Rantes Human

What is RANTES/CCL5 and what are its primary functions in human physiology?

RANTES, also known as CCL5, is a member of the C-C (beta)-family chemokines initially discovered through subtractive hybridization as a transcript expressed in T cells but absent in B cells . This pro-inflammatory chemokine primarily functions as a chemoattractant, mediating the migration and navigation of multiple cell types including T cells, monocytes, basophils, eosinophils, natural killer cells, dendritic cells, and mast cells . RANTES induces migration of mononuclear phagocytes across the blood-brain barrier to inflammation sites and possesses eosinophil-chemotactic activities when released by thrombin-stimulated human platelets . Unlike other chemokines, RANTES can stimulate T cells through two distinct mechanisms: the short-term mobilization of calcium ions through G protein-coupled receptors leading to cell polarization and migration, and the chronic increase of calcium ions dependent on protein tyrosine kinase, which can trigger T cell proliferation, apoptosis, or cytokine release .

Which cell types and tissues express RANTES/CCL5 in humans?

RANTES expression patterns in humans are diverse and context-dependent. While initially discovered in T cells, subsequent research has identified numerous cellular sources. Primary producers include T cells and platelets, but RANTES is also expressed by renal tubular epithelium, synovial fibroblasts, and selected tumor cells . Immunohistological studies using anti-RANTES monoclonal antibodies have revealed that while most normal adult tissues contain few RANTES-positive cells, expression dramatically increases at inflammatory sites . Notably, megakaryocytes, certain tumors, and select fetal tissues express high levels of RANTES message and protein . In the context of neurological disease, human astrocytic cells can be induced to express RANTES, particularly in response to pro-inflammatory stimuli like TNF-alpha . This wide expression pattern suggests multiple physiological roles beyond what was previously appreciated .

What are the primary receptors for human RANTES/CCL5 and how do they mediate its biological effects?

Human RANTES/CCL5 exerts its biological effects through binding to multiple C-C chemokine receptors, primarily CCR5, CCR3, and CCR1 . Upon receptor binding, RANTES activates signaling pathways that orchestrate immune cell trafficking and inflammatory responses. The binding to these G protein-coupled receptors triggers short-term mobilization of calcium ions, leading to cell polarization and subsequent migration toward the chemotactic gradient . Additionally, chronic calcium increase dependent on protein tyrosine kinase can induce numerous cellular responses including T cell proliferation or apoptosis, and the release of interleukin-2 (IL-2), interleukin-5 (IL-5), or interferon gamma (IFN-γ) . This dual mechanism of T cell stimulation is relatively unique among chemokines and contributes to RANTES' diverse biological effects . The affinity and specificity of RANTES for its multiple receptors allow for fine-tuned regulation of different cell populations during inflammatory processes.

What are the most effective methods for measuring RANTES/CCL5 levels in human samples?

For quantitative assessment of RANTES/CCL5 levels in human samples, researchers should consider several validated methodological approaches. Based on the scientific literature, magnetic bead-based multiplex assays provide excellent sensitivity and specificity for RANTES detection in plasma samples. The Human Neurodegenerative Disease Magnetic Bead Panel 3 kit (HNDG3MAG-36K, Millipore) has been successfully employed in clinical studies examining RANTES levels in Alzheimer's disease patients .

When collecting blood samples, it is recommended to use DPPIV Protease Inhibitor Cocktail to preserve protein integrity, followed by immediate centrifugation and storage at -80°C until analysis . For immunohistochemical detection of RANTES in tissue sections, researchers can use characterized anti-RANTES monoclonal antibodies generated against recombinant human RANTES protein, which allow for visualization of RANTES-expressing cells in both normal and diseased tissues . This approach can be complemented with in situ hybridization using RANTES mRNA-specific oligomeric probes to confirm active transcription .

For functional studies, recombinant human CCL5/RANTES protein preparations are available (such as catalog #278-RN), which can be reconstituted at 100 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin . The biological activity of recombinant RANTES can be confirmed through chemotaxis assays, where functional RANTES will chemoattract cells expressing appropriate receptors, such as BaF3 mouse pro-B cells transfected with human CCR5, with an ED50 of approximately 1-5 ng/mL .

How should researchers design experiments to study RANTES/CCL5 signaling pathways in human cells?

