Discovery of small-molecules targeting the CCL20/CCR6 axis as first-in-class inhibitors for inflammatory bowel diseases

Using Olink Proteomics to Identify Inflammatory Biomarkers in the Cerebrospinal Fluid in Guillain-Barré Syndrome

Purpose

The precise etiology of Guillain-Barré syndrome (GBS) is uncertain; however, it is linked to immunological and inflammatory processes. Thus, this research aims to investigate new inflammatory biomarkers for GBS diagnosis.

Patients and Methods

In this work, Olink proteomics was used to compare the expression levels of 92 inflammation-related proteins in the cerebrospinal fluid (CSF) of patients with non-inflammatory neurological diseases (n=14) and GBS (n=23). Differentially expressed proteins (DEPs) were then analyzed biologically and in terms of their relationship to clinical features, and logistic regression models were built. We also downloaded GEO data to validate DEPs at the mRNA level.

Results

We identified twenty DEPs. The PPI network screened six key DEPs (including TNF, CCL20, IL8, MCP-1, IL10, and IL5). These DEPs were enriched in the chemokine signaling pathway, the IL-17 signaling pathway, cytokines and their receptor interactions, and other pathways. TNFRSF9 and IL-10RB showed the strongest correlation of expression in CSF. CCL20 and IL5 could be used as potential independent predictors for the diagnosis of GBS. Seven DEPs (MCP-1, CXCL1, MCP-4, MMP-10, CXCL10, CCL28, and CCL20) had some predictive value for the severity of GBS. Based on the validation of the GEO data, the mRNA expression of MCP-1 and CXCL9 was found to be upregulated at the peak of EAN, and the enriched pathways at the gene transcription level were consistent with the results of this study.

Conclusion

DEPs linked to inflammation (such as TNF, CCL20, IL8, MCP-1, IL10, and IL5) could be useful biomarkers for GBS diagnosis. More research is required to determine their precise mechanisms in GBS.

Zinc Finger Protein 639 Expression Is a Novel Prognostic Determinant in Breast Cancer

PURPOSE

Zinc finger protein 639 (ZNF639) is often found within the overlapping amplicon of PIK3CA, and previous studies suggest its involvement in the pathogenesis of esophageal and oral squamous cell carcinomas. However, its expression and significance in breast cancer remain uncharacterized.

METHODS

Immunohistochemical analysis of ZNF639 was performed using tissue microarrays. Functional studies, including colony formation, Transwell cell migration, and in vivo metastasis, were conducted on breast tumor cells with ZNF639 knockdown via small interfering RNA transfection.

RESULTS

Reduced ZNF639 immunoreactivity was observed in 82% of the breast cancer samples, independent of hormone receptor and human epidermal growth factor receptor 2 status. In multivariate Cox regression analyses, ZNF639 expression was associated with favorable survival outcomes, including recurrence-free survival (hazard ratio, 0.35; 95% confidence interval [CI], 0.14-0.89) and overall survival (hazard ratio, 0.41; 95% CI, 0.16-1.05). ZNF639 knockdown increased clonogenicity, cell motility, and lung metastasis in NOD/SCID mice. Following the ZNF639 knockdown, the expression of Snail1, vimentin, and C-C chemokine ligand 20 (CCL20) was upregulated, and the changes in cell phenotype mediated by ZNF639 were reversed by the subsequent knockdown of CCL20.

CONCLUSION

Low ZNF639 expression is a novel prognostic factor for recurrence-free survival in patients with breast cancer.

