CWH36 Antibody

What is CD36 and why is it an important target for antibody development?

CD36 is a multifunctional transmembrane glycoprotein (88 kDa) that serves as a scavenger receptor class B member 3 (SCARB3). It functions as a receptor for numerous ligands including:

• Extracellular matrix proteins (thrombospondin-1, collagen)

• Oxidized low-density lipoproteins (oxLDL)

• Long-chain fatty acids

• Advanced glycation end products

• Apoptotic cells

• Beta-amyloid fibrils

CD36 plays critical roles in lipid metabolism, inflammation, atherosclerosis, tumor immunity, and metastatic invasion through various molecular mechanisms . Its expression pattern includes monocytes/macrophages, platelets, adipocytes, microvascular endothelium, dendritic cells, and erythroid precursors, making it a valuable research target across multiple disciplines .

What distinguishes CWH36 antibodies from CD36 antibodies?

While CD36 antibodies target the mammalian CD36 receptor, CWH36 antibodies target an entirely different protein found in yeast:

CWH36 (Cell Wall Hydrolysis) is associated with yeast cell wall biogenesis and integrity, representing a distinct research area from the mammalian CD36 protein .

How should researchers select appropriate anti-CD36 antibodies for specific applications?

Selection criteria should include:

• Target species reactivity: Confirm whether the antibody recognizes human, mouse, or both CD36 proteins. For example, clone eBioNL07 recognizes human CD36, while clone HM36 is specific for mouse CD36 .

• Application compatibility: Verify validation data for your specific application:

  • Flow cytometry: Most anti-CD36 antibodies are validated for this application

  • Western blot: Antibodies like CAB14714 are validated for detecting CD36 in cell lysates

  • Immunohistochemistry: Some clones (e.g., FA6-152) are compatible with both paraffin and frozen sections

• Epitope location: Different antibodies bind distinct regions of CD36, which can affect their utility:

  • FA6-152 binds a region that may compete with human anti-CD36 antibodies

  • Clones GZ-70 and GZ-608 demonstrate higher reactivity (92.9% vs. 42.9%) in antigen capture assays

• Conjugation: Select appropriate fluorochromes for flow cytometry applications or unconjugated formats for flexibility .

How is CD36 expression analyzed in research contexts?

Several methodologies are employed to analyze CD36 expression:

• Flow cytometry: The predominant method for analyzing cell surface CD36 expression on immune cells, platelets, and other populations. Protocols typically involve:

  • Co-staining with lineage markers to identify specific populations

  • Blocking with anti-mCD16/32 antibodies to prevent non-specific binding

  • Use of dead cell exclusion dyes

  • Appropriate isotype controls

• RT-PCR: For detection of CD36 mRNA expression in tissues and cells

• Western blot: For quantification of total CD36 protein, with typical detection at approximately 85-90 kDa under reducing conditions

• Immunohistochemistry: For visualizing CD36 distribution in tissue sections

Example flow cytometry panel for analyzing CD36 on immune cells:

• Anti-CD36-APC or PE

• Lineage markers (CD3, CD19, CD14, etc.)

• LD-NIR (live/dead stain)

• Anti-mCD16/32 (Fc block)

How can humanized CD36 mouse models advance preclinical research?

Humanized CD36 (hCD36) mouse models represent a crucial development for translational research. These models have been generated by replacing the extracellular domains of mouse CD36 with the corresponding human sequences while maintaining the transmembrane and cytoplasmic domains.

Key research applications include:

• Tumor immunotherapy evaluation: hCD36 mice enable testing of human-specific anti-CD36 antibodies in immunocompetent settings, providing crucial insights into their efficacy and mechanism of action. For example, treatment with the CD36 monoclonal antibody 1G04 achieved significant tumor growth inhibition (TGI) in hCD36 mice with established MC38 colon tumors (47.3% TGI at 10 mg/kg) .

