Anti-Mouse H-2Kb (MHC Class I) [Clone Y-3] - Purified in vivo PLATINUM™ Functional Grade

Clone Y3 is a monoclonal antibody targeting mouse MHC class I molecules (specifically H2K haplotypes b, k, q, r, s), and its most common in vivo applications in mice include blocking MHC class Imediated antigen presentation, modulating immune responses, and investigating T cell function.

Key in vivo applications include:

• In vivo blockade of MHC class I–mediated antigen presentation: By binding to the MHC class I molecules (H2K), Y3 can block the interaction between antigenpresenting cells and CD8+ T cells, allowing researchers to examine the roles of these cells in immune responses, transplant rejection, or infection models.
• Functional assays of immune cell activity: Administrating Y3 is used to study the dependence of immune responses on MHC class I, as it can inhibit CD8+ T cell responses in vivo, clarifying the role of cytotoxic T lymphocytes (CTLs) in various models (autoimmunity, infections, tumors).
• Immunomodulation for transplantation or immunopathology studies: Y3 is used to manipulate or suppress MHC class I–dependent immune mechanisms, such as graft rejection or tolerance.
• Preclinical assessment of therapies: The antibody’s blockade helps evaluate the impact of impairing MHC class I presentation on efficacy or safety of immunotherapies, vaccine responses, and immunomodulatory strategies.

Other reported uses (primarily ex vivo but sometimes translated for in vivo mechanistic studies) include:

• Immunopeptidomics: Dissecting the peptides presented by MHC class I in various disease models.
• Depletion or inhibition of specific cell populations: Though more characteristic of some other antibodies, blockade with Y3 can transiently alter CD8+ T cell function for mechanistic or depletion studies.

Y3 should not be confused with the similarly named Y3P (which targets MHC class II IA molecules)—the Y3 clone specifically targets MHC class I.

In summary, clone Y3 is mainly used in vivo for blocking MHC class I function, dissecting CD8+ T cell roles, and investigating the immune consequences of MHC class I inhibition in various disease and transplantation models.

Commonly used antibodies or proteins with Y3 (antimouse H2Kb, MHC Class I, Clone Y3) include: actin, GFP, CD markers (like CD31), and various secondary antibodies for detection. These are employed either as controls, markers, or for multiplex analyses in immunological and cell biology experiments.

• Actin is often used as a loading or reference control in Western blot or immunofluorescence to normalize target protein detection.
• GFP (Green Fluorescent Protein) is frequently detected in cells expressing GFPtagged recombinant proteins, allowing identification or localization in the same experiment as MHC I detection.
• CD markers like CD31 (an endothelial cell marker) and others (e.g., CD3, CD45, CD11b, depending on cell type or tissue) are routinely used for multicolor flow cytometry or immunostaining alongside Y3 to differentiate and analyze specific immune cell populations.
• Secondary antibodies conjugated with fluorescent dyes or enzymes (like HRP or AP) are essential for amplifying the detection signal of Y3 in both immunofluorescence and Western blotting.

These combinations enable researchers to study the expression of MHC Class I in context with other cell typespecific markers or protein functions, and to ensure the validity and robustness of their experimental results.

Key findings from clone Y3 citations in scientific literature are as follows:

• Specificity: Clone Y3 is a mouse monoclonal antibody that is highly specific for the H2Kb MHC class I molecule found on mouse cells. It distinguishes H2K haplotypes (notably b, but also k, q, r, s) and does not crossreact with the d haplotype.

• Functional Use: This antibody is widely used to identify, block, or deplete cells expressing H2Kb in vivo and in vitro, making it a valuable tool for experiments that require targeting or removal of specific mouse MHC class Ipositive populations.

• Applications:

  • Frequently employed in immunological studies, especially those involving transplantation biology, tumor immunology, and basic mouse immunogenetics.
  • Used in flow cytometry, affinity binding assays, and functional assays to quantify or block H2Kb expression.
  • Plays a critical role in experiments that need to block antigen presentation or interfere with T cell recognition mediated through H2Kb.

• Validation: Clone Y3 is validated and cited for use in multiple established protocols and assay types, highlighting its reliability and widespread acceptance within the scientific community.

There are no key findings linking clone Y3 to TIM3, KIR, or human immunology, as its specificity and scientific citations are focused on mouse H2Kb (MHC class I) molecules.

Dosing regimens for clone Y3 (an antimouse MHC Class I antibody) vary between mouse models depending on the target cell population, mouse strain, and the specific experimental context, such as whether the goal is depletion versus simple detection or blockade. However, the available literature and product datasheets do not provide standardized or broadly cited dosing protocols specific for clone Y3; regimens are generally tailored based on preliminary titration and the desired degree of immunomodulation.

Essential context and supporting details:

• Strain dependence: The effectiveness and necessary dosage of clone Y3 may be influenced by the genetic background of the mouse, especially since Y3 targets the H2(^b), H2(^k), H2(^q), H2(^r), and H2(^s) haplotypes, but not H2(^d). This necessitates adjustments in dosing schedules and possible changes in administration route.
• Experimental aim: For in vivo lymphocyte depletion or blocking (e.g., of MHC class I for NK cell function studies), dosing must be optimized according to desired depletion efficacy, which may differ with mouse strain or the tissue distribution of the targeted cells. In analogous depletion antibody studies (e.g., antiCD8 or antiNK1.1), typical doses range from 100 to 500 μg per mouse, administered intraperitoneally or intravenously, every 3 to 7 days, but these numbers are not specifically established for Y3 and require empirical determination.
• Product guidelines: Commercial suppliers generally encourage titration in each new experimental model. For example, one supplier notes that “dosing regimens of clone Y3 can vary across mouse models," implying no universal protocol for all settings.
• Published data gap: Most of the available information on Y3 focuses on specificity and applications, but not on detailed dosage schedules for in vivo experimental use across strains or disease models.

In summary, researchers should empirically optimize the dosing regimen of clone Y3 for each mouse model and experimental setup, considering factors such as strain, cell population targeted, administration route, and endpoint. If establishing a new protocol, it is advisable to conduct doseresponse pilot studies and reference analogous depletion protocols as a starting point. Direct consultation of primary studies or supplier technical support may yield additional dosing recommendations for similar applications in the intended mouse model.