Ccl7 Antibody

What are the common synonyms and alternative designations for CCL7 in the literature?

Researchers should be aware of the multiple synonyms for CCL7 when conducting literature searches:

• MCP-3 (Monocyte Chemotactic Protein 3)

• MARC

• MCP3

• NC28

• SCYA6

• SCYA7

• C-C motif chemokine 7

• FIC

The most commonly used alternative designation is MCP-3, particularly in older literature. When designing search strategies for comprehensive literature reviews, it's essential to include all these terms to ensure complete coverage of relevant research.

Which cell types express CCL7, and what stimuli regulate its production?

CCL7 is expressed by multiple cell types, including:

• Fibroblasts

• Mast cells

• Astrocytes

• Endothelial cells

• Monocytes

• Macrophages

• B cells

CCL7 expression is upregulated in response to various stimuli:

• In mononuclear leukocytes: IL-1β, IFN-α, IFN-β, measles virus, poly I-C, or Con A

• In fibroblasts: Synergistic induction by IL-1β and IFN-γ

• In murine fibroblasts: TGF-β

• In astrocytes: TNF-α

Conversely, anti-inflammatory cytokines such as IL-4, IL-10, and IL-13 inhibit CCL7 expression in monocytes . This complex regulation makes CCL7 a sensitive indicator of inflammatory conditions and immune activation states.

What are the primary receptors for CCL7 and which cell types express them?

CCL7 signals through multiple chemokine receptors:

• CCR1 (CD191)

• CCR2 (CD192)

• CCR3 (CD193)

• CCR5 (CD195)

These receptors are expressed on various cell types, including:

• Monocytes

• Macrophages

• Dendritic cells, particularly conventional type 1 dendritic cells (cDC1)

• T cells

• NK cells

• Eosinophils

• Basophils

The broad range of receptors explains CCL7's ability to attract and activate diverse immune cell populations, making it a versatile chemokine in the regulation of immune responses.

What are the principal applications of CCL7 antibodies in laboratory research?

CCL7 antibodies serve multiple applications in research settings:

• Western Blotting: Used to detect and quantify CCL7 protein expression in cell or tissue lysates. Particularly useful for analyzing changes in CCL7 expression under different experimental conditions .

• Enzyme-Linked Immunosorbent Assay (ELISA): Enables quantitative measurement of CCL7 in serum, plasma, or culture supernatants. This is valuable for biomarker studies and for measuring CCL7 secretion in response to various stimuli .

• Immunohistochemistry (IHC): Allows visualization of CCL7 distribution in tissue sections, providing insights into its localization and expression patterns in different pathological conditions .

• Flow Cytometry: Using intracellular staining protocols, CCL7 antibodies can detect CCL7-producing cells within heterogeneous populations .

• Neutralization Studies: CCL7-neutralizing antibodies can block CCL7 function in experimental models, helping to elucidate its role in various biological processes .

Each application requires specific validation steps to ensure specificity and sensitivity of the antibody in the particular experimental context.

How should researchers validate CCL7 antibodies for specific experimental applications?

A systematic validation approach for CCL7 antibodies should include:

• Specificity Testing:

  • Positive controls: Use recombinant CCL7 protein or cell lines known to express CCL7

  • Negative controls: Use CCL7-knockout samples or cell lines that don't express CCL7

  • Cross-reactivity assessment: Test against related chemokines (CCL2, CCL8) to ensure specificity

• Application-Specific Validation:

  • For Western Blot: Confirm single band at expected molecular weight (~11.2 kDa, may appear larger due to glycosylation)

  • For IHC: Include appropriate positive and negative tissue controls

  • For ELISA: Generate standard curves with recombinant CCL7 to establish sensitivity and dynamic range

  • For Flow Cytometry: Compare with isotype controls and use CCL7-stimulated versus unstimulated cells

• Species Cross-Reactivity:

  • If working with animal models, verify antibody reactivity with the species of interest (mouse, rat, etc.)