• Validation strategy: When validating these models, researchers should:

  • Confirm selective expression of human CD36 using species-specific antibodies

  • Verify normal lymphocyte subpopulation distribution in blood, spleen, and lymph nodes

  • Assess normal blood parameters and biochemistry

  • Validate using known CD36-targeting therapeutics

• Mechanism studies: These models allow detailed investigation of CD36's role in:

  • Lipid metabolism pathways

  • Tumor microenvironment interactions

  • Macrophage polarization and function

  • Metastatic processes

The development of hCD36 mice addresses the critical need for models that recapitulate human CD36 expression patterns, facilitating the translation of preclinical findings to clinical applications .

What methodological approaches enhance the detection of anti-CD36 antibodies in clinical samples?

Detection of anti-CD36 antibodies presents technical challenges that require specialized approaches:

• Monoclonal antibody selection for antigen capture assays: Research demonstrates that carefully selected capture antibodies significantly improve detection rates. In monoclonal antibody immobilization of platelet antigen (MAIPA) assays:

  • Using the reference anti-CD36 mAb FA6-152 detected anti-CD36 antibodies in only 42.9% of sera

  • Using novel mAbs GZ-70 and GZ-608 improved detection to 92.9% of sera

  • This difference is attributed to the epitope specificity, where some mAbs compete with human anti-CD36 antibodies while others do not

• Strategic immunization approaches: Generating non-competing anti-CD36 mAbs through:

  • Immunizing CD36-deficient mice with mouse CD36-transfected cells

  • Selecting clones that cross-react with human CD36

  • This approach avoids recognition of highly immunogenic regions (residues 155-183) that harbor major epitopes of human anti-CD36 antibodies

• Flow cytometry validation: Testing antibody binding to:

  • CD36-transfected cell lines

  • CD36-positive and CD36-negative primary cells

  • Comparing reactivity across genotypes

These methodological refinements are particularly important for detecting anti-CD36 antibodies in clinical conditions including fetal/neonatal alloimmune thrombocytopenia (FNAIT) and transfusion-related acute lung injury .

How does CD36 expression on red blood cells impact transfusion medicine research?

Recent research has challenged the conventional understanding that CD36 is absent from mature red blood cells (RBCs):

• Evidence for RBC expression: Flow cytometric analysis of blood from multiple donors has detected CD36 expression on mature RBCs and reticulocytes. This finding is supported by proteomic datasets showing CD36-derived peptides enriched in RBC membrane fractions .

• Genetic basis of CD36 deficiency: Sequencing has identified the molecular basis for CD36 deficiency:

  • Homozygosity for c.1133G>T/p.Gly378Val (rs146027667:T) with a global minor allele frequency of 0.1%

  • This variant results in abolished CD36 expression

• Clinical implications: Recognition of CD36 as a red cell antigen has significant implications:

  • Anti-CD36 antibodies are implicated in severe fetal anemia

  • CD36 meets criteria for designation as a novel blood group system

  • This finding expands the clinical significance of CD36 beyond its established role in fetal/neonatal alloimmune thrombocytopenia (FNAIT)

• Research methodology: Investigators studying CD36 in transfusion medicine should:

  • Use sensitive flow cytometry techniques optimized for detecting low-abundance antigens

  • Include appropriate controls from CD36-deficient individuals

  • Consider proteomic approaches to confirm expression

These findings necessitate a reevaluation of CD36's role in transfusion medicine and highlight the need for prospective studies on the clinical significance of anti-CD36 antibodies in transfusion reactions and hemolytic disease of the fetus and newborn.

What functional assays can demonstrate CD36-blocking efficacy of novel antibodies?

When developing and characterizing novel anti-CD36 antibodies, several functional assays can demonstrate their blocking efficacy:

• Lipid uptake inhibition assays:

  • Treatment of macrophage-like THP-1 cells with anti-CD36 antibodies followed by oxidized LDL (oxLDL) challenge

  • Quantification of lipid accumulation using Oil Red O staining

  • Measurement of foam cell formation inhibition

  • RT-qPCR analysis of lipid metabolism genes

• Tumor sphere formation assays:

  • Treatment of cancer cells (e.g., HepG2) with anti-CD36 antibodies prior to palmitate stimulation

  • Assessment of clonogenicity inhibition

  • Quantification of sphere number and size

• Competition binding assays:

