Clone RMP114 is most commonly used in vivo in mice for studies involving blocking PD1 signaling, especially in the context of cancer immunotherapy, preclinical antitumor efficacy, and immune regulation.

Key in vivo applications include:

• Cancer immunotherapy studies: RMP114 is a standard tool for evaluating PD1 blockade as a therapeutic strategy, frequently used in syngeneic and genetically engineered mouse tumor models (e.g., MC38 colon carcinoma, B16 melanoma). It is employed to test the effect of PD1 inhibition on immune cellmediated tumor clearance, tumor growth reduction, and survival outcomes.

• Mechanistic studies of immune regulation: The antibody is applied to dissect mechanisms of T cell exhaustion, tolerance, and overall immunoregulation, since PD1 plays a key role in dampening T cell activity during chronic infection and tumor progression.

• Combination immunotherapy research: RMP114 is frequently used in tandem with other immunemodulating agents (such as antiCTLA4 antibodies or chemotherapy) to study synergistic effects and design combination strategies for cancer treatment.

• In vivo functional assays: Beyond blocking studies, researchers use RMP114 to probe T cell responses and cytokine production by disrupting PD1:PDL1/PDL2 engagement, often assessing outcomes such as T cell proliferation and cytokine release.

Practical features:

• Dosing protocols: Standard regimens are 200–500 μg per mouse every 3–4 days, delivered intraperitoneally; specific dose may be adjusted for tumor type and experimental needs.
• Buffer/diluents: Commonly formulated in phosphatebuffered saline (PBS) or normal saline for in vivo injection, ensuring antibody stability and animal safety.
• Isotype/effector function: RMP114 is usually a rat IgG2a, which can engage mouse Fc receptors and trigger additional effector functions such as antibodydependent cellular cytotoxicity (ADCC).
• Specificity: It binds mouse PD1 with high affinity and is not crossreactive with human PD1, making it suitable for mouse models but not humanized scenarios.

RMP114 is a benchmark antibody for mouse PD1 blockade studies, valued for its wellestablished protocols, extensive publication record, and reliability.

Commonly used antibodies or proteins employed in combination with RMP114 (murine antiPD1) in the literature include other antiPD1 clones (such as 1A12 and J43), PDL1/PDL2 Fc fusion proteins (to assay blocking activity), and immune checkpoint reagents like antiPDL1, antiCTLA4, and various markers or modulators for T cell studies.

Key antibodies and proteins frequently used with RMP114:

• Other antiPD1 clones:

  • 29F.1A12: Often directly compared with or used alongside RMP114 in mechanistic, blocking, and functional studies due to its higher avidity and blocking capacity.
  • J43: Another common antiPD1 clone assessed for functional overlap or synergy with RMP114.
  • RMP130: Sometimes used in parallel for epitope mapping or staining experiments.

• PDL1 and PDL2 fusion proteins:
  Used to directly test the blocking capacity of RMP114 against PD1 ligand interactions.

• AntiPDL1 monoclonal antibodies:
  Such as 10F.9G2 and MIH6, often used in combination or comparison with RMP114 to dissect PD1/PDL1 pathway mechanisms.

• AntiCTLA4 monoclonal antibodies:
  Frequently combined with RMP114 for studying synergistic effects in tumor immunotherapy models.

• Other combinations and reagents:

  • SEMA4D antibodies: Used in some studies for combination therapy approaches.
  • Surface markers like CD8, CD4, or other T cell/immune markers for phenotyping and functional assays.

• Humanized checkpoint inhibitors for comparison:
  Nivolumab and pembrolizumab (human antiPD1s) are sometimes referenced or modeled against RMP114 in murine studies to parallel clinical strategies.

Summary table:

The most common combinations in the literature are RMP114 with 29F.1A12 and J43 for PD1 functional studies, and RMP114 with antiPDL1 or antiCTLA4 for combination immunotherapeutic models. Using multiple antiPD1 clones can help clarify blocking versus agonistic properties, while combining RMP114 with checkpoint pathway antibodies (PDL1, CTLA4) enables detailed immune interaction studies relevant to cancer immunotherapy.

Clone RMP114 is a rat IgG2a monoclonal antibody widely used in preclinical research to block the mouse PD1 immune checkpoint, primarily for in vivo studies of cancer immunotherapy and T cell biology. The key scientific findings from citations involving RMP114 are:

• Proven Efficacy in Preclinical Tumor Models: RMP114 reliably enhances antitumor immune responses, reduces tumor growth, and improves survival in various mouse cancer models, establishing it as an effective tool for investigating PD1 blockade.

