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

Clone 145-2C11 is a monoclonal antibody targeting the mouse CD3? chain and is widely used in in vivo mouse studies primarily for T cell activation, depletion, and immunomodulation.

Key in vivo uses of 145-2C11 in mice include:

• T cell Activation and Cytokine Release: Upon in vivo administration, 145-2C11 crosslinks CD3? on the surface of T cells, causing robust T cell activation, release of cytokines like TNF, IFN?, and IL-6, and often transient T cell receptor (TCR) downregulation. This property is exploited to model T cell activation or immune storm conditions in experimental animals.
• In vivo T Cell Depletion: 145-2C11 can induce rapid depletion of peripheral T cells; this is widely used to study immune responses or generate T cell-deficient models. The antibody can induce apoptosis in immature thymocytes and deplete mature T cells in peripheral organs.
• Immunosuppression: By triggering profound T cell modulation and depletion, 145-2C11 immunosuppresses mice, making it a surrogate for testing anti-CD3 therapies and mechanisms of tolerance induction.

Additional details and considerations:

• Dosing and Monitoring: Studies have reported single or repeated intraperitoneal injections (e.g., 20?µg per mouse) causing acute T cell activation, rapid surface TCR downregulation, profound cytokine release, and temporary body weight loss (attributable to cytokine storm).
• In vivo vs. in vitro utility: While 145-2C11 is also used in vitro for T cell activation and flow cytometry, in vivo its immunomodulatory and depleting effects predominate.
• Use in Pathogenesis and Therapy Models: The antibody is used to mimic clinical anti-CD3 therapy, assess immune reconstitution, or study T cell-mediated pathologies.

Special preparation is required for in vivo applications (e.g., low endotoxin formulations such as Ultra-LEAF™) to prevent experimental confounding by contaminants.

In summary, 145-2C11 is most commonly used in vivo for T cell depletion, activation, and functional modulation in a range of immunological and disease models in mice.

In the literature, 145-2C11 (an anti-mouse CD3 antibody) is frequently used alongside several other antibodies and proteins to study T cell biology and immunomodulation in mice. Commonly co-used molecules include:

• Anti-CD4 and Anti-CD8 Antibodies: These are routinely combined with 145-2C11 for immunophenotypic analyses of distinct T cell subsets by flow cytometry.
• Concanavalin A (Con A): This lectin is utilized as an alternate T cell stimulator to assess T cell proliferative capacity in comparison or combination with anti-CD3 stimulation.
• Methylprednisolone (Glucocorticoids): High-dose glucocorticoids are employed to modulate or prevent cytokine release syndrome induced by 145-2C11 administration.
• Anti-TCR Antibodies: These may be used to monitor changes in TCR expression following treatment with 145-2C11.
• TGF-? (Transforming Growth Factor Beta) Measurement: Levels of TGF-? are assessed to investigate the immunoregulatory or tolerogenic consequences of 145-2C11-induced T cell apoptosis.
• Fc?R-related Antibodies or Ligands: Studies using Fc-modified or surrogate anti-CD3 antibodies (like 2C11-Novi) often involve comparisons with 145-2C11 to analyze Fc receptor interactions and downstream effects.
• PLP139–151 Peptide: Used in experimental autoimmune encephalomyelitis (EAE) models to investigate the immunotherapeutic effects of anti-CD3 antibodies.

These antibodies and proteins are utilized in applications such as flow cytometry, immunohistochemistry, Western blotting, and in vivo functional studies. The precise combination depends on the experimental design, such as immune cell depletion, functional assays, cytokine profiling, or T cell activation studies.

Clone 145-2C11 is a widely used monoclonal antibody that targets the CD3? chain of the T cell receptor (TCR) complex in mice, and its scientific literature citations reveal several key findings regarding T cell activation, depletion, and immunomodulation.

Key findings:

• Specificity and Function: 145-2C11 binds specifically to the 25-kDa ? chain of murine CD3, a crucial component of the TCR complex on thymocytes, mature T cells, and peripheral T cells. This binding is used routinely for identification and analysis of T cells by flow cytometry and other immunological assays.