  • Flow cytometric analysis to test whether novel antibodies compete with established anti-CD36 antibodies

  • Assessment of binding to CD36-expressing cells versus CD36-deficient controls

  • Evaluation of cross-reactivity with mouse and human CD36

• In vivo tumor growth inhibition:

  • Assessment of antibody efficacy in humanized CD36 mouse models

  • Measurement of tumor growth inhibition

  • Monitoring of body weight and potential toxicity

  • Analysis of immune cell infiltration in the tumor microenvironment

Recent research demonstrated that a novel human anti-CD36 single-chain variable fragment (scFv), called D11, effectively competes with commercial anti-CD36 antibodies, reduces uptake of CD36 ligands, impairs foam cell phenotype acquisition in macrophages, and inhibits the enhanced clonogenicity of cancer cells stimulated by fatty acids .

What considerations are important when studying CD36 in different research contexts?

The multifunctional nature of CD36 requires context-specific research approaches:

• Cardiovascular research:

  • Focus on macrophage foam cell formation using oxidized LDL uptake assays

  • Consider the role of CD36 in atherosclerotic plaque formation

  • Analyze inflammatory cytokine production in response to CD36 ligation

  • Evaluate CD36's function in different vascular beds and cell types

• Cancer research:

  • Investigate fatty acid uptake and metabolism in cancer cells

  • Study the role of CD36 in metastatic processes

  • Analyze tumor microenvironment interactions, particularly with tumor-associated macrophages

  • Consider CD36 as both a therapeutic target and biomarker

• Metabolic disease research:

  • Focus on adipocyte and muscle expression of CD36

  • Analyze long-chain fatty acid transport activity

  • Consider interaction with other metabolic receptors and pathways

  • Study tissue-specific roles using conditional knockout models

• Technical considerations across contexts:

  • Different CD36 antibody clones may be better suited for specific applications

  • CD36 protein may run at different molecular weights depending on glycosylation (85-140 kDa)

  • Expression can be regulated by various metabolic and inflammatory stimuli

  • Post-translational modifications affect trafficking and function

By tailoring research approaches to these context-specific considerations, investigators can more effectively study CD36's diverse functions and therapeutic potential.

What are the optimal protocols for detecting CD36 expression by flow cytometry?

For reliable detection of CD36 by flow cytometry, researchers should implement these methodological approaches:

• Sample preparation:

  • For blood samples: Use ACK lysis buffer to remove red blood cells before staining

  • For tissue samples: Generate single-cell suspensions through enzymatic digestion and mechanical disruption

  • Include viability dye (e.g., LD-NIR) to exclude dead cells

  • Block Fc receptors with anti-mCD16/32 antibodies for 10 minutes at 4°C

• Antibody selection and titration:

  • For human samples: Clones CB38, FA6-152, or eBioNL07 conjugated to APC or PE

  • For mouse samples: Clone HM36 conjugated to APC or PE

  • Optimal working concentration typically ≤0.5 μg per test (approximately 10^5 to 10^8 cells)

  • Perform titration experiments to determine optimal antibody concentration

• Control samples:

  • Include appropriate isotype controls (e.g., mouse IgG1 for anti-human CD36)

  • Use CD36-deficient cells as negative controls when available

  • Include fluorescence-minus-one (FMO) controls for multicolor panels

• Analysis parameters:

  • Acquire ≥5,000 events for reliable detection

  • Use appropriate compensation when using multiple fluorochromes

  • Consider fixation impact (80% methanol fixation is compatible with some anti-CD36 antibodies)

Following these guidelines will ensure consistent and reliable detection of CD36 expression across different experimental conditions and cell types.

How can researchers troubleshoot cross-reactivity issues with anti-CD36 antibodies?