When designing experiments to investigate RANTES/CCL5 signaling pathways in human cells, researchers should employ a multi-faceted approach that addresses both immediate signaling events and downstream transcriptional changes. Based on existing literature, the following experimental framework is recommended:

First, establish appropriate cell models that express RANTES receptors (CCR1, CCR3, and CCR5). Human astrocytic cell lines have been effectively used to study RANTES signaling in the context of neuroinflammation . For mechanistic studies focusing on NF-κB pathway activation, researchers should monitor calcium mobilization immediately after RANTES exposure, as this represents an early signaling event .

For transcription factor analysis, electrophoretic mobility shift assays (EMSAs) can detect increased NF-κB DNA-binding activity, while supershift assays with specific antibodies can identify the involved subunits (p65 and p50 have been identified as components of the activated NF-κB transcription factor complex in RANTES signaling) . To confirm the functional relevance of NF-κB activation, researchers should employ multiple NF-κB inhibitors and assess their impact on RANTES-induced gene expression at both mRNA and protein levels .

To establish causality in signaling pathways, design experiments with specific pathway inhibitors and genetic approaches (siRNA knockdown or CRISPR-Cas9 gene editing) targeting key signaling components. Validation of findings across multiple cell types is essential, as RANTES signaling may exhibit cell-type specific features. Finally, in vivo confirmation using appropriate animal models complements in vitro findings and establishes physiological relevance of the identified pathways.

What are the best approaches for studying cross-species functionality of RANTES/CCL5?

When investigating the cross-species functionality of RANTES/CCL5, researchers should implement systematic comparative approaches that account for both structural and functional conservation. The literature indicates that human and mouse RANTES exhibit cross-species activity on cells from both species, making mouse models viable for studying certain aspects of human RANTES biology .

A comprehensive experimental strategy should begin with sequence analysis comparing mature human CCL5 with the homologous proteins from experimental animal species. Human CCL5 shares 75-84% amino acid sequence identity with canine and cotton rat homologs, providing a basis for predicting functional conservation . Following in silico analysis, experimental validation should be conducted using purified recombinant proteins from different species.

Functional cross-species assays should include chemotaxis experiments using target cells (such as T cells or monocytes) from one species exposed to RANTES from another. For example, BaF3 mouse pro-B cells transfected with human CCR5 have been successfully used to assess human RANTES functionality, demonstrating chemoattraction with an ED50 of 1-5 ng/mL . Receptor binding studies comparing the affinity of RANTES from different species to human receptors (CCR1, CCR3, CCR5) provide additional mechanistic insights.

For in vivo validation, researchers should design experiments where human RANTES is administered to suitable animal models, with subsequent assessment of immune cell recruitment and inflammatory responses. Conversely, animal RANTES can be tested on human cells or in humanized mouse models. These complementary approaches will establish the extent of functional conservation and identify species-specific differences that might impact translational research.

How is RANTES/CCL5 implicated in Alzheimer's disease pathogenesis?

RANTES/CCL5 has emerged as a significant factor in Alzheimer's disease (AD) pathophysiology, with potential utility as a peripheral biomarker for early disease stages. Recent observational studies have demonstrated substantially elevated plasma RANTES levels in AD patients compared to healthy controls . Notably, a negative correlation exists between RANTES levels and disease duration, Fazekas scale score, and medial temporal lobe atrophy (MTA) score (Scheltens's scale) in AD patients, indicating that higher RANTES levels correspond to earlier disease stages .

The mechanistic connection between RANTES and AD pathogenesis involves neuroinflammatory processes. RANTES levels in AD patients positively correlate with pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), consistent with the established inflammatory component of AD pathology . This relationship suggests RANTES may participate in the inflammatory cascade that contributes to neurodegeneration. Additionally, metabolic factors may play a role, as RANTES levels in AD patients show positive correlations with insulin levels, insulin resistance (HOMA-R), and pancreatic beta cell function (HOMA-F) .

The table below illustrates the significant difference in RANTES levels between AD patients and healthy controls, along with other inflammatory markers:

These findings suggest RANTES may serve as a promising peripheral marker for early AD detection, potentially offering a less invasive and less expensive alternative to cerebrospinal fluid biomarkers or neuroimaging methods .

What is the relationship between RANTES/CCL5 expression and neuroinflammatory diseases?

RANTES/CCL5 plays a critical role in neuroinflammatory diseases through its ability to orchestrate immune cell migration into the central nervous system (CNS). Research has established RANTES as a key mediator in multiple neuroinflammatory conditions, with particularly strong evidence in multiple sclerosis (MS) and Alzheimer's disease.

