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Interleukin‐8 (IL‐8) is a critical chemokine regulating immune cells' chemotaxis as well as their physiological or pathological activations. In fish cells, recombinant IL‐8 proteins induced transcriptions of pro‐inflammatory cytokines. Nonetheless, the exact mechanisms underlying the function of fish IL‐8 as a pro‐inflammatory cytokine are still unclear. In this paper, the authors first prepared recombinant grass carp IL‐8 (rgcIL‐8) using an Escherichia coli expression system, and later confirmed rgcIL‐8 increased gene expression of il8, il1β and tumour necrosis factor alpha (tnfα) in grass carp head kidney leukocytes (HKLs). Using signalling pathway inhibitors, the authors showed that rgcIL‐8 regulated transcriptions of pro‐inflammatory cytokines via MAPK and/or NF‐κB signalling pathways. They cloned gcIL‐8‐specific receptor CXCR1 and subsequently discovered that gcIL‐8 could increase the activity of NF‐κB and the transcription of IL‐1β via CXCR1. Simultaneously, antibody neutralization assay showed that endogenous IL‐8 is partially relevant to the self‐regulation of IL‐1β. Moreover, rgcIL‐8 led to the expression of inducible nitric oxide synthase gene, causing an accumulation of nitric oxide in the culture medium of HKLs, suggesting the potential of gcIL‐8 to mediate inflammatory response. This study not only enriched the function of IL‐8 in teleost but also revealed it as a potential target for the inflammatory control in grass carp. [ABSTRACT FROM AUTHOR]

Cadherin EGF LAG seven‐pass G‐type receptors (CELSRs) are involved in the progression of various types of cancer. CELSR3, a crucial signalling molecule in the WNT/PCP pathway, is believed to be associated with tumorigenesis and metastasis. However, its role in lung adenocarcinoma (LUAD) remains unclear. In this paper, we analysed the expression of CELSR family members using the Oncomine, GEPIA and UALCAN databases. We used a Kaplan‐Meier plotter to assess the effect of CELSRs on tumour prognosis. Next, gene ontology (GO), KEGG pathway, miRNA target, kinase target and transcription factor‐target enrichment were analysed by GSEA. Simultaneously, we conducted functional assays including cell viability, colony formation and transwell assays, to determine the oncogenic role of CELSR3 in LUAD. Finally, we used the TIMER and TISIDB databases to analyse the correlation between CELSR3 and immune infiltration and the potential chemokine receptor axis causing immune cell expression. High expression of CELSR3 is in LUAD predicts poor prognosis and early progression of the tumour. KEGG and GO enrichment analysis revealed the functional relationship between CELSR3 and cell adhesion, the cell cycle, and DNA replication. Down‐regulation of CELSR3 suppressed cell proliferation to a significant extent, in addition to inhibiting invasion and migration in LUAD cells. Finally, CELSR3 expression was significantly correlated with the infiltration level of CD8+T cells through the CCL17/CCR4 axis in LUAD. These results indicate that CELSR3 can serve as a prognostic biomarker for determining prognosis and immune infiltration in LUAD. [ABSTRACT FROM AUTHOR]

Chemokines constitute a superfamily of small chemotactic cytokines with functions that are based on interactions with their corresponding receptors. It has been found that, among other functions, chemokines regulate the migratory and invasive abilities of cancer cells. Multiple studies have confirmed that chemokine receptor 9 (CCR9) and its exclusive ligand, chemokine 25 (CCL25), are overexpressed in a variety of malignant tumors and are closely associated with tumor proliferation, apoptosis, invasion, migration and drug resistance. This review evaluates recent advances in understanding the role of CCR9/CCL25 in cancer development. First, we outline the general background of chemokines in cancer and the structure and function of CCR9 and CCL25. Next, we describe the basic function of CCR9/CCL25 in the cancer process. Then, we introduce the role of CCR9/CCL25 and related signaling pathways in various cancers. Finally, future research directions are proposed. In general, this paper is intended to serve as a comprehensive repository of information on this topic and is expected to contribute to the design of other research projects and future efforts to develop treatment strategies for ameliorating the effects of CCR9/CCL25 in cancer. [ABSTRACT FROM AUTHOR]

Aims: Postoperative cognitive dysfunction (POCD) is prevalent among the elderly, characterized primarily by cognitive decline after surgery. This study aims to explore how extracellular vesicles (EVs) derived from BV2 microglial cells, with and without the C‐C chemokine receptor type 5 (CCR5), affect neuroinflammation, neuronal integrity, and cognitive function in a POCD mouse model. Methods: We collected EVs from LPS‐stimulated BV2 cells expressing CCR5 (EVsM1) and from BV2 cells with CCR5 knockdown (EVsM1‐CCR5). These were administered to POCD‐induced mice. Protein interactions between CCR5, G‐protein‐coupled receptors (GPCRs), and Ras were analyzed using structure‐based docking and co‐immunoprecipitation (Co‐IP). We assessed the phosphorylation of p38 and Erk, the expression of synaptic proteins PSD95 and MAP2, and conducted Morris Water Maze tests to evaluate cognitive function. Results: Structure‐based docking and Co‐IP confirmed interactions between CCR5, GPR, and Ras, suggesting a CCR5‐GPCRs‐Ras‐MAPK pathway involvement in neuroinflammation. EVsM1 heightened neuroinflammation, reduced synaptic integrity, and impaired cognitive function in POCD mice. In contrast, EVsM1‐CCR5 reduced neuroinflammatory markers, preserved synaptic proteins, enhanced dendritic spine structure, and improved cognitive outcomes. Conclusion: EVsM1 induced neuroinflammation via the CCR5‐GPCRs‐Ras‐MAPK pathway, with EVsM1‐CCR5 showing protective effects on POCD progression, suggesting a new therapeutic strategy for POCD management via targeted modification of microglial EVs. [ABSTRACT FROM AUTHOR]

Macrophages regulate essential aspects of innate immunity against pathogens. In response to microbial components, macrophages activate primary and secondary inflammatory gene programs crucial for host defense. The liver X receptors (LXRα, LXRβ) are ligand‐dependent nuclear receptors that direct gene expression important for cholesterol metabolism and inflammation, but little is known about the individual roles of LXRα and LXRβ in antimicrobial responses. Here, the results demonstrate that induction of LXRα transcription by prolonged exposure to lipopolysaccharide (LPS) supports inflammatory gene expression in macrophages. LXRα transcription is induced by NF‐κB and type‐I interferon downstream of TLR4 activation. Moreover, LPS triggers a reprogramming of the LXRα cistrome that promotes cytokine and chemokine gene expression through direct LXRα binding to DNA consensus sequences within cis‐regulatory regions including enhancers. LXRα‐deficient macrophages present fewer binding of p65 NF‐κB and reduced histone H3K27 acetylation at enhancers of secondary inflammatory response genes. Mice lacking LXRα in the hematopoietic compartment show impaired responses to bacterial endotoxin in peritonitis models, exhibiting reduced neutrophil infiltration and decreased expansion and inflammatory activation of recruited F4/80lo‐MHC‐IIhi peritoneal macrophages. Together, these results uncover a previously unrecognized function for LXRα‐dependent transcriptional cis‐activation of secondary inflammatory gene expression in macrophages and the host response to microbial ligands. [ABSTRACT FROM AUTHOR]

Cholangiocarcinoma (CCA) is characterized by rapid onset and high chance of metastasis. Therefore, identification of novel therapeutic targets is imperative. E26 transformation‐specific homologous factor (EHF), a member of the E26 transformation‐specific transcription factor family, plays a pivotal role in epithelial cell differentiation and cancer progression. However, its precise role in CCA remains unclear. In this study, through in vitro and in vivo experiments, we demonstrated that EHF plays a profound role in promoting CCA by transcriptional activation of glioma‐associated oncogene homolog 1 (GLI1). Moreover, EHF significantly recruited and activated tumor‐associated macrophages (TAMs) through the C‐C motif chemokine 2/C‐C chemokine receptor type 2 (CCL2/CCR2) axis, thereby remodeling the tumor microenvironment. In human CCA tissues, EHF expression was positively correlated with GLI1 and CCL2 expression, and patients with co‐expression of EHF/GLI1 or EHF/CCL2 had the most adverse prognosis. Furthermore, the combination of the GLI1 inhibitor, GANT58, and CCR2 inhibitor, INCB3344, substantially reduced the occurrence of EHF‐mediated CCA. In summary, our findings suggest that EHF is a potential prognostic biomarker for patients with CCA, while also advocating the therapeutic approach of combined targeting of GLI1 and CCL2/CCR2‐TAMs to inhibit EHF‐driven CCA development. [ABSTRACT FROM AUTHOR]