Cross-reactivity can complicate CD36 research, particularly when studying across species. The following approaches help address this issue:

• Validating species reactivity:

  • Test antibodies on cell lines from target species expressing CD36

  • Compare with CD36-negative controls from the same species

  • Verify results with orthogonal methods (e.g., Western blot, RT-PCR)

• Confirming epitope specificity:

  • Use competition assays with well-characterized anti-CD36 antibodies

  • Test binding to CD36 variants or truncated constructs

  • Consider peptide blocking experiments to confirm epitope specificity

• Addressing non-specific binding:

  • Implement stringent blocking steps with serum matching the secondary antibody species

  • Include proper isotype controls at matching concentrations

  • Titrate antibody to find optimal signal-to-noise ratio

• Strategic selection of cross-reactive antibodies:

  • Some antibodies (e.g., 1G04) are specifically designed to cross-react with both human and mouse CD36

  • For humanized mouse models, such antibodies allow comparative studies between wild-type and humanized systems

  • Verify comparable binding kinetics to both human and mouse CD36

• Advanced cross-reactivity prevention:

  • Generate species-specific antibodies through careful immunization strategies

  • Consider using CD36-deficient animals for immunization to avoid highly conserved epitopes

  • Employ phage display techniques to select for species-specific binding

These approaches minimize cross-reactivity issues and ensure reliable, species-specific detection of CD36 in complex experimental systems.

What methodologies exist for studying CWH36 in yeast research?

While information on CWH36 research is limited in the provided search results, the following methodological approaches can be inferred based on standard yeast research techniques and the available data:

• Antibody-based detection:

  • Commercial anti-CWH36 antibodies (e.g., CSB-PA340713XA01SVG) targeting Saccharomyces cerevisiae CWH36 (Uniprot: P25603)

  • Typically applied in Western blot analysis of yeast cell extracts

  • May require specialized extraction methods to solubilize membrane-associated proteins

• Genetic manipulation approaches:

  • Generation of CWH36 knockout strains to study loss-of-function phenotypes

  • Complementation studies with wild-type or mutant CWH36

  • Fusion proteins (e.g., GFP-CWH36) for localization studies

• Phenotypic analysis techniques:

  • Cell wall integrity assays using stressors like Calcofluor White or Congo Red

  • Osmotic sensitivity tests to evaluate cell wall function

  • Microscopic examination of cell morphology and wall architecture

• Biochemical approaches:

  • Analysis of cell wall composition in wild-type versus CWH36-deficient strains

  • Enzymatic activity assays to assess hydrolytic functions

  • Protein-protein interaction studies to identify functional partners

These methodologies represent standard approaches in yeast cell wall research that would likely be applicable to CWH36 studies, though specific protocols would need to be optimized for this particular protein.

How are anti-CD36 antibodies being developed for tumor immunotherapy?

Anti-CD36 antibodies show promising potential in tumor immunotherapy through several mechanistic approaches:

• Targeting lipid metabolism in cancer:

  • CD36 facilitates fatty acid uptake that fuels tumor growth and metastasis

  • Blocking antibodies like 1G04 disrupt this metabolic dependency

  • In humanized CD36 mice, 1G04 treatment achieved significant tumor growth inhibition (47.3% at 10 mg/kg and 31.6% at 3 mg/kg) against MC38 colon tumors

• Novel antibody formats:

  • Fully human single-chain variable fragments (scFvs) like D11 show efficacy in blocking CD36

  • These antibodies reduce lipid accumulation and clonogenicity in cancer cells

  • Their human origin minimizes immunogenicity concerns for clinical development

• Combination therapy opportunities:

  • Anti-CD36 antibodies may enhance sensitivity to standard therapies by altering metabolism

  • CD36 is implicated in therapy resistance mechanisms in breast cancer

  • Targeting CD36 could reverse metabolic rewiring that promotes resistance to HER2-targeted therapies

• Development challenges:

  • Most CD36 antibodies remain in preclinical and biological testing stages

  • Few antibodies specifically targeting human CD36 have advanced clinically

  • Humanized CD36 mouse models now provide valuable tools to accelerate translation

Future directions include developing antibodies with enhanced specificity for tumor-associated CD36, exploring antibody-drug conjugates targeting CD36-expressing cells in the tumor microenvironment, and identifying biomarkers to select patients most likely to benefit from anti-CD36 therapy.

What are the emerging roles of CD36 antibodies in blood group research?

