Anti-Mouse MHC Class II (I-A) [Clone Y-3P] – Purified in vivo GOLD™ Functional Grade

The Y-3P clone is extensively used in in vivo mouse studies for MHC class II blocking and TCR stimulation blockade, making it a valuable tool for immunological research.

Primary Applications in In Vivo Studies

MHC Class II Blocking: Y-3P is commonly employed to block MHC class II molecules in living mice, which prevents antigen presentation to CD4+ T cells. This application is particularly useful for studying immune responses and understanding the role of antigen presentation in various disease models.

TCR Stimulation Blockade: The antibody is used to inhibit T cell receptor (TCR) stimulation by blocking the interaction between MHC class II molecules and CD4+ T cells. This mechanism allows researchers to examine T cell-dependent immune responses and their role in experimental conditions.

Mechanism of Action

Y-3P targets the I-A subregion-controlled A?:A? complexes found on professional antigen-presenting cells (APCs), including macrophages, monocytes, dendritic cells, and B cells. The antibody reacts with multiple mouse MHC class II haplotypes including I-Ab, I-Af, I-Ap, I-Aq, I-Ar, I-As, I-Au, I-Av, and weakly with I-Ak, but notably does not react with the H-2d haplotype.

Practical Considerations

The Y-3P antibody is formulated specifically for in vivo use as an InVivoMAb product, ensuring high purity (>95%), low endotoxin levels (<2EU/mg), and sterility through 0.2 µm filtration. It's produced in animal-free facilities and purified using Protein G to meet the stringent requirements for in vivo applications.

The antibody is reported to inhibit I-A-restricted T cell responses, making it an effective tool for functional studies examining the role of MHC class II-mediated immune activation in mouse models. Researchers typically use this antibody to create controlled experimental conditions where MHC class II-dependent immune responses can be selectively blocked or modulated.

The correct storage temperature for sterile packaged clone Y-3P (anti-mouse MHC Class II, Clone Y-3P) depends on the intended duration of storage:

• Short-term storage (up to one month): Store sterile as received at 2–8°C (standard refrigerator temperature).
• Long-term storage: Aliquot the antibody aseptically (without diluting) and store at ? –70°C (ultra-low freezer).

Avoid repeated freeze-thaw cycles to maintain antibody integrity, and reference lot-specific datasheets for any manufacturer updates or particular formulations. These guidelines conform generally to practices for monoclonal antibody storage.

Commonly Used Antibodies and Proteins with Y-3P in the Literature

Y-3P is a monoclonal antibody specific for mouse MHC class II (I-A), frequently used in immunology research to block T cell receptor (TCR) stimulation and MHC class II-mediated antigen presentation. Its primary function is to interfere with the interaction between MHC class II molecules and CD4+ T cells. In the literature, Y-3P is often used in conjunction with other antibodies and proteins that target key components of the immune response, especially in studies involving T cell activation, antigen presentation, and immune regulation.

Associated Antibodies

• Anti-CD3/Anti-CD28: Antibodies targeting the CD3 and CD28 molecules on T cells are commonly used alongside Y-3P to study T cell activation. Anti-CD3 stimulates the TCR complex, while anti-CD28 provides co-stimulatory signals. Y-3P can be used to block MHC class II-mediated signals in these assays, allowing researchers to dissect the relative contributions of TCR and co-stimulatory signals versus antigen presentation.
• Anti-CD4: Since CD4 molecules interact directly with MHC class II and augment TCR signaling, antibodies against CD4 are sometimes used in parallel with Y-3P to further modulate T cell responses and study the role of MHC class II–CD4 interactions in immune activation.
• Anti-Class I MHC: To compare the roles of MHC class I and class II in antigen presentation and T cell activation, researchers may use antibodies against MHC class I (e.g., anti-H-2K, anti-H-2D) in conjunction with Y-3P.
• Isotype Controls: Non-specific antibodies of the same isotype (e.g., mouse IgG) are typically used as negative controls to demonstrate the specificity of Y-3P’s effects.

Associated Proteins

• MHC Class II (I-A): The direct target of Y-3P, these glycoproteins are essential for presenting exogenous antigens to CD4+ T cells.
• TCR/CD3 Complex: The primary receptor complex on T cells that interacts with peptide–MHC complexes. Y-3P blocks the engagement of this complex with MHC class II, thereby preventing T cell activation.
• CD4: This co-receptor stabilizes the interaction between the TCR and MHC class II and is critical for signal transduction in helper T cells.
• Antigen-Presenting Cell (APC) Markers: Antibodies against markers such as CD11c (dendritic cells), CD19 (B cells), F4/80 (macrophages), and Ly-6G (neutrophils) are used to identify and sort professional APCs in experiments involving Y-3P. These markers help contextualize where and how MHC class II is being expressed and blocked.

Experimental Contexts

• In Vivo Blockade: Y-3P is injected into mice to block MHC class II-mediated immune responses in vivo, often in studies of autoimmunity, transplantation, and infectious disease.
• In Vitro Assays: Y-3P is used in vitro to block antigen presentation by APCs to CD4+ T cells, frequently in mixed lymphocyte reactions or T cell proliferation assays.
• Flow Cytometry and Staining: Y-3P (often biotinylated or fluorescently labeled) can be used alongside other fluorophore-conjugated antibodies for multiparameter flow cytometry to identify and characterize MHC class II-expressing cells.

Summary Table

Key Takeaways

Y-3P is predominantly used with antibodies and proteins that target T cell activation (anti-CD3, anti-CD28), co-receptors (anti-CD4), and markers of antigen-presenting cells. These combinations allow researchers to dissect the mechanisms of MHC class II-mediated immune responses, compare class I and class II functions, and validate the specificity of Y-3P’s effects using appropriate controls.

Clone Y-3P is a monoclonal antibody used in immunology research, particularly for targeting Mouse MHC Class II (I-A) molecules. Key findings and applications from scientific literature involving clone Y-3P include:

1. MHC Class II Blocking and TCR Stimulation: Y-3P is commonly used for in vivo blockade of TCR stimulation and MHC class II blocking, which are crucial in understanding immune responses and antigen presentation.

2. Expression and Regulation on Immature Dendritic Cells: Studies have shown that Y3P reactivity varies with dendritic cell maturation state. It is associated with higher levels of class II MHC expression on more mature dendritic cells, indicating its role in monitoring dendritic cell maturation.

3. Anti-Ab Antibody and MHCII Expression: In mice lacking conventional MHC class II genes, Y3P is used alongside other antibodies to detect MHCII expression on B cells and other cells, highlighting its utility in studying MHC class II-deficient mice.

These findings illustrate the significance of clone Y-3P in studying antigen presentation, immune cell maturation, and the role of MHC class II molecules in various immune contexts.