Lymphocyte-specific chemokine receptor CXCR3: regulation, chemokine binding and gene localization

HTLV-1 induces an inflammatory CD4+CD8+ T cell population in HTLV-1-associated myelopathy

Human T cell leukemia virus type 1 (HTLV-1) is a retrovirus with preferential CD4+ T cell tropism that causes a range of conditions spanning from asymptomatic infection to adult T cell leukemia and HTLV-1-associated myelopathy (HAM), an inflammatory disease of the CNS. The mechanisms by which HTLV-1 induces HAM are poorly understood. By directly examining the ex vivo phenotype and function of T cells from asymptomatic carriers and patients with HAM, we show that patients with HAM have a higher frequency of CD4+CD8+ double-positive (DP) T cells, which are infected with HTLV-1 at higher rates than CD4+ T cells. Displaying both helper and cytotoxic phenotypes, these DP T cells are highly proinflammatory and contain high frequencies of HTLV-1-specific cells. Mechanistically, we demonstrate that DP T cells arise by direct HTLV-1 infection of CD4+ and CD8+ T cells. High levels of CD49d and CXCR3 expression suggest that DP T cells possess the ability to migrate to the CNS, and when cocultured with astrocytes, DP T cells induce proinflammatory astrocytes that express high levels of CXCL10, IFN-γ, and IL-6. These results demonstrate the potential of DP T cells to directly contribute to CNS pathology.

The Role of CXCL11 and its Receptors in Cancer: Prospective but Challenging Clinical Targets

Chemokine ligand 11 is a member of the CXC chemokine family and exerts its biological function mainly through binding to CXCR3 and CXCR7. The CXCL11 gene is ubiquitously overexpressed in various human malignant tumors; however, its specific mechanisms vary among different cancer types. Recent studies have found that CXCL11 is involved in the activation of multiple oncogenic signaling pathways and is closely related to tumorigenesis, progression, chemotherapy tolerance, immunotherapy efficacy, and poor prognosis. Depending on the specific expression of its receptor subtype, CXCL11 also has a complex 2-fold role in tumours; therefore, directly targeting the structure-function of CXCL11 and its receptors may be a challenging task. In this review, we summarize the biological functions of CXCL11 and its receptors and their roles in various types of malignant tumors and point out the directions for clinical applications.

CXCR3 Provides a Competitive Advantage for Retention of Mycobacterium tuberculosis-Specific Tissue-Resident Memory T Cells Following a Mucosal Tuberculosis Vaccine

Mycobacterium tuberculosis is a major human pathogen, and new vaccines are needed to prevent transmission. Mucosal vaccination may confer protection against M. tuberculosis by stimulating tissue-resident memory (TRM) CD4+ T cells in the lungs. The chemokine receptor CXCR3 promotes lung recruitment of T cells, but its role in TRM development is unknown. This study demonstrates the recombinant influenza A virus vaccine PR8.p25, expressing the immunodominant M. tuberculosis T cell epitope p25, induces CXCR3 expression on p25-specific CD4+ T cells in the lungs so that the majority of vaccine-induced CD4+ TRM expresses CXCR3 at 6 weeks. However, CXCR3-/- mice developed equivalent antigen-specific CD4+ T cell responses to wild-type (WT) mice following PR8.p25, and surprisingly retained more p25-specific CD4+ TRM in the lungs than WT mice at 6 weeks. The adoptive transfer of CXCR3-/- and WT P25 T cells into WT mice revealed that the initial recruitment of vaccine-induced CD4+ T cells into the lungs was independent of CXCR3, but by 6 weeks, CXCR3-deficient P25 T cells, and especially CXCR3-/- TRM, were significantly reduced compared to CXCR3-sufficient P25 T cells. Therefore, although CXCR3 was not essential for CD4+ TRM recruitment or retention, it provided a competitive advantage for the induction of M. tuberculosis-specific CD4+ TRM in the lungs following pulmonary immunization.