• T Cell Activation and Depletion: In vivo, administration of 145-2C11 potently activates T cells, leading to upregulation of activation markers such as CD69 and CD25, cytokine release (TNF, IFN?, IL-6), and T cell receptor (TCR) downregulation. 145-2C11 induces rapid, substantial TCR internalization, with recovery of surface expression occurring within five days after treatment. It also mediates T cell depletion via activation-induced cell death (AICD) and is more effective in this respect than Fc-modified variants.

• Cytokine Release and Tolerogenic Effects: 145-2C11 administration results in robust cytokine secretion and can induce a tolerogenic (immune tolerance-promoting) response characterized by increased TGF-? levels. This property is linked to phagocyte-mediated clearance of apoptotic T cells, which is a source of tolerogenic cytokines.

• Applications: The antibody is extensively used for:

  • Flow cytometry to detect murine T cells.
  • In vitro and in vivo T cell activation and proliferation assays.
  • T cell depletion in mouse models, both by apoptosis induction (especially in immature thymocytes) and by triggering activation-induced death.
  • Blocking CTL-mediated cytolysis and other functional studies of T cells.
  • Additional uses include immunoprecipitation, immunohistochemistry (when not formalin-fixed), and Western blotting.

• Blocking Activity: 145-2C11 can block binding of other anti-CD3 antibodies (e.g., 17A2) to CD3?, making it useful in competitive or blocking experiments.

• Historical Note: The clone was first described following immunization of Armenian hamsters with murine cytolytic T cells and identified as specific for the murine T3 (CD3) complex.

Summary Table:

These core findings make 145-2C11 a gold-standard tool in murine immunology research, especially for studies involving T cell function, modulation, and depletion.

Clone 145-2C11 dosing regimens in mice vary widely depending on the purpose of the experiment, target cell population, anticipated immune modulation intensity, and the formulation (whole antibody vs. F(ab’)? fragment). The most commonly reported dose range is 1–400 ?g per mouse per administration, delivered by intraperitoneal injection, and dosing schedules also vary significantly across studies and mouse models.

Key variations in dosing regimens:

• Typical dose ranges and single-dose studies:
  • Single doses of 145-2C11 reported as low as 20 ?g and as high as 400 ?g per mouse. For example, a study compared a single 20 ?g dose of 145-2C11 (i.p.) to a 50 ?g dose of a related antibody in naïve mice to test T-cell activation and receptor modulation. Another cited earlier work used a single 400 ?g dose to deplete ~40% of CD4+ T cells in naïve mice. Doses of 5–50 ?g per mouse are most often described as standard for in vivo studies, depending on the required efficacy.
• Multiple dose regimens:
  • Repeated injections are also common, particularly for studies aiming for robust T-cell depletion or modulation:
    • Five doses of 50 ?g every 24 hours (total 250 ?g).
    • Four doses of 25 ?g every 72 hours (total 100 ?g).
    • Lower-dose schedules: Four doses of 2 ?g every 72 hours achieved only partial CD3 occupancy.
    • Five consecutive daily injections of 25 ?g have been used with related anti-CD3 antibodies and variants to achieve more durable T-cell depletion.
    • For F(ab’)? fragments, 150 ?g every other day has been reported.
• Variable responses by cell type and fragment:
  • Higher or more frequent dosing is required for deep immune cell depletion (versus transient activation/modulation).
  • F(ab’)? fragments of 145-2C11 (lacking Fc-mediated effects) are dosed comparably to whole IgG for inflammation or tolerance induction (e.g., 150 ?g every other day), but effects on cell populations and recovery kinetics may differ from intact antibody.
• Effect of strain and disease context:
  • Most regimens are established in C57BL/6 or BALB/c mice, but finer adjustments in dose or interval may be made for autoimmune, cancer, or transplant models based on sensitivity or immune status of the strain.
• Route of administration:
  • Intraperitoneal (i.p.) injection is the standard route in most models.

Table: Selected Regimens for Clone 145-2C11 in Mice

Summary of variation:

• Most published studies use 20–50 ?g/mouse per injection for single or multi-dose studies,
• Total doses for robust effects commonly range from 100–400 ?g/mouse,
• Dose and frequency are increased for deeper or longer immune modulation or for immunodepleted environments.

In summary, the optimal regimen for 145-2C11 in mice depends on the immune endpoint, with significantly higher or repeated dosing for T-cell depletion versus transient T-cell receptor modulation or immune activation. The choice of mouse strain and specific disease model may also necessitate further adjustment.