Progress of CCL20-CCR6 in the airways: a promising new therapeutic target

The chemokine CCL20, a small cytokine that belongs to the C-C chemokine family, interacts with its homologous receptor CCR6, which is expressed on wide range of cell types. According to current research, the CCL20-CCR6 has been established as acritical player in a diverse range of inflammatory, oncogenic, and autoimmune diseases. Within the respiratory system, CCL20-CCR6 demonstrates heightened expression in conditions such as allergic asthma, chronic airway inflammation, non-small cell lung cancer (NSCLC), chronic obstructive pulmonary disease (COPD), and other respiratory diseases, which is conducive to the inflammatory mediators recruitment and tumor microenvironment remodeling. Numerous studies have demonstrated that therapeutic interventions targeting CCL20 and CCR6, including antibodies and antagonists, have the potential to mitigate disease progression. Despite the promising research prospects surrounding the CCL20-CCR6 chemokine axis, the precise mechanisms underlying its action in respiratory diseases remain largely elusive. In this review, we delve into the potential roles of the CCL20-CCR6 axis within the respiratory system by synthesizing and analyzing current research findings. Our objective is to provide a comprehensive understanding of the CCL20-CCR6 axis and its implications for respiratory health and disease. And we aspire to propel research endeavors in this domain and furnish valuable insights for the development of future therapeutic strategies.

Benzofuran-2-Carboxamide Derivatives as Immunomodulatory Agents Blocking the CCL20-Induced Chemotaxis and Colon Cancer Growth

The correlation between the CCL20/CCR6 axis and autoimmune and non-autoimmune disorders is widely recognized. Inhibition of the CCL20-dependent cell migration represents therefore a promising approach for the treatment of many diseases, such as inflammatory bowel diseases and colorectal cancer. We report herein our efforts to explore the biologically relevant chemical space around the benzofuran scaffold of MR120, a modulator of the CCL20/CCR6 axis previously discovered by our group. A functional screening allowed us to identify C4 and C5-substituted derivatives as the most effective inhibitors of the CCL20-induced chemotaxis of human peripheral blood mononuclear cells (PBMC). Moreover, selected compounds (16 e and 24 b) also proved to potently inhibit the growth of different colon cancer cell lines, with cytotoxic/cytostatic and antiproliferative activity.

Development of a NanoBRET Assay Platform to Detect Intracellular Ligands for the Chemokine Receptors CCR6 and CXCR1

A conserved intracellular allosteric binding site (IABS) was recently identified at several G protein-coupled receptors (GPCRs). This target site allows the binding of allosteric modulators and enables a new mode of GPCR inhibition. Herein, we report the development of a NanoBRET-based assay platform based on the fluorescent ligand LT221 (5), to detect intracellular binding to CCR6 and CXCR1, two chemokine receptors that have been pursued as promising drug targets in inflammation and immuno-oncology. Our assay platform enables cell-free as well as cellular NanoBRET-based binding studies in a nonisotopic and straightforward manner. By combining this screening platform with a previously reported CXCR2 assay, we investigated CXCR1/CXCR2/CCR6 selectivity profiles for both known and novel squaramide analogues derived from navarixin, a known intracellular CXCR1/CXCR2 antagonist and phase II clinical candidate for the treatment of pulmonary diseases. By means of these studies we identified compound 10, a previously reported tert-butyl analogue of navarixin, as a low nanomolar intracellular CCR6 antagonist. Further, our assay platform clearly indicated intracellular binding of the CCR6 antagonist PF-07054894, currently evaluated in phase I clinical trials for the treatment of ulcerative colitis, thereby providing profound evidence for the existence and the pharmacological relevance of a druggable IABS at CCR6.

T cell trafficking in human chronic inflammatory diseases

Circulating T cells, which migrate from the periphery to sites of tissue inflammation, play a crucial role in the development of various chronic inflammatory conditions. Recent research has highlighted subsets of tissue-resident T cells that acquire migratory capabilities and re-enter circulation, referred to here as "recirculating T cells." In this review, we examine recent advancements in understanding the biology of T cell trafficking in diseases where T cell infiltration is pivotal, such as multiple sclerosis and inflammatory bowel diseases, as well as in metabolic disorders where the role of T cell migration is less understood. Additionally, we discuss current insights into therapeutic strategies aimed at modulating T cell circulation across tissues and the application of state-of-the-art technologies for studying recirculation in humans. This review underscores the significance of investigating T trafficking as a novel potential target for therapeutic interventions across a spectrum of human chronic inflammatory diseases.

