Anti-Mouse CD115 (CSF-1R) [Clone AFS98] — Purified in vivo GOLD™ Functional Grade

Clone AFS98 is a monoclonal antibody commonly used in in vivo mouse studies to target and block the CSF1R (CD115) receptor—also known as the macrophage colony-stimulating factor receptor, expressed on monocytes, macrophages, dendritic cells, and osteoclasts.

In vivo uses of AFS98 include:

• Depletion of macrophages: AFS98 efficiently depletes tissue macrophages in mice when administered over time, likely via receptor blockade and possible direct cytotoxic effects.
• Blocking CSF1R signaling: The antibody inhibits both main ligands (CSF-1 and IL-34) binding to CSF1R, resulting in the suppression of monocyte and macrophage proliferation and function.
• Functional studies: Researchers use AFS98 to investigate the role of CSF1R signaling in various physiological and pathological processes, including inflammation, diabetes, renal pathology, and bone remodeling.

Administration and experimental protocols:

• AFS98 is typically administered by intraperitoneal injection in mice (dosing varies by study and objective).
• It is used for both short-term functional blockade (e.g., to study ligand-receptor binding in vivo) and long-term depletion experiments (ranging from several days up to weeks) to assess physiological consequences of macrophage loss.

Key example applications:

• In one frequently cited application, mice pre-treated with AFS98 lost the capacity to bind exogenously administered CSF1, confirming receptor occupancy/blockade.
• Long-term AFS98 treatment led to macrophage depletion and altered metabolic or skeletal disease progression in mouse disease models.

Summary of mechanism:
AFS98 binds the extracellular domain of CSF1R, blocks ligand binding, induces receptor internalization, and consequently results in the rapid and specific depletion or functional inactivation of macrophages in targeted tissues.

Caveats:

• The antibody's action is specific but prolonged treatment can have pleiotropic effects, affecting several tissue macrophage populations and potentially impacting unrelated tyrosine kinases due to homology.

In short, clone AFS98 is a well-established tool in mouse research for macrophage depletion and CSF1R functional studies in vivo.

Several antibodies and proteins are commonly used alongside AFS98 (an anti-mouse CSF1R/CD115 monoclonal antibody) in research, especially when studying tumor-associated macrophages (TAMs), myeloid cells, or murine immune systems.

Key antibodies and proteins frequently co-used with AFS98 include:

• F4/80: a classic marker for murine macrophages, routinely used in immunohistochemistry (IHC) and flow cytometry to identify and quantify macrophage populations.
• CD163: a marker for M2-type macrophages, often used to characterize macrophage polarization and depletion effects after AFS98 treatment.
• Foxp3: a key transcription factor for regulatory T cells (Tregs), especially in studies examining immune compensation mechanisms involving CSF1R+ macrophages and Tregs.
• CSF-1 (M-CSF): the ligand for CSF1R; measured in serum or used in blocking/competition studies to verify antibody specificity and functional effects.
• Ly6C: a marker distinguishing macrophage subtypes or monocyte populations, common in flow cytometry panels with AFS98 for myeloid cells.
• Isotype controls: always included to verify antibody specificity in IHC or flow cytometry.

Common experimental techniques combining these antibodies/proteins with AFS98:

• Immunohistochemistry (IHC): with anti-F4/80 and anti-CD163 to characterize and quantify macrophages in tissue sections.
• Flow cytometry (FC/FACS): multiparameter panels including AFS98, F4/80, Ly6C, and Foxp3 to analyze immune cell populations in various tissues or tumors.
• Immunofluorescence (IF): to visualize co-localization and depletion of specific cell subsets after AFS98 treatment.
• ELISA assays: to measure circulating CSF-1 levels as a functional readout of AFS98 blocking activity.

In typical literature, researchers combine AFS98 with F4/80, CD163, Foxp3, Ly6C, and CSF-1–either as markers or readouts–for a comprehensive assessment of macrophage populations, polarization, and interactions with other immune cells in mouse models.

If you need a specific antibody panel or application, please clarify.

