Anti-Mouse CD279 (PD-1) [Clone 29F.1A12] - Purified in vivo PLATINUM™ Functional Grade

In Vivo Applications of Clone 29F.1A12 in Mice

Clone 29F.1A12 is a rat monoclonal antibody raised against mouse programmed death1 (PD1), also known as CD279. This clone is widely utilized in preclinical mouse models for immune checkpoint blockade studies, especially in the context of cancer immunotherapy.

Major In Vivo Uses

• Immune Checkpoint Blockade in Tumor Models: 29F.1A12 is extensively employed to investigate the effects of PD1 pathway inhibition on tumor growth and immune response. It is used to block the interaction between PD1 and its ligands (PDL1/PDL2), thereby enhancing antitumor immune responses in vivo.
• Cancer Immunotherapy Studies: The antibody is applied in various mouse cancer models to assess the therapeutic potential of PD1 blockade, either alone or in combination with other immunotherapies. Its use has been documented in delaying tumor onset and extending survival in certain genetic contexts, although efficacy can vary across different models.
• Mechanistic Studies of PD1 Signaling: Researchers use 29F.1A12 to dissect the role of PD1 in immune regulation, including its impact on Tcell activation, exhaustion, and tolerance in vivo. The clone is also suitable for studying combinatorial effects with other checkpoint inhibitors or conventional therapies.
• Preclinical Evaluation of Immune Responses: The antibody is used to evaluate how PD1 blockade affects immune cell populations, cytokine profiles, and overall host defense mechanisms in mouse models of cancer, infection, and autoimmunity.

Technical Considerations

• High PD1 Blocking Affinity: 29F.1A12 is reported to have approximately 100fold higher PD1 blocking affinity than other common clones (e.g., RMP114), making it particularly effective for in vivo studies where robust blockade is desired.
• NonDepleting: Like other antiPD1 antibodies used in mice, 29F.1A12 functions by sterically blocking PD1/PDL1 interactions rather than depleting PD1expressing cells.
• Formulation and Purity: The antibody is available in highly purified, lowendotoxin formulations specifically optimized for in vivo use, ensuring minimal offtarget effects and maximal reproducibility.
• Administration: Typically administered via intraperitoneal injection in preclinical studies, with dosing regimens optimized for the specific experimental model.

Comparative Context

29F.1A12 is one of the three most commonly used antimouse PD1 clones for in vivo research, alongside RMP114 and J43. The choice among these clones depends on the specific research question, desired affinity, and compatibility with the experimental setup.

Summary Table: Key Features of 29F.1A12 In Vivo Use

Conclusion

Clone 29F.1A12 is a cornerstone tool for in vivo PD1 blockade studies in mice, especially in cancer immunotherapy research. Its high blocking affinity, specificity, and suitability for combinatorial approaches make it a preferred choice for mechanistic and therapeutic investigations in preclinical models.

The antiPD1 antibody 29F.1A12 is commonly used in conjunction with several other antibodies or proteins in the literature, especially those targeting the PD1/PDL1 axis. Frequently paired and comparative antibodies include:

• AntiPD1 (RMP130): Used for costaining, validation, and comparative studies with 29F.1A12, due to recognition of overlapping subpopulations and differences in blocking efficacy.
• AntiPD1 (RMP114): Utilized for comparative blocking studies, with noted differences in binding and blocking efficiency compared to 29F.1A12.
• AntiPD1 (J43): Another clone regularly used in PD1 research alongside or as an alternative to 29F.1A12, particularly in immunotherapy and functional assays.
• AntiPDL1 (10F.9G2 and MIH6): These antibodies are often employed with 29F.1A12 to assess comprehensive pathway inhibition and to study the functional blockade of the PD1/PDL1 interaction in vivo.

Additional proteins and controls commonly used include:

• Recombinant PDL1: To assess the efficacy of blockade by 29F.1A12 in functional experiments.
• Isotype controls (e.g., rat IgG2b, antikeyhole limpet hemocyanin and antitrinitrophenol): Used for specificity and background control in immunological studies.
• Other checkpoint modulators: In combination therapy mouse models, 29F.1A12 is sometimes used with antibodies targeting other immune pathways (such as antiCD28), to study combinatorial effects and mechanistic aspects of immune blockade.

These combinations allow researchers to analyze:

• Specificity of PD1 detection
• PD1/PDL1 blockade efficacy
• Comprehensive immune checkpoint dynamics
• Functional outcomes in cancer and chronic infection models

In summary, 29F.1A12 is routinely used with antiPD1 clones like RMP130, RMP114, J43, and antiPDL1 clones like 10F.9G2, MIH6, as well as recombinant PDL1 and various isotype controls for rigorous experimental design in immunology and preclinical cancer research.