• Lot-to-Lot Consistency:

  • When receiving new antibody lots, compare results with previous lots using standardized samples

Thorough validation ensures reliable and reproducible results, particularly important when studying chemokines that often have high sequence similarity within their families.

What methodological considerations are important when using CCL7 antibodies for intracellular staining?

When performing intracellular staining for CCL7 detection by flow cytometry, researchers should consider:

• Cell Stimulation Protocol:

  • Use appropriate stimuli known to induce CCL7 production (e.g., IL-1β, IFN-γ)

  • Include protein transport inhibitors (e.g., Brefeldin A, Monensin) to accumulate CCL7 intracellularly

• Fixation and Permeabilization:

  • Use validated protocols like the Intracellular Fixation and Permeabilization Buffer Set

  • Optimize fixation time and temperature to preserve epitope recognition while maintaining cellular integrity

• Antibody Titration:

  • Determine optimal antibody concentration (typically around 0.06 μg per test)

  • Test multiple concentrations to achieve maximum signal-to-noise ratio

• Controls:

  • Include unstimulated cells as negative controls

  • Use isotype controls to assess non-specific binding

  • Consider fluorescence-minus-one (FMO) controls for accurate gating

• Fluorophore Selection:

  • Choose appropriate fluorophores based on instrument capabilities (e.g., eFluor 660 requires red laser excitation)

  • Consider brightness requirements based on expected expression levels

• Sample Size:

  • Cell numbers should be empirically determined but typically range from 10^5 to 10^8 cells per test

Proper optimization of these parameters ensures reliable detection of CCL7-producing cells in heterogeneous populations.

How does CCL7 contribute to leukocyte recruitment in inflammatory conditions?

CCL7 orchestrates leukocyte recruitment through several mechanisms:

• Direct Chemotactic Activity: CCL7 directly attracts multiple immune cell types including:

  • Monocytes

  • Eosinophils

  • T cells

  • NK cells

  • Basophils

• Cell-Specific Receptor Engagement: CCL7 interacts with multiple chemokine receptors (CCR1, CCR2, CCR3, CCR5) expressed differentially on various leukocyte populations . This broad receptor engagement explains its ability to recruit diverse immune cell types.

• Amplification of Inflammatory Cascades: In acute kidney injury models, B cell-derived CCL7 facilitates neutrophil and monocyte recruitment to injured kidney tissues . This suggests CCL7 can initiate amplification loops where initial CCL7 production by one cell type (e.g., B cells) leads to recruitment of additional cell types that may themselves produce inflammatory mediators.

• Orchestration of Conventional Dendritic Cell Type 1 (cDC1) Recruitment: In tumor microenvironments, CCL7 specifically recruits cDC1 cells, which subsequently promote CD8+ and CD4+ T cell expansion and activation . This demonstrates CCL7's role in coordinating both innate and adaptive immune responses.

• Regulation by Inflammatory Context: The inhibition of CCL7 expression by anti-inflammatory cytokines (IL-4, IL-10, IL-13) indicates context-dependent regulation that helps fine-tune immune responses.

The multifaceted role of CCL7 in leukocyte recruitment makes it an important target for studying inflammatory disease mechanisms and potential therapeutic interventions.

What experimental approaches can effectively modulate CCL7 function in disease models?

Several experimental strategies have been employed to modulate CCL7 function:

• Antibody-Mediated Neutralization:

  • In acute kidney injury models, CCL7 blockade using neutralizing antibodies reduced myeloid cell infiltration and ameliorated injury

  • This approach allows temporal control of CCL7 inhibition without genetic manipulation

• Genetic Knockout or Knockdown:

  • CCL7-deficient mice showed impaired recruitment of cDC1, CD4+, and CD8+ T cells in tumor microenvironments

  • Tissue-specific or inducible knockout systems can provide spatial and temporal control

• Viral Vector-Mediated Overexpression:

