Anti-Mouse IL-21R (Clone 4A9) – Purified in vivo PLATINUM™ Functional Grade

Clone 4A9 is most commonly used in vivo in mice as a blocking antibody against the Interleukin-21 receptor (IL-21R, CD360), thereby inhibiting IL-21-mediated signaling pathways. The antibody is specifically designed and validated for such functional blockade in living animals to study the role of IL-21R in immune regulation, including T cell, B cell, and NK cell differentiation, antibody responses, and immunopathology.

Key in vivo applications in mice include:

• Functional blockade of IL-21R to dissect the role of IL-21/IL-21R signaling in immune cell development, differentiation, and function.
• Studies on immune regulation: Used to determine the involvement of IL-21R in B cell and T cell responses and immunoglobulin class switching during infection, autoimmunity, or immunization.
• Investigation of chronic infections and antiviral CD8+ T cell survival, examining how IL-21R signaling affects persistence and efficacy of immune responses.
• Evaluation of inflammatory and autoimmune mechanisms by blocking IL-21R to study changes in disease phenotypes and cytokine profiles in vivo.

Additional technical notes:

• Clone 4A9 is a rat IgG2a monoclonal antibody with extremely low endotoxin levels, making it suitable and safe for repeated in vivo administration in mice.
• It is also validated for ex vivo and in vitro assays such as flow cytometry, ELISA, and immunoprecipitation, but its defining use in vivo is as a functional blocking agent for dissecting immune signaling pathways.

In summary, the most common in vivo use of clone 4A9 in mice is for the targeted functional blockade of IL-21R during immunological studies to assess the receptor's role in various immune processes.

In the literature, the anti-Aldolase C antibody [4A9] is commonly used in research applications such as Western blot, immunocytochemistry, and immunohistochemistry. This antibody is often used to study Aldolase C, a protein expressed in glial cells and some neuronal populations. While specific combinations of other proteins or antibodies used directly with anti-Aldolase C [4A9] are not detailed in the available literature, several classes of antibodies and proteins are frequently used in similar applications:

1. Secondary Antibodies: These are crucial for detecting primary antibodies like anti-Aldolase C [4A9] in various assays. Common secondary antibodies are produced in hosts such as goat, donkey, or rabbit and can be conjugated with enzymes like horseradish peroxidase (HRP) or fluorescent dyes for enhanced detection.

2. MAP2 Antibody: In studies involving neuronal tissue, MAP2 (Microtubule-associated protein 2) antibodies are often used alongside Aldolase C antibodies to differentiate between neuronal and glial cell populations. For example, MAP2 is used to stain dendrites and perikarya of mature neurons.

3. Vimentin Antibody: This antibody is used to identify cells expressing vimentin, such as astrocytes or other intermediate filament proteins. It is often used in parallel with Aldolase C to study cellular composition in brain tissue.

For other contexts involving different antibodies labeled as "4A9," such as those targeting IL-21R or Mincle, typical combinations depend on the specific research question:

• IL-21R Antibody [4A9]: This antibody is used in immunology research to study the IL-21 receptor, which plays a role in the immune response. It could be used with other antibodies targeting immunological markers or cytokines.

• Mincle Antibody [4A9]: This antibody targets Mincle, an essential receptor involved in the immune response to mycobacterial infections. It might be used with antibodies recognizing other innate immune receptors or cytokines.

These examples illustrate general practices rather than specific combinations directly involving anti-Aldolase C [4A9] with other proteins or antibodies.

Based on the available information, clone 4A9 is a monoclonal antibody directed against murine Interleukin-21 Receptor (IL-21R, also known as CD360). The key findings from scientific literature regarding this clone include:

Antibody Characteristics and Specificity

Clone 4A9 was generated by immunizing Lewis rats with IL-21R-transfected YB2/0 cells, followed by fusion of immunized spleen cells to SP2/0. The antibody demonstrates high selectivity, as evidenced by FACS analysis and immunoprecipitation studies showing that 4A9 selectively binds to IL-21R. Notably, the antibody stains the majority of spleen cells from wild-type C57BL/6 mice but not IL-21R deficient mice, confirming its specificity.

Functional Properties

A critical functional characteristic of clone 4A9 is that IL-21 blocks its binding to IL-21R-transfected YB2/0 cells, indicating that the antibody likely binds to or near the IL-21 binding site on the receptor. This property makes it useful for studying receptor-ligand interactions and potentially blocking IL-21 signaling pathways.

Expression Pattern Detection

The antibody has been used to characterize IL-21R expression patterns, revealing that the receptor is expressed on most B cells as well as some T cells and natural killer cells. This distribution pattern is consistent with the known biological functions of IL-21R in regulating proliferation and differentiation of these immune cell populations.

The antibody has proven valuable for applications including flow cytometry, immunoprecipitation, and functional studies examining the role of IL-21R in immune cell development and function.

Dosing regimens of clone 4A9 (an anti-mouse IL-21R monoclonal antibody or an anti-Mincle antibody, depending on context) vary primarily based on the application (blockade vs. depletion), target antigen, specific mouse model, and experimental goals. The two most well-documented applications for clone 4A9 are:

• Anti-IL-21R antibody clone 4A9 (for cytokine signaling studies)
• Anti-Mincle antibody clone 4A9 (for immune modulation studies)

Anti-IL-21R (Clone 4A9): Dosing Regimens

• Low-dose Regimen: A dose of 25 μg/day administrated for 3 consecutive days (days 7 to 9 after immunization) was used in a mouse immunization model to block IL-21R signaling.
• High-dose Regimen: 500 μg/day for 3 days has been reported for more substantial blockade effects in vivo.
• General Guidelines: Doses for in vivo monoclonal antibodies in mouse models commonly range from 100–500 μg/mouse per injection, delivered intraperitoneally every few days depending on the kinetics and half-life of the specific antibody.

Factors Influencing Dose:

• C57BL/6 mice were commonly used, but doses could be adjusted for strain differences or body weight.
• The regimen (single vs. multiple dosing) is chosen based on the persistence of the target molecule and the half-life of the antibody as well as the immunological endpoint (acute suppression vs. sustained blockade).

Anti-Mincle (Clone 4A9): Dosing and Application

• In vitro and Flow Cytometry: Used at 5–10 μg/mL for staining or immunoprecipitation.
• In vivo use: No primary source specifies an in vivo dosing regimen for anti-Mincle 4A9 in mice in the search results, but comparable monoclonal antibodies are typically administered at 100–500 μg/mouse every few days intraperitoneally. Experimental dosing may depend on the outcome measure (e.g., inflammation reduction, survival, cytokine production).

Additional Context

• Many mouse immunotherapy and immune cell depletion studies standardize monoclonal antibody dosing around 100–250 μg/mouse delivered 2–3 times per week.
• The optimal regimen depends on desired depth of target modulation, antibody pharmacokinetics, and the immune status or disease model of the mouse.

Summary Table: Common Dosing Ranges

*For anti-Mincle 4A9, use the general in vivo mAb dosing guide as specific in vivo data were not found in the search results.

Key Points

• Clone 4A9 anti-IL-21R is most frequently used in the 25–500 μg/mouse dosing range, frequency based on whether transient or persistent blockade is needed.
• Dosing varies with mouse model, endpoint, and experimental design. C57BL/6 mice are common, but always verify for the specific strain used.
• For anti-Mincle 4A9, consult general monoclonal antibody guidelines for initial dosing, optimizing based on pilot studies or literature in similar models.