In MS, RANTES is implicated in the pathological migration of peripheral blood leukocytes to brain lesions . As a C-C (beta)-family chemokine, it facilitates the recruitment of T cells and other immune cells across the blood-brain barrier, contributing to the inflammatory demyelinating process characteristic of MS . The molecular mechanism involves RANTES-induced migration of mononuclear phagocytes to sites of inflammation within the CNS .

Astrocytes represent a significant source of RANTES in neuroinflammatory conditions. TNF-alpha, a pro-inflammatory cytokine elevated in many neuroinflammatory diseases, induces RANTES gene expression in human astrocytic cells through NF-κB-dependent mechanisms . Specifically, TNF-alpha activation leads to increased NF-κB DNA-binding activity, with p65 and p50 subunits forming the activated transcription factor complex that drives RANTES expression . Experimental blockade of NF-κB activation using known inhibitors significantly reduces TNF-alpha-induced RANTES expression at both mRNA and protein levels, confirming the causal relationship .

Beyond MS and AD, altered RANTES levels and expression patterns have been reported in Parkinson's disease and other neurodegenerative conditions where neuroinflammation plays a contributory role . These findings collectively position RANTES as a central participant in neuroinflammatory processes and a potential therapeutic target for CNS inflammatory diseases.

How do RANTES/CCL5 levels correlate with disease progression in inflammatory conditions?

RANTES/CCL5 demonstrates complex relationships with disease progression across various inflammatory conditions, with patterns that may differ depending on the specific pathology. In Alzheimer's disease (AD), research has revealed an intriguing negative correlation between plasma RANTES levels and disease duration, Fazekas scale score, and medial temporal lobe atrophy (MTA) score . This pattern indicates that higher RANTES levels correspond to earlier stages of AD, suggesting potential utility as an early biomarker rather than a progression marker .

In multiple sclerosis and other neuroinflammatory conditions, RANTES contributes to the migration of immune cells to CNS lesions, but comprehensive longitudinal studies correlating RANTES levels with disease progression markers are still needed . The complex expression patterns observed across different tissues and inflammatory states indicate that RANTES may serve multiple physiological roles .

For researchers studying inflammatory conditions, these findings highlight the importance of contextualizing RANTES measurements with disease stage, other inflammatory markers, and clinical parameters. Time-course studies and multivariate analyses are recommended to fully elucidate the relationship between RANTES and disease progression in specific inflammatory conditions.

How can researchers effectively manipulate RANTES/CCL5 expression for experimental studies?

Effective manipulation of RANTES/CCL5 expression requires tailored approaches depending on the experimental goals and cellular contexts. Based on the scientific literature, several validated strategies can be implemented:

For upregulation of RANTES expression, researchers can utilize TNF-alpha stimulation, particularly in human astrocytic cells where this approach has been well-characterized. TNF-alpha treatment induces RANTES gene expression through NF-κB-dependent mechanisms . The activation of NF-κB leads to increased binding to the promoter of the human RANTES gene, resulting in enhanced expression at both mRNA and protein levels .

Conversely, for RANTES downregulation, targeting the NF-κB pathway presents an effective approach. Multiple NF-κB inhibitors have been shown to markedly reduce TNF-alpha-induced RANTES expression . Researchers should consider combining multiple inhibitors to confirm results, as this approach has successfully demonstrated that reduction in NF-κB binding activity to the RANTES gene promoter parallels decreased RANTES expression .

For more precise genetic manipulation, CRISPR-Cas9 gene editing or siRNA approaches targeting RANTES or its transcriptional regulators can be employed. When using recombinant RANTES protein for functional studies, proper reconstitution protocols are critical - recombinant human CCL5/RANTES protein should be reconstituted at 100 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin . For carrier-free applications, reconstitution in sterile PBS alone is recommended .

Validation of successful manipulation should include both mRNA quantification (qRT-PCR) and protein assessment (ELISA, Western blot, or functional chemotaxis assays). The BaF3 mouse pro-B cell line transfected with human CCR5 provides a useful system for functional validation, with effective RANTES demonstrating chemoattraction with an ED50 of 1-5 ng/mL .

What are the most promising therapeutic approaches targeting RANTES/CCL5 in human diseases?