  • Lentiviral vectors expressing CCL7 (Lenti-CCL7) administered into lungs significantly prolonged survival and inhibited tumor development in lung cancer models

  • This approach allows localized enhancement of CCL7 function

• Receptor Antagonism:

  • Targeting CCL7 receptors (CCR1, CCR2) using specific antagonists can block CCL7 signaling

  • Since these receptors bind multiple chemokines, this approach may have broader effects than CCL7-specific targeting

• Combined Approaches:

  • Combining CCL7 modulation with immune checkpoint inhibitors (e.g., anti-PD-1) showed enhanced efficacy against tumors compared to either approach alone

  • This demonstrates the potential for CCL7-targeting strategies in combination therapies

These approaches provide researchers with flexible tools to investigate CCL7's role in diverse pathological conditions.

What is the functional significance of CCL7 in dendritic cell recruitment and T cell activation?

CCL7 plays a critical role in orchestrating dendritic cell (DC) recruitment and subsequent T cell activation:

• Preferential Recruitment of cDC1:

  • CCL7 specifically recruits conventional type 1 dendritic cells (cDC1) into the tumor microenvironment

  • cDC1 cells express high levels of CCR1, CCR2, and CCR3, the primary receptors for CCL7

• Enhancement of T Cell Priming and Expansion:

  • CCL7-mediated recruitment of cDC1 facilitates:

    • Uptake of tumor antigens by cDC1

    • Migration of antigen-loaded cDC1 to draining lymph nodes

    • Presentation of antigens to naive T cells

    • Expansion of CD8+ and CD4+ T cells

• Impact on Anti-tumor Immunity:

  • In CCL7-deficient mice, the numbers of CD8+IFNγ+ T cells in bronchial draining lymph nodes and tumor-infiltrating lymphocytes were significantly decreased

  • This resulted in enhanced tumor growth and reduced survival

• Mechanism of Action:

  • CCL7 does not directly affect T cell proliferation or differentiation

  • Instead, it indirectly promotes T cell responses by optimizing DC recruitment and function

  • T cells themselves express minimal levels of CCR1/2/3, suggesting they are not direct targets of CCL7

• Therapeutic Implications:

  • Administration of CCL7 into lungs significantly increased infiltration of cDC1 and CD8+ T cells

  • Combined treatment of CCL7 and anti-PD-1 checkpoint inhibitors showed superior anti-tumor effects compared to anti-PD-1 alone

These findings highlight CCL7's role as a key orchestrator of cellular immunity, particularly in connecting innate and adaptive immune responses in the context of cancer and potentially other diseases.

How does CCL7 expression correlate with cancer progression and patient outcomes?

The relationship between CCL7 expression and cancer outcomes shows interesting context-dependent patterns:

These divergent findings suggest that CCL7's role in cancer is complex and tissue-specific, potentially promoting anti-tumor immunity in some contexts while facilitating tumor progression in others. Researchers should carefully consider these context-dependent effects when studying CCL7 in different cancer types.

What mechanisms underlie CCL7's effects on tumor growth and metastasis?

CCL7 influences tumor biology through several distinct molecular and cellular mechanisms:

• Immune-Mediated Mechanisms (Anti-tumorigenic):

  • Recruitment of cDC1 into the tumor microenvironment, promoting antigen presentation

  • Facilitation of CD8+ T cell expansion and infiltration into tumors

  • Enhancement of anti-PD-1 checkpoint immunotherapy efficacy by improving T cell responses

• Direct Effects on Tumor Cells (Pro-tumorigenic):

  • Activation of the PI3K/AKT signaling pathway in hepatocellular carcinoma cells

  • Promotion of epithelial-mesenchymal transition (EMT), a key process in metastasis

  • Enhancement of tumor cell proliferation, migration, and invasion capacities

• Angiogenesis Regulation:

  • Induction of VEGF secretion by tumor cells, promoting tumor vascularization

  • This effect is mediated through CCR1 and CCR2 receptors and activation of the PI3K/AKT pathway