Background: Natural killer (NK) cells, CD3− lymphocytes, are critical players in cancer immune surveillance. This study aimed to assess two types of CD3− NK cell classifications (subsets), that is, convectional subsets (based on CD56 and CD16 expression) and new subsets (based on CD56, CD27, and CD11b expression), and their functional molecules in the peripheral blood of patients with breast cancer (BC) in comparison with healthy donors (HDs). Methods: Thirty untreated females with BC and 20 age‐matched healthy women were enrolled. Peripheral blood samples were collected and directly incubated with fluorochrome‐conjugated antibodies against CD3, CD56, CD16, CD27, CD11b, CD96, NKG2C, NKG2D, NKp44, CXCR3, perforin, and granzyme B. Red blood cells were then lysed using lysing solution, and the stained cells were acquired on four‐color flow cytometer. Result: Our results indicated 15% of lymphocytes in peripheral blood of patients with BC and HDs had NK cells phenotype. However, the frequency of total NK cells (CD3−CD56+), and NK subsets (based on conventional and new classifications) was not significantly different between patients and HDs. We observed mean fluorescent intensity (MFI) of CXCR3 in total NK cells (p =.02) and the conventional cytotoxic (CD3−CD56dim CD16+) NK cells (p =.03) were significantly elevated in the patients with BC compared to HDs. Despite this, the MFI of granzyme B expression in conventional regulatory (CD3−CD56brightCD16−/+) NK cells and CD3−CD56−CD16+ NK cells (p =.03 and p =.004, respectively) in the patients was lower than healthy subjects. Conclusion: The higher expression of chemokine receptor CXCR3 on total NK cells in patients with BC may be associated with increased chemotaxis‐related NK cell infiltration. However, lower expression of granzyme B in conventional regulatory NK cells and CD3−CD56−CD16+ NK cells in the patients compared to HDs suggests reduced cytotoxic activity of the NK cells in BC. These results might demonstrate accumulating NK subsets with a dysfunctional phenotype in the peripheral blood of patients with BC. [ABSTRACT FROM AUTHOR]

Cancer is one of the most common cause of death in the world with high negative emotional, economic, and social impacts. Conventional therapeutic methods, including chemotherapy and radiotherapy, have not proven satisfactory and relapse is common in most cases. Recent studies have focused on targeted therapy with more precise identification and targeted attacks to the cancer cells. For this purpose, chemokine receptors are proper targets and among them, CXCR4 and CCR7, with a crucial role in cancer metastasis, are being considered as desired candidates for investigation. In this review paper, the most important experimental results are highlighted on the potential targeted therapies based on CXCR4 and CCR7 chemokine receptors. [ABSTRACT FROM AUTHOR]

Vicriviroc or SCH 417690 is a potent and selective antagonist of the CCR5 receptor. CCR5 receptor antagonists have the potential for the treatment of HIV infections. Four distinct isotopically labelled forms of SCH 417690 were synthesized. Low specific activity [3H]SCH 417690 was prepared for a preliminary absorption, distribution, metabolism and excretion evaluation of the compound and [14C]SCH 417690 for more definitive absorption, distribution, metabolism and excretion work, including an absorption, metabolism and excretion study in man. In addition, high specific activity [3H]SCH 417690 was prepared for CCR5 receptor binding work and [2H4]SCH 417690 was prepared as an internal standard for a liquid chromatography-mass spectrometry bioanalytical method. The paper discusses the synthesis of four isotopically labelled forms of SCH 417690. [ABSTRACT FROM AUTHOR]

Non‐alcoholic fatty liver disease (NAFLD), newly renamed metabolic dysfunction‐associated liver disease (MASLD), is a leading cause of liver disease in children and adults. There is a paucity of data surrounding potential biomarkers and therapeutic targets, especially in pediatric NAFLD. Leukocyte cell‐derived chemotaxin 2 (LECT2) is a chemokine associated with both liver disease and skeletal muscle insulin resistance. Our aim was to determine associations between LECT2 and common clinical findings of NAFLD in pediatric patients. Enzyme‐linked immunosorbent assay (ELISA) was used to measure serum LECT2 concentrations in children (aged 2–17 years) with and without NAFLD. LECT2 concentrations were then correlated to clinical parameters in NAFLD. Mean LECT2 was significantly elevated in children with NAFLD versus healthy controls (n = 63 vs. 42, 5.83 ± 1.98 vs. 4.02 ± 2.02 ng/mL, p < 0.005). Additionally, LECT2 had strong correlations with body mass index (BMI) (Pearson r = 0.301, p = 0.002). A LECT2 concentration of 3.76 mg/mL predicts NAFLD with a sensitivity of 90.5% and specificity of 54.8%. Principal component analysis and logistic regression models further confirmed associations between LECT2 and NAFLD status. This study demonstrates increased serum LECT2 concentrations in pediatric NAFLD, which correlates with BMI and shows strong predictive value within these patients. Our data indicate that LECT2 is a potential diagnostic biomarker of disease and should be further investigated in pediatric as well as adult NAFLD. [ABSTRACT FROM AUTHOR]

Background and Purpose: Glioblastoma (GBM) is the most aggressive brain tumour in the central nervous system, but the current treatment is very limited and unsatisfactory. PGE2‐initiated cAMP signalling via EP2 and EP4 receptors is involved in the tumourigenesis of multiple cancer types. However, whether or how EP2 and EP4 receptors contribute to GBM growth largely remains elusive. Experimental Approach: We performed comprehensive data analysis of gene expression in human GBM samples and determined their expression correlations through multiple bioinformatics approaches. A time‐resolved fluorescence energy transfer (TR‐FRET) assay was utilized to characterize PGE2‐mediated cAMP signalling via EP2 and EP4 receptors in human glioblastoma cells. Using recently reported potent and selective small‐molecule antagonists, we determined the effects of inhibition of EP2 and EP4 receptors on GBM growth in subcutaneous and intracranial tumour models. Key Results: The expression of both EP2 and EP4 receptors was upregulated and highly correlated with a variety of tumour‐promoting cytokines, chemokines, and growth factors in human gliomas. Further, they were heterogeneously expressed in human GBM cells, where they compensated for each other to mediate PGE2‐initiated cAMP signalling and to promote colony formation, cell invasion and migration. Inhibition of EP2 and EP4 receptors revealed that these receptors might mediate GBM growth, angiogenesis, and immune evasion in a compensatory manner. Conclusion and Implications: The compensatory roles of EP2 and EP4 receptors in GBM development and growth suggest that concurrently targeting these two PGE2 receptors might represent a more effective strategy than inhibiting either alone for GBM treatment. [ABSTRACT FROM AUTHOR]

Existing therapeutics for autoimmune diseases remain problematic due to low efficacy, severe side effects, and difficulties to reach target tissues. Herein, we design multifunctional fusion nanovesicles that can target lesions for the treatment of autoimmune skin diseases. The grapefruit‐derived exosome‐like nanovesicles (GEVs) with anti‐inflammatory and antioxidant effects are first encapsulated with CX5461, an immunosuppressant with anti‐proliferative properties to form GEV@CX5461. In order to enhance therapeutic efficiency and safety, GEV@CX5461 are then fused with CCR6+ nanovesicles derived from membranes of engineered gingiva‐derived mesenchymal stem cells (GMSCs). The resulting FV@CX5461 not only maintain the bioactivity of GEVs, CX5461, and GMSC membranes but also home to inflamed tissues rich in chemokine CCL20 through the chemotaxis function of CCR6 on FVs. Moreover, FV@CX5461 reduce the secretion of inflammatory factors, calm down Th17 cell activation, and induce Treg cell infiltration. Finally, impressive therapeutic efficiency in both psoriasis and atopic dermatitis disease models is demonstrated using FV@CX5461 to reshape the unbalanced immune microenvironment. A nanotherapeutic drug delivery strategy is developed using fusion nanovesicles derived from plant and animal cells with high clinical potential. [ABSTRACT FROM AUTHOR]

This work is concerned with the mathematical analysis of a general cell–fluid Navier–Stokes model with the inclusion of chemotaxis. This general model relays on a mixture theory multiphase formulation. It consists of two mass balance equations and two general momentum balance equations, respectively, for the cell and fluid phase, combined with a convection–diffusion–reaction equation for oxygen. We investigate the existence of weak solutions in a two‐ or three‐dimensional bounded domain when the fluids are assumed to be incompressible with constant volume fraction. [ABSTRACT FROM AUTHOR]