Therapeutic approaches targeting RANTES/CCL5 represent an emerging frontier in treating inflammatory and neurodegenerative conditions. Based on current research, several strategies show particular promise:

Receptor antagonism presents a direct approach, with CCR5 antagonists being the most advanced in development. These compounds disrupt RANTES binding to its primary receptor, potentially limiting inflammatory cell recruitment. This strategy may be particularly relevant for neuroinflammatory conditions like multiple sclerosis, where RANTES mediates leukocyte migration to brain lesions . The established role of CCR5 in HIV entry has already led to approved CCR5 antagonists that could potentially be repurposed for inflammatory conditions.

NF-κB pathway modulation offers an upstream intervention point. Since TNF-alpha-induced RANTES expression in human astrocytic cells operates through NF-κB-dependent mechanisms, compounds that inhibit NF-κB activation could reduce pathological RANTES expression . This approach might be especially valuable in conditions with localized inflammation, such as neuroinflammatory diseases.

Neutralizing antibodies against RANTES represent another promising strategy. Monoclonal antibodies generated against recombinant human RANTES protein have been characterized and could be developed into therapeutic agents . These antibodies would directly bind and neutralize circulating RANTES, preventing receptor engagement and downstream inflammatory effects.

For Alzheimer's disease, the markedly elevated RANTES levels in early disease stages suggest potential for early intervention . The positive correlation between RANTES levels and insulin parameters (insulin levels, insulin resistance, pancreatic beta cell function) in AD patients indicates possible metabolic connections that could be therapeutically exploited .

Any therapeutic development must consider RANTES' physiological roles and the potential for side effects from complete inhibition. Tissue-specific or context-dependent targeting approaches may offer the best balance of efficacy and safety.

How do genetic variations in RANTES/CCL5 or its receptors impact human disease susceptibility?

Genetic variations in RANTES/CCL5 and its receptors (particularly CCR5, CCR3, and CCR1) can significantly impact disease susceptibility through alterations in expression levels, protein structure, and receptor-ligand interactions. While the provided search results don't directly address genetic variations, extrapolation from the functional data allows for informed discussion of this important research area.

The critical role of RANTES in mediating immune cell migration suggests that polymorphisms affecting its expression or function could modulate inflammatory responses. Since RANTES expression is regulated through NF-κB-dependent mechanisms , genetic variants in the RANTES promoter region that alter NF-κB binding sites could influence baseline and induced expression levels. Similarly, polymorphisms affecting the stability or translation efficiency of RANTES mRNA could impact protein availability.

The most extensively studied genetic variation related to this pathway is the CCR5-Δ32 deletion mutation, which produces a truncated, non-functional CCR5 receptor. Homozygosity for this mutation provides protection against HIV infection, as CCR5 serves as a co-receptor for viral entry. This same variation likely impacts RANTES-mediated inflammatory responses, potentially altering susceptibility to conditions where RANTES plays a pathological role.

Given RANTES' involvement in Alzheimer's disease pathophysiology , genetic variants affecting RANTES expression or receptor function might influence AD risk or progression. The observation that RANTES levels correlate with insulin parameters and inflammatory markers in AD patients suggests that genetic variations in RANTES could interact with metabolic and inflammatory risk factors.

For researchers investigating genetic associations, comprehensive approaches should include:

• Sequencing of RANTES coding and regulatory regions

• Analysis of receptor gene variants (CCR5, CCR3, CCR1)

• Functional validation of identified variants

• Integration with clinical and biomarker data to establish disease relevance

These studies would contribute to understanding individual disease susceptibility and potentially identify new targets for personalized therapeutic interventions.

What unresolved questions about RANTES/CCL5 should researchers prioritize?

Despite significant advances in understanding RANTES/CCL5 biology, several critical knowledge gaps remain that warrant prioritized research attention:

First, the precise mechanistic relationship between elevated RANTES levels and early-stage Alzheimer's disease requires clarification. While studies have demonstrated substantially higher plasma RANTES levels in AD patients compared to controls (74,858 pg/mL vs. 832 pg/mL) , with negative correlations to disease duration and brain atrophy measures, the causative versus consequential nature of this relationship remains unclear. Does RANTES directly contribute to early pathological processes, or does it represent a compensatory response? Longitudinal studies tracking RANTES levels from pre-symptomatic through disease progression stages would provide valuable insights.

Second, the cell-specific contributions to RANTES production in different pathological contexts need further characterization. While RANTES is known to be produced by T cells, platelets, renal tubular epithelium, synovial fibroblasts, astrocytes, and selected tumor cells , the relative importance of these sources in specific disease states remains poorly defined. Single-cell sequencing approaches combined with spatial transcriptomics could map RANTES expression patterns with unprecedented resolution.

