bearing mice, maximum tolerated dose studies, and biodistribution:
• General antibody dosing across models:
• Considerations for indication- or context-specific regimen: ,