Background and Purpose: Low‐grade inflammation, a common feature of both diabetes and periodontitis, partly accounts for the complexity and refractoriness of diabetes‐associated periodontitis. Adiponectin (APN), the most abundant adipokine in human blood, has been widely reported to have anti‐inflammatory functions. Herein, we investigated the ability of an APN receptor agonist, AdipoAI, to alleviate diabetes‐associated periodontitis. Furthermore, we revealed the possible mechanism underlying its anti‐inflammatory effects. Experimental Approach: The maxillary first molar of Zucker diabetic fatty (ZDF) rats was ligated to construct a diabetes‐associated periodontitis model, and rats were administered AdipoAI by gavage. We examined diabetes‐related indexes, pathological changes in insulin target organs, alveolar bone resorption and systemic and local inflammation. In vitro, transwell assays were used to evaluate monocyte/macrophage migration induced by human gingival fibroblasts (hGFs) with/without AdipoAI treatment. Additionally, we examined chemokine expression levels in hGFs and hGF‐induced monocyte/macrophage migration upon siRNA knockdown of Adiponectin receptor expression. Expression of Adipo1/Adipo2 receptors and inflammation‐related signalling pathways were examined by IHC and WB, followed by confirmation with an NF‐κB P65 inhibitor (BAY 11‐7082). Key Results: AdipoAI lowered fasting blood glucose and serum insulin in ZDF rats and alleviated inflammation in insulin target tissues. Locally, AdipoAI reduced alveolar bone absorption and gingival inflammation. Mechanistically, AdipoAI inhibited hGF‐induced monocyte/macrophage migration by reducing CCL2 secretion. In hGFs, AdipoAI attenuated LPS‐induced activation of NF‐κB P65 and CCL2 expression, which was dependent on the Adipo receptor 1. Conclusion and Implications: AdipoAI, with its ability to alleviate inflammatory damage in tissues, is a candidate for diabetes‐associated periodontitis treatment. [ABSTRACT FROM AUTHOR]

The present study investigated the presence of CXCR1 gene polymorphisms and their association with clinical mastitis, reproductive disorders and performance traits in Hardhenu cattle. Genotyping of the targeted SNP rs211042414 (C>T) at the g.106216468 loci of the CXCR1 gene was performed through PCR amplification and Bsa1 restriction enzyme digestion. The genotypic frequencies revealed three genotypes: CC, CT and TT, with the C allele being the most prevalent. Significant associations were found between the targeted SNP and clinical mastitis occurrence using chi‐square and logistic regression analyses. The CC genotype showed higher susceptibility to clinical mastitis with a higher odds ratio of 3.47 compared to TT (1.00) and CT (2.90) genotypes (p <.05). Furthermore, least squares analysis revealed significant associations between genotypes and performance traits such as total milk yield, 305‐day milk yield and peak yield (p <.05). The CC genotype exhibited higher milk yields than CT and TT genotypes, indicating a positive association between the C allele and increased milk production. These findings have practical implications for the genetic improvement of Hardhenu cattle. Incorporating the identified CXCR1 gene polymorphisms into existing selection criteria can help enhance disease resistance and milk production traits. However, further validation with a larger sample size is necessary to strengthen the observed associations and ensure their practical applicability. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the lipid‐lowering and antiplatelet combined strategies on the expression of the receptors CCR2, CCR5, and CX3CR1 and the percentage of CCR2, CCR5, and CX3CR1 cells in monocyte subtypes after acute myocardial infarction. Methods: Prospective, randomized, open‐label study, with blinded analyses of endpoints (PROBE, ClinicalTrials.gov Identifier: NCT02428374, registration date: April 28, 2015). Participants were treated with rosuvastatin 20 mg or simvastatin 40 mg plus ezetimibe 10 mg, as well as ticagrelor 90 mg or clopidogrel 75 mg. The chemokine receptors CCR2, CCR5, and CX3CR1 were analyzed by real‐time polymerase chain reaction as well as the percentages of CCR2, CCR5, and CX3CR1 cells in the monocyte subtypes (classical, intermediate, and non‐classical), which were quantified by flow cytometry, at baseline, and after 1 and 6 months of treatment. Results: After comparisons between the three visits, regardless of the treatment arm, there was an increase in CCR2 expression after treatment, as well as an increase in intermediate monocytes CCR2+ and a reduction in non‐classical monocytes CCR2+ at the end of treatment. There was also a lower expression of CCR5 after treatment and an increase in classical and non‐classical monocytes CCR5+. Concerning CX3CR1, there were no differences in the expression after treatment; however, there were reductions in the percentage of intermediate and non‐classical monocytes CX3CR1+ at the end of treatment. Conclusions: The results suggest the persistence of the inflammatory phenotype, known as trained immunity, even with the highly‐effective lipid‐lowering and antiplatelet therapies. Geriatr Gerontol Int 2023; 23: 700–707. [ABSTRACT FROM AUTHOR]

Background: One of the main causes of lung cancer‐related death is brain metastasis (BM). Finding early indicators of BM derived from lung cancer is crucial. Therefore, this study was designed to determine if serum hsa_circ_0072309 may be employed as a potential biomarker for BM induced by non‐small‐cell lung cancer (NSCLC) and to understand its possible underlying mechanism. Methods: Primary lung cancer and healthy neighboring tissues were obtained from all patients, while BM tissues were taken from BM+ patients. Serum specimens were collected from all patients and healthy volunteers. Hsa_circ_001653, miR‐100, and ACKR3 RNA expressions were analyzed by quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR), and atypical chemokine receptor 3 (ACKR3) protein expression by western blotting (WB), immunohistochemistry (IHC), and enzyme‐linked immunosorbent assay (ELISA). In order to examine the effect of serum hsa_circ_0072309 and its relevant mechanism on BM development, an NSCLC‐associated BM model in mice was established. Results: According to the results, miR‐100 expression was down‐regulated in primary lung cancer tissues compared to healthy lung tissues in all NSCLC patients, and circ_0072309 and ACKR3 expression were up‐regulated. In BM tissues compared with primary lung tumors of BM+ patients, in serum samples from all patients compared to healthy volunteers, and in lung tumors of BM+ patients compared to those from BM− patients. Patients' serum exhibits the same level of hsa_circ_0072309/miR‐100/ACKR3 expression as in BM samples. Advanced tumor‐node‐metastasis (TNM) stage, higher BM, shorter post‐operative overall survival (OS), and progression‐free survival (PFS) are all substantially associated with increased serum circ_0072309 levels in BM+ patients. In animal models, serum owning hsa_circ_0072309 from BM+ patients facilitates BM formation by regulating the miR‐100/ACKR3 pathway. Conclusions: The current preliminary research reveals serum hsa_circ_0072309 as a possible biomarker and target for early diagnosis, prognosis, and therapy of NSCLC‐derived BM and suggests a substantial role for the hsa_circ_0072309/miR‐100/ACKR3 axis in the formation of BM from NSCLC. [ABSTRACT FROM AUTHOR]

Today, 10 years after the discovery of IL-8, chemokines (chemotactic cytokines) are seen as the stimuli that largely control leucocyte migration. Chemokines are low molecular weight chemoattractant cytokines secreted by a variety of cells, including leucocytes, epithelial cells, endothelial cells, fibroblasts and numerous other cell types. They are produced in response to exogenous stimuli, such as viruses and bacterial LPS, and endogenous stimuli, such as IL-1, TNF and IFN. These factors mediate chemotaxis and leucocyte activation. They also regulate leucocyte extravasation from the blood and/or lymph vessel luminal surface to the tissue space, the site of inflammation. There is no doubt that chemokines and chemokine receptors are critical for defence against infectious pathogens. It is also clear that these pathogens have evolved to accommodate the workings of the host immune system. Survival of these infectious agents appears dependent upon strategies that can evade, suppress, counteract or otherwise confound the constellation of host responses to invading pathogens. In this regard, the chemokines and their receptors are a major target. Reviewed in the present paper are several examples in which microbial pathogens have usurped the mammalian chemokine system to subvert the host immune response. [ABSTRACT FROM AUTHOR]

Although most patients with acute viral myocarditis recover spontaneously, some patients progress to heart failure. Perturbations in innate immunity may partially explain the heterogeneity of clinical outcomes. As the most abundant immune cells in the heart, cardiac macrophages have heterogeneous origins, including embryonic‐derived resident macrophages (ResMϕs) and monocyte‐derived macrophages (MoMFs). However, the time course change and role of cardiac macrophage subsets has not been fully explored. In the present study, we found that BALB/c mice had prolonged MoMF accumulation and low proportions of ResMϕs that could not be restored to normal levels. MoMFs of BALB/c mice generally exhibit an M1‐dominant functional phenotype. Moreover, the preferential depletion of MoMF by a C‐C chemokine receptor type 2 (CCR2) inhibitor resulted in improved acute myocarditis and chronic fibrosis, as well as the recovery of ResMϕs number and reduced CD4+ T cell expansion. Hence, immunomodulatory therapy that targets the balance among cardiac macrophages and modulates their function is expected to prevent the progression of cardiac injury to overt heart failure and improve adverse outcomes. [ABSTRACT FROM AUTHOR]

