Anti-Mouse MHC Class I (H-2Kd, H-2Dd) [Clone 34-1-2S] — Purified in vivo GOLD™ Functional Grade

Clone 34-1-2S is most commonly applied in vivo in mice for the functional blockade and depletion of MHC class I molecules (H-2Kd, H-2Dd), manipulation of antigen presentation to CD8+ T cells, and experimental studies of immune responses involving cytotoxic T lymphocytes.

Key in vivo applications include:

• Blockade of MHC class I–mediated antigen presentation: 34-1-2S can be administered to mice to block the interaction between MHC class I molecules and CD8+ T cells, thereby inhibiting the recognition of target cells by CTLs (cytotoxic T lymphocytes). This is especially useful in experimental models to study the role of MHC class I in immune responses and transplant rejection.

• Depletion or functional inhibition of MHC class I expressing cells: Due to its cytotoxic activity (can induce complement-mediated cytotoxicity), 34-1-2S may be used to deplete MHC class I–positive cells or inhibit their function in vivo.

• Modulation of antigen-presenting cell (APC) activation: The antibody is also reported to be used for in vivo activation of APCs, possibly through cross-linking MHC class I molecules on their surface.

• Immune tolerance and selection studies: In vivo blockade allows investigation of thymic selection, immune tolerance mechanisms, and the development of CD8+ T cell repertoire, given the key role of MHC class I in presenting antigens during these processes.

• Experimental models of transplantation and autoimmunity: By interfering with MHC class I interactions, 34-1-2S helps in dissecting the contribution of donor versus recipient MHC molecules in graft rejection or autoimmune pathology.

These applications exploit the specificity of 34-1-2S for a common epitope in the α3 domain of H-2Kd and H-2Dd, enabling the selective targeting of these mouse MHC class I haplotypes in vivo. Dosage and administration routes are determined empirically for specific experimental goals and require careful titration to avoid off-target effects.

The most commonly used antibodies or proteins in combination with 34-1-2S (which targets mouse MHC Class I, specifically H-2Kd and H-2Dd) in the literature are those involved in immune cell characterization and antigen presentation studies. While specific pairings vary by experiment, several commonly co-used antibodies and proteins include:

• CD8: Frequently used to identify cytotoxic T lymphocytes, which interact with MHC Class I molecules.
• CD3/TCR: These antibodies are used to mark all T cells, as CD3 and T cell receptor (TCR) complexes are present on the surface of all mature T cells participating in antigen recognition alongside MHC Class I.
• Other MHC Class I Antibodies: Antibodies against H-2Kb, H-2Kq, H-2Kr, and H-2Kp are commonly used to distinguish different mouse strains or to characterize MHC expression broadly.
• CD45 and lineage markers (e.g., CD4, CD19): Including pan-leukocyte marker CD45, and others such as CD4 for helper T cells or CD19 for B cells, in multi-color flow cytometry panels with 34-1-2S.
• β2 Microglobulin: As a component of MHC Class I molecules (required for stable expression of the α3 domain recognized by 34-1-2S), studies may include β2 microglobulin detection.
• Isotype controls: For proper gating and compensation in flow cytometry, matching IgG2a isotype controls are standard.
• Functional peptides (e.g., OVA peptide 323-339, FLAG tag peptide): Sometimes used when profiling antigen-specific T cell responses alongside MHC detection.

These antibodies and proteins are typically used in applications such as:

• Flow cytometry: For immune profiling, cell sorting, and analysis of antigen presentation.
• Immunohistochemistry & immunofluorescence: For tissue-based localization of MHC Class I molecules.
• Immunoprecipitation & electron microscopy: For biochemical characterization of immune complexes.

In summary, the most commonly paired antibodies/proteins with 34-1-2S are those targeting CD8, CD3/TCR, other MHC Class I molecules (like H-2Kb), lineage markers (CD45, CD4, CD19), β2 microglobulin, and isotype controls, depending on the experimental context.

Clone 34-1-2S is a widely cited monoclonal antibody used for identifying and studying mouse MHC class I antigens, specifically H-2K(^d) and H-2D(^d), with notable applications and biological findings in immunology and transplantation research.

Key findings from its scientific literature citations include:

• Binding Specificity: 34-1-2S targets a determinant in the α3 domain common to H-2K(^d) and H-2D(^d). It also binds—with lower affinity—to H-2K(^b), and may cross-react with additional MHC class I molecules (such as s, r, q, p). This specificity arises whether or not β2-microglobulin is present.

• Epitope Use: This clone is a standard reagent for flow cytometry, immunohistochemistry, and complement-mediated cytotoxicity assays in murine models. Its ability to stain nucleated cells is leveraged to probe MHC class I expression, track immune populations, and study transplantation immunology.

• Mechanistic Research Findings: Recent high-profile studies have used 34-1-2S to show that:

  • Its binding pattern (high affinity for K(^d) and D(^d), weak for L(^d)) can affect susceptibility to antibody-mediated acute lung injury by varying the density of bound antibody on different mouse strains.
  • The breadth of binding (to multiple MHC class I antigens) distinguishes 34-1-2S from other clones and facilitates induction of specific immune or pathologic responses (e.g., lung injury in H-2(^d) mice).

• Functional Applications:

  • In animal models, 34-1-2S is used to deplete/target MHC I+ cells or block MHC class I function, with outcomes in T cell development, graft rejection, and autoimmunity studies.
  • Its use to trigger complement-dependent cytotoxicity has been central to dissecting immune injury mechanisms in transplantation and transfusion models.

• Antigen Presentation Studies: The clone has helped elucidate roles of MHC I in CD8+ T cell selection and activation, and the consequences of altering MHC I dynamics in different immunological settings.

• Technical Features: The antibody is usually supplied as an IgG2a monoclonal and can be conjugated to PE, FITC, APC, biotin, or used unconjugated for specialized applications.

Summary Table: Key Attributes of 34-1-2S in Literature

These findings highlight 34-1-2S as a foundational tool for mouse MHC class I research, with ongoing impact demonstrated in both basic and translational immunology.

The dosing regimens for the 34-1-2S monoclonal antibody, which targets MHC Class I H-2Kd and H-2Dd in mice, primarily depend on the application rather than the mouse model itself. This antibody is commonly used in flow cytometric analysis to study the expression of MHC class I antigens on nucleated cells from mice of the H-2Kd/H-2Dd haplotype.

General Guidelines for Use:

• The recommended concentration for flow cytometry is less than or equal to 0.25 µg per test, with each test typically involving a final volume of 100 µL and cell numbers ranging from 10^5 to 10^8 cells/test.
• There is no specific mention of varying dosages across different mouse models. Instead, the focus is on optimizing the dose for the specific application, such as flow cytometry.

Variation Considerations:While there is no detailed information on varying dosing regimens across different mouse models for clone 34-1-2S specifically, dosing strategies in immunological research often depend on the experimental goals (e.g., depletion of specific cell subsets, modulation of immune responses). However, for most applications involving this antibody, the dosage is standardized for flow cytometry rather than being tailored to specific mouse models.