206 Antibody

What is CD206 and why is it significant in immunological research?

CD206, also known as the mannose receptor C type 1 (MRC1), is a ~175-185 kDa single-pass type I transmembrane glycoprotein belonging to the C-type lectin family of pattern recognition receptors. It contains multiple carbohydrate recognition motifs that facilitate binding to mannose residues on microorganism surfaces. CD206 plays crucial roles in both innate and adaptive immunity through recognition of pathogen-associated molecular patterns and aiding in the uptake of macromolecules such as lipoproteins . Its significance in research stems from its involvement in Alzheimer's disease, Gaucher's disease, sepsis, and its role as a key marker for alternatively activated (M2) macrophages, making it valuable for studying inflammation, tissue repair, and tumor microenvironments .

Which cell types express CD206, and how does expression vary in different conditions?

CD206 is predominantly expressed by:

• Immature dendritic cells

• Tissue-resident macrophages

• Specific subpopulations of endothelial cells

• Sperm cells

• Certain skin cells under inflammatory conditions

Expression levels can fluctuate significantly in response to cytokines, growth factors, and inflammatory stimuli. Under inflammatory conditions, previously CD206-negative skin cells may begin expressing the receptor. In macrophages, CD206 expression is upregulated during alternative (M2) activation, making it a useful marker for distinguishing between classical (M1) and alternatively activated macrophage populations .

What are the main applications for CD206 antibodies in research settings?

CD206 antibodies serve multiple research applications:

These applications enable researchers to investigate CD206's role in immune regulation, disease pathogenesis, and tissue homeostasis .

How can researchers optimize CD206 antibody-based detection in different sample types?

Optimization strategies vary by sample type and detection method:

For Western Blot detection:

• Human samples show CD206 at approximately 185-201 kDa under reducing conditions

• Mouse samples show CD206 at approximately 180 kDa

• Optimal antibody concentration: typically 1 μg/mL

• Sample preparation: use Immunoblot Buffer Group 1 (for mouse samples) or Group 8 (for human samples)

• Loading: 3-12 μg of tissue lysate yields detectable signal

• Membrane type: PVDF membranes provide optimal results

For Immunohistochemistry/Immunofluorescence:

• Frozen sections: 5-25 μg/mL antibody concentration

• Paraffin-embedded sections: effectiveness varies by antibody clone

• Incubation: Overnight at 4°C yields optimal results

• Signal amplification: HRP-DAB or fluorochrome-conjugated secondary antibodies

• Counterstaining: Hematoxylin (for bright-field) or DAPI (for fluorescence)

For Immunocytochemistry:

• Cell preparation: Immersion fixation preserves antigenic structure

• For PBMCs: Follow specialized protocols for non-adherent cells

• For dendritic cells: Standard protocols with appropriate controls

What validation steps should researchers perform when using CD206 antibodies in novel experimental contexts?

When implementing CD206 antibodies in new experimental systems, rigorous validation is essential:

• Cross-reactivity assessment: Check reactivity with other species (some human CD206 antibodies show ~20-45% cross-reactivity with mouse CD206 and vice versa)

• Positive control tissues:

  • For human studies: Immature dendritic cells, liver tissue, or alternatively activated macrophages

  • For mouse studies: Lung macrophages, testis (spermatocytes), or liver tissue

• Blocking experiments: Pre-incubate antibody with recombinant CD206 protein to confirm binding specificity

• Comparison with established markers: Co-stain with other M2 macrophage markers to confirm cell identification

• Knockout/knockdown controls: Where available, CD206-deficient samples provide definitive negative controls

• Multiple antibody clones: When possible, confirm key findings with different antibody clones targeting distinct CD206 epitopes

How can CD206 antibodies be used to distinguish M2 macrophage phenotypes in heterogeneous samples?

M2 macrophages represent a spectrum of alternatively activated states with CD206 serving as a key identifier. For robust phenotyping:

• Multiparameter flow cytometry approach:

  • Combine CD206 with other M2 markers (CD163, CD209, etc.)

