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

Clone RM134L is commonly used in vivo in mice as a blocking antibody to inhibit the OX40L–OX40 signaling pathway, thereby allowing researchers to study the functional consequences of this pathway in immune responses, particularly in models of autoimmunity, inflammation, and T cell regulation.

Key in vivo applications include:

• Blocking OX40L-OX40 Costimulatory Signaling: RM134L is primarily administered to mice to block the interaction between OX40L (CD252) on antigen-presenting cells and OX40 (CD134) on T cells. This costimulatory interaction is essential for T cell proliferation, survival, and cytokine production during immune responses.
• Autoimmune Disease Models: RM134L has been used in experimental autoimmune encephalomyelitis (EAE, a mouse model for multiple sclerosis). Treatment with RM134L ameliorates disease severity by reducing the accumulation of pathogenic OX40+ CD4 T cells in the central nervous system, indicating a key role for OX40L in autoimmune T cell responses.
• Probing T cell Clonal Expansion: Administration of RM134L in vivo inhibits T cell clonal expansion induced by poly(I:C)/CD40 or antigen challenge, helping to distinguish the specific requirement for OX40L-mediated costimulation in T cell activation and proliferation.
• Therapeutic Targeting: Due to its blocking function, RM134L is used experimentally to explore therapeutic strategies to modulate the immune response, especially in immunopathology, inflammation, and tolerance induction models.

Summary of in vivo uses:

In summary, the main in vivo application of RM134L is to functionally block OX40L in mouse models to dissect its role in T cell biology and disease, with a strong emphasis on immune modulation and autoimmune pathogenesis.

Commonly used antibodies or proteins in the literature alongside RM134L (anti-mouse OX40L/CD252) include those that modulate or detect key lymphocyte activation pathways and cell surface markers, depending on experimental goals.

Key combinations include:

• Anti-IgM antibodies: Trigger B-cell activation, which leads to upregulation of OX40L/CD252, often used in in vitro stimulation protocols with RM134L to investigate immune activation.
• Anti-CD40 antibodies: Used to stimulate B cells or antigen-presenting cells in conjunction with anti-IgM, further enhancing OX40L expression and costimulatory signaling.
• OX40-Ig fusion proteins or anti-OX40 (CD134) antibodies: Employed to engage or block the OX40-OX40L signaling axis from the T-cell perspective, useful for studying the effects of OX40L blockade with RM134L on T cell responses.
• Antibodies recognizing key lymphocyte markers, including:
  • CD4 and CD8: To distinguish helper and cytotoxic T-cell subsets in flow cytometry panels with RM134L.
  • B-cell markers (e.g., B220/CD19): To analyze OX40L expression and function on B cells.
• CD3 antibodies: For T-cell activation studies, occasionally used together to examine co-stimulation effects in immunological assays.

Additional context:

• Stimulation with poly(I:C)/CD40 (a model for T-cell proliferation responses) is used in vivo to test the effects of RM134L on immune cell activation, where the antibody is often paired with other pathway agonists or inhibitors.
• In functional studies, cytokine detection reagents (e.g., for IL-2, IFN-γ) may be used alongside RM134L to measure downstream T-cell or APC responses.

These combinations are regularly used to interrogate roles of OX40L in immune cell activation, costimulation, and disease models such as infection, autoimmunity, and cancer.

Clone RM134L is a rat monoclonal antibody (IgG2b, κ) that recognizes mouse CD252 (OX40 Ligand), and its use in scientific research has generated several important findings across multiple disease models and immunological contexts.

Autoimmune Disease Models

In experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis, RM134L treatment demonstrated dose-dependent therapeutic effects. When administered to mice with actively induced or adoptively transferred EAE, the antibody ameliorated clinical signs of disease. The mechanism involved significant inhibition of OX40-expressing CD4+ T cell accumulation and reduced migration of pathogenic T cells into the central nervous system, though it had minimal effect on the proliferation of IFN-γ producing Th1 cells in draining lymph nodes. These findings highlighted the substantial contribution of OX40L signaling to EAE pathogenesis, particularly in the T cell priming process.

Cardiac Inflammation

RM134L demonstrated anti-inflammatory effects in a cardiovascular disease model. When administered to mice surviving lethal coxsackievirus B3 (CVB3) infection, anti-OX40L blockade using RM134L resulted in significant reduction in cardiac inflammation. This finding suggests a role for OX40-OX40L interactions in inflammatory cardiac pathology following viral infection.

Immune Cell Activation and Costimulation

The antibody has proven valuable for understanding OX40L biology in immune responses. RM134L effectively blocks the binding of OX40-Ig fusion proteins to OX40L-expressing cells and inhibits the costimulatory activity of OX40L. In functional studies, RM134L was shown to inhibit poly(I:C)/CD40-stimulated proliferation of CD4 T cells in vivo. The antibody successfully stains B cells activated for four days with anti-IgM plus anti-CD40 antibodies, confirming its utility for detecting OX40L expression on activated B cells.

Hepatitis B Virus Research

RM134L has been employed in studies examining OX40/OX40L interactions in hepatitis B virus immunity, where blocking OX40L signaling helped elucidate the pathway's role in directing successful immune responses.

These collective findings establish the OX40-OX40L pathway as a critical costimulatory mechanism in both protective and pathogenic immune responses, with RM134L serving as an essential tool for dissecting these interactions across diverse experimental systems.

Dosing regimens for clone RM134L (anti-mouse OX40L) can vary substantially depending on the mouse disease model and specific experimental goals.

Key details from published regimens:

• Viral infection models (such as vaccinia virus):

  • A commonly cited regimen is 150 μg per mouse delivered via intraperitoneal (i.p.) injection.

• Collagen-induced arthritis (CIA) models:

  • One protocol administered 100 μg/mouse/day intraperitoneally for 4 consecutive days after the second immunization, with dosing either shortly after immunization (days 1–4) or later in disease progression (days 14–17).
  • Evaluations were conducted at subsequent time points (days 28 and 39) to assess the effects of early versus delayed treatment.

• General in vivo use:

  • Some sources indicate that the typical route is intraperitoneal injection, with overall dose and schedule adjusted according to the disease model and desired immune modulation endpoint.
  • Short treatment courses (e.g., 4 days) are common, but dose per mouse and timing can be adjusted for autoimmune, infectious, or tumor models.

Summary Table of Example Dosing Regimens:

• Notes: Adjustments to dose and duration are often made depending on severity, timing of disease induction, and the intended immune readout.

Additional considerations:

• Lower or higher doses may be tested for dose-response or toxicity studies, but the above represent published regimens for efficacy studies in mice.
• Regimens in other disease models (e.g., transplants, allergies, tumors) may differ, emphasizing the importance of model-specific pilot studies.

These details should guide experimental planning, but protocol optimization for your specific mouse model and research question is recommended.