Discovery of the Clinical Candidate IDOR-1117-2520: A Potent and Selective Antagonist of CCR6 for Autoimmune Diseases

Migration of immune cells to sites of inflammation is a critical step in the body's response to infections but also during autoimmune flares. Chemokine receptors, members of the GPCR receptors, are instrumental in directing specific cell types to their target organs. Herein, we describe a highly potent small molecule antagonist of the chemokine receptor CCR6, which came out of fine-tuned structural elaborations from a proprietary HTS hit. Three main issues in the parent chemical series-cytotoxicity, phototoxicity, and hERG, were successfully solved. Biological characterization demonstrated that compound 45 (IDOR-1117-2520) is a selective and insurmountable antagonist of CCR6. In vivo proof-of-mechanism studies in a mouse lung inflammation model using a representative compound from the chemical class of 45 confirmed that the targeted CCR6+ cells were efficiently inhibited from migrating into the bronchoalveoli. Finally, ADMET and physicochemical properties were well balanced and the preclinical package warranted progress in the clinic.

Role of the CCL20/CCR6 axis in tubular epithelial cell injury: Kidney-specific translational insights from acute kidney injury to chronic kidney disease

This study investigated the role of the axis involving chemokine receptor 6 (CCR6) and its ligand chemokine (C-C motif) ligand 20 (CCL20) in acute kidney disease (AKD) using an ischemia-reperfusion injury (IRI) model. The model was established by clamping the unilateral renal artery pedicle of C57BL/6 mice for 30 min, followed by evaluation of CCL20/CCR6 expression at 4 weeks post-IRI. In vitro studies were conducted to examine the effects of hypoxia and H2 O2 -induced oxidative stress on CCL20/CCR6 expression in kidney tissues of patients with AKD and chronic kidney disease (CKD). Tubular epithelial cell apoptosis was more severe in C57BL/6 mice than in CCL20 antibody-treated mice, and CCR6, NGAL mRNA, and IL-8 levels were higher under hypoxic conditions. CCL20 blockade ameliorated apoptotic damage in a dose-dependent manner under hypoxia and reactive oxygen species injury. CCR6 expression in IRI mice indicated that the disease severity was similar to that in patients with the AKD phenotype. Morphometry of CCL20/CCR6 expression revealed a higher likelihood of CCR6+ cell presence in CKD stage 3 patients than in stage 1-2 patients. Kidney tissues of patients with CKD frequently contained CCL20+ cells, which were positively correlated with interstitial inflammation. CCL20/CCR6 levels were increased in fibrotic kidneys at 4 and 8 weeks after 5/6 nephrectomy. These findings suggest that modulating the CCL20/CCR6 pathway is a potential therapeutic strategy for managing the progression of AKD to CKD.

Effects of Golimumab and Ustekinumab on Circulating Dendritic Cell Migratory Capacity in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic condition which includes ulcerative colitis (UC) and Crohn's disease (CD), the origins of which are not yet fully understood. Both conditions involve an exacerbated immune response in the intestinal tract, leading to tissue inflammation. Dendritic cells (DCs) are antigen-presenting cells crucial for maintaining tolerance in the gastrointestinal mucosa. Previous research has indicated that DC recruitment to the intestinal mucosa is more pronounced in individuals with IBD, but the specific mechanisms governing this migration remain unclear. This study aimed to assess the expression of various homing markers and the migratory abilities of circulating DC subsets in response to intestinal chemotactic signals. Additionally, this study examined how golimumab and ustekinumab impact these characteristics in individuals with IBD compared to healthy controls. The findings revealed that a particular subset of DCs known as type 2 conventional DCs (cDC2) displayed a more pronounced migratory profile compared to other DC subsets. Furthermore, the study observed that golimumab and ustekinumab had varying effects on the migratory profile of cDC1 in individuals with CD and UC. While CCL2 did not exert a chemoattractant effect on DC subsets in this patient cohort, treatment with golimumab and ustekinumab enhanced their migratory capacity towards CCL2 and CCL25 while reducing their migration towards MadCam1. In conclusion, this study highlights that cDC2 exhibits a heightened migratory profile towards the gastrointestinal mucosa compared to other DC subsets. This finding could be explored further for the development of new diagnostic biomarkers or the identification of potential immunomodulatory targets in the context of IBD.

