CCL4 Antibody

What is CCL4 and why is it a significant target for antibody-based research?

CCL4, also known as Macrophage inflammatory protein-1β (MIP-1β), is a CC chemokine with specificity for CCR5 receptors and one of the major HIV-suppressive factors produced by CD8+ T cells. It functions as a chemoattractant for monocytes, NK cells, dendritic cells, and T lymphocytes, selectively attracting CD4+ T cells to sites of injury and inflammation . CCL4 is involved in acute and chronic inflammatory responses, and has been implicated in numerous pathological conditions including atherosclerosis, diabetes, and viral infections .

The significance of CCL4 as a research target stems from its multifaceted roles:

• It regulates immune cell trafficking and activation

• It participates in the host response to bacterial, viral, parasite, and fungal pathogens

• It protects against type I diabetes by suppressing islet beta-cell inflammatory responses

• Its binding to CCR5 inhibits HIV entry and reduces cell surface expression of CCR5

• It contributes to atheroma plaque development and vulnerability

What types of CCL4 antibodies are available and how should I select the appropriate one for my research?

CCL4 antibodies are available in several formats, each optimized for different applications:

Selection criteria should include:

• Target species reactivity (human, mouse, rat, chicken)

• Intended application (WB, IHC, neutralization)

• Isotype requirements

• Validated performance in your specific experimental system

For neutralization experiments, antibodies with proven blocking function and known ND50 values should be prioritized .

How can CCL4 antibodies be effectively used in neutralization assays?

Neutralization assays are critical for studying CCL4 function. Based on validated protocols:

Recommended methodology:

• Chemotaxis assay - The most common approach uses CCR5-transfected cell lines (e.g., BaF3-hCCR5) to measure CCL4-induced migration:

  • Plate cells (typically 1-5×10^5) in upper chambers of transwell systems

  • Add recombinant CCL4 (5-40 ng/mL) to lower chambers

  • Pre-incubate CCL4 with increasing concentrations of anti-CCL4 antibody

  • Measure migration after 2-4 hours using Resazurin or cell counting

  • Calculate ND50 (typically 0.3-9 μg/mL for human CCL4 and 4-12 μg/mL for mouse CCL4)

• In vivo neutralization - For animal models:

  • Administer 10-20 μg/mouse of anti-CCL4 antibody via intravenous injection

  • Use appropriate isotype control (e.g., Rat IgG2a kappa)

  • Administer at specified intervals (typically pre-infection and at days 1, 3, and 5 post-intervention)

  • Monitor disease parameters and immune responses

The neutralization potency varies significantly between antibody clones, with effective doses ranging from 0.01-0.1 μg/mL for high-affinity antibodies to 1.5-9 μg/mL for others .

What are the optimal protocols for detecting CCL4 using immunohistochemistry or immunofluorescence?

For successful IHC/IF detection of CCL4:

Protocol optimization considerations:

• Tissue preparation:

  • For paraffin sections: Use 15 μg/mL of anti-CCL4 antibody with overnight incubation at 4°C

  • For frozen sections: Fixation with 4% paraformaldehyde is recommended

• Antigen retrieval:

  • Heat-induced epitope retrieval using citrate buffer (pH 6.0) improves signal

  • For atherosclerotic plaques, additional protease treatment may be beneficial

• Detection systems:

  • For IHC: HRP-AEC systems provide excellent results for CCL4 detection in brain and vascular tissues

  • For IF: Use of NorthernLights™ 557-conjugated secondary antibodies with DAPI counterstain is effective for cellular localization

• Controls:

  • Include CCL4-rich tissues (PMA/LPS-stimulated monocytes) as positive controls

  • Isotype-matched IgG at the same concentration as essential negative controls

Research has shown that CCL4 expression can be effectively evaluated in atherosclerotic plaques, where it colocalizes with macrophage markers (F4/80) .

How have CCL4 antibodies been used to investigate atherosclerosis pathogenesis?

CCL4 antibodies have provided significant insights into atherosclerosis mechanisms:

Key experimental approaches and findings:

• Direct CCL4 inhibition in atherosclerotic mouse models:

  • Administration of CCL4-specific antibodies (10 μg) to ApoE knockout mice decreased vascular inflammation

  • Treatment reduced plaque area and stabilized atheroma vulnerability

  • CCL4 antibody treatment decreased macrophage infiltration (F4/80 marker) within plaques

  • Treatment increased fibrous cap thickness and reduced necrotic areas

• Molecular mechanisms revealed:

  • CCL4 inhibition reduced circulating inflammatory cytokines (IL-6, TNF-α)

  • Treatment decreased MMP2 and MMP9 expression in plaques

  • CCL4 blockade improved lipid profiles via upregulation of liver X receptor

  • CCL4 inhibition suppressed endothelial activation and macrophage recruitment

• Cellular effects:

  • Neutralization of CCL4 prevented TNF-α- and ox-LDL-induced adhesion molecule expression

  • CCL4 antibody treatment affected NFκB signaling pathway in endothelial cells

  • Blockade of CCL4 altered infiltrating immune cell phenotype in vascular tissues

These findings demonstrate that CCL4 antibodies can be powerful tools for both mechanistic studies and potential therapeutic development in atherosclerosis.

