Anti-Human CD11c [Clone 3.9] – Purified in vivo PLATINUM™ Functional Grade

Clone 3.9, a monoclonal antibody against human CD11c, is most commonly used in vivo in mice to identify, characterize, and manipulate human myeloid and dendritic cells within humanized mouse models.

Key in vivo applications of clone 3.9 in mice include:

• Detection and characterization of human myeloid and dendritic cells: Clone 3.9 binds specifically to the activated form of human CD11c, enabling researchers to label and track these cells in mice transplanted with human hematopoietic stem cells or used in other human immune system reconstitution models.

• Functional modulation of human CD11c-positive cells: The antibody can partially block the interaction between CD11c and its ligand ICAM-4, providing a tool for studying the functional role of these cells in immunity and inflammation within humanized mouse models.

• Immunological profiling and mechanistic studies: In vivo administration of clone 3.9 allows for the analysis of cell populations involved in vaccine responses, autoimmunity, and other human-specific immunological processes in humanized mice.

• Validation for multiple in vivo and ex vivo analytic techniques: While clone 3.9 is directly used in “in vivo” staining, it is also validated for downstream applications such as flow cytometry (FC), immunohistochemistry (IHC), functional assays (FA), and western blotting (WB), enabling comprehensive study of human CD11c-expressing cells after in vivo treatment.

Additional relevant information:

• Clone 3.9 is specific for the I domain of CD11c and preferentially binds the activated form of the receptor.
• The antibody is used predominantly in humanized mouse models, not in standard murine immunology, as its specificity is for human, not mouse, CD11c.
• Studies have employed clone 3.9 to facilitate research on human dendritic cell migration, activation, and therapeutic targeting in the context of cancer, vaccine studies, and autoimmunity.

In summary, clone 3.9 is an essential reagent for in vivo identification and functional interrogation of human dendritic and myeloid cells in humanized mice, broadly supporting studies in immunology, vaccine development, and disease modeling.

The 3.9 antibody, most commonly referring to the mouse anti-human CD11c (clone 3.9), is frequently used in immunology for identifying and isolating human dendritic cells and certain monocyte and macrophage populations. In the literature, several other antibodies or proteins are commonly used alongside CD11c (3.9) depending on the experimental context:

• CD18 (Integrin β2): CD11c associates with CD18 to form the CD11c/CD18 heterodimer, crucial for leukocyte adhesion and migration. CD18 is almost always assessed in studies focusing on CD11c function or presence.
• Other myeloid and dendritic cell markers:
  • CD14 (monocyte/macrophage marker)
  • CD11b (Integrin αM, also pairs with CD18)
  • HLA-DR (MHC class II, a dendritic cell activation marker)
  • CD80, CD83, CD86 (co-stimulatory molecules for dendritic cell maturation)
• Lymphoid cell markers for contrast:
  • CD3 (T cells)
  • CD19 or CD20 (B cells)
  • CD56 (NK cells)

In most flow cytometry, immunohistochemistry, or immunoprecipitation experiments involving anti-CD11c (3.9), isotype controls such as mouse IgG1 (e.g., clone 15H6) are also included to control for non-specific binding.

Functional ligands:

• CD54 (ICAM-1): A ligand for CD11c/CD18 heterodimer, often measured in studies investigating cell adhesion.

Summary Table: Commonly Used Antibodies/Proteins with CD11c (3.9)

These combinations are chosen based on the specific goals, such as distinguishing dendritic cell subsets, monitoring activation, or functional blocking experiments.

Clone 3.9 is an anti-CD11c monoclonal antibody that has been extensively studied in immunology research, with several key findings emerging from its use in scientific literature.

Binding Specificity and Mechanism

The most significant finding regarding clone 3.9 is its preferential binding to the activated form of CD11c, distinguishing it from other CD11c antibodies that bind both resting and activated states. This antibody recognizes the α-chain (CD11c) of the CD11c/CD18 complex and is specifically targeted to the I domain of CD11c.

Functional Properties and Applications

Clone 3.9 recognizes CD11c, also known as Integrin alpha X (αX Integrin/ITGAX) or p150,95 Integrin alpha chain. The CD11c molecule is a 150 kDa integrin alphaX chain that non-covalently associates with beta2 integrin to form the CD11c/CD18 complex.

The antibody has been validated across multiple experimental techniques, with reported applications including:

Flow cytometry - Successfully used for analyzing CD11c expression on human peripheral blood leukocyte populations

Immunohistochemistry on frozen sections - Demonstrated utility in tissue analysis, including studies on rheumatoid arthritis synovial lining layer macrophages

Immunoprecipitation - Used to study ligand binding properties of the p150,95 antigen on monocytic cells

Blocking assays - Applied in studies investigating complement receptors CR3 (CD11b/CD18) and CR4 (CD11c/CD18) in phagocytosis of bacteria by dendritic cells, as well as characterizing ICAM-4 as a ligand for the CD11c/CD18 integrin

Research Impact

Clone 3.9 has been cited in 23 publications and is regularly employed in immunology research involving flow cytometry, immunohistochemistry, and functional assays. Studies using this clone have contributed to understanding macrophage populations in autoimmune diseases, dendritic cell activation, and integrin-ligand interactions in immune responses.

Dosing regimens of clone 3.9 (an anti-human CD11c monoclonal antibody) vary notably across mouse models, depending on disease context (e.g., immunotherapy, cell depletion), immune background, and experimental goals. There is no single standard regimen; dosing is tailored to model specifics and study endpoints.

Essential details include:

• In immunotherapy studies, dosing may differ from protocols aimed at cell depletion or those using different immune backgrounds.
• Disease context (infection, tumor models, autoimmune, etc.) and the desired pharmacodynamic effect (e.g., transient blockade, sustained depletion) influence dose volume, frequency, and route.
• For cell depletion, higher or repeated doses may be utilized to ensure effective reduction of target cell populations.
• Mouse model background (e.g., immunodeficient, humanized, syngeneic) impacts dose adjustments due to differences in antibody clearance, immune component presence, and mechanism of action.

Published supplier and manufacturer references emphasize:

• Many preclinical studies titrate doses empirically to find minimal effective or maximally tolerated dose, commonly starting from ranges used with similar antibodies (often 5–10 mg/kg, but conditions vary widely).
• Injection routes are typically intraperitoneal (i.p.) or intravenous (i.v.), with schedules ranging from a single administration to dosing every few days over several weeks, adjusted by observed pharmacodynamics.
• Some antibodies are used in combination with other immunomodulators, which might necessitate further dose and schedule adjustments.

In summary, clone 3.9 dosing regimens are not universal; they must be tailored for the mouse model and research application. Direct consultation of the specific supplier protocol and primary literature in your disease area is recommended before initiating studies.