Establishment of a Novel Anti-Human CCR6 Monoclonal Antibody C6Mab-19 with the High Binding Affinity in Flow Cytometry

CC chemokine receptor 6 (CCR6) is a member of the G-protein-coupled receptor family that is highly expressed in B lymphocytes, effector and memory T cells, regulatory T cells, and immature dendritic cells. CCR6 has been revealed to have important functions in many pathological conditions, such as cancer, intestinal bowel disease, psoriasis, and autoimmune diseases. The only CCR6 chemokine ligand, CC motif chemokine ligand 20 (CCL20), is also involved in pathogenesis by interacting with CCR6. The CCL20/CCR6 axis is drawing attention as an attractive therapeutic target for various diseases. In this study, we developed novel monoclonal antibodies (mAbs) against human CCR6 (hCCR6) using the peptide immunization method, which are applicable to flow cytometry and immunohistochemistry. The established anti-hCCR6 mAb, clone C6Mab-19 (mouse IgG1, kappa), reacted with hCCR6-overexpressed Chinese hamster ovary-K1 (CHO/hCCR6), human liver carcinoma (HepG2), and human differentiated hepatoma (HuH-7) cells in flow cytometry. The dissociation constant (KD) of C6Mab-19 was determined as 3.0 × 10-10 M for CHO/hCCR6, 6.9 × 10-10 M for HepG2, and 1.8 × 10-10 M for HuH-7. Thus, C6Mab-19 could bind to exogenously and endogenously expressed hCCR6 with extremely high affinity. Furthermore, C6Mab-19 could stain formalin-fixed paraffin-embedded lymph node tissues from a patient with non-Hodgkin lymphoma by immunohistochemistry. Therefore, C6Mab-19 is suitable for detecting hCCR6-expressing cells and tissues and could be useful for pathological analysis and diagnosis.

Identification of the Binding Epitope of an Anti-Mouse CCR6 Monoclonal Antibody (C6Mab-13) Using 1× Alanine Scanning

CC chemokine receptor 6 (CCR6) is one of the members of the G-protein-coupled receptor (GPCR) family that is upregulated in many immune-related cells, such as B lymphocytes, effector and memory T cells, regulatory T cells, and immature dendritic cells. The coordination between CCR6 and its ligand CC motif chemokine ligand 20 (CCL20) is deeply involved in the pathogenesis of various diseases, such as cancer, psoriasis, and autoimmune diseases. Thus, CCR6 is an attractive target for therapy and is being investigated as a diagnostic marker for various diseases. In a previous study, we developed an anti-mouse CCR6 (mCCR6) monoclonal antibody (mAb), C₆Mab-13 (rat IgG₁, kappa), that was applicable for flow cytometry by immunizing a rat with the N-terminal peptide of mCCR6. In this study, we investigated the binding epitope of C₆Mab-13 using an enzyme-linked immunosorbent assay (ELISA) and the surface plasmon resonance (SPR) method, which were conducted with respect to the synthesized point-mutated-peptides within the 1-20 amino acid region of mCCR6. In the ELISA results, C₆Mab-13 lost its ability to react to the alanine-substituted peptide of mCCR6 at Asp11, thereby identifying Asp11 as the epitope of C₆Mab-13. In our SPR analysis, the dissociation constants (K_D) could not be calculated for the G9A and D11A mutants due to the lack of binding. The SPR analysis demonstrated that the C₆Mab-13 epitope comprises Gly9 and Asp11. Taken together, the key binding epitope of C₆Mab-13 was determined to be located around Asp11 on mCCR6. Based on the epitope information, C₆Mab-13 could be useful for further functional analysis of mCCR6 in future studies.