• Mechanism of Action: RMP114 specifically binds to the extracellular domain of mouse PD1, blocking interactions with its ligands PDL1 and PDL2, thereby preventing inhibitory signaling and promoting T cell activation.

• Functional Role as a Blocker: While some antiPD1 clones (e.g., RMP130) display agonist activity and immunosuppressive effects in certain contexts, RMP114 predominantly acts as a blocking antibody and is not associated with significant agonist or depletion activity.

• Binding Affinity and Comparative Efficacy: Comparative studies show RMP114 has strong binding affinity and blocking function among mousespecific antiPD1 clones, although clones like 1A12 exhibit higher avidity and greater potency at lower concentrations. Against J43, RMP114 showed more potent tumor inhibition and survival benefits, attributed to its higher binding affinity.

• WellCharacterized Dosing Protocols and Consistency: RMP114’s dosing and administration schemes have been extensively validated, reducing study variability and troubleshooting requirements for new experiments.

• Development and Origin: RMP114 was generated via hybridoma technology from rats immunized with mouse PD1 protein, with selection for high specificity, high affinity, and potent blockade.

• SpeciesSpecificity: It is highly effective for mouse studies but lacks binding to human PD1, highlighting the importance of species crossreactivity in translational research.

• Availability and Benchmarking: RMP114's broad commercial availability and extensive citation base make it a standard for benchmarking in immunooncology research, facilitating reproducibility and robust conclusions.

• Structural and Sequence Insights: Sequencing of RMP114's heavy and light chain has defined its molecular signature and identified complementaritydetermining regions key to binding.

• Role in Tumor Microenvironment Studies: RMP114 has helped establish scientific bases for clinical strategies targeting the tumor immune microenvironment to enhance immunotherapies.

In summary, RMP114 is an established, wellcharacterized blocking antibody for mouse PD1, utilized extensively to model and understand immune checkpoint blockade, optimize dosing, and develop preclinical cancer therapies. It provides consistent, speciesspecific results with validated protocols, serving as a benchmark and reliable reagent for immunooncology studies.

Dosing regimens for clone RMP114 in mouse models vary based on study objectives, tumor models, mouse strains, immune competency, and administration route, but typical protocols use 200–500 µg per mouse intraperitoneally every 3–4 days. Adjustments are made depending on the specific mouse model, tumor biology, and desired pharmacodynamic effects.

Key variations across different mouse models:

• Tumor type and strain: Dosing and efficacy may vary with tumor type (e.g., MC38 colon carcinoma, B16 melanoma), mouse strain, and immune system status. Some strains or models may require dose or frequency adjustments for optimal results.

• Route of administration: Intraperitoneal (IP) injection is standard, but intravenous (IV) administration is also used and has shown comparable efficacy in certain syngeneic models (e.g., MC38).

• Published examples:

  • Syngeneic tumor models (MC38, B16): Frequently use 200 µg per dose IP every 3–4 days.
  • Custom schedules: Some experiments use 3 injections spaced 3 days apart (e.g., days 0, 3, 7).
  • Lower doses: Certain studies use doses as low as 100 µg per injection, particularly in immunophenotyping or when combined with other therapies.

• Buffer/diluents: Antibody is commonly diluted in phosphatebuffered saline (PBS) or normal saline for injection.

• Mouse model/tumorspecific considerations: Variable tumor growth rates or immune responses (due to strain or tumor selection) may dictate modifications in dose and interval. Strainspecific immune differences can influence both pharmacodynamics and safety of RMP114.

• Humanized models: Efficacy can differ when using humanized mouse models versus standard inbred strains, particularly if crossreactivity with human PD1 is relevant.

Summary Table: Typical RMP114 Dosing Regimens in Mice

Important additional notes:

• Dosing may need optimization in each new tumor type, strain, or combination therapy setting.
• Responses can differ due to mouse strainspecific immunity and tumor microenvironment.
• Clones may not crossreact with nonmouse PD1; using RMP114 in nonmurine or humanized models requires careful validation.

In sum, the 200–500 µg IP every 3–4 days regimen is the most widely used but requires adjustment for specific models or study objectives. Always consult primary data and pilot studies for your particular model.