• Receptor-Mediated Signaling:

  • Primary engagement of CCR1 and CCR2 on tumor cells to enhance growth and metastasis

  • CCR1/CCR2 silencing prevented CCL7 from activating the PI3K/AKT signaling pathway in cancer cells

• Interactions with Other Oncogenic Pathways:

  • Positive correlation with ABCE1 expression in lung cancer

  • ABCE1 may change the tumor microenvironment through the CCL7 pathway

These mechanisms demonstrate that CCL7 can exert both pro-tumorigenic and anti-tumorigenic effects depending on the cancer type, the predominant cell types in the tumor microenvironment, and the specific molecular context. This complexity may explain the apparently contradictory roles of CCL7 in different cancer types.

How can CCL7 be leveraged in cancer immunotherapy research?

CCL7's unique properties make it a promising target for enhancing cancer immunotherapy approaches:

• Combination with Immune Checkpoint Inhibitors:

  • In preclinical models, combining CCL7 administration with anti-PD-1 therapy significantly:

    • Prolonged survival of lung cancer mouse models

    • Inhibited tumor development more effectively than anti-PD-1 alone

    • Increased infiltration of CD11c+ or XCR1+ DCs and CD8+ T cells in tumors

• Biomarker Applications:

  • CCL7 levels in patient samples may predict responsiveness to immunotherapy:

    • Higher CCL7 levels were observed in NSCLC patients who responded to anti-PD-1 therapy

    • This suggests CCL7 could serve as a predictive biomarker alongside PD-L1 expression

  • For metastatic colorectal cancer, CCL7 in combination with CEA shows promise as a prognostic biomarker

• Local Delivery Approaches:

  • Lentivirus-mediated delivery of CCL7 to the lung microenvironment demonstrated therapeutic efficacy:

    • Intranasally administered Lenti-CCL7 significantly prolonged survival and inhibited tumor development

    • This approach increased cDC1 infiltration and CD8+IFNγ+ T cell numbers in tumor-burdened lungs

• Targeting Specific Cellular Interactions:

  • Enhancing the cDC1-T cell axis appears particularly promising:

    • CCL7 promotes recruitment of cDC1, which are critical for anti-tumor T cell responses

    • This approach may be especially valuable for "cold" tumors with poor immune infiltration

• Considerations for Clinical Translation:

  • Timing is important: CCL7 administration was effective even when initiated 6 weeks after tumor induction

  • Local vs. systemic delivery should be carefully evaluated to maximize efficacy while minimizing off-target effects

  • Cancer type-specific approaches may be necessary given CCL7's divergent roles in different cancers

These findings suggest CCL7-based strategies could enhance current immunotherapies, particularly for patients with poor immune infiltration in their tumors or resistance to existing checkpoint inhibitors.

What technical challenges exist in studying CCL7 in the tumor microenvironment?

Researchers face several technical challenges when investigating CCL7 in the tumor context:

• Spatial and Temporal Dynamics:

  • CCL7 gradients within tumors are difficult to capture using conventional techniques

  • Different cell types may produce CCL7 at different stages of tumor development

  • Recommended approach: Use spatial transcriptomics or multiplex immunofluorescence to map CCL7 distribution relative to immune cell populations

• Source Attribution:

  • Multiple cell types produce CCL7, including immune cells and tumor cells

  • Determining the primary cellular sources in heterogeneous tumors is challenging

  • Recommended approach: Single-cell RNA sequencing combined with flow cytometry sorting of tumor-infiltrating populations

• Functional Assessment:

  • Distinguishing direct effects of CCL7 on tumor cells from indirect effects mediated by immune cells

  • CCL7 may have opposing roles depending on the predominant receptor expression pattern

  • Recommended approach: Cell type-specific knockout models and conditional expression systems

• Receptor Redundancy:

  • CCL7 signals through multiple receptors (CCR1, CCR2, CCR3, CCR5)