A systemic and local inflammatory immune imbalance is thought to be the cause of traumatic tracheal stenosis (TS). However, with CD4+ T lymphocytes being the predominant immune cells in TS, the mechanism of action and recruitment has not been described. In our research, using flow cytometry, ELISA, immunofluorescence, and Transwell chamber assays, the expression, distribution, and potential chemotactic function of CD4+ T cells in TS patients were examined before and after treatment. The results showed that the untreated group had significantly more CD4+ T cells and their secreted TGF‐β1 than the treated group. Additionally, the untreated group's CD4+ T cells showed a significant rise in CCL22 and CCL1, as well as a larger proportion of CCR4 and CCR8. CD4+ T cells and CD68+ macrophages located in TS also expressed CCL1 and CCL22. In vitro, anti‐CCL1 and anti‐CCL22 can partially block the chemoattractant effect of TS bronchoalveolar lavage (BAL) on purified CD4+ T cells. The findings of this study indicated that TS contained unbalanced CD4 immune cells that were actively recruited locally by CCR4/CCL22 and CCR8/CCL1. As a result, it is anticipated that CD4 immune rebalancing can serve as a novel treatment for TS. [ABSTRACT FROM AUTHOR]

Characterization of immune cells is essential to advance our understanding of immunology and flow cytometry is an important tool in this context. Addressing both cellular phenotype and antigen‐specific functional responses of the same cells is valuable to achieve a more integrated understanding of immune cell behavior and maximizes information obtained from precious samples. Until recently, panel size was limiting, resulting in panels generally focused on either deep immunophenotyping or functional readouts. Ongoing developments in the field of (spectral) flow cytometry have made panels of 30+ markers more accessible, opening up possibilities for advanced integrated analyses. Here, we optimized immune phenotyping by co‐detection of markers covering chemokine receptors, cytokines and specific T cell/peptide tetramer interaction using a 32‐color panel. Such panels enable integrated analysis of cellular phenotypes and markers assessing the quality of immune responses and will contribute to our understanding of the immune system. [ABSTRACT FROM AUTHOR]

Platelet factor 4 (PF4, synonym: CXCL4) is an evolutionary old chemokine with proposed roles in hemostasis and antimicrobial defense. In addition, PF4 has attracted considerable attention as a crucial mediator of one of the most prothrombotic adverse drug effects affecting blood cells, heparin‐induced thrombocytopenia (HIT). Interest in PF4 substantially increased in 2021 when it was identified as the target antigen in the life‐threatening adverse effect, vaccine‐induced immune thrombotic thrombocytopenia (VITT). We address the concept that a major biological function of PF4—a strongly cationic chemokine—is to bind to negatively‐charged prokaryotic microorganisms, resulting in structural changes in PF4 that trigger a danger signal recognized by the adaptive immune system. Application of biophysical tools has provided substantial insights into the molecular mechanisms by which PF4 becomes immunogenic, providing insights into a new mechanism of autoimmunity. Binding of autoantibodies with high affinity induces conformational change(s) in the endogenous protein, which are then recognized as foreign antigen, as exemplified by the prothrombotic disorders, autoimmune HIT and VITT. The final part of our review summarizes current assays for HIT and VITT, explaining how structural aspects of anti‐PF4 pathobiology relate to assay design and performance characteristics. Currently, functional (platelet activation) assays using washed platelets detect HIT antibodies when heparin is added, and VITT antibodies when PF4 is added. Solid‐phase PF4‐dependent immunoassays using microtiter plates are sensitive for both HIT and VITT antibodies, while rapid immunoassays, in which the PF4/heparin antigen is coated on beads, are sensitive and specific for HIT, but not for VITT antibodies. [ABSTRACT FROM AUTHOR]

Objectives: To assess the differences in circulating DNA methylation levels of CXCR5 between rheumatoid arthritis (RA) and osteoarthritis (OA) and healthy controls (HC), and the correlation of methylation changes with clinical characteristics of RA patients. Methods: Peripheral blood samples were collected from 239 RA patients, 30 patients with OA, and 29 HC. Target region methylation sequencing to the promoter region of CXCR5 was achieved using MethylTarget. The methylation level of cg04537602 and methylation haplotype were compared among the three groups, and the correlation between methylation levels and clinical characteristics of RA patients was performed by Spearman's rank correlation analysis. Results: The methylation level of cg04537602 was significantly higher in the peripheral blood of RA patients compared with OA patients (p = 1.3 × 10−3) and in the HC group (p = 5.5 × 10−4). The sensitivity was enhanced when CXCR5 methylation level combined with rheumatoid factor and anti–cyclic citrullinated peptide with area under curve (AUC) of 0.982 (95% confidence interval 0.970–0.995). The methylation level of cg04537602 in RA was positively correlated with C‐reactive protein (CRP) (r =.16, p =.01), and in RA patients aged 60 years and above, cg04537602 methylation levels were positively correlated with CRP (r =.31, p = 4.7 × 10−4), tender joint count (r =.21, p =.02), visual analog scales score (r =.21, p =.02), Disease Activity Score in 28 joints (DAS28) using the CRP level DAS28‐CRP (r =.27, p = 2.1 × 10−3), and DAS28‐ESR (r =.22, p =.01). We also observed significant differences of DNA methylation haplotypes in RA patients compared with OA patients and HC, which was consistent with single‐loci‐based CpG methylation measurement. Conclusion: The methylation level of CXCR5 was significantly higher in RA patients than in OA and HC, and correlated with the level of inflammation in RA patients, our study establishes a link between CXCR5 DNA methylation and clinical features that may help in the diagnosis and disease management of RA patients. [ABSTRACT FROM AUTHOR]

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease with a genetic predisposition, and the traditional Chinese medicine Morinda officinalis and its roots are characterized with anti‐inflammatory effects and have been used for the treatment of various disease. However, it is still largely unknown whether Morinda officinalis extract (MOE) can be used for the treatment of AD. Objectives: In our study we aimed to determine whether MOE could ameliorate 2,4‐dinitrochlorobenzene (DNCB)‐induced AD and elucidate molecular mechanisms. Methods: We established an AD mouse model by using DNCB. Skin pathological analysis and ELISA assay were used to detect the effect of MOE on the inflammation of AD model mouse skin and the expression changes of inflammatory factors, and further functional verification was performed in TNF‐α/IFN‐γ‐induced HaCaT cells. Results: Our in vivo experiments confirmed that MOE remarkably reduced DNCB‐induced AD lesions and symptoms, such as epidermal and dermal thickness and mast cell infiltration and inflammatory cytokines secretion in the mice models. In addition, the underlying mechanisms by which MOE ameliorated AD had been uncovered, and we verified that MOE inhibited MALAT1 expression in AD, resulting in attenuated expression of C‐C chemokine receptor type 7 (CCR7) regulated by MALAT1‐sponge miR‐590‐5p in a competing endogenous RNA (ceRNA) mechanisms‐dependent manner, thereby inhibiting TNF‐α/IFN‐γ‐induced cellular proliferation and inflammation. [ABSTRACT FROM AUTHOR]

We demonstrate that CD193, the eotaxin receptor, is highly expressed on circulating B cells in paediatric schistosomiasis mansoni. CD193 plays a role in directing granulocytes into sites of allergic‐like inflammation in the mucosa, but little is known about its functional significance on human B cells. We sought to characterize CD193 expression and its relationship with S. mansoni infection. We found that CD193+ B cells increased with the intensity of schistosome infection. In addition, a significant negative association was observed between CD193 expression by B cells and IgE production. Decreased IgE levels are generally associated with susceptibility to re‐infection. B cell stimulation with eotaxin‐1 increased CD193 levels whereas IL‐4 led to a reduction. This was supported by plasma levels of eotaxin‐1 correlating with CD193 levels on B cells and other cells. In contrast, CD193 expression was induced on naive B cells with a combination of IL‐10 and schistosome antigens. Whereas T cells had a modest increase in CD193 expression, only B cell CD193 appeared functionally chemotactic to eotaxin‐1. Thus, CD193+ B cells, which co‐express CXCR5, may be enroute to sites with allergic‐like inflammation, such as gastrointestinal follicles, or even to Th2 granulomas, which develop around parasite eggs. Overall, our results suggest that schistosome infection may promote CD193 expression and suppress IgE via IL‐10 and other undefined mechanisms related to B cell trafficking. This study adds to our understanding of why young children may have poor immunity. Nonetheless, praziquantel treatment was shown to reduce percentages of circulating CD193+ B cells lending hope for future vaccine efforts. [ABSTRACT FROM AUTHOR]

