Clone AFS98 is a rat monoclonal antibody that specifically targets the CSF1R (CD115) receptor on mouse cells, including monocytes, macrophages, dendritic cells, and osteoclasts. Common in vivo applications of this antibody in mice include:

• Macrophage Depletion: Clone AFS98 is used to deplete macrophages in mice, which helps in studying the role of macrophages in various biological processes and diseases.
• Neutralization and Blocking of CSF1R Signaling: The antibody is effective in blocking CSF1R signaling, which is crucial for the proliferation and differentiation of cells in the monocytic lineage.
• Functional Assays: It is used in various functional assays to study biological pathways affected by CSF1R signaling, such as bioanalytical PK and ADA assays.
• Flow Cytometry: The antibody can be used for flow cytometry to identify and analyze myeloid lineage cells.
• Cancer Research: Clone AFS98 is utilized in cancer research to study the role of macrophages in tumor environments.

Overall, clone AFS98 is a versatile tool for in vivo studies, particularly in immunology and oncology research.

Commonly used antibodies or proteins coapplied with AFS98 (antimouse CD115/CSF1R) in the literature include markers for macrophage identification, myeloid/immune subset analysis, and isotype controls.

Key antibodies and proteins used with AFS98:

• F4/80: A classic marker for murine macrophages, frequently used to label macrophage populations by immunohistochemistry (IHC) and flow cytometry alongside AFS98 to dissect myeloid compartments.
• CD163: Another macrophage marker, more specific for M2type (alternatively activated) macrophages. Used in combination with AFS98 to characterize macrophage polarization states.
• Isotype Controls (e.g., Rat IgG2a): Used as negative controls to assess antibody specificity, especially in immunophenotyping or blocking studies.
• CSF1 (MCSF, the ligand for CD115): Sometimes used in binding or blocking assays, or to detect increases in serum CSF1 following AFS98 treatment as a pharmacodynamic readout.

Other frequently coused antibodies and markers:

• Ly6C, Ly6G: To distinguish monocyte and granulocyte subsets.
• CD11b, CD11c: Markers of myeloid lineage to further classify macrophage and dendritic cells.
• CD45: Panleukocyte marker for gating immune populations in multicolor flow cytometry panels.
• Lineage cocktail markers (e.g., Ter119, B220, CD3, NK1.1, etc.): For exclusion of nonmyeloid leukocytes in immunophenotyping panels.

These combinations are especially common in:

• Macrophage depletion or tracking studies.
• Tumor microenvironment and inflammation models.
• Phenotyping of tumorassociated macrophages (TAMs) or myeloidderived suppressor cells.

The frequent use of F4/80 and CD163 alongside AFS98 is documented in both experimental protocols and commercial antibody datasheets, reflecting their central role in myeloid cell characterization in murine models.

Clone AFS98 is a monoclonal antibody targeting mouse CSF1R (CD115), widely cited in scientific literature for its role in depleting macrophages and blocking CSF1R signaling in vivo. The key findings from studies using AFS98 can be summarized as follows:

• Macrophage depletion: Administration of AFS98 leads to robust depletion of monocytes/macrophages, including both total F4/80+ and CD163+ M2polarized subsets, in various murine tissues and tumor models. Dendritic cells and neutrophils remain largely unaffected.
• Tumor growth inhibition: Depleting tumorassociated macrophages (TAMs) using AFS98 disrupts the protumoral microenvironment and inhibits tumor growth in mouse models.
• Elevation of circulating CSF1: Treatment with AFS98 increases serum CSF1 levels, a consequence of blocking CSF1 clearance by CD115mediated endocytosis.
• Mechanism of action: Macrophage depletion is primarily due to blockade of CSF1R signaling, rather than complementdependent cytotoxicity or antibodydependent cellmediated cytotoxicity (ADCC); AFS98 is equally effective in mice deficient for C3 or FcγR.
• Effects on bone biology: AFS98 is as potent as bisphosphonates in reducing osteoclast numbers and bone lesions, highlighting its role in osteoclast differentiation and activity.
• Research tool: AFS98 is frequently used for flow cytometry to identify or deplete myeloid lineage cells, and as a functional blocking/neutralizing antibody in vitro and in vivo.

Additional context:

• CSF1R/CD115 is a receptor for colonystimulating factor 1 (CSF1), regulating monocyte/macrophage, dendritic cell, and osteoclast proliferation and differentiation.
• The antibody has enabled investigation into myeloid cell biology, cancer microenvironments, bone remodeling, and immune modulation.

In summary, clone AFS98 is a validated tool for selectively depleting CSF1R+ cells, dissecting macrophage functions in immunological and cancer biology, and modulating osteoclastmediated bone resorption in preclinical mouse models.

Dosing regimens for clone AFS98—an antimouse CD115 (CSF1R) monoclonal antibody—vary considerably by mouse model and study objective, but several patterns are evident:

• In tumor immunology models, doses typically range from 1.5 mg/mouse (~75 mg/kg) to as much as 50 mg/kg, often administered by intraperitoneal (IP) injection every 23 days.
• For syngeneic tumor models, a common protocol is 1.5 mg/mouse (usually corresponding to about 75 mg/kg if using 20 g mice), but higher doses from 25–50 mg/kg are used in other tumor settings and for more robust macrophage or monocyte depletion.
• In a detailed study, 50 mg/kg IP was given 3 times per week for 3 weeks, with significant biological effects on macrophage depletion and tumor progression.
• Some protocols administer 20 mg/kg IP every 3 days, particularly around day 5 posttumor implantation.
• In metabolic disease models (e.g., obese db/db mice), dosing has included 25 mg/kg IP every second day for 6 weeks.

Key considerations:

• Dose and frequency are often tailored to model type (metabolic vs. cancer), the desired degree of macrophage depletion, and therapeutic endpoints.
• Duration and starting point (e.g., after tumor implantation, or at specific disease stages) further distinguish regimens.
• Optimal dosing often requires titration, as suggested by vendors and observed in pharmacodynamic studies, particularly for achieving robust CSF1R saturation and depletion of target cell populations.

Summary:
Regimens with AFS98 range from low (1.5 mg/mouse) to high (50 mg/kg) doses, given every 2–3 days for periods of several weeks, with individual protocols depending on the specific disease model and research aim.