CCR6 as a Potential Target for Therapeutic Antibodies for the Treatment of Inflammatory Diseases

The CC chemokine receptor 6 (CCR6) is a G protein-coupled receptor (GPCR) involved in a wide range of biological processes. When CCR6 binds to its sole ligand CCL20, a signaling network is produced. This pathway is implicated in mechanisms related to many diseases, such as cancer, psoriasis, multiple sclerosis, HIV infection or rheumatoid arthritis. The CCR6/CCL20 axis plays a fundamental role in immune homeostasis and activation. Th17 cells express the CCR6 receptor and inflammatory cytokines, including IL-17, IL-21 and IL-22, which are involved in the spread of inflammatory response. The CCL20/CCR6 mechanism plays a crucial role in the recruitment of these pro-inflammatory cells to local tissues. To date, there are no drugs against CCR6 approved, and the development of small molecules against CCR6 is complicated due to the difficulty in screenings. This review highlights the potential as a therapeutic target of the CCR6 receptor in numerous diseases and the importance of the development of antibodies against CCR6 that could be a promising alternative to small molecules in the treatment of CCR6/CCL20 axis-related pathologies.

Probing the effects of MR120 in preclinical chronic colitis: A first-in-class anti-IBD agent targeting the CCL20/CCR6 axis

Concerning the growing interest in the role played by the CCL20/CCR6 axis in IBD pathogenesis and in the search for novel anti-IBD small molecules, we have recently discovered the first small-molecule (MR120) endowed with protective action against TNBS-induced colitis and zymosan-induced peritonitis. This protective action occurs through interference with the CCL20/CCR6 signaling. The aim of the present work is to expand the preclinical investigation of MR120, evaluating its beneficial anti-inflammatory effect on a model of chronic colitis obtained by cyclically exposing C57BL/6 mice to 3% DSS. Subcutaneous administration of MR120 at 1 mg/kg, the same dose effective against acute inflammation, helped attenuate several systemic and local inflammatory responses induced by DSS. Besides significantly improving murine health conditions, MR120 counteracted mucosal macroscopic injury, the increase of colonic edema and neutrophils oxidative activity, and mitigated spleen enlargement, while not significantly lowering intestinal IL-6 concentration. Overall, repeated daily treatment with MR120 for approximately 30 days was well tolerated and showed moderate protection in a relevant model of chronic colitis, in line with the beneficial effect previously observed in acute models of intestinal inflammation. Although more potent analogues of MR120 will be needed to more fully evaluate their clinical translatability, the present work provides a valuable example of in vivo efficacy of CCL20/CCR6 modulators in a chronic model of IBD.

Escherichia coli enhances Th17/Treg imbalance via TLR4/NF-κB signaling pathway in oral lichen planus

Oral lichen planus (OLP) is a T-cell-mediated immunoinflammatory disease. Several studies have proposed that Escherichia coli (E. coli) may participate in the progress of OLP. In this study, we examined the functional role of E. coli and its supernatant via toll-like receptor 4 (TLR4)/nuclear factor-kappab (NF-κB) signaling pathway in regulating T helper (Th) 17/ regulatory T (Treg) balance and related cytokines and chemokines profile in OLP immune microenvironment. We discovered that E. coli and supernatant could activate the TLR4/NF-κB signaling pathway in human oral keratinocytes (HOKs) and OLP-derived T cells and increase the expression of interleukin (IL)-6, IL-17, C-C motif chemokine ligand (CCL) 17 and CCL20, thereby increasing the expression of retinoic acid-related orphan receptor (RoRγt) and the proportion of Th17 cells. Furthermore, the co-culture experiment revealed that HOKs treated with E. coli and supernatant increased T cell proliferation and migration, which promoted HOKs apoptosis. TLR4 inhibitor (TAK-242) successfully reversed the effect of E. coli and its supernatant. Consequently, E. coli and supernatant activated the TLR4/NF-κB signaling pathway in HOKs and OLP-derived T cells, leading to increased cytokines and chemokines expression and Th17/Treg imbalance in OLP.