Anti-Mouse CD22 – Purified in vivo PLATINUM™ Functional Grade

Clone Cy34.1 is a monoclonal antibody commonly used in vivo in mice for targeting CD22, a molecule highly expressed on B cells. Its main applications are:

• B cell depletion: Cy34.1 is frequently used alone or in combination with other antibodies (e.g., anti-CD19 clone 1D3 and anti–rat κ light chain clone MAR 18.5) to efficiently deplete B cells in mice for immunological studies.
• Modulation of B cell function: Cy34.1 is employed to modulate B cell signaling and proliferation. For example, it can augment B cell proliferation in response to specific stimuli such as LPS.
• Flow cytometry: The antibody is used for ex vivo or in vivo labeling of CD22 to analyze B cell populations by flow cytometry.
• Immunoprecipitation: It can be used to pull down CD22 in protein studies from mouse samples.
• Combination depletion and mechanistic studies: Cy34.1 is often used together with other B cell–depleting antibodies to investigate B cell biology and immune regulation in disease models (e.g., autoimmunity, transplantation).

Emerging but less common uses include:

• Neuroimmunology research: Recent studies indicate a role for Cy34.1 in modulating immunity in neuroinflammatory conditions, though this is less established compared to B cell depletion and modulation.

Cy34.1 is valuable when in vivo depletion or modulation of mouse B cells is required, and also supports detection and functional dissection of B cell populations via flow cytometry or biochemical methods.

Commonly Used Antibodies and Proteins with Cy34.1 in the Literature

Cy34.1 is a monoclonal antibody targeting mouse CD22, a sialic acid-binding immunoglobulin-like lectin (Siglec-2) primarily expressed on mature B cells. In research, Cy34.1 is often used in combination with other antibodies or proteins for in vivo B cell depletion studies, as well as for immunophenotyping and functional assays.

Frequent Combinations

• Anti-CD19 (Clone 1D3): Cy34.1 is commonly paired with anti-CD19 (clone 1D3), another B cell marker, to achieve comprehensive B cell depletion in mouse models. This combination is standard for depleting different B cell subsets in vivo.
• Anti-rat κ Light Chain (Clone MAR 18.5): This antibody is also frequently used in conjunction with Cy34.1 and anti-CD19 for B cell depletion studies, particularly in mice to enhance the effectiveness of antibody-mediated B cell removal.
• Flow Cytometry Panels: For immunophenotyping, Cy34.1 (often FITC-conjugated for flow cytometry) is used alongside antibodies to other B cell markers such as B220 and IgM, especially when analyzing B cell maturation in the bone marrow. These combinations allow for detailed characterization of B cell populations at different developmental stages.

Additional Proteins and Functional Assays

• Lipopolysaccharide (LPS) or Anti-Igμ Chain: The Cy34.1 antibody has been shown to augment B cell proliferation in response to LPS or anti-mouse Ig μ chain in vitro, demonstrating its use in functional assays beyond simple cell surface labeling.
• Sialoside Probes: In studies probing CD22’s lectin function, Cy34.1 has been used alongside sialoside probes (e.g., Neu5Gcα2-6Galβ1-4GlcNAcβ-SpNH-PAA) to investigate CD22’s binding properties at the cell surface.

Other Combinations in the Literature

• Cytokines: While not directly combined with Cy34.1 in the cited literature, related studies may use cytokines like IL-4 to study CD22 expression modulation on activated B cells.
• General Isotype Controls: In vivo studies often include appropriate isotype controls (e.g., InVivoMAb mouse IgG1 isotype control), especially when assessing specificity of depletion or signaling effects.

Summary Table

Key Points

• Cy34.1 is most frequently combined with anti-CD19 (1D3) and anti-rat κ light chain (MAR 18.5) for in vivo B cell depletion in mice.
• For detailed immunophenotyping, it is paired with B220 and IgM antibodies, especially in studies of B cell development.
• Functional assays may include LPS or anti-Igμ chain to study B cell proliferation.
• Isotype controls and sialoside probes are used for experimental specificity and lectin function studies, respectively.