Recent discoveries have expanded the significance of CD36 in transfusion medicine:

• CD36 as a novel blood group system:

  • Evidence now confirms CD36 expression on mature red blood cells and reticulocytes

  • CD36 fulfills International Society of Blood Transfusion criteria for designation as a blood group

  • Anti-CD36 antibodies are implicated in both fetal/neonatal alloimmune thrombocytopenia (FNAIT) and fetal anemia

• Genetic basis of CD36 deficiency:

  • Homozygosity for c.1133G>T/p.Gly378Val (rs146027667:T) results in abolished CD36 expression

  • This variant has a global minor allele frequency of 0.1%

  • CD36-negative individuals may develop alloantibodies when exposed to CD36-positive blood products

• Research methodologies:

  • Flow cytometry with sensitive protocols can detect CD36 on RBCs

  • Genetic analysis identifies individuals at risk of alloimmunization

  • Antigen capture assays using non-competing monoclonal antibodies improve detection of anti-CD36 antibodies

• Clinical implications:

  • Testing for anti-CD36 antibodies should be considered in unexplained fetal anemia cases

  • CD36 typing may become relevant in specific transfusion scenarios

  • Further research is needed to define the clinical significance of this newly recognized blood group system

This emerging area highlights how continued research into fundamental aspects of CD36 biology continues to reveal new clinical applications for CD36 antibodies beyond their established roles in cardiovascular and cancer research.

How might further characterization of CWH36 inform broader research in cell wall biology?

Although specific information on CWH36 research is limited in the provided search results, we can infer potential research directions based on its classification as a cell wall-related protein in Saccharomyces cerevisiae:

• Evolutionary conservation analysis:

  • Comparative studies of CWH36 across fungal species could reveal conserved domains

  • Identification of functional motifs might suggest mechanistic roles

  • Structural comparisons with related proteins could illuminate evolutionary adaptations

• Cell wall integrity pathways:

  • Investigation of CWH36's position in signaling cascades controlling cell wall synthesis

  • Interaction studies with known cell wall integrity pathway components

  • Transcriptional profiling of CWH36 under various cell wall stressors

• Translational potential:

  • CWH36's role in cell wall biogenesis could identify it as a potential antifungal target

  • Antibodies against CWH36 might serve as research tools for cell wall assembly studies

  • Structure-function analysis might reveal druggable domains

• Methodological advancements:

  • Development of specific antibodies against different CWH36 domains

  • Creation of conditional expression systems to study temporal aspects of function

  • Application of advanced microscopy techniques to visualize CWH36 dynamics during cell wall remodeling

These research directions would contribute to our understanding of fungal cell wall biology and potentially inform therapeutic strategies targeting fungal cell walls.

What collaborative approaches could advance both CD36 and CWH36 antibody research?

Although CD36 and CWH36 function in different biological contexts (mammalian metabolism versus yeast cell wall integrity), certain collaborative research approaches could benefit both fields:

• Shared antibody development technologies:

  • Advanced antibody engineering platforms could be applied to both targets

  • Phage display libraries could generate high-affinity binders for both proteins

  • Humanization techniques for therapeutic applications of CD36 antibodies might inform optimization of CWH36 antibodies for research applications

• Cross-disciplinary structural approaches:

  • Comparative structural analysis might reveal unexpected functional parallels

  • Similar epitope mapping strategies could enhance antibody characterization in both fields

  • Shared expertise in membrane protein crystallography or cryo-EM could accelerate structural determination

• Integrated bioinformatic analysis:

  • Application of machine learning algorithms to predict functional domains across species

  • Network analysis to identify common interacting partners or pathways

  • Evolutionary analysis to trace functional divergence of these proteins

• Methodological exchanges:

  • Adaptation of yeast genetic manipulation techniques to study CD36 variants in humanized yeast systems

  • Application of mammalian cell imaging approaches to visualize CWH36 dynamics

  • Development of shared reporter systems to monitor protein trafficking and localization

Such collaborative approaches would not only advance both research areas but could potentially reveal unexpected connections between these seemingly disparate biological systems.

Comparison of Anti-CD36 Antibody Clones for Research Applications

Methodological Comparison for CD36 Detection Techniques

CD36 Expression Across Different Cell Types