Triptoquinone A and B exercise a therapeutic effect in systemic lupus erythematosus by regulating NLRC3

The autoimmune disorder systemic lupus erythematosus (SLE) is multifaceted, with limited therapeutic alternatives and detrimental side effects, particularly on bones and joints. This research endeavors to examine the curative potential and underlying mechanisms of in addressing SLE-associated bone and joint complications. Triptoquinone A and triptoquinone B, constituents of Tripterygium wilfordii polyglycoside tablets (TGTs), exhibit antioxidant and anti-inflammatory attributes; nonetheless, its function in SLE therapy remains elusive. This investigation delves into the role of oxidative stress in systemic lupus erythematosus (SLE) and probes the prospective remedial effects of triptoquinone A and triptoquinone B on inflammation and cartilage deterioration in SLE-affected joints. Employing bioinformatics analyses, differentially expressed genes (DEGs) and protein-protein interactions were discerned in SLE, rheumatoid arthritis (RA), and osteoarthritis (OA) datasets. Enrichment analyses unveiled shared genes implicated in immune system regulation and toll-like receptor signaling pathways, among others. Subsequent examination of triptoquinone A and triptoquinone B revealed their capacity to diminish NLRC3 expression in chondrocytes, resulting in decreased pro-inflammatory cytokine levels and cartilage degradation enzyme expression. Suppression of NLRC3 augmented the protective effects of triptoquinone A and B, implying that targeting NLRC3 may constitute a potential therapeutic strategy for inflammation and cartilage degeneration-associated conditions in SLE patients. Our discoveries indicate that triptoquinone A and triptoquinone B may impede SLE progression via the NLRC3 axis, offering potential benefits for SLE-affected bone and joint health.

Integrated Bioinformatics Analysis to Screen Hub Gene Signatures for Fetal Growth Restriction

Background. Fetal growth restriction (FGR) is the impairment of the biological growth potential of the fetus and often leads to adverse pregnancy outcomes. The molecular mechanisms for the development of FGR, however, are still unclear. The purpose of this study is to identify critical genes associated with FGR through an integrated bioinformatics approach and explore the potential pathogenesis of FGR. Methods. We downloaded FGR-related gene microarray data, used weighted gene co-expression network analysis (WGCNA), differentially expressed genes (DEGs), and protein-protein interaction (PPI) networks to screen hub genes. The GSE24129 gene set was used for validation of critical gene expression levels and diagnostic capabilities. Results. A weighted gene co-expression network was constructed, and 5000 genes were divided into 12 modules. Of these modules, the blue module showed the closest relationship with FGR. Taking the intersection of the DEGs and genes in the blue module as pivotal genes, 277 genes were identified, and 20 crucial genes were screened from the PPI network. The GSE24129 gene set verified the expression of 20 genes, and CXCL9, CXCR3, and ITGAX genes were identified as actual pivotal genes. The expression levels of CXCL9, CXCR3, and ITGAX were increased in both the training and validation sets, and ROC curve validation revealed that these three pivotal genes had a significant diagnostic ability for FGR. Single-gene GSEA results showed that all three core genes activated “hematopoietic cell lineage” and “cell adhesion molecules” and inhibited the “cGMP-PKG signaling pathway” in the development of FGR. CXCL9, CXCR3, and ITGAX may therefore be closely associated with the development of FGR and may serve as potential biomarkers for the diagnosis and treatment of FGR.

A Protective Role of NOD2 on Oxazolone-induced Intestinal Inflammation Through IL-1β-mediated Signalling Pathway

BACKGROUND AND AIMS

NOD2 has emerged as a critical player in the induction of both Th1 and Th2 responses for potentiation and polarisation of antigen-dependent immunity. Loss-of-function mutations in the NOD2-encoding gene and deregulation of its downstream signalling pathway have been linked to Crohn's disease. Although it is well documented that NOD2 is capable of sensing bacterial muramyl dipeptide, it remains counter-intuitive to link development of overt intestinal inflammation to a loss of bacterial-induced inflammatory response. We hypothesised that a T helper bias could also contribute to an autoimmune-like colitis different from inflammation that is fully fledged by Th1 type cells.