  • These receptors also bind other chemokines, creating functional redundancy

  • Recommended approach: Use receptor-specific antagonists in combination with CCL7 neutralization to delineate specific signaling pathways

• Model System Limitations:

  • Mouse models may not fully recapitulate human CCL7 biology

  • Patient-derived xenografts often lack complete immune components

  • Recommended approach: Use humanized mouse models when possible and validate findings across multiple model systems

• Biomarker Standardization:

  • Variable detection methods and cutoff values for "high" vs. "low" CCL7 expression

  • Post-translational modifications affecting antibody recognition

  • Recommended approach: Establish standardized protocols for CCL7 quantification in clinical samples and include appropriate controls

Addressing these challenges requires integrated approaches combining multiple technologies and careful experimental design to accurately characterize CCL7's complex roles in the tumor microenvironment.

What emerging technologies are advancing CCL7 research?

Several cutting-edge technologies are transforming our ability to study CCL7 biology:

• Single-Cell Analysis Technologies:

  • Single-cell RNA sequencing (scRNA-seq) enables identification of specific cell populations producing CCL7 within heterogeneous tissues

  • Single-cell proteomics can detect CCL7 production at the protein level with cellular resolution

  • These approaches have revealed previously unrecognized roles for B cells in producing CCL7 during acute kidney injury

• CRISPR-Cas9 Gene Editing:

  • Precise manipulation of CCL7 or its receptors in specific cell populations

  • Creation of reporter cell lines for real-time monitoring of CCL7 expression

  • Development of animal models with tissue-specific or inducible CCL7 modulation

• Spatial Transcriptomics and Proteomics:

  • Mapping of CCL7 expression patterns within tissue microenvironments with spatial resolution

  • Correlation of CCL7 gradients with immune cell distributions and activation states

  • Understanding the spatial relationship between CCL7-producing and CCL7-responsive cells

• Advanced Imaging Techniques:

  • Intravital microscopy to visualize CCL7-dependent cell migration in real-time

  • Multiplex immunofluorescence to simultaneously detect CCL7 and multiple cell markers

  • These approaches can reveal dynamic aspects of CCL7 function not captured by static analyses

• Organoid and Microphysiological Systems:

  • 3D culture systems incorporating multiple cell types to model CCL7-mediated interactions

  • Microfluidic platforms that can establish chemokine gradients and monitor cellular responses

  • These systems bridge the gap between simplified in vitro models and complex in vivo environments

These technologies are enabling researchers to address previously intractable questions about CCL7 biology and function, particularly in complex disease contexts such as cancer and inflammatory conditions.

How do post-translational modifications affect CCL7 function and antibody recognition?

Post-translational modifications (PTMs) significantly impact CCL7 biology and create important considerations for antibody-based detection:

• O-Glycosylation:

  • CCL7 undergoes O-glycosylation, which can affect:

    • Protein stability and half-life in circulation

    • Receptor binding affinity and specificity

    • Immunogenicity and interaction with extracellular matrix components

  • Glycosylation patterns may vary between different tissue contexts and disease states

• Proteolytic Processing:

  • Like other chemokines, CCL7 can undergo N-terminal processing by proteases including:

    • Matrix metalloproteinases (MMPs)

    • CD26/dipeptidyl peptidase IV

  • This processing can modify receptor specificity or convert CCL7 into receptor antagonists

  • Studies suggest processed forms may have altered biological activities

• Impact on Antibody Recognition:

  • PTMs can mask epitopes recognized by certain antibodies

  • Different antibody clones may preferentially detect specific modified or unmodified forms

  • This can lead to discrepancies in results between different detection methods or antibodies

• Methodological Considerations:

  • Western blotting may show multiple bands or size shifts due to PTMs

  • ELISA kits may have variable sensitivity to different modified forms

  • Researchers should select antibodies validated for their specific application

• Experimental Strategies:

  • Use multiple antibody clones recognizing different epitopes

  • Include deglycosylation controls to assess impact on detection

  • Consider using mass spectrometry to characterize PTM patterns in experimental samples

Understanding and accounting for PTMs is crucial for accurate detection and functional assessment of CCL7 in biological systems, particularly when comparing results across different experimental platforms or antibody sources.