What methodological approaches are effective for studying CCL4's role in diabetes using neutralizing antibodies?

Research on CCL4's role in diabetes has employed several effective approaches:

Experimental design considerations:

• Animal model selection:

  • High-fat diet (HFD)-induced diabetes in C57BL/6 mice is the preferred model

  • CCL4 knockout mice provide complementary insights to antibody neutralization

• Anti-CCL4 antibody administration:

  • Dosage: Anti-mouse CCL4 mAb (clone 46907) at 20 μg/mouse

  • Route: Intravenous administration via retro-orbital sinus

  • Schedule: Treatment at days -1, 1, 3, and 5 relative to HFD initiation

• Key parameters to monitor:

  • Glucose homeostasis (fasting glucose, glucose tolerance tests)

  • Lipid parameters (total cholesterol, triglycerides)

  • Inflammatory markers (circulating cytokines)

  • Gut microbiota composition analysis by 16S rRNA sequencing

• Mechanistic verification:

  • Fecal microbiota transplantation (FMT) from CCL4 knockout mice

  • Measurement of trimethylamine N-oxide levels as inflammatory metabolite marker

Results indicate that CCL4 inhibition modifies gut microbiota profiles, particularly affecting family Muribaculaceae and Atopobiaceae, while suppressing proinflammatory metabolites and improving insulin resistance in diabetes models .

How can I optimize CCL4 antibody selection for flow cytometry and intracellular staining applications?

For optimal flow cytometry results with CCL4 antibodies:

Technical optimization strategies:

• Antibody selection:

  • Choose fluorochrome-conjugated monoclonal antibodies (e.g., clone FL34Z3L for human CCL4)

  • APC conjugates offer excellent sensitivity for intracellular CCL4 detection

  • Pre-titrated antibodies (5 μL/0.06 μg per test) simplify protocol development

• Cell stimulation conditions:

  • For monocytes/macrophages: PMA (50 ng/mL) + LPS (1 μg/mL) + Brefeldin A (10 μg/mL) for 6 hours

  • For T cells: PHA or anti-CD3/CD28 stimulation with monensin for optimal detection

  • Include protein transport inhibitors 4-6 hours before staining

• Staining protocol refinement:

  • Surface marker staining before fixation/permeabilization

  • Use of commercial fixation/permeabilization kits compatible with chemokine detection

  • Longer incubation times (30-45 minutes) at optimal antibody concentrations

  • Inclusion of proper FMO (fluorescence minus one) controls

• Gating strategy:

  • Initial gating on viable cells (using viability dye)

  • Identification of CCL4-producing cells within specific immune subpopulations

  • Analysis of CCL4 expression intensity (MFI) compared to isotype controls

Cross-reactivity checks are essential - some anti-CCL4 antibodies show up to 4% cross-reactivity with CCL3/MIP-1 alpha and should be validated in your specific system .

What are the critical considerations when using CCL4 antibodies in vivo, particularly for therapeutic development?

When using CCL4 antibodies in vivo, especially for therapeutic development:

Critical considerations:

• Antibody format selection:

  • Ultra-LEAF™ (Low Endotoxin, Azide-Free) preparations are essential

  • Endotoxin levels should be <0.01 EU/μg (<0.001 ng/μg) as determined by LAL test

  • Antibodies purified by affinity chromatography minimize contamination

• Dosing and administration:

  • Effective neutralizing dose varies by model (10-20 μg/mouse)

  • Administration route affects distribution (IV, IP, or subcutaneous)

  • Treatment frequency should account for antibody half-life and study duration

• Controls and monitoring:

  • Isotype-matched control antibodies are essential (e.g., Rat IgG2b, κ)

  • Regular monitoring of CCL4 levels in circulation

  • Assessment of target engagement through analysis of downstream biomarkers

• Potential off-target effects:

  • Monitor lymphocyte counts (CCR5 is expressed on multiple immune cell subsets)

  • Assess potential interference with related chemokines (CCL3) due to receptor sharing

  • Consider compensatory upregulation of other chemokines

The experience with mogamulizumab (anti-CCR4) development demonstrates that while targeted therapies against chemokine pathways can be effective, careful monitoring of immune parameters is essential to avoid unintended consequences .

How can I validate the specificity of my CCL4 antibody across different applications?

