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

Clone 145-2C11 is extensively used in in vivo mouse studies for several key applications related to T cell manipulation and immunological research.

T Cell Depletion

The primary use of 145-2C11 in vivo is for T cell depletion. This antibody effectively removes T cells from circulation, making it valuable for studies investigating immune system function in the absence of T cells or for creating immunocompromised models.

T Cell Activation and Stimulation

145-2C11 serves as a potent T cell activator in vivo, inducing proliferation and cytokine production. When administered to mice, it triggers robust T cell activation as evidenced by increased expression of activation markers like CD69 and CD25 on CD4+ T cells. This activation leads to the release of inflammatory cytokines including TNF, IFN?, and IL-6.

CD3-TCR Complex Modulation

The antibody induces rapid downregulation of the CD3-TCR complex from the cell surface. This effect occurs quickly after administration, with almost complete reduction of TCR expression on CD4+ T cells observed in blood, lymph nodes, and spleen. The recovery kinetics vary depending on the specific formulation used, with some variants maintaining prolonged TCR suppression for over 5 days.

Immunosuppressive Applications

145-2C11 is used to model immunosuppressive therapies, particularly as a surrogate for anti-human CD3 antibodies used in clinical settings. However, the standard 145-2C11 clone has limitations due to its binding to mouse Fc?R, which triggers unwanted cytokine release and side effects like body weight loss.

Dosing Considerations

Typical dosing ranges from 20-50 ?g per mouse administered intraperitoneally. The effects are dose-dependent, with higher doses producing more pronounced T cell depletion and activation responses.

The clone's ability to simultaneously deplete T cells while providing insights into T cell activation mechanisms makes it an invaluable tool for immunological research, transplantation studies, autoimmune disease models, and cancer immunotherapy investigations.

The correct storage temperature for the sterile packaged clone 145-2C11 antibody solution is between 2°C and 8°C. It should be stored undiluted and protected from prolonged exposure to light. Do not freeze the antibody solution to maintain its integrity and effectiveness.

Commonly used antibodies or proteins often paired with 145-2C11 (anti-mouse CD3?) in the literature include other immune cell markers and functional reagents, such as anti-CD4, anti-CD8, and cytokine detection antibodies, as well as proteins like concanavalin A for functional assays.

Essential context and supporting details:

• Anti-CD4 and anti-CD8 antibodies: These are routinely used alongside 145-2C11 for characterizing T cell populations, identifying CD4^+^ (helper) and CD8^+^ (cytotoxic) T cells, especially in flow cytometry assays assessing depletion and activation.
• Concanavalin A (Con A): A plant lectin that serves as a positive control for T cell proliferation in assays, often used in conjunction with anti-CD3 stimulation to compare mitogenic responses.
• Cytokine detection antibodies: Detection of cytokines such as TNF-?, IL-2, and IL-6 is commonly performed after 145-2C11 administration, since activation leads to cytokine release syndrome. These detection antibodies help profile the inflammatory response and are used in ELISA or flow cytometry panels.
• Glucocorticoids (e.g., methylprednisolone): Not an antibody, but frequently described in combination studies, where high-dose glucocorticoids are used to suppress the cytokine release brought on by 145-2C11, providing insight into the mitigation of side effects in experimental models.
• Fc-modified anti-human CD3 mAbs or their murine surrogates (such as 2C11-Novi): These are used in comparative studies with 145-2C11 to assess differences in immune activation and cytokine release mechanisms.

Additional relevant information:

• Other commonly used antibodies in T cell research can include anti-CD25, anti-CD44, anti-CD62L, and anti-TCR?, depending on the experimental context.
• The application dictates antibody usage; for example, immunofluorescence, immunohistochemistry, and immunoprecipitation panels may feature additional markers such as anti-B220 (B cells), anti-Gr1 (myeloid cells), and anti-FoxP3 (Tregs).

In summary, anti-CD4, anti-CD8, concanavalin A, cytokine detection antibodies, and glucocorticoids are commonly used alongside 145-2C11, with the specific combination depending on whether the investigation centers on T cell activation, immune suppression, or cytokine profiling.

Clone 145-2C11 is a widely used monoclonal antibody targeting the murine CD3? chain on T cells, with key findings in scientific literature establishing its roles in T cell activation, depletion, apoptosis, and as an essential experimental tool for mouse immunology research.

Key findings:

• Target Specificity: 145-2C11 specifically binds to the 25-kDa ? chain of the T-cell receptor (TCR)-associated CD3 complex in mice, expressed on thymocytes, mature T cells, and NK-T cells.

• Mechanism of Action: The antibody can strongly activate T cells both in vitro and in vivo, particularly when crosslinked, triggering signal transduction through CD3?. Soluble 145-2C11 requires accessory cells for T cell activation, while plate-bound forms can do so independently. It can activate naïve and memory T cells, induce proliferation, cytokine production, or, under certain conditions, apoptotic cell death (activation-induced cell death, AICD).

• T Cell Depletion & Apoptosis: 145-2C11 is capable of depleting T cells in vivo, often through induction of apoptosis in both immature thymocytes and peripheral T cells. For example, it induces a rapid reduction in TCR surface expression on CD4^+^ T cells and can trigger higher T cell depletion and TGF-? secretion compared to modified anti-CD3 antibodies.

• Immunomodulation: Administration can lead to cytokine release (such as TNF, IFN-?, IL-6) and modulation of immune responses. Its ability to induce tolerogenic cytokines like TGF-? is of particular interest in immune tolerance research.

• Experimental Applications:

  • Used extensively for T cell functional assays, including stimulation, proliferation, cytokine induction, and blocking CTL-mediated lysis.
  • Useful in flow cytometry, immunoprecipitation, immunohistochemistry, Western blotting, and in vivo depletion studies.
  • It can also block binding of certain other anti-CD3 antibodies, often used for specificity controls.

• Limitations: 145-2C11 is not suitable for studies involving formalin-fixed paraffin-embedded samples due to diminished epitope recognition, and does not cross-react with rat leukocytes.

• Historical Significance: It was originally described as a monoclonal antibody specific for murine T3 (CD3) and has since become the standard for T cell manipulation in mouse models.

These findings underscore 145-2C11's critical and versatile roles in probing murine T cell biology and modeling immune responses in research settings.