Clone AFS98 is a rat monoclonal antibody targeting mouse CD115 (CSF-1R, M-CSF-R/c-Fms), a receptor pivotal for the regulation of monocyte and macrophage proliferation, differentiation, and survival, as well as osteoclast development and bone resorption.

Key scientific findings from studies citing AFS98 include:

• Therapeutic Depletion of Tumor-Associated Macrophages (TAMs): Treatment with AFS98 depletes TAMs in murine tumor models, reducing both total macrophage populations (F4/80+) and M2-polarized macrophages (CD163+), thereby inhibiting tumor growth.

• Blockage of CSF-1/CD115 Binding and Increased Serum CSF-1: AFS98 blocks the interaction between CSF-1 and CD115, leading to a dramatic increase in circulating CSF-1 levels as the ligand is no longer cleared from the blood—a measurable pharmacodynamic marker of antibody efficacy. This effect is dose-dependent and sustained for weeks following administration.

• No Significant Suppression of Tumor Angiogenesis: While AFS98 reduces TAMs, it does not markedly inhibit angiogenesis in some models, as assessed by endothelial marker (CD31) staining, indicating its TAM-depleting activity does not always extend to anti-angiogenic effects.

• Utility in Flow Cytometry and Cellular Analysis: AFS98 is widely used to identify and quantify mouse monocyte/macrophage and osteoclast populations by flow cytometry due to its specificity for CD115, with robust performance and validation reported.

• Preclinical Research Applications: AFS98 enables mechanistic studies of myeloid cell biology and immune responses by allowing selective interference with CSF-1R signaling.

• Target Specificity: The antibody specifically recognizes mouse CD115, which is expressed on monocytes, macrophages, dendritic cells, osteoclasts, and their precursors.

In summary, clone AFS98 is both a research tool for studying myeloid cell populations and a preclinical therapeutic candidate for TAM-targeted cancer immunotherapy, with its effects on macrophage depletion, CSF-1 pharmacodynamics, and immune microenvironment well documented in the literature.

The dosing regimens of clone AFS98 (anti-mouse CSF-1R/CD115) vary considerably depending on the mouse model, experimental aim, and disease context:

• Syngeneic Tumor Models (e.g., KPC, B78H1):

  • Dosing: 1.5 mg per mouse (approx. 75 mg/kg), administered intraperitoneally (IP).
  • Schedules Explored:
    • Pre/Post (days 1, 4, 8, 11),
    • Pre (days 1, 4),
    • Post (days 8, 11).
  • Purpose: Timing relative to tumor inoculation or immunotherapy impacts tumor-associated macrophage (TAM) depletion efficacy, so schedules are adapted accordingly.

• Metastasis Model in Nude Mice:

  • Dosing: 50 mg/kg IP, three times per week.
  • Duration: Often for 2–3 weeks or matched to disease progression.
  • Notes: Higher doses (25–50 mg/kg) led to sustained elevation of serum CSF-1, indicating receptor blockade efficacy at these regimens.
  • Experimental Contexts: Used for both early and late intervention in tumor-bearing mice and osteolysis/metastasis models.

• General Remarks:

  • Administration Route: Intraperitoneal (IP) injection is standard across studies.
  • Dose Range: Reported doses span from 1.5 mg per mouse (~75 mg/kg) to 50 mg/kg, reflecting variance in mouse strain, body weight, and immunological status (immunocompetent vs. immunodeficient).
  • Optimal Dosing: May require titration per specific experimental application.
  • Flow Cytometry: For ex vivo applications (not in vivo depletion), suggested ?0.25??g per 10? cells for cell staining.

Key determinants of dosing differences:

• Mouse strain and immune status (e.g., C57BL/6 vs. nude mice).
• Experimental objectives (acute depletion, chronic blockade, therapeutic vs. mechanistic studies).
• Disease model (solid tumor, metastasis, osteolysis).

In summary, clone AFS98 is most often administered at 1.5 mg/mouse (approx. 75 mg/kg) for syngeneic tumor immunology models and at higher doses (25–50 mg/kg) three times weekly in metastatic or late-stage cancer models, always via intraperitoneal injection.

If a specific disease model or strain is of interest, protocols and optimal doses may need adjustment and should be validated for each application.