  • Include M1 markers (CD80, CD86, etc.) to distinguish polarization states

  • Add lineage markers (CD14, CD11b) to confirm macrophage identity

• Multiplex immunohistochemistry:

  • Spatial distribution analysis of CD206+ cells relative to other cell types

  • Sequential staining protocols to overcome antibody species limitations

  • Quantification of signal intensity to assess expression levels

• Functional verification:

  • Combine CD206 detection with functional assays (phagocytosis, cytokine secretion)

  • Correlate CD206 expression with known M2-associated gene expression profiles

The mouse anti-human CD206 antibody clone 15-2 has been extensively validated for monitoring mannose receptor modulation in macrophages treated with various cytokines and growth factors, making it particularly suitable for M2 polarization studies .

How does CD206 expression correlate with pathological conditions, and how can antibodies help elucidate these relationships?

CD206 expression changes significantly in several pathological conditions, offering research opportunities:

Alzheimer's Disease:

• CD206+ microglia/macrophages are found in the vicinity of amyloid plaques

• CD206 antibodies can assess the balance between pro-inflammatory and resolution-promoting microglia

• Quantification of CD206+ cells in brain tissue provides insights into disease progression

Gaucher's Disease:

• CD206 participates in the clearance of glycolipids that accumulate in this condition

• Antibody-based detection can reveal macrophage dysfunction patterns

• Flow cytometric analysis of CD206 expression on monocyte-derived macrophages serves as a cellular phenotyping tool

Sepsis:

• Soluble CD206 is elevated in plasma during acute sepsis

• Antibody-based ELISAs can quantify this potential biomarker

• Longitudinal monitoring can correlate with disease severity and treatment response

Cancer:

• Tumor-associated macrophages (TAMs) often display high CD206 expression

• CD206 antibodies help characterize the tumor microenvironment

• Spatial distribution analysis of CD206+ cells may predict therapeutic responses and patient outcomes

What are the technical challenges when using CD206 antibodies in disease model systems?

Researchers face several challenges when applying CD206 antibodies in disease models:

• Tissue-specific expression variations:

  • CD206 expression patterns differ between tissue-resident macrophage populations

  • Background staining can vary significantly between tissues

  • Optimization for each tissue type is recommended (antibody concentration, incubation time, detection method)

• Disease-induced conformational changes:

  • Inflammatory conditions may alter glycosylation patterns of CD206

  • Some epitopes may become masked or exposed in disease states

  • Multiple antibody clones targeting different regions may be necessary

• Soluble vs. membrane-bound CD206:

  • CD206 exists in both membrane-bound and soluble forms

  • Distinguish between these forms using appropriate antibodies and techniques

  • Consider how disease conditions might alter the ratio of soluble to membrane-bound forms

• Species differences:

  • Mouse models show important differences in CD206 expression compared to humans

  • Human CD206 antibodies typically show <45% cross-reactivity with mouse CD206

  • Select species-specific antibodies for cross-species comparisons

How can researchers effectively combine CD206 antibodies with other markers for comprehensive immune cell profiling?

Multidimensional immune profiling with CD206 antibodies requires strategic approaches:

• Panel design for flow cytometry:

  • Combine CD206-APC (or other fluorochromes) with complementary markers

  • Include lineage markers (CD14, CD11b, F4/80 for mouse)

  • Add activation markers (CD80/CD86 for M1; CD163 for M2)

  • Consider additional functional markers (cytokine receptors, scavenger receptors)

• Sequential multiplexed immunohistochemistry:

  • Start with CD206 detection using primary-secondary antibody pairs

  • Strip or inactivate the first round of antibodies

  • Proceed with subsequent markers

  • Digital image analysis to quantify co-expression patterns

• Mass cytometry (CyTOF) integration:

  • Metal-conjugated CD206 antibodies enable high-parameter analysis

  • Combine with dozens of other markers for comprehensive immune profiling

  • Algorithm-based clustering identifies novel cell populations

• Single-cell RNA-seq correlation:

  • Sort CD206+ cells using fluorescently-labeled antibodies

  • Perform single-cell transcriptomics to identify heterogeneity within CD206+ populations

  • Validate findings with protein-level detection using additional antibodies

What protocols yield optimal results when detecting CD206 in challenging sample types?

