Anti-Mouse CD252 (OX40L) [Clone RM134L] – Purified in vivo GOLD™ Functional Grade

The RM134L clone is used in in vivo mouse studies primarily as a blocking antibody to inhibit OX40L-OX40 signaling pathways and study their functional roles in immune responses.

Primary Applications in In Vivo Studies

Blocking OX40L-OX40 Interactions: The RM134L antibody effectively blocks the costimulatory activity of OX40L, preventing its interaction with the OX40 receptor. This blocking function is crucial for researchers studying the role of OX40/OX40L signaling in various immune processes.

T Cell Proliferation Studies: In vivo treatment with RM134L has been demonstrated to inhibit the poly(I:C)/CD40 stimulated proliferation of CD4 T cells. This makes it valuable for investigating T cell activation and proliferation mechanisms in mouse models.

Molecular Target and Mechanism

The RM134L antibody targets mouse OX40L (CD134L), a 35 kDa member of the TNF superfamily that is expressed on activated B cells and antigen presenting cells. OX40L serves as the ligand for OX40 (CD134), and this signaling pathway regulates both CD4 and CD8 T cell clonal expansion.

Functional Characteristics

Costimulatory Signal Modulation: By blocking OX40L, the RM134L antibody prevents the costimulatory signals that would normally be provided to antigen-reacting naive T cells, thereby reducing prolonged proliferation and diminishing the production of cytokines including IL-2.

Quality and Specifications: The antibody is available in specialized formulations for in vivo use, including LEAF™ purified versions (Endotoxin <0.1 EU/µg, Azide-Free, 0.2 µm filtered) that are specifically recommended for functional in vivo assays. The antibody maintains high purity standards (?95%) suitable for in vivo applications.

Research Applications

Researchers commonly use RM134L in mouse studies to investigate immune regulation, T cell activation pathways, and the role of OX40/OX40L signaling in various disease models. The blocking capability allows scientists to observe what happens when this important costimulatory pathway is inhibited, providing insights into immune system function and potential therapeutic targets.

The correct storage temperature for the sterile packaged clone RM134L (specifically, for the CD252/OX40 Ligand monoclonal antibody) is 4°C, protected from light, and the product should not be frozen. The recommendation from the manufacturer is consistent across sources, emphasizing storage at this temperature and explicitly stating “DO NOT FREEZE”.

Maintaining the antibody at refrigerated but not freezing conditions is crucial for preserving its activity and stability for effective use in applications such as flow cytometry. If you are unsure about the specific storage requirements for your exact clone or format, always consult the product datasheet or manufacturer directly for the most reliable information.

The antibody RM134L is a rat monoclonal antibody specific for mouse OX40L (CD252, CD134L), commonly used for blocking or neutralizing OX40L in immunological studies. Several other antibodies and proteins are frequently used alongside RM134L in the literature, especially in studies examining co-stimulatory pathways or T cell activation.

Commonly used antibodies/proteins in combination with RM134L include:

• Anti-IgM: Frequently used for B cell activation, often in combination with anti-CD40 to stimulate B cell proliferation, making them suitable targets for RM134L staining.
• Anti-CD40 (Clone HM40-3): Used to activate B cells and promote the expression of OX40L, a prerequisite for effective binding or detection by RM134L.
• OX40-Ig fusion protein: Used as a reagent to detect or compete with OX40L binding, serving to verify the presence or functional blockade of OX40L following RM134L treatment.
• Anti-OX40 (CD134) antibodies: Utilized to study OX40-OX40L interactions, particularly in T cell functional assays and immunotherapy models. Blocking or activating anti-OX40 is often tested alongside OX40L blockade.
• Antibodies against T cell or B cell markers: For example, anti-CD4 (for helper T cells), anti-CD8 (for cytotoxic T cells), anti-CD19, etc., are used to assess the impact of OX40L blockade on specific cell populations.
• Cytokine measurement antibodies: Used in multiplex assays to measure cytokine production (e.g., IFN-?, IL-4, IL-17) from T cells after OX40L blockade to assess immune modulation.

Researchers may also combine RM134L with:

• Anti-PD-1 or anti-CTLA-4 antibodies in checkpoint blockade combinations for cancer immunotherapy models.
• Peptides for disease models (such as PLP 139–151 for inducing experimental autoimmune encephalomyelitis (EAE)), often co-administered with RM134L to assess immunological effects.

In summary, RM134L is commonly used with anti-IgM, anti-CD40, OX40-Ig fusion proteins, anti-OX40 antibodies, and antibodies recognizing key lymphocyte markers, depending on the experimental goal and model system.

The RM134L clone has been extensively studied in scientific literature, with key findings spanning several important areas of immunological research. This monoclonal antibody targets mouse OX40L (CD252/CD134L), a critical costimulatory molecule in immune responses.

Asthma and Allergic Disease Research

One of the most significant findings comes from research on asthma pathogenesis. The RM134L antibody was instrumental in demonstrating the critical role of OX40 ligand in the development of pathogenic Th2 cells in murine asthma models. This research, published in the European Journal of Immunology, revealed that OX40L signaling is essential for the formation of disease-causing T helper 2 cells that drive allergic inflammation and asthma symptoms. The study provided crucial mechanistic insights into how costimulatory pathways contribute to allergic airway disease.

Cardiovascular Disease and Myocarditis

The RM134L clone has proven particularly valuable in cardiovascular research, specifically in studies of viral myocarditis. In research examining coxsackievirus B3 (CVB3)-induced myocarditis, treatment with the RM134L antibody showed significant therapeutic potential. The key findings include:

Anti-inflammatory effects: When administered to mice surviving lethal CVB3 infection, anti-OX40L blockade using RM134L resulted in a significant reduction in cardiac inflammation. Histological examination at day 45 post-infection revealed markedly decreased inflammatory infiltration in heart tissue compared to untreated controls.

Treatment protocol efficacy: The therapeutic regimen involved three injections of 150 ?g of RM134L antibody per mouse on days 15, 17, and 19 after infection. This treatment successfully halted the progression of myocarditis severity, demonstrating the potential for OX40L blockade as a therapeutic intervention in viral heart disease.

Immunological Mechanisms

The research has elucidated several important mechanisms of OX40L function through studies using the RM134L antibody:

T cell regulation: The RM134L antibody effectively blocks the costimulatory activity of OX40L, which normally provides crucial signals to antigen-reacting naive T cells. This blocking capability has been demonstrated to inhibit poly(I:C)/CD40 stimulated proliferation of CD4 T cells in vivo.

Costimulatory pathway modulation: OX40L signaling, as revealed through RM134L studies, regulates both CD4 and CD8 T cell clonal expansion and augments production of several cytokines, including IL-2. The antibody's ability to interrupt these pathways has made it a valuable tool for understanding immune regulation.

Broader Therapeutic Implications

The collective findings from RM134L research suggest that OX40L blockade represents a promising therapeutic strategy for inflammatory diseases. The antibody has consistently demonstrated the ability to reduce pathological immune responses while maintaining overall immune competence. This balance is particularly important for developing treatments that can control harmful inflammation without compromising necessary immune functions.

The research utilizing the RM134L clone has fundamentally advanced our understanding of the OX40/OX40L costimulatory pathway and its role in both protective and pathological immune responses, establishing a foundation for potential therapeutic applications in allergic diseases, autoimmune conditions, and viral infections affecting the heart.