Dendritic cell (DC) migration is a fundamental step during execution of its adaptive immunity functions. Studying DC migration characteristics is critical for development of DC-dependent allergy treatments, vaccines, and cancer immunotherapies. Here, a microfluidics-based single-cell migration platform is described that enables high-throughput and precise bidirectional cell migration assays. It also allows selective retrieval of cell subpopulations that have different migratory potentials. Using this microfluidic platform, DC migration is investigated in response to different chemoattractants and inhibitors, quantitatively describe DC migration patterns and retrieve DC subpopulations of different migratory potentials for differential gene expression analysis. This platform opens an avenue for precise characterization of cell migration and potential discovery of therapeutic modulators. [ABSTRACT FROM AUTHOR]

The CXCR4 chemokine receptor is implicated in a number of diseases including HIV infection and cancer development and metastasis. Previous studies have demonstrated that configurationally restricted bis-tetraazamacrocyclic metal complexes are high-affinity CXCR4 antagonists. Here, we present the synthesis of Cu2+ and Zn2+ acetate complexes of six cross-bridged tetraazamacrocycles to mimic their coordination interaction with the aspartate side chains known to bind them to CXCR4. X-ray crystal structures for three new Cu2+ acetate complexes and two new Zn2+ acetate complexes demonstrate metal-ion-dependent differences in the mode of binding the acetate ligand concomitantly with the requisite cis-V-configured cross-bridged tetraazamacrocyle. Concurrent density functional theory molecular modelling studies produced an energetic rationale for the unexpected [Zn(OAc)(H2O)]+ coordination motif present in all of the Zn2+ cross-bridged tetraazamacrocycle crystal structures, which differs from the chelating acetate [Zn(OAc)]+ structures of known unbridged and side-bridged tetraazamacrocyclic Zn2+-containing CXCR4 antagonists. [ABSTRACT FROM AUTHOR]

The late asthmatic response (LAR) occurring during experimental allergic asthma is a recognized model for the study of asthma mechanisms.[1] It involves inflammatory processes, such as eosinophil recruitment and activation and mast cell and basophil activation, and activated lymphocytes and their Th2 cytokines.[2] It has been suggested that protective anti-inflammatory mechanisms, particularly Treg, are defective during the LAR phase.[3] We aimed to study the (anti-)inflammatory systemic immune responses occurring at baseline and after mite exposure in allergic asthma in the early asthmatic response (EAR) vs. the LAR. In the stable state, but not during a LAR, the immune response is balanced by CCR4-expressing Treg cells, although Treg express immunosuppressive CD39 during a LAR. (B) Cytokines gl Thus, allergen exposure induced a typical inflammatory response during LAR that combined lung-homing T cells and IL2 and IL5 cytokines on one hand, and on the other the expression of CD39 on Treg cells. [Extracted from the article]

Microglia have been implicated in multiple sclerosis (MS) pathogenesis. The fractalkine receptor CX3CR1 limits the activation of pathogenic microglia and the human polymorphic CX3CR1I249/M280 (hCX3CR1I249/M280) variant increases disease progression in models of MS. However, the role of hCX3CR1I249/M280 variant on microglial activation and central nervous system repair mechanisms remains unknown. Therefore, using transgenic mice expressing the hCX3CR1I249/M280 variant, we aimed to determine the contribution of defective CX3CR1 signaling to neuroinflammation and remyelination in the cuprizone model of focal demyelination. Here, we report that mice expressing hCX3CR1I249/M280 exhibit marked demyelination and microgliosis following acute cuprizone treatment. Nanostring gene expression analysis in demyelinated lesions showed that hCX3CR1I249/M280 but not CX3CR1‐deficient mice up‐regulated the cuprizone‐induced gene profile linked to inflammatory, oxidative stress, and phagocytic pathways. Although CX3CR1‐deficient (CX3CR1‐KO) and fractalkine‐deficient (FKN‐KO) mice displayed a comparable demyelination and microglial activation phenotype to hCX3CR1I249/M280 mice, only CX3CR1‐deficient and CX3CR1‐WT mice showed significant myelin recovery 1 week from cuprizone withdrawal. Confocal microscopy showed that hCX3CR1I249/M280 variant inhibits the generation of cells involved in myelin repair. Our results show that defective fractalkine signaling contributes to regional differences in demyelination, and suggest that the CX3CR1 pathway activity may be a key mechanism for limiting toxic gene responses in neuroinflammation. Cover Image for this issue: https://doi.org/10.1111/jnc.15416 [ABSTRACT FROM AUTHOR]

The aim of this study was to elucidate the mechanism underlying the effects of Kukoamine A (KuA) treatment on endotoxin‐induced lung injury/inflammation. The study was performed in lipopolysaccharide (LPS)‐exposed mouse models of lung injury and LPS‐induced alveolar epithelial cell model. Relevant kits were used to detect levels of inflammation‐related indicators, oxidative stress indicators, and mitochondrial function. Hematoxylin and eosin staining was to detect lung injury. Then, C‐C motif chemokine receptor 5 (CCR5) overexpression plasmid was transfected into alveolar epithelial cells to investigate the mechanism of KuA in lung injury. The results showed that LPS induction increased the expression of inflammatory factors, oxidative stress markers, and mitochondrial dysfunction in both animal and cellular models. In the mouse model, KuA treatment improved lung tissue injury, decreased wet‐to‐dry ratio and MPO levels, reduced the expression of inflammatory factors, and ameliorated oxidative stress and mitochondrial dysfunction. The protective effect of KuA in the cell model remained whereas was markedly reversed after CCR5 overexpression. Taken together, KuA might improve LPS‐induced lung injury by inhibiting CCR5. This might also provide a novel theory for KuA in the treatment of lung injury. [ABSTRACT FROM AUTHOR]

The CXC chemokine receptors (CXCRs) are members of the seven transmembrane (7‐TM) G‐protein‐coupled receptor superfamily that involves innate and adaptive immune systems. In this study, CXCR3a and CXCR3b from Nile tilapia (Oreochromis niloticus) were cloned and identified, designated as OnCXCR3a and OnCXCR3b. The open reading frames of OnCXCR3a and OnCXCR3b were 1074 and 1080 bp, encoding the predicted proteins of 357 and 359 amino acids, respectively. Multiple alignment analysis of OnCXCR3a‐ and OnCXCR3b‐deduced protein sequences with the mammalian and bird sequences indicated the presence of typical structural features of chemokine receptors, including a 7‐TM domain and conserved motifs. Quantitative real‐time PCR analysis revealed that OnCXCR3a and OnCXCR3b were constitutively expressed in a wide range of tissues. When stimulated with Streptococcus agalactiae, Aeromonas hydrophila, polyinosinic:polycytidylic acid and lipopolysaccharide in vivo or in vitro on leukocytes, the mRNA levels of OnCXCR3a and OnCXCR3b were significantly upregulated. Overall, these results indicated that OnCXCR3s might be involved in host immune responses in Nile tilapia. [ABSTRACT FROM AUTHOR]

Extramedullary disease ( EMD), defined as an infiltrate of clonal plasma cells at an anatomic site distant from the bone marrow, is an uncommon manifestation of multiple myeloma. Six hundred and sixty-three consecutive patients with multiple myeloma who underwent stem cell transplantation between January 2005 and December 2011 were assessed for the presence of EMD. A cohort of 55 patients with biopsy-proven EMD was identified, comprising 8·3% of the total study population. EMD was present at the time of diagnosis in 14·5% of cases and at the time of relapse in 76% of patients. The most common EMD presentations at relapse were liver involvement and pleural effusions. EMD specimens had high expression of CD44 (92%) and moderate expression of CXCR4. The median overall survival from time of myeloma diagnosis was 4·1 years (95% CI: 3·1, 5·1) and the median overall survival from time of EMD diagnosis was 1·3 years (95% CI: 0·8, 2·3). This report demonstrates that the incidence of EMD has not increased with the introduction of novel agents and stem cell transplantation. The most common EMD presentations in the relapsed setting were liver and pleural fluid. The presence of CD44 and CXCR4 expression may represent new markers of EMD that warrant further investigation. [ABSTRACT FROM AUTHOR]

