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

Clone Y-3P is widely used in mice for in vivo blockade of MHC class II (I-A) molecules, primarily to inhibit I-A-restricted T cell responses or manipulate antigen presentation, making it a key tool in immunological blockading and functional studies.

Common in vivo applications include:

• Blocking MHC Class II-mediated antigen presentation: Y-3P is administered to mice to prevent antigen-presenting cells from activating CD4+ T cells via I-A MHC class II molecules, thereby inhibiting immune responses dependent on this pathway.
• Immunological tolerance and autoimmunity research: Used in models such as experimental autoimmune encephalomyelitis (EAE), Y-3P can help dissect mechanisms of autoimmune disease by blocking MHC II-dependent T cell activation.
• Functional studies of immune response: By blocking TCR stimulation through MHC II, researchers can isolate and study the roles of CD4+ T cells, antigen-presenting cells, and specific antigenic pathways in various models of infection, transplantation, and immune regulation.
• MHC II immunopeptidomics and molecular studies: Y-3P facilitates the study of peptide presentation and antigen repertoire by blocking or isolating specific I-A haplotypes in vivo and ex vivo.
• Studying tolerance induction and pathogen clearance: The antibody is used in tolerance models to understand the requirement for MHC II-TCR interaction during tolerance induction or immune clearance of pathogens.

Summary table:

Y-3P is reported to react with various I-A haplotypes (I-A^b^, I-A^f^, I-A^p^, etc.), allowing use across multiple mouse strains. Its specificity is to the I-A subtype, not I-E. Typical in vivo applications focus on immune blockade experiments where antigen-specific MHC II:T cell interactions need to be interrupted.

These uses are broadly supported by product documentation, research antibody suppliers, and peer-reviewed studies using Y-3P for in vivo immunological modulation.

Commonly, Y-3P (an anti-mouse MHC class II antibody) is used alongside antibodies and proteins targeting T cell activation and differentiation, especially in immunological studies focused on antigen presentation and T cell responses.

Frequently co-used antibodies and proteins include:

• Anti-CD3: Marks the T cell receptor complex, essential for analyzing or stimulating T cell activation as it engages with the MHC class II/TCR axis.
• Anti-CD28: Provides the co-stimulatory signal necessary for full T cell activation, often included in studies assessing T cell function or activation.
• Anti-CD4: Identifies helper T cells and is involved in co-receptor signaling with MHC class II molecules.
• Markers for antigen-presenting cells (APCs): This includes markers for macrophages, dendritic cells, monocytes, and B cells, as these cells constitutively express MHC class II and are integral to studies using Y-3P.

In experimental setups, researchers often combine Y-3P with these antibodies in:

• Assessing T helper cell activation
• Blocking assays to dissect MHC class II–dependent T cell responses
• Flow cytometry panels evaluating APC or T cell populations.

Other relevant antibodies can include isotype controls (e.g., Mouse IgG2a), specific peptide:MHC II–recognizing antibodies such as Y-Ae (for Eα:IA^b complexes), or anti-MHC II antibodies that recognize different haplotypes for comparative or blocking studies.

These combinations are essential for characterizing cell interactions within the immune response and for functional studies of antigen presentation, tolerance, and transplantation immunology.

Clone Y-3P is a widely used monoclonal antibody that targets mouse MHC class II (I-A) molecules, and its citations in scientific literature reveal several key applications and findings:

• Blockade of MHC Class II and TCR Stimulation: Y-3P is frequently employed for in vivo blockade of MHC class II, effectively interrupting antigen presentation and T cell receptor (TCR) stimulation in mice. This blockade is crucial for dissecting the roles of MHC class II molecules in immune responses, tolerance, and autoimmunity.

• Inhibition of T Cell Responses: The antibody is reported to inhibit I-A-restricted T cell responses in functional assays. This allows researchers to specifically assess the MHC class II dependence of immune phenomena by blocking the interaction between antigen-presenting cells and CD4+ T cells.

• Assessment of MHC II Expression: Y-3P is commonly used as a detection reagent in flow cytometry and immunostaining to assess and quantify the expression of MHC class II molecules (I-A) on the surface of various cell types, including B cells and dendritic cells. This is critical for studies examining immune cell phenotypes and dynamics.

• Immunological Blockade Experiments: The antibody is a standard tool for in vivo immunological blockade experiments, particularly in mouse models of disease where the function of MHC class II needs to be transiently eliminated to understand its contribution to pathogenesis or tolerance.

• High Citation in Foundational Immunology Studies: Y-3P is cited in numerous foundational studies investigating T cell selection, antigen processing, autoimmunity, and self-peptide presentation by MHC class II molecules (for example: positive selection in the thymus, CNS immune privilege, and formation of peptide-MHC complexes).

• Detection of Empty vs. Loaded MHC Molecules: The antibody has also been instrumental in recognizing both loaded and "empty" MHC class II molecules, assisting in research on peptide loading and editing within antigen-presenting cells.

In summary, Y-3P is a foundational tool antibody in mouse immunology, providing specific blockade, detection, and mechanistic interrogation of MHC class II (I-A)-mediated processes throughout the literature. Its versatility and specificity are reflected in many landmark immunological publications.

Dosing regimens for the Y-3P clone, which targets mouse MHC class II (I-A), can vary significantly across different mouse models. The dosing strategy often depends on several factors, including:

• Experimental Objective: Whether the goal is to deplete certain cells, functionally inactivate MHC class II, or interfere with antigen presentation.
• Route of Administration: While intraperitoneal (i.p.) injections are commonly used, other routes like intravenous (i.v.) or subcutaneous (s.c.) may also be employed depending on the study design.
• Mouse Strain: Different strains may have varying responses to the antibody due to genetic differences affecting immune responses.

A typical dosing range for functionally similar MHC class II blocking antibodies, such as Y-3P, is generally between 100–250 μg per mouse. However, specific dosing regimens in the literature may vary based on the experimental design and desired outcomes. Investigators often need to determine their own optimal working dilution and dosing schedule based on the specific requirements of their study.

For precise dosing, it is crucial to consult the specific literature related to the mouse model being used, as dosing can significantly impact the efficacy and relevance of experimental results.