These combinations are standard in the literature for studies of B cell biology, immune regulation, and antibody-mediated depletion in mouse models.

Clone Cy34.1 is a monoclonal antibody highly specific for mouse CD22 (Siglec-2), a transmembrane protein important in B cell regulation and immune homeostasis. Scientific literature using Cy34.1 has led to several key findings:

• B Cell Phenotyping and Distribution: Cy34.1 is widely used for flow cytometric identification of CD22 expression patterns on murine B cells. It established that CD22 is highly expressed on mature peripheral B lymphocytes, follicular and marginal zone B cells, B-1 cells, and plasma cells.

• Alloantigen Specificity: The antibody is specific to mouse strains expressing the Lyb-8.2 alloantigen, such as A, BALB/c, CBA, C3H/He, C57BL/6, and others. Notably, strains like AKR, DBA/1, DBA/2, NZB, and PL do not bind Cy34.1 due to polymorphisms affecting the Lyb-8.2 epitope.

• Functional Modulation of B Cells: Cy34.1 binding to CD22 augments B cell proliferative responses when stimulated with LPS (lipopolysaccharide) or anti-mouse Igµ. This indicates a functional role for CD22 in B cell activation and signaling.

• CD22 as a Negative Regulator: Studies with Cy34.1 contributed to the identification of CD22 as a negative regulator of B cell activation, implicated in preventing excessive immune responses and autoimmunity. CD22-deficient mice, studied with this and related antibodies, show hyperresponsive B cells and propensity for autoimmunity.

• B Cell Depletion and Immunotherapy: Cy34.1 is used for in vivo B cell depletion (often in combination with other antibodies), a valuable tool for studying B cell function, immunodeficiencies, autoimmune models, and therapeutic research.

• Regulation and Disease Relevance: Dysregulated CD22 expression, mapped with Cy34.1, is implicated in murine models of leukemia, lymphoma, and autoimmune diseases, suggesting therapeutic potential for targeting CD22 in these conditions.

• Other Technical Applications: Cy34.1 has been adapted for multiple conjugations (e.g., fluorochromes like AF488 or PE/Cy5) for diverse applications, such as flow cytometry and fluorescence microscopy, facilitating spatial and quantitative studies of B cell subsets in situ and ex vivo.

Cy34.1 and its literature citations underpin much of our current understanding of CD22's biology in mice, its role in B cell physiology, immune regulation, and disease pathology, and have directly informed research toward targeted therapeutic development in immunological diseases.

Dosing regimens for clone Cy34.1, an anti-mouse CD22 monoclonal antibody, vary significantly across mouse models depending on several key factors including experimental objectives, targeted cell populations, administration routes, and the specific application being studied.

Application-Specific Dosing Variations

The most well-documented dosing regimen involves B cell depletion studies, where Cy34.1 is used in combination with other antibodies. The antibody is reported to facilitate in vivo B cell depletion when combined with anti-CD19 (clone 1D3) and anti-rat κ Light Chain (clone MAR 18.5). However, specific dosing information for this combination therapy is not widely standardized in publicly available data.

In xenograft tumor models, particularly Raji xenograft mice, studies have demonstrated efficacy using 10 mg/kg administered weekly. This regimen resulted in 60% tumor regression, with rapid antibody internalization observed.

For neurological disease models, specifically neuromyelitis optica spectrum disorder (NMOSD) mice, a much lower dose of 100 μg per mouse has been used via intrastriatal injection as a single dose. This represents a dramatically different approach compared to other applications, reflecting the localized nature of brain-targeted therapies.

Route and Model Considerations

The administration route significantly influences dosing strategies. While intraperitoneal injection is common for systemic immune cell depletion studies (typically at 200-250 μg per mouse for other CD markers), the brain-infused or intrastriatal routes used in neurological studies require substantially different doses.

The lack of standardized protocols across different mouse models reflects the diverse experimental objectives for this antibody. Researchers must consider factors such as the desired level of CD22 modulation, the specific mouse strain (as Cy34.1 recognizes mice with the Lyb-8.2 alloantigen, including A and BALB/c strains), and whether the goal is B cell depletion, functional modulation, or therapeutic intervention in disease models.