Thorough validation of CCL4 antibodies requires multiple approaches:

Comprehensive validation strategy:

• Positive and negative controls:

  • Positive controls: PMA/LPS-stimulated THP-1 cells express high CCL4 levels

  • Recombinant CCL4-transfected HEK-293 cells serve as excellent positive controls

  • Unstimulated cells or unrelated cell lines as negative controls

• Cross-reactivity testing:

  • Test against related chemokines (CCL3/MIP-1α, CCL5/RANTES)

  • Documented cross-reactivity: Some antibodies show <4% cross-reactivity with rhCCL3

  • Verify no cross-reactivity with rhCXCL8/IL-8, rhCXCL1, rhCXCL2, or rhCXCL3

• Multi-method validation:

  • Western blot: Confirm molecular weight (10 kDa) and band specificity

  • ELISA: Test antibody detection limits and linearity

  • IHC/IF: Compare staining patterns with published literature

  • Flow cytometry: Verify specificity by stimulation/inhibition experiments

• Knockout/knockdown systems:

  • CCR5 knockout mice provide an excellent system to validate antibody specificity

  • siRNA knockdown of CCL4 in cellular systems can confirm antibody specificity

When validated properly, high-quality CCL4 antibodies show consistent performance across multiple applications with minimal cross-reactivity to related chemokines.

What are the most common technical challenges in Western blot detection of CCL4 and how can they be overcome?

CCL4 detection by Western blot presents several challenges:

Common challenges and solutions:

• Protein size and detection issues:

  • CCL4 is a small protein (10 kDa) that can be difficult to retain on membranes

  • Solution: Use 15-20% gels and PVDF membranes with 0.2 μm pore size

  • Recommended fixation: Brief methanol treatment post-transfer

• Sample preparation:

  • CCL4 forms high molecular weight aggregates that affect migration

  • Solution: Use reducing conditions (β-mercaptoethanol) and heat samples at 95°C

  • For secreted CCL4, concentrate culture supernatants using TCA precipitation

• Antibody selection and dilution:

  • Recommended dilution ranges: 1:500-1:1000 for polyclonal antibodies

  • For monoclonal antibodies, test multiple clones as epitope accessibility varies

  • Longer incubation times (overnight at 4°C) may improve sensitivity

• Signal development:

  • Enhanced chemiluminescence provides superior results to colorimetric methods

  • For low abundance samples, use signal enhancers or more sensitive substrates

  • Background reduction: Use milk-based blockers instead of BSA for some antibodies

• Positive controls:

  • Include recombinant CCL4 protein (5-10 ng) as a positive control

  • PMA/LPS-treated THP-1 cell lysates serve as excellent biological positive controls

Researchers should optimize blocking conditions, antibody concentrations, and incubation times based on their specific experimental system.

How are CCL4 antibodies being used to explore the relationship between CCL4 and viral infections beyond HIV?

Recent research has expanded CCL4 antibody applications to multiple viral systems:

Emerging research applications:

• Arthritogenic alphaviruses:

  • CCL4 neutralization experiments in Mayaro virus (MAYV) infection models

  • Administration of anti-mouse CCL4 mAb (clone 46907, 20 μg/mouse) at days -1, 1, 3, and 5 post-infection

  • Assessment of weight loss, footpad swelling, and viremia

  • Analysis of immune cell profiles in blood and affected tissues

• Complementary genetic approaches:

  • CCR5 knockout (CCR5−/−) mice used alongside antibody neutralization

  • Analysis of disease development and immune cell profiles between CCR5−/− and wild type mice

  • Research findings show that despite CCL4 upregulation in MAYV infection, CCL4-CCR5 pathway may not be critical for disease development

• Technical considerations:

  • CCL4 measurements at different infection timepoints (2 and 7 dpi)

  • Combination of antibody treatments with recombinant CCL4 protein administration

  • Careful timing of interventions relative to viral replication cycles

This emerging research demonstrates how CCL4 antibodies can be used to dissect chemokine functions in virus-host interactions beyond the well-established HIV model.

What are the current methodological approaches for studying CCL4's role in T cell differentiation and function?

To investigate CCL4's role in T cell biology:

Advanced methodological approaches:

• Flow cytometry applications:

  • Multiparameter analysis combining CCL4 with T cell subset markers

  • Intracellular staining using optimized fixation/permeabilization protocols

  • Analysis of CCL4 production by different T cell subsets following activation

• Functional assays:

  • T cell differentiation cultures with CCL4 neutralization

  • Assessment of CCL4's effect on Th1/Th2/Th17/Treg differentiation

  • Chemotaxis assays examining preferential migration of CD4+ vs CD8+ T cells

• Receptor analysis:

  • Investigation of CCR5 expression on different T cell subsets

  • Analysis of CCL4-induced receptor internalization

  • Correlation between CCR5 expression and T cell responses to CCL4

• Therapeutic implications:

  • Lessons from mogamulizumab (anti-CCR4) indicate the importance of targeting specific T cell populations

  • CCL4 appears more selective than related chemokines, primarily attracting CD4+ T lymphocytes with preference for naive phenotypes

  • Potential applications in T cell-mediated diseases beyond infectious contexts

These approaches have revealed that CCL4 selectively attracts CD4+ T cells, while related chemokines like CCL3 preferentially attract CD8+ T cells, highlighting the specificity of chemokine functions in T cell biology .