Fabry disease (FD) is a rare X-linked disorder of lipid metabolism, characterized by the accumulation of globotriaosylceramide (Gb3) due to defective the lysosomal enzyme, α-galactosidase. Gb3 deposits activate immune-mediated systemic inflammation, ultimately leading to life-threatening consequences in multiple organs such as the heart and kidneys. Enzyme replacement therapy (ERT), the standard of care, is less effective with advanced tissue injury and inflammation in patients with FD. Here, we showed that MCP-1 and TNF-α cytokine levels were almost doubled in plasma from ERT-treated FD patients. Chemokine receptor CCR2 surface expression was increased by twofold on monocytes from patients with low eGFR. We also observed an increase in IL12B transcripts in unstimulated peripheral blood mononuclear cells (PBMCs) over a 2-year period of continuous ERT. Apabetalone is a clinical-stage oral bromodomain and extra terminal protein inhibitor (BETi), which has beneficial effects on cardiovascular and kidney disease related pathways including inflammation. Here, we demonstrate that apabetalone, a BD2-selective BETi, dose dependently reduced the production of MCP-1 and IL-12 in stimulated PBMCs through transcriptional regulation of their encoding genes. Reactive oxygen species production was diminished by up to 80% in stimulated neutrophils following apabetalone treatment, corresponding with inhibition of NOX2 transcription. This study elucidates that inhibition of BET proteins by BD2-selective apabetalone alleviates inflammatory processes and oxidative stress in innate immune cells in general and in FD. These results suggest potential benefit of BD2-selective apabetalone in controlling inflammation and oxidative stress in FD, which will be further investigated in clinical trials. [ABSTRACT FROM AUTHOR]

The N‐terminal segment of CCR5 contains four tyrosine residues, sulphation of two of which is essential for high‐affinity binding to gp120. In the present study, the interactions of gp120YU2 with a 27‐residue N‐terminal CCR5 peptide sulphated at position Y10 and Y14, i.e. Nt‐CCR5, were studied using 13C‐edited‐HMQC methyl‐NOESY [1H(13C)‐1H], combined with transferred NOE NMR spectroscopy. A large number of pairwise interactions were observed between the methyl protons of methionine, threonine, valine and isoleucine residues of gp120, and the aromatic tyrosine‐protons of Nt‐CCR5. M434, V120 and V200 of gp120 were found to interact with all four tyrosine residues, Y3, sY10, sY14 and Y15. Particularly intriguing was the observation that Y3 and Y15 interact with the same gp120 methyl protons. Such interactions cannot be explained by the single cryo‐EM structure of gp120/CD4/CCR5 complex published recently (Nature, 565, 318–323, 2019). Rather, they are consistent with the existence of a dynamic equilibrium involving two or more binding modes of Nt‐CCR5 to gp120. These different modes of binding can coexist because the surface of gp120 contains two sites that can optimally interact with a sulphated tyrosine residue and two sites that can interact favorably with a non‐sulphated tyrosine residue. Modelling of gp120YU2 complexed with the Nt‐CCR5 peptide or with the entire CCR5 receptor provides an explanation for the NMR observations and the existence of these different binding modes of the disordered N‐terminus of CCR5. The data presented extend our understanding of the two‐step model and suggest a more variable binding mode of Nt‐CCR5 with gp120. [ABSTRACT FROM AUTHOR]

Aims: Chronic hyperammonaemia and inflammation synergistically induce neurological impairment, including motor incoordination, in hepatic encephalopathy. Hyperammonaemic rats show neuroinflammation in the cerebellum which enhances GABAergic neurotransmission leading to motor incoordination. We aimed to identify underlying mechanisms. The aims were (1) to assess if S1PR2 is involved in microglial and astrocytic activation in the cerebellum of hyperammonaemic rats; (2) to identify pathways by which enhanced S1PR2 activation induces neuroinflammation and alters neurotransmission; (3) to assess if blocking S1PR2 reduces neuroinflammation and restores motor coordination in hyperammonaemic rats. Methods: We performed ex vivo studies in cerebellar slices from control or hyperammonaemic rats to identify pathways by which neuroinflammation enhances GABAergic neurotransmission in hyperammonaemia. Neuroinflammation and neurotransmission were assessed by immunochemistry/immunofluorescence and western blot. S1PR2 was blocked by intracerebral treatment with JTE‐013 using osmotic mini‐pumps. Motor coordination was assessed by beam walking. Results: Chronic hyperammonaemia enhances S1PR2 activation in the cerebellum by increasing its membrane expression. This increases CCL2, especially in Purkinje neurons. CCL2 activates CCR2 in microglia, leading to microglial activation, increased P2X4 membrane expression and BDNF in microglia. BDNF enhances TrkB activation in neurons, increasing KCC2 membrane expression. This enhances GABAergic neurotransmission, leading to motor incoordination in hyperammonaemic rats. Blocking S1PR2 in hyperammonaemic rats by intracerebral administration of JTE‐013 normalises the S1PR2‐CCL2‐CCR2‐BDNF‐TrkB‐KCC2 pathway, reduces glial activation and restores motor coordination in hyperammonaemic rats. Conclusions: Enhanced S1PR2‐CCL2‐BDNF‐TrkB pathway activation mediates neuroinflammation and incoordination in hyperammonaemia. The data raise a promising therapy for patients with hepatic encephalopathy using compounds targeting this pathway. [ABSTRACT FROM AUTHOR]

The involvement of intervertebral disc (IVD) tissues, whole blood (WB) cytokines, and chemokines in pain in patients with lumbar degenerative disc disease (LDD) is unknown. We investigated the relationships between inflammatory cytokines and chemokines in human IVD tissues and WB samples and their association with pain. Expression levels of chemokines and cytokine gene expression were measured in samples from 20 patients with LDD and compared between IVD tissues and WB samples. The associations between WB chemokine and cytokine gene expression levels and pain intensity (numeric rating scale) were also analyzed. The mRNA of C‐C chemokine ligand 20 (CCL20), C‐C chemokine receptor 6 (CCR6), interleukin‐6 (IL‐6), IL‐1β, IL‐17, and tumor necrosis factor‐α (TNF‐α) was expressed in degenerated IVD tissues. Pearson's product–moment correlation analysis produced positive correlations between CCR6 and IL‐6 expression levels in IVD tissues (r = 0.845, p < 0.001) and WB samples (r = 0.963, p < 0.001). WB IL‐6 and CCR6 mRNA expression levels correlated significantly with present pain, maximum pain, and average pain. By contrast, low back pain (LBP) did not correlate with serum chemokine/cytokine expression. This is the first study to report correlations between chemokine and inflammatory cytokine gene expression levels in IVD tissues and WB samples in patients with LDD in relation to pain intensity. WB CCR6 and IL‐6 gene expression levels correlated significantly with present pain, maximum pain, and average pain, but not with LBP. These data provide a new understanding of the role of chemokines and inflammatory cytokines in patients with LDD and may lead to new treatment strategies for pain. [ABSTRACT FROM AUTHOR]

Background: Systemic sclerosis (SSc) is a multiorgan autoimmune disease characterized by inflammation, vascular modification, and progressive fibrosis of the skin and several visceral organs. Innate and adaptive immune cells, including myeloid, B and T cells, are believed to be central to the pathogenesis of SSc. However, the role and functional state of neutrophil granulocytes (neutrophils) are ill‐defined in SSc. Methods: We performed a prospective study of neutrophils freshly isolated from SSc patients and healthy donors (HD) by measuring in these neutrophils (i) functional cell surface markers, including CD16, CD62L, CD66b, CD66c, CXCR1, CXCR2, and CXCR4; (ii) cytokine‐activated intracellular signal transducer and activator of transcription (STAT) pathways, such as phosphorylated STAT3 (pSTAT3), pSTAT5, and pSTAT6; (iii) production of neutrophil extracellular traps (NET) and intracellular myeloperoxidase (MPO); and (iv) phagocytosis of bacteria by the neutrophils. Results: Neutrophils of SSc patients expressed lower CD16 and CD62L and higher pSTAT3 and pSTAT6 compared to HD. Moreover, neutrophils of SSc patients lacked CXCR1 and CXCR2, the receptors responding to the potent neutrophil chemoattractant CXCL8. Neutrophils of SSc patients were also deficient in MPO levels, NET formation, and phagocytosis of bacteria. Conclusions: Neutrophils of patients with SSc display several functional defects affecting cell migration, NET formation, and phagocytosis of bacteria. [ABSTRACT FROM AUTHOR]