METHODS

An oedematous bowel wall with a mixed Th1/Th2 response was induced in mice by intrarectal instillation of the haptenating agent oxazolone. Survival and clinical scoring were evaluated. At several time points after instillation, colonic damage was assessed by macroscopic and microscopic observations. To evaluate the involvement of NOD2 in immunochemical phenomena, quantitative polymerase chain reaction [PCR] and flow cytometry analysis were performed. Bone marrow chimera experimentation allowed us to evaluate the role of haematopoietic/non-hematopoietic NOD2-expressing cells.

RESULTS

Herein, we identified a key regulatory circuit whereby NOD2-mediated sensing of a muramyl dipeptide [MDP] by radio-resistant cells improves colitis with a mixed Th1/Th2 response that is induced by oxazolone. Genetic ablation of either Nod2 or Ripk2 precipitated oxazolone colitis that is predominantly linked to a lack of interferon-gamma. Bone marrow chimera experiments revealed that inactivation of Nod2 signalling in non-haematopoietic cells is causing a biased M1-M2 polarisation of macrophages and a decreased frequency of splenic regulatory T cells that correlates with an impaired activation of CD4 + T cells within mesenteric lymph nodes. Mechanistically, mice were protected from oxazolone-induced colitis upon administration of MDP in an interleukin-1- and interleukin-23-dependent manner.

CONCLUSIONS

These findings indicate that Nod2 signalling may prevent pathological conversion of T helper cells for maintenance of tissue homeostasis.

CXCL10 Chemokine: A Critical Player in RNA and DNA Viral Infections

Chemokines constitute a group of small, secreted proteins that regulate leukocyte migration and contribute to their activation. Chemokines are crucial inflammatory mediators that play a key role in managing viral infections, during which the profile of chemokine expression helps shape the immune response and regulate viral clearance, improving clinical outcome. In particular, the chemokine ligand CXCL10 and its receptor CXCR3 were explored in a plethora of RNA and DNA viral infections. In this review, we highlight the expression profile and role of the CXCL10/CXCR3 axis in the host defense against a variety of RNA and DNA viral infections. We also discuss the interactions among viruses and host cells that trigger CXCL10 expression, as well as the signaling cascades induced in CXCR3 positive cells.

Stage-Specific Effect of Inositol Hexaphosphate on Cancer Stem Cell Pool during Growth and Progression of Prostate Tumorigenesis in TRAMP Model

Herein, we assessed the stage-specific efficacy of inositol hexaphosphate (IP6, phytic acid), a bioactive food component, on prostate cancer (PCa) growth and progression in a transgenic mouse model of prostate cancer (TRAMP). Starting at 4, 12, 20, and 30 weeks of age, male TRAMP mice were fed either regular drinking water or 2% IP6 in water for ~8-15 weeks. Pathological assessments at study endpoint indicated that tumor grade is arrested at earlier stages by IP6 treatment; IP6 also prevented progression to more advanced forms of the disease (~55-70% decrease in moderately and poorly differentiated adenocarcinoma incidence was observed in advanced stage TRAMP cohorts). Next, we determined whether the protective effects of IP6 are mediated via its effect on the expansion of the cancer stem cells (CSCs) pool; results indicated that the anti-PCa effects of IP6 are associated with its potential to eradicate the PCa CSC pool in TRAMP prostate tumors. Furthermore, in vitro assays corroborated the above findings as IP6 decreased the % of floating PC-3 prostaspheres (self-renewal of CSCs) by ~90%. Together, these findings suggest the multifaceted chemopreventive-translational potential of IP6 intervention in suppressing the growth and progression of PCa and controlling this malignancy at an early stage.

Local delivery of a CXCR3 antagonist decreases the progression of bone resorption induced by LPS injection in a murine model

OBJECTIVES

This experimental study was carried out to investigate the effects of locally delivered nanoparticles (AMG-487 NP) containing a CXCR3 antagonist in inhibiting the progression of LPS-induced inflammation, osteoclastic activity, and bone resorption on a murine model.

