Anti-Mouse CD3ε [Clone 145-2C11] — Purified in vivo PLATINUM™ Functional Grade

Clone 145-2C11 is a widely used monoclonal antibody in mouse studies, particularly for applications involving in vivo T cell manipulation. Some of its common in vivo applications in mice include:

• T Cell Depletion: This antibody is commonly used to deplete T cells in mice, which helps in studying immune functions and disease models.
• T Cell Activation and Modulation: It can activate T cells in vivo, inducing proliferation and cytokine production, which is useful for studying T cell functions and responses in immunological models.
• Immune Response Studies: Clone 145-2C11 is utilized to study various aspects of the immune response by modulating T cell responses, which is crucial for understanding disease mechanisms and developing therapeutic strategies.

Overall, the 145-2C11 clone is versatile and supports a range of in vivo applications related to T cell biology and immunology in mice.

In the literature, 145-2C11, an anti-mouse CD3ε monoclonal antibody, is often used alongside other antibodies or proteins to study T cell subsets and function. Here are some commonly used molecules in combination with 145-2C11:

1. Anti-CD4 and Anti-CD8 Antibodies: These are frequently co-used with 145-2C11 for immunophenotypic analyses of distinct T cell subsets by flow cytometry. This combination allows researchers to study CD4+ and CD8+ T cells separately or together, providing insights into T cell populations and their functions.

2. Glucocorticoids (e.g., methylprednisolone): These are used to attenuate cytokine release syndrome induced by 145-2C11. High doses of methylprednisolone administered before 145-2C11 can prevent the release of cytokines such as TNF-alpha, IL-2, and IL-6.

3. Surrogate Antibodies: Proteins like 2C11-Novi are used as surrogate antibodies for modeling human CD3-directed therapies. These are designed to mimic human CD3 therapeutic antibodies in murine models without causing the same level of cytokine release.

4. Other Anti-CD3 Variants: Fc-modified or chimeric anti-CD3 antibodies are used in some studies to compare their effects on T cell activation and cytokine release with those of 145-2C11.

Clone 145-2C11 is a monoclonal antibody targeting mouse CD3ε, widely used to study T cell biology due to its ability to modulate T cell activation, proliferation, and apoptosis. Key findings from scientific literature concerning this clone include:

• T Cell Activation and Proliferation: 145-2C11 crosslinks the TCR, initiating biochemical pathways that lead to cellular activation and proliferation, often used as a standard reagent for functional and depletion assays in mouse T cells.

• TCR Downregulation and Signal Transduction: Binding of 145-2C11 causes rapid and near-complete downregulation of the surface CD3-TCR complex on T cells, likely due to its effect on receptor internalization and signaling, with recovery of surface TCR typically occurring within five days post-treatment.

• Cytokine Release and Immunomodulation: Administration of 145-2C11 induces robust cytokine release (e.g., TNF, IFNγ, IL-6), as observed in in vivo models, and leads to transient body weight loss in mice, which is used as a readout for T cell activation and the systemic effects of antibody-mediated T cell modulation.

• Cell Depletion and Apoptosis: 145-2C11 can induce apoptosis in T cells and is used for targeted cell depletion experiments, exploiting the role of the CD3 complex in antigen-recognition signal transduction.

• Redirected Lysis: The antibody can induce redirected lysis of target cells by cytotoxic T lymphocyte clones and block antigen-specific CTL responses, demonstrating its utility in functional assays like cytotoxicity and immune regulation.

• Comparison to Fc-engineered Analogues: Studies contrasting 145-2C11 and engineered variants (e.g., 2C11-Novi) show that its Fc domain mediates interactions with FcγRs, contributing to both mitogenicity and off-target immune effects, such as cytokine storm and body weight loss. Loss of FcγR binding in engineered clones abrogates these effects but retains TCR modulation when immobilized.

• Broad Utility in Flow Cytometry and Immunohistochemistry: 145-2C11 is validated for flow cytometric analysis, immunoprecipitation, western blot, and immunohistochemistry for mouse thymocytes and splenocytes, highlighting its specificity and reliability for CD3ε detection.

• CD3 Complex Biology: The antibody illuminates the role of the CD3 complex—composed of gamma, delta, epsilon, and zeta subunits—in T cell receptor assembly, trafficking, and immune signal transduction. Defects in CD3 lead to immunodeficiency.

• Blocking of Other Antibodies: It has been shown to block binding of other anti-CD3 antibodies (e.g., clone 17A2) on CD3ε+ T lymphocytes, which is relevant for epitope mapping and competitive binding experiments.

In summary, 145-2C11 is a cornerstone antibody for murine T cell research, offering reliable functional and analytical capabilities for investigating T cell activation, depletion, and immune signal transduction.

Dosing regimens of the anti-CD3 antibody clone 145-2C11 in mice vary dramatically depending on the mouse model, targeted effect (depletion, activation, immune modulation), dose schedule, and formulation (intact antibody vs. F(ab')₂ fragment). The range spans from as little as 1 µg to as much as 400 µg per mouse per dose, with different regimens tailored for different strains and experimental goals.

Key regimen variations across mouse models:

• BALB/c and NOD/ShiLtJ mice (Type 1 diabetes, T-cell modulation studies):

  • Regimens include:
    • 5 × 50 µg daily (total 250 µg/mouse)
    • 4 × 25 µg every 3 days (total 100 µg)
    • 3–4 × 5, 2, or 1 µg every 3 days (for a total dose of 4–20 µg/mouse)
  • Lower, repeated doses are sometimes used to minimize side-effects or induce partial T-cell modulation rather than full depletion.

• Single-dose studies (activation or acute modulation):

  • Single intraperitoneal doses have ranged from 20 µg (to induce T cell activation, measured by CD69/CD25 upregulation and cytokine release) up to 400 µg (to achieve acute CD4⁺ T cell depletion in naïve mice).
  • A 400 µg single dose was associated with ~40% CD4⁺ T cell depletion in naïve mice.

• Fragment vs. Intact antibody:

  • F(ab')₂ fragments, engineered variants, and Fc-modified forms have separate dose-response characteristics.
  • For F(ab')₂ and engineered variants, protocols have tested 5 daily injections of 25 µg, revealing similar depletion efficacy by day 3 post-treatment for CD4⁺, CD8⁺, and regulatory T cells.

• Typical standard dosing guidance:

  • 5–50 µg/mouse intraperitoneally is cited as a commonly effective range for immune activation studies.
  • For in vitro T cell stimulation, as low as 2 µg/mL plate-bound is reported.

Dosing considerations:

• The magnitude and duration of immune effects differ by regimen and mouse strain; for example, some strains recover TCR/CD3 expression more quickly than others post-treatment.
• Dosing is tailored for application:
  • High doses for strong, transient T-cell depletion or modulation (e.g., tolerance induction, transplantation).
  • Lower, repeated doses for chronic disease models or when aiming for partial, more tolerable immune modulation.
• Route of administration is almost always intraperitoneal.

Summary Table: Example 145-2C11 Dosing Regimens in Mice

In summary: The 145-2C11 dosing regimen is highly variable and must be matched to the experimental design, strain background, endpoint (depletion vs. activation), and antibody formulation. Most protocols use 5–50 µg per dose, given as single or repeated i.p. injections, but higher or lower doses are used for specific goals in particular disease models.