In monocytes and macrophages, the interaction of Porphyromonas gingivalis with Toll-like receptor 2 ( TLR2) leads to the activation of a MyD88-dependent antimicrobial pathway and a phosphatidylinositol-3 kinase ( PI3K) -dependent pro-adhesive pathway, which activates the β2-integrin complement receptor 3 ( CR3). By means of its fimbriae, P. gingivalis binds CXC-chemokine receptor 4 ( CXCR4) and induces crosstalk with TLR2 that inhibits the MyD88-dependent antimicrobial pathway. In this paper, we investigated the impact of the P. gingivalis- CXCR4 interaction on the pro-adhesive pathway. Using human monocytes, mouse macrophages, or receptor-transfected cell lines, we showed that the binding of P. gingivalis fimbriae to CXCR4 induces CR3 activation via PI3K, albeit in a TLR2-independent manner. An isogenic strain of P. gingivalis expressing mutant fimbriae that do not interact with CXCR4 failed to efficiently activate CR3, leading to enhanced susceptibility to killing in vivo compared with the wild-type organism. This in vivo observation is consistent with previous findings that activated CR3 mediates safe entry of P. gingivalis into macrophages. Taken together with our previous work, these results indicate that the interaction of P. gingivalis with CXCR4 leads to inhibition of antimicrobial responses and enhancement of pro-adhesive responses, thereby maximizing its adaptive fitness in the mammalian host. [ABSTRACT FROM AUTHOR]

Radiation attenuated sporozoite (RAS), a whole‐parasite vaccine approach, provides sterile protection against malaria. However, RAS immunization does not confer protection for long, and that has been correlated with the waning parasite–induced memory CD8+ T‐cell responses. Interestingly, an intermittent infectious (wild type) sporozoite challenge to the RAS‐vaccinated mice lengthened the protection period from 6 to 18 months. Herein, we have studied the changes induced by the infectious sporozoites in RAS‐induced memory CD8+ T cells for conferring lengthened protection. We observed that the infectious sporozoite challenge boosted the frequency of foreign antigen–experienced memory CD8+ T cells. In those CD8+ T cells, it has reduced the Annexin‐V reactivity, raised Bcl‐2 expression, and also more cells undergo homeostatic proliferation (Ki‐67+). It has also scaled down the frequency of Nur77 and CX3CR1 high expressing cells in those memory CD8+ T‐cell populations which we further correlated with better survival signals. [ABSTRACT FROM AUTHOR]

Reviews of the articles are presented including one on chemokine receptor 4 (CXCR4), which appeared "Histopathology" journal, the diagnostics of inflammatory bowel disease in "Journal of Internal Medicine" and vegetarianism as a protective factor for adenomas in "Digestive Diseases and Sciences."

Regulatory T cells (Tregs) are impaired in human systemic lupus erythematosus (SLE) and involved in disease pathogenesis. However, the mechanisms responsible for the Treg dysfunction in SLE remain unclear. In this study, we aimed to investigate the chemotaxis of Treg response to inflammatory stimulation. Sixty two patients were enrolled, and chemokine receptors, including CCR4, CCR5, CCR6, CCR8 and CXCR3 on CD4+Foxp3+Tregs and non‐Treg CD4 T cells, were analysed using FACS. The expression of CCR4 and CCR6 on Tregs of SLE patients decreased, while the expression of CCR4 on non‐Treg CD4 T cells increased, as compared with those of age‐ and sex‐matched healthy donors. In parallel, in SLE, the chemotactic capacity of non‐Treg CD4 T cells response to CCR4 and CCR6 ligands dramatically increased, while that of Tregs significantly decreased. Moreover, we found that cytokines IL‐6 and IL‐10 positively and negatively modulate the expression of those receptors respectively. IL‐6, the significantly increased cytokine in active SLE, dramatically elevated CCR4 and CCR6 expression on non‐Treg CD4 T cells. However, as for Tregs, these cells produced more IL‐10 than non‐Treg CD4 T cells upon IL‐6 stimulation, and these IL‐10 led to the inhibition of CCR4 and CCR6. In sum, our data provided new evidence suggesting a functional deficiency of Tregs in SLE. It may suggest that those dysfunctional Tregs have less access to the inflammation locus to exert inhibitory capacity. [ABSTRACT FROM AUTHOR]

Eotaxin at 10 nM significantly enhanced basophil histamine release triggered by anti-IgE antibody and C5a (Figure 1A); release was similarly enhanced in highly pure (purity: ~90%) basophils (Figure 1B). Keywords: allergy; basophils; eotaxin (CCL11); histamine; leukotriene C4 EN allergy basophils eotaxin (CCL11) histamine leukotriene C4 3549 3552 4 11/01/21 20211101 NES 211101 ACKNOWLEDGEMENTS The authors thank Drs Kei Onuma, Ryo Hatano (Juntendo University) and Hiroshi Kawasaki (JCHO Yugawara Hospital) for kindly providing us with anti-CCR3 hybridoma, Ms Sayaka Igarashi for helpful advice on the experimental procedures, Dr Hirokazu Sakasegawa for his critical reading of this manuscript, and Ms Yasuko Asada for her excellent secretarial work. [Extracted from the article]

Rheumatoid arthritis (RA) may not be a multifactorial disease; it can be hypothesized that RA is developed through a series of events following a triggering event, which is the emergence of a chemokine for neutrophils in the synovium. IL‐17A, secreted by infiltrated neutrophils, stimulates synoviocytes to produce CCL20, which attracts various CCR6‐expressing cells, including Th17 cells. Monocytes (macrophages) appear after neutrophil infiltration according to the natural course of inflammation and secrete IL‐1β and TNFα. Then, IL‐17A, IL‐1β, and TNFα stimulate synoviocytes to produce CCL20, amplifying the inflammation. Varieties of chemokines secreted by infiltrating cells accumulate in the synovium and induce synoviocyte proliferation by binding to the corresponding G protein‐coupled receptors, thus expanding the synovial tissue. CCL20 in this tissue attracts circulating monocytes that express both CCR6 and receptor activator of NF‐κB (RANK), which differentiate into osteoclasts in the presence of RANKL. In this way, pannus is formed, and bone destruction begins. [ABSTRACT FROM AUTHOR]

Background: Destruction of melanocytes mediated by autoimmunity is currently believed as the main cause of vitiligo. This article aims to identify the role of CC chemokine ligand 17 (CCL17)–CC chemokine receptor 4 (CCR4) axis in vitiligo and provide new possibilities for the clinical treatment of vitiligo. Methods: A total of 30 patients with vitiligo from Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University were recruited based on the inclusion and exclusion criteria. Trephine was used to obtain skin samples from the lesion area and its surrounding normal areas, and the expression levels of CCL17, CCR4, Tbx21, Eomes, and Blimp1 were determined by quantitative reverse transcription polymerase chain reaction. Vitiligo mouse model was established by adoptively transferring CFP‐PMEL CD8+ T cells into sublethally irradiated Krt14‐Kitl* mice. Recipient mice received intraperitoneal injection of 1 × 106 plaque‐forming units of rVV‐hPMEL on the same day of transfer. The degree of depigmentation was scored blindly by one observer 5 weeks after vitiligo induction. CFP‐PMEL CD8+ T cells migration to skin, draining lymph nodes, spleen, and blood were detected by flow cytometry. CCR4 blockade was performed by intraperitoneal injection of neutralizing antibody. Results: The expression levels of CCL17, CCR4, Tbx21, Eomes, and Blimp1 in skin lesions were significantly increased compared with that in surrounding normal areas. CCL17−/− and CCR4−/− mice exhibited significantly lower disease scores than WT mice. The CFP‐PMEL CD8+ T cells accumulation was significantly decreased in the skin of CCL17−/− and CCR4−/− mice, but was not changed in draining lymph nodes, spleen, and blood. Administration of CCR4 neutralizing antibody decreased the degree of depigmentation and the recruitment of CFP‐PMEL CD8+ T cells to the skin, while keeping the number of T cells in draining lymph nodes unchanged. Conclusion: Targeting CCL17‐CCR4 axis might inhibit T cell migrating to skin and alleviate vitiligo progression. [ABSTRACT FROM AUTHOR]