MATERIALS AND METHODS

Thirty, 7-week-old C57BL/6 J male mice were used. Inflammatory bone loss was induced by Porphyromonas gingivalis-lipopolysaccharide (P.g.-LPS) injections between the first and second maxillary molars, bilaterally, twice a week for 6 weeks (n = 20). AMG-487 NP were incorporated into a liposome carrier and locally delivered on sites where P.g.-LPS was injected. Control mice (n = 10) were injected with vehicle only. Experimental groups included (1) control, (2) LPS, and (3) LPS + NP. At the end of 1 and 6 weeks, mice were euthanized, maxillae harvested, fixed, and stored for further analysis.

RESULTS

Volumetric bone loss analysis revealed, at 1 week, an increase in bone loss in the LPS group (47.9%) compared to control (27.4%) and LPS + NP (27.8%) groups. H&E staining demonstrated reduced inflammatory infiltrate in the LPS + NP group compared to LPS group. At 6 weeks, volumetric bone loss increased in all groups; however, treatment with the CXCR3 antagonist (LPS + NP) significantly reduced bone loss compared to the LPS group. CXCR3 antagonist treatment significantly reduced osteoclast numbers when compared to LPS group at 1 and 6 weeks.

CONCLUSIONS

This study showed that local delivery of a CXCR antagonist, via nanoparticles, in a bone resorption model, induced by LPS injection, was effective in reducing inflammation, osteoclast numbers, and bone loss.

CLINICAL RELEVANCE

CXCR3 blockade can be regarded as a novel target for therapeutic intervention of bone loss. It can be a safe and convenient method for periodontitis treatment or prevention applicable in clinical practice.

Evolution, Expression and Functional Analysis of CXCR3 in Neuronal and Cardiovascular Diseases: A Narrative Review

Chemokines form a sophisticated communication network wherein they maneuver the spatiotemporal migration of immune cells across a system. These chemical messengers are recognized by chemokine receptors, which can trigger a cascade of reactions upon binding to its respective ligand. CXC chemokine receptor 3 (CXCR3) is a transmembrane G protein-coupled receptor, which can selectively bind to CXCL9, CXCL10, and CXCL11. CXCR3 is predominantly expressed on immune cells, including activated T lymphocytes and natural killer cells. It thus plays a crucial role in immunological processes like homing of effector cells to infection sites and for pathogen clearance. Additionally, it is expressed on several cell types of the central nervous system and cardiovascular system, due to which it has been implicated in several central nervous system disorders, including Alzheimer's disease, multiple sclerosis, dengue viral disease, and glioblastoma, as well as cardiovascular diseases like atherosclerosis, Chronic Chagas cardiomyopathy, and hypertension. This review provides a narrative description of the evolution, structure, function, and expression of CXCR3 and its corresponding ligands in mammals and zebrafish and the association of CXCR3 receptors with cardiovascular and neuronal disorders. Unraveling the mechanisms underlying the connection of CXCR3 and disease could help researchers investigate the potential of CXCR3 as a biomarker for early diagnosis and as a therapeutic target for pharmacological intervention, along with developing robust zebrafish disease models.

Biological Characteristics and Predictive Model of Biopsy-Proven Acute Rejection (BPAR) After Kidney Transplantation: Evidences of Multi-Omics Analysis

Objectives: Early diagnosis and detection of acute rejection following kidney transplantation are of great significance for guiding the treatment and improving the prognosis of renal transplant recipients. In this study, we are aimed to explore the biological characteristics of biopsy-proven acute rejection (BPAR) and establish a predictive model.

Methods: Gene expression matrix of the renal allograft samples in the GEO database were screened and included, using Limma R package to identify differentially expressed transcripts between BPAR and No-BPAR groups. Then a predictive model of BPAR was established based on logistic regression of which key transcripts involved in the predictive model were further explored using functional enrichment analyses including Gene Ontology analysis (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Gene Set Enrichment Analysis (GSEA).