Clone 29F.1A12 is a widely used monoclonal antibody specific for mouse PD1 (CD279), and its citations in scientific literature highlight several key findings relevant to both mechanistic immunology and preclinical therapy development:

• Potent PD1/PDL1 Pathway Blockade: 29F.1A12 is characterized as a highly effective blocking antibody—it prevents PD1 from interacting with its ligand PDL1, thereby inhibiting PD1–mediated immune suppression. This makes it extensively used for studying immune checkpoint blockade in vivo and in vitro.

• Detection and Specificity:

  • 29F.1A12 is validated to detect surface PD1 protein on live murine T cells and certain tumor cell lines (e.g., B16F10 melanoma).
  • The clone demonstrates brightest staining intensity among several PD1–targeting clones, making it a preferred option for flow cytometrybased detection of PD1 expression on murine cells.
  • When used in competition assays, 29F.1A12’s blocking is so effective that it can completely prevent PD1 detection by most other antiPD1 clones—an essential consideration for experimental design. Researchers must sequence antibody incubations carefully to avoid false negatives.

• Crossreactivity and Artifacts:

  • There is documented crossreactivity with a nuclear antigen that becomes exposed in dead or dying cells, which can cause false positive signals if viability dyes or careful gating are not employed.
  • Literature notes a preference for livecell assays due to this artifact, and researchers are advised to interpret results in light of potential nonspecific staining on nonviable cells.

• Therapeutic and Biological Activity:

  • 29F.1A12 has been used to demonstrate that immune checkpoint blockade can delay tumor growth and extend survival in certain mouse cancer models, though efficacy can vary depending on genetic background and model system (e.g., Pold1, Pole mutant mice).
  • Comparative studies indicate the blocking activity of 29F.1A12 surpasses other clones like RMP130, but activity may differ from RMP114 and J43 depending on context.

• Experimental Considerations:

  • Costaining with 29F.1A12 and other PD1 antibodies (like RMP130) shows that they recognize overlapping cell populations, supporting its specificity for PD1.
  • 29F.1A12 binding and detection increase in threedimensional (3D) tumor spheroid cultures compared to twodimensional conditions, reflecting contextdependent PD1 expression.
  • Some studies report that certain PD1 clones, including 29F.1A12, can deplete PD1+ T cells in vivo, which could confound interpretations in preclinical immunotherapy experiments focusing on T cell responses.

Summary Table: Key Properties of 29F.1A12

Researchers using clone 29F.1A12 should consider its potent blocking ability, strong detection of livecell PD1, crossreactivity concerns with dead cells, and contextdependent therapeutic effects in preclinical models. Proper experimental controls and awareness of clone interactions are essential for accurate data interpretation.

Dosing regimens of clone 29F.1A12 (antimouse PD1 antibody) in mouse models commonly range from 100–200 μg per mouse via intraperitoneal (i.p.) injection every 3 days for three doses, but both the dose and schedule are frequently adjusted based on model and experimental goals. In some studies, doses as low as 10 μg or as high as 7.5 mg/kg are used, and the injection interval can be varied (twice weekly, every 3–4 days, or weekly).

Key variations in dosing regimens include:

• Standard regimen: 100–200 μg per mouse, i.p., every 3 days, typically for three doses.
• Alternative by body weight: 2.5–7.5 mg/kg, i.p., administered twice a week (especially when precise dosing by mass is required).
• Adjusted frequency/intervals: Sometimes biweekly (twice weekly), or weekly doses (e.g., 100 μg once every 7 days for three doses), depending on the study design and tumor model.
• Lower or higher doses: Studies may decrease the dose (e.g., 50 μg or even 10 μg every three days) to investigate pharmacodynamics and effects on receptor saturation, or increase the dose for larger mice or different experimental endpoints.
• Combination therapy and modelspecific adjustments: Dosing may be adjusted when combined with other agents (e.g., antiCTLA4) or according to the mouse strain or tumor burden.

Applications covered by these regimens include:

• Cancer immunotherapy (syngeneic tumor models, e.g., MC38, B16 melanoma)
• Reinvigorating exhausted T cells in chronic infection models
• Testing combination immunotherapies and mechanistic studies of immune checkpoint blockade.

Summary Table: Dosing Regimen Variations for 29F.1A12

In summary, clone 29F.1A12 is administered using a flexible dosing strategy with a core range of 100–200 μg/mouse i.p. every 3 days, but regimens vary with the mouse model, experimental objective, and combination therapies.