Emerging evidence suggests that immune cells not only communicate with each other through cytokines, chemokines, and cell surface receptors, but also by releasing small membranous structures known as extracellular vesicles (EVs). EVs carry a variety of different molecules that can be taken up by recipient cells. Parasitic worms are well known for their immunomodulatory properties, but whether they can affect immune responses by altering EV‐driven communication between host immune cells remains unclear. Here we provide evidence that stimulation of bone marrow‐derived macrophages (BMDMs) with soluble products of Trichuris suis (TSPs), leads to the release of EVs with anti‐inflammatory properties. Specifically, we found that EVs from TSP‐pulsed BMDMs, but not those from unstimulated BMDMs can suppress TNFα and IL‐6 release in LPS‐stimulated BMDMs and BMDCs. However, no polarization toward M1 or M2 was observed in macrophages exposed to EVs. Moreover, EVs enhanced reactive oxygen species (ROS) production in the exposed BMDMs, which was associated with a deregulated redox homeostasis as revealed by pathway analysis of transcriptomic data. Proteomic analysis identified cytochrome p450 (CYP450) as a potential source of ROS in EVs from TSP‐pulsed BMDMs. Finally, pharmacological inhibition of CYP450 activity could suppress ROS production in those BMDMs. In summary, we find that TSPs can modulate immune responses not only via direct interactions but also indirectly by eliciting the release of EVs from BMDMs that exert anti‐inflammatory effects on recipient cells. [ABSTRACT FROM AUTHOR]

Studies showed that the increase of myeloid‐derived suppressor cells (MDSCs) in tumour microenvironment is closely related to the resistant treatment and poor prognosis of metastatic breast cancer. However, the effect of tumour‐derived exosomes on MDSCs and its mechanism are not clear. Here, we reported that breast cancer cells (4T1)‐secreted exosomes (BCC‐Ex) were able to differentiate bone marrow cells into MDSCs and significantly inhibited the proliferation of T lymphocytes to provide an immunosuppressive microenvironment for cancer cells in vivo and in vitro. The number of MDSCs in bone marrow and spleen of 4T1 tumour‐bearing mice and BCC‐Ex infused mice was significantly higher than that of normal mice, whereas the number of T lymphocytes in spleen was significantly decreased. In addition, BCC‐Ex markedly promoted the differentiation of MDSCs from bone marrow cells or bone marrow cells derived macrophages, seen as the increased expressions of MDSCs‐related functional proteins Arginase‐1 (Arg‐1) and inducible nitric oxide synthase (iNOS). Furthermore, BCC‐Ex significantly down‐regulated the expressions of chemokine receptor CXCR4 and markedly up‐regulated the levels of inflammatory cytokines IL‐6 and IL‐10 in bone marrow cells and macrophages and remarkably inhibited the division and proliferation of T cells. Importantly, CXCR4 agonist, CXCL12, could reverse the function of BCC‐Ex, indicating that BCC‐Ex‐induced MDSCs might be dependent on the down‐regulation of CXCR4. Western blot showed that BCC‐Ex significantly promoted the phosphorylation of STAT3 in bone marrow cells, resulting in the inhibitions of the proliferation and apoptosis of bone marrow cells, and the aggravation of the differentiation of bone marrow cells into MDSCs. [ABSTRACT FROM AUTHOR]

The C‐X‐C chemokine receptor 7 (CXCR7) has evolved as a promising, druggable target mainly in the immunology and oncology fields modulating plasma concentrations of its ligands CXCL11 and CXCL12 through receptor‐mediated internalization. This "scavenging" activity creates concentration gradients of these ligands between blood vessels and tissues that drive directional cell migration. This randomized, double‐blind, placebo‐controlled first‐in‐human study assessed the safety, tolerability, pharmacokinetics, and pharmacodynamics of ACT‐1004‐1239, a first‐in‐class drug candidate small‐molecule CXCR7 antagonist. Food effect and absolute bioavailability assessments were also integrated in this multipurpose study. Healthy male subjects received single ascending oral doses of ACT‐1004‐1239 (n = 36) or placebo (n = 12). At each of six dose levels (1–200 mg), repeated blood sampling was done over 144 hours for pharmacokinetic/pharmacodynamic assessments using CXCL11 and CXCL12 as biomarkers of target engagement. ACT‐1004‐1239 was safe and well tolerated up to the highest tested dose of 200 mg. CXCL12 plasma concentrations dose‐dependently increased and more than doubled compared with baseline, indicating target engagement, whereas CXCL11 concentrations remained unchanged. An indirect‐response pharmacokinetic/pharmacodynamic model well described the relationship between ACT‐1004‐1239 and CXCL12 concentrations across the full dose range, supporting once‐daily dosing for future clinical studies. At doses ≥ 10 mg, time to reach maximum plasma concentration ranged from 1.3 to 3.0 hours and terminal elimination half‐life from 17.8 to 23.6 hours. The exposure increase across the dose range was essentially dose‐proportional and no relevant food effect on pharmacokinetics was determined. The absolute bioavailability was 53.0% based on radioactivity data after oral vs. intravenous 14C‐radiolabeled microtracer administration of ACT‐1004‐1239. Overall, these comprehensive data support further clinical development of ACT‐1004‐1239. [ABSTRACT FROM AUTHOR]

The N‐terminal segment of the chemokine receptor Human CC chemokine receptor 5 (CCR5), Nt‐CCR5, contains four tyrosine residues, Y3, Y10, Y14, and Y15. Sulfation of at least two of these tyrosine residues was found to be essential for high‐affinity binding of CCR5 to its chemokine ligands. Here, we show that among the monosulfated Nt‐CCR5(8‐20) peptide surrogates (sNt‐CCR5) those sulfated at Y15 and Y14 have the highest affinity for the CC chemokine ligand 5 (CCL5) chemokine in comparison with monosulfation at position Y10. Sulfation at Y3 was not investigated. A peptide sulfated at both Y14 and Y15 has the highest affinity for CCL5 by up to a factor of 3, in comparison with the other disulfated (sNt‐CCR5) peptides. Chemical shift perturbation analysis and transferred nuclear Overhauser effect measurements indicate that the sulfated tyrosine residues interact with the same CCL5‐binding pocket and that each of the sulfated tyrosines at positions 10, 14, and 15 can occupy individually the binding site on CCL5 in a similar manner, although with somewhat different affinity, suggesting the possibility of allovalency in sulfated Nt‐CCR5 peptides. The affinity of the disulfated peptides to CCL5 could be increased by this allovalency and by stronger electrostatic interactions. [ABSTRACT FROM AUTHOR]

Background: Clear cell renal cell carcinoma (ccRCC) is an aggressive subtype of renal cell carcinoma. X‐C motif chemokine receptor 1 (XCR1) exerts important roles in tumor progression; however, its role in ccRCC is unclear. Methods: We utilized publicly available data from The Cancer Genome Atlas (TCGA) to assess the role of XCR1 in ccRCC and validated the results in 36 samples from patients with ccRCC who underwent curative resection in Xinqiao Hospital Chongqing. XCR1 overexpression was identified in ccRCC, which was confirmed by qRT‐PCR assay and immunohistochemical staining of ccRCC samples. Results: For the TCGA and clinical data, Kaplan–Meier survival analysis revealed that higher XCR1 expression in ccRCC was related to longer overall survival. Cox regression analysis suggested that XCR1 is an independent risk factor for ccRCC. GSEA analysis suggested that XCR1 is associated with the JAK/STAT signaling pathway. XCR1 knockdown by small interfering RNA (siRNA) significantly increased ccRCC cell proliferation and migration, and decreased cell apoptosis. Conclusion: We found higher XCR1 expression in ccRCC compared with that in normal tissues is related to longer overall survival in patients with ccRCC. XCR1 knockdown significantly increased RCC cells proliferation and migration, and decreased apoptosis. XCR1 might be used as a prognostic biomarker in ccRCC in the future. [ABSTRACT FROM AUTHOR]

Immunopathogenic roles for both Th1 (CD4+IFN‐γ+) and Th17 (CD4+IL‐17A+) cells have been demonstrated in experimental autoimmune uveitis (EAU). However, the role for Th17/Th1 (CD4+ T cells co‐expressing IFN‐γ and IL‐17A) cells in EAU is not yet understood. Using interphotoreceptor retinoid‐binding protein peptide‐induced EAU in mice, we found increased levels of Th17/Th1 cells in EAU retinae (mean 9.6 ± 4.2%) and draining LNs (mean 8.4 ± 3.9%; p = 0.01) relative to controls. Topical dexamethasone treatment effectively reduced EAU severity and decreased retinal Th1 cells (p = 0.01), but had no impact on retinal Th17/Th1 or Th17 cells compared to saline controls. Using in vitro migration assays with mouse CNS endothelium, we demonstrated that Th17/Th1 cells were significantly increased within the migrated population relative to controls (mean 15.6 ± 9.5% vs. 1.9 ± 1.5%; p = 0.01). Chemokine receptor profiles of Th17/Th1 cells (CXCR3 and CCR6) did not change throughout the transendothelial migration process and were unaffected by dexamethasone treatment. These findings support a role for Th17/Th1 cells in EAU and their resistance to steroid inhibition suggests the importance of targeting both Th17 and Th17/Th1 cells for improving therapy. [ABSTRACT FROM AUTHOR]