Certain sample types present distinct challenges for CD206 detection:

Formalin-fixed paraffin-embedded (FFPE) tissues:

• Antigen retrieval is critical: citrate buffer (pH 6.0) or EDTA buffer (pH 9.0)

• Extended primary antibody incubation (overnight at 4°C)

• Signal amplification systems (polymer-HRP, tyramide) enhance detection

• Mouse monoclonal antibody clone 15-2 has been validated for human FFPE samples

Adipose tissue:

• High autofluorescence and lipid content interfere with detection

• Sudan Black B treatment reduces autofluorescence

• Increase antibody concentration (typically 2-3× standard protocols)

• Extended washing steps remove non-specific binding

Lung tissue:

• High autofluorescence from elastin fibers

• TrueBlack® or similar reagents reduce background

• Focus on macrophage-rich regions (alveolar spaces, peribronchial areas)

• AF2535 antibody has been validated for mouse lung tissue at 25 μg/mL

Cultured macrophages:

• Activation state affects CD206 expression levels

• Standardize culture conditions prior to antibody staining

• Consider cell permeabilization for total (surface + intracellular) CD206 detection

• Include time course experiments to capture expression dynamics

What are the considerations for using IL-6 antibody AF-206-NA in relation to CD206 research?

While distinct from CD206 antibodies, IL-6 antibody AF-206-NA offers complementary research applications:

• Dual detection in inflammation studies:

  • CD206 identifies alternatively activated macrophages

  • IL-6 antibody AF-206-NA detects this key inflammatory cytokine

  • Combined analysis reveals relationships between macrophage polarization and cytokine production

• Technical considerations for IL-6 detection:

  • AF-206-NA detects a 20-22 kDa band in Western blot

  • Optimal for immunocytochemistry of LPS-treated PBMCs

  • Effective neutralization at ≤125 ng/mL against 2.5 ng/mL recombinant human IL-6

• Experimental applications:

  • Study how CD206+ macrophages respond to or produce IL-6

  • Investigate IL-6 blockade effects on macrophage polarization

  • Explore how soluble CD206 levels correlate with IL-6 production in disease states

What are common pitfalls when working with CD206 antibodies, and how can they be addressed?

Researchers may encounter several challenges when using CD206 antibodies:

How can researchers validate CD206 antibody specificity and performance?

Robust validation ensures reliable experimental outcomes:

• Positive controls:

  • For human samples: Immature dendritic cells show consistent CD206 expression

  • For mouse samples: Lung tissue macrophages and testis spermatocytes

  • Western blot of appropriate tissue lysates (liver for mouse)

• Negative controls:

  • Isotype-matched control antibodies at the same concentration

  • CD206-negative cell lines (e.g., most lymphocyte populations)

  • Competitive blocking with recombinant CD206 protein

• Orthogonal validation:

  • Confirm protein expression with mRNA detection methods

  • Use multiple antibody clones targeting different epitopes

  • Compare results across different detection platforms

• Cross-reactivity assessment:

  • Test on samples from multiple species if conducting comparative studies

  • Note that human CD206 antibodies typically show <45% cross-reactivity with mouse CD206

What controls should be implemented when studying CD206 in complex biological systems?

Complex systems research requires comprehensive controls:

• Tissue-specific controls:

  • Include tissue-matched normal samples when studying disease states

  • Process all experimental groups simultaneously with identical protocols

  • For human studies, account for age, sex, and medication effects on CD206 expression

• Functional validation:

  • Confirm that CD206+ cells display expected functional properties

  • Verify mannose-binding capacity using fluorescently labeled mannosylated BSA

  • Assess phagocytic activity as a functional readout of CD206 activity

• Treatment response controls:

  • For polarization studies, include canonical M1 (IFNγ+LPS) and M2 (IL-4) stimuli

  • Monitor CD206 expression kinetics throughout the experimental timeline

  • Include dose-response assessments for treatments affecting CD206 expression

• Context-dependent interpretation:

  • CD206 expression alone is insufficient to definitively classify macrophage populations

  • Include additional markers (CD163, CD80/86, etc.) for comprehensive phenotyping

  • Consider tissue context when interpreting CD206 expression patterns