Third, the isoform-specific functions of RANTES require deeper investigation. Post-translational modifications of RANTES, including potential proteolytic processing, may generate variants with distinct biological activities. Comprehensive proteomic characterization of naturally occurring RANTES isoforms in different tissues and disease states would address this knowledge gap.

Finally, the interplay between RANTES and metabolic factors deserves focused attention, particularly given the observed correlations with insulin parameters in AD patients . Understanding how RANTES interfaces with metabolic pathways could reveal novel therapeutic approaches for conditions where both inflammation and metabolic dysfunction contribute to pathology.

How might emerging technologies advance our understanding of RANTES/CCL5 biology?

Emerging technologies offer unprecedented opportunities to deepen our understanding of RANTES/CCL5 biology across multiple scales, from molecular interactions to systemic functions. Several technological frontiers hold particular promise:

Single-cell multi-omics approaches can revolutionize our understanding of RANTES production and response patterns. By simultaneously profiling transcriptomes, proteomes, and epigenomes at single-cell resolution, researchers can identify cell populations that produce or respond to RANTES with high specificity. This technology would help clarify the heterogeneity in RANTES expression reported across different tissues and could identify previously unrecognized cellular sources or targets.

CRISPR-based functional genomics, including CRISPR activation and interference screens, provides powerful tools for systematically mapping genes involved in RANTES regulation and signaling. These approaches could uncover novel transcription factors that work alongside NF-κB in controlling RANTES expression , or identify unappreciated components of receptor-mediated signaling pathways.

Advanced imaging technologies, particularly intravital multiphoton microscopy combined with fluorescent RANTES reporters, would enable real-time visualization of RANTES-mediated cell recruitment in living tissues. This approach could transform our understanding of RANTES function in neuroinflammatory conditions, where it mediates leukocyte migration to specific brain regions .

Artificial intelligence and machine learning algorithms applied to integrated multi-omics datasets could identify complex patterns connecting RANTES expression with disease phenotypes. This computational approach would be particularly valuable for exploring the relationship between RANTES and Alzheimer's disease progression, where current evidence suggests intriguing correlations with disease stage and inflammatory markers .

Finally, organ-on-chip and patient-derived organoid technologies offer platforms for studying RANTES function in physiologically relevant human tissue systems. These models could help translate findings from animal studies, leveraging the cross-species activity of RANTES while maintaining human-specific features.

What are the potential applications of RANTES/CCL5 as a biomarker in clinical settings?

RANTES/CCL5 demonstrates significant potential as a clinical biomarker across multiple disease contexts, with particularly promising applications in neurodegenerative and inflammatory conditions. Based on current research, several applications warrant further development:

In Alzheimer's disease, plasma RANTES levels show remarkable potential as an early-stage biomarker. The substantial elevation of RANTES in AD patients compared to controls (74,858 pg/mL vs. 832 pg/mL, p<0.001) , combined with the negative correlation with disease duration and brain atrophy measures, suggests utility for early detection. Importantly, as a peripheral blood biomarker, RANTES measurement offers advantages over cerebrospinal fluid biomarkers or neuroimaging in terms of accessibility, cost, and patient comfort . Further validation studies with larger, longitudinal cohorts would strengthen its clinical applicability.

For neuroinflammatory conditions like multiple sclerosis, where RANTES mediates leukocyte migration to brain lesions , monitoring RANTES levels could potentially track inflammatory activity or predict disease flares. The established role of RANTES in immune cell recruitment suggests it may reflect ongoing inflammatory processes before clinical manifestations appear.

The positive correlation between RANTES levels and inflammatory markers (IL-6, TNF-α) in AD patients indicates potential utility in monitoring inflammatory components of disease processes. This could be particularly valuable for identifying patients who might benefit from anti-inflammatory interventions or for tracking treatment responses.

For clinical implementation, standardized measurement protocols using validated assays such as the Human Neurodegenerative Disease Magnetic Bead Panel would be essential. Reference ranges need establishment across different populations, accounting for potential confounding factors like age, sex, and comorbidities. Combining RANTES measurement with other biomarkers in multiparameter panels might enhance diagnostic accuracy and prognostic value, particularly in complex conditions like Alzheimer's disease where multiple pathological processes contribute to disease progression.