Anti-Mouse CD48 (Clone HM48-1) – Purified in vivo GOLD™ Functional Grade

Common In Vivo Applications of Clone HM48-1 in Mice

Blocking CD48-Mediated Interactions

• Inhibition of Cell–Cell Interactions: Clone HM48-1 is widely used in vivo to block CD48-mediated interactions, specifically those between CD48 and its primary counter-receptors, CD2 and CD244, in mice. This function is crucial for studying the role of these receptor–ligand pairs in immune cell adhesion and activation.
• Modulation of Immune Responses: The antibody modulates in vivo CD48 functions, including inhibition of the proliferative response of mitogen-activated spleen cells, which is relevant for studying immune regulation and tolerance.
• Prolongation of Allograft Survival: HM48-1 has been demonstrated to prolong cardiac allograft survival in vivo, likely by attenuating T cell activation and the subsequent immune response against the graft.
• Functional Studies of Hematopoietic Progenitors: While most noted for its applications in blocking and immunomodulation, CD48 expression is also a marker for identifying and isolating functionally distinct hematopoietic progenitors, though this is more commonly a flow cytometry or ex vivo application.

Mechanism and Specificity

• Epitope Recognition: HM48-1 recognizes an epitope on mouse CD48 (also known as BCM1, Blast-1 in humans, OX-45 in rats), a 45-kDa GPI-linked glycoprotein expressed broadly on hematopoietic cells.
• In Vivo Suitability: Commercially available HM48-1 antibodies are formulated with ultra-low endotoxin levels, making them suitable for direct intravenous, intraperitoneal, or other in vivo administration in mice.
• Isotype: The functional grade in vivo HM48-1 is often of the rat IgG2a isotype, optimized for minimal nonspecific binding and minimal effector function in mice.

Typical Experimental Uses

• Transplantation Models: Inhibition of graft rejection via blockade of CD48-CD2/CD244 interactions.
• Inflammation and Autoimmunity: Investigation of immune cell activation and adhesion pathways in disease models.
• T Cell and B Cell Activation Studies: Testing the role of CD48 in adaptive immune responses by blocking its interactions with CD2 and CD244 in vivo.

Summary Table

Clone HM48-1 is a critical tool in mouse immunology research, primarily for blocking CD48-mediated interactions in vivo to study immune regulation, transplantation, and cell activation pathways.

Based on the functional properties of HM48-1 and its mechanisms of action, several antibodies and proteins are commonly used alongside this anti-CD48 antibody in research applications.

Co-Stimulatory and T Cell Activation Studies

The HM48-1 antibody is frequently combined with anti-CD3ε antibodies to study T cell activation and proliferation. When cross-linked with anti-CD3ε mAbs, HM48-1 augments the proliferative response of spleen cells, making this combination valuable for investigating T cell costimulation pathways.

Transplantation and Allograft Studies

Anti-CD2 antibody (clone 12-15) represents a particularly important companion to HM48-1 in transplantation research. In vivo administration of HM48-1 can prolong cardiac allograft survival, and this effect is greatly enhanced when combined with the anti-CD2 mAb 12-15. This synergistic approach targets both CD48 and its ligand CD2, providing more comprehensive blockade of these critical immune interactions.

Target Proteins and Ligands

The primary counter-receptors that HM48-1 functionally interacts with include CD2 (LFA-2) and CD244 (2B4 antigen). The HM48-1 antibody specifically blocks binding of soluble CD2 to CD48-bearing cells and inhibits CD48/CD244 interactions. These blocking capabilities make studies involving these molecules particularly relevant when using HM48-1.

Cell Surface Markers for Flow Cytometry

Since CD48 is expressed on various leukocyte populations including T cells, B cells, monocytes, and macrophages, HM48-1 is often used in multi-color flow cytometry panels alongside other leukocyte markers to identify and characterize specific immune cell subsets. The antibody is commonly used with mitogens in proliferation assays to study spleen cell responses.

The HM48-1 monoclonal antibody is used to study the mouse CD48 antigen, which is a member of the SLAM family and Ig superfamily. Key findings from its citations in scientific literature include:

1. CD48 Expression and Function: CD48 is a 45 kDa GPI-linked glycoprotein expressed on the majority of hematopoietic cells, playing a critical role in adhesion and T cell activation. In mice, CD48 primarily interacts with CD2 and CD244 as counter-receptors.

2. Hematopoietic Progenitor Identification: The differential expression of CD48, along with other SLAM family members like CD150 and CD244, helps distinguish functionally distinct bone marrow hematopoietic progenitors. For example, hematopoietic stem cells (HSCs) are typically CD150(+)CD244(-)CD48(-), while non-self-renewing multipotent progenitors are CD244(+)CD150(-)CD48(-).

3. Applications of HM48-1 Antibody: The HM48-1 antibody has been used in various applications, including flow cytometry for analyzing mouse splenocytes and in vivo studies to modulate CD48 functions. It can block CD48 interactions with CD2 and CD244, affect T cell activation, and prolong cardiac allograft survival.

4. Role in Immune Response: CD48, through its interactions, influences cell adhesion and proliferation among immune cells, including NK cells and T cells. It also plays a role in eosinophil activation and is involved in diseases like allergic rhinitis and asthma.

Dosing regimens of clone HM48-1 (anti-mouse CD48 antibody) vary depending on experimental context and mouse model application, but published regimens for in vivo use typically employ doses around 300 μg per mouse by intraperitoneal injection (i.p.), with schedule and frequency adjusted to the model’s requirements.

Key findings from published sources:

• For in vivo depletion or blockade (e.g., immune modulation or disease models), a common regimen is 300 μg/dose, i.p., administered at key experimental timepoints (such as days -1 and 2 relative to disease induction). For example, this dose suppressed leukocytes and lymphocytes in a disease model, indicating strong efficacy.

• Application notes from antibody suppliers and prior literature indicate that dosing and frequency should be tailored: the antibody "should be titrated for optimal performance for each application" and lower endotoxin formulations (such as Ultra-LEAF™) are recommended for sensitive in vivo experiments.

• In a published autoimmune encephalomyelitis (EAE) model, anti-CD48 (using an unspecified but likely comparable regimen, as per literature precedents for functional monoclonal antibodies in mice) was administered on days 4 and 7 after immunization, though the precise dose was not stated. This design highlights the typical approach: interval dosing surrounding disease onset or intervention.

For in vitro functional studies and flow cytometry:

• Recommended usage is much lower, about ≤0.25 μg per 1 million cells per 100 μl (for staining and blocking in culture). Such applications do not reflect system-level pharmacokinetics and are not directly comparable to in vivo mouse dosing.

Dosing strategy may need adjustment based on:

• Mouse strain (e.g., BALB/c, C57BL/6)
• Disease/experimental model (e.g., autoimmune disease, cancer)
• Route of administration (i.p. is most common)
• Purpose (blockade, depletion, or simple detection)
• Desired pharmacodynamic effect (single depletion vs. sustained blockade)

Summary Table: Example Dosing Regimens for Clone HM48-1 in Mouse Models

References for application-specific adjustment:

• The antibody is "useful for blocking in vitro and in vivo CD48 mediated interactions," and titration is recommended for new applications.

Search results do not provide a comprehensive survey of all published clone HM48-1 dosing regimens across every mouse disease model. However, regimens in the range of 200–300 μg per mouse i.p., given every 2–3 days or at key timepoints, are well supported for functional in vivo studies, consistent with broader standards for functional antibodies in mice. Always adapt dosing to your specific mouse model and confirm details with up-to-date, peer-reviewed protocols or primary publications using HM48-1 in similar contexts.