What are the key considerations for developing CCL7-targeting therapeutic approaches?

Developing therapeutic strategies targeting CCL7 requires careful consideration of several factors:

• Target Specificity:

  • CCL7 signals through multiple receptors (CCR1, CCR2, CCR3, CCR5) that also bind other chemokines

  • Blocking CCL7 alone may have limited efficacy if redundant chemokines compensate

  • Potential approaches include:

    • CCL7-specific neutralizing antibodies for selective targeting

    • Receptor antagonists for broader chemokine signaling inhibition

    • Combination approaches targeting multiple chemokines or receptors

• Context-Dependent Effects:

  • CCL7 has divergent roles in different diseases:

    • Anti-tumorigenic in some cancers (NSCLC) by promoting immune infiltration

    • Pro-tumorigenic in other cancers (HCC, mCRC) by enhancing tumor cell functions

    • Pro-inflammatory in acute kidney injury

  • Therapeutic strategies must be tailored to the specific disease context

• Delivery Considerations:

  • Systemic vs. local delivery impacts efficacy and side effect profiles

  • Local delivery approaches demonstrated in mouse models include:

    • Intranasal administration of Lenti-CCL7 for lung cancer

    • Targeted delivery systems using nanoparticles or tissue-specific vehicles

  • For enhancement approaches, controlled release systems may optimize therapeutic window

• Combination Therapy Opportunities:

  • CCL7 modulation shows particular promise in combination with:

    • Immune checkpoint inhibitors (anti-PD-1) in cancer

    • Anti-inflammatory agents in acute inflammatory conditions

    • Anti-angiogenic therapies in cancers where CCL7 promotes VEGF production

• Biomarker-Guided Patient Selection:

  • CCL7 levels or CCR1/2 expression patterns may identify patients likely to respond

  • The tumor immune microenvironment composition influences the impact of CCL7 modulation

  • Companion diagnostics could include:

    • Serum CCL7 measurement

    • Tissue assessment of CCL7 and relevant receptor expression

    • Immune profiling to assess cDC1 and T cell infiltration

These considerations highlight the complexity of developing CCL7-targeted therapies and the importance of precision medicine approaches that match specific strategies to appropriate disease contexts and patient populations.

What are the most significant recent advances in understanding CCL7 biology?

Recent research has substantially expanded our understanding of CCL7's biological functions beyond its classical role as a monocyte chemoattractant:

• Novel Cellular Sources:

  • The identification of B cells as important producers of CCL7 during acute kidney injury represents a significant paradigm shift

  • This finding highlights previously unrecognized roles for B cells in orchestrating innate immune responses

• Critical Role in Anti-tumor Immunity:

  • The discovery that CCL7 specifically recruits conventional type 1 dendritic cells (cDC1) to the tumor microenvironment

  • This recruitment is essential for effective T cell priming and subsequent anti-tumor responses

  • CCL7 administration enhances the efficacy of checkpoint inhibitor immunotherapy in preclinical models

• Diverse Roles in Cancer Biology:

  • Context-dependent effects of CCL7 across different cancer types:

    • Beneficial prognostic factor in NSCLC by promoting immune infiltration

    • Negative prognostic indicator in metastatic colorectal cancer

    • Direct pro-tumorigenic effects in hepatocellular carcinoma through PI3K/AKT pathway activation

• Molecular Pathway Interactions:

  • Identification of the relationship between ABCE1 and CCL7 in lung cancer progression

  • Elucidation of CCL7's role in promoting epithelial-mesenchymal transition and VEGF secretion in cancer cells

• Therapeutic Potential:

  • Demonstration that local delivery of CCL7 can reprogram the tumor microenvironment to enhance immunotherapy responses

  • Development of CCL7 as a biomarker for patient stratification in cancer treatment