Results: A total of four studies (GSE129166, GSE48581, GSE36059, and GSE98320) were included for extensive analysis of differential expression. 32 differential expressed transcripts were observed to be significant between two groups after the pooled analysis. Afterward, a predictive model containing the five most significant transcripts (IDO1, CXCL10, IFNG, GBP1, PMAIP1) showed good predictive efficacy for BPAR after kidney transplantation (AUC = 0.919, 95%CI = 0.902–0.939). Results of functional enrichment analysis showed that The functions of differential genes are mainly manifested in chemokine receptor binding, chemokine activity, G protein-coupled receptor binding, etc. while the immune infiltration analysis indicated that immune cells mainly related to acute rejection include Macrophages. M1, T cells gamma delta, T cells CD4 memory activated, eosinophils, etc.

Conclusion: We have identified a total of 32 differential expressed transcripts and based on that, a predictive model with five significant transcripts was established, which was suggested as a highly recommended tool for the prediction of BPAR after kidney transplantation. However, an extensive study should be performed for the evaluation of the predictive model and mechanism involved.

Innate Immune Pathways Promote Oligodendrocyte Progenitor Cell Recruitment to the Injury Site in Adult Zebrafish Brain

The oligodendrocyte progenitors (OPCs) are at the front of the glial reaction to the traumatic brain injury. However, regulatory pathways steering the OPC reaction as well as the role of reactive OPCs remain largely unknown. Here, we compared a long-lasting, exacerbated reaction of OPCs to the adult zebrafish brain injury with a timely restricted OPC activation to identify the specific molecular mechanisms regulating OPC reactivity and their contribution to regeneration. We demonstrated that the influx of the cerebrospinal fluid into the brain parenchyma after injury simultaneously activates the toll-like receptor 2 (Tlr2) and the chemokine receptor 3 (Cxcr3) innate immunity pathways, leading to increased OPC proliferation and thereby exacerbated glial reactivity. These pathways were critical for long-lasting OPC accumulation even after the ablation of microglia and infiltrating monocytes. Importantly, interference with the Tlr1/2 and Cxcr3 pathways after injury alleviated reactive gliosis, increased new neuron recruitment, and improved tissue restoration.

C-X-C Motif Chemokine Ligand 9 and Its CXCR3 Receptor Are the Salt and Pepper for T Cells Trafficking in a Mouse Model of Gaucher Disease

Gaucher disease is a lysosomal storage disease, which happens due to mutations in GBA1/Gba1 that encodes the enzyme termed as lysosomal acid β-glucosidase. The major function of this enzyme is to catalyze glucosylceramide (GC) into glucose and ceramide. The deficiency of this enzyme and resultant abnormal accumulation of GC cause altered function of several of the innate and adaptive immune cells. For example, augmented infiltration of T cells contributes to the increased production of pro-inflammatory cytokines, (e.g., IFNγ, TNFα, IL6, IL12p40, IL12p70, IL23, and IL17A/F). This leads to tissue damage in a genetic mouse model (Gba1^9V/-) of Gaucher disease. The cellular mechanism(s) by which increased tissue infiltration of T cells occurs in this disease is not fully understood. Here, we delineate role of the CXCR3 receptor and its exogenous C-X-C motif chemokine ligand 9 (CXCL9) in induction of increased tissue recruitment of CD4⁺ T and CD8⁺ T cells in Gaucher disease. Intracellular FACS staining of macrophages (Mϕs) and dendritic cells (DCs) from Gba1^9V/- mice showed elevated production of CXCL9. Purified CD4⁺ T cells and the CD8⁺ T cells from Gba1^9V/- mice showed increased expression of CXCR3. Ex vivo and in vivo chemotaxis experiments showed CXCL9 involvement in the recruitment of Gba1^9V/- T cells. Furthermore, antibody blockade of the CXCL9 receptor (CXCR3) on T cells caused marked reduction in CXCL9- mediated chemotaxis of T cells in Gba1^9V/- mice. These data implicate abnormalities of the CXCL9-CXCR3 axis leading to enhanced tissue recruitment of T cells in Gaucher disease. Such results provide a rationale for blockade of the CXCL9/CXCR3 axis as potential new therapeutic targets for the treatment of inflammation in Gaucher disease.

Transcriptomic Analysis of the Effects of Chemokine Receptor CXCR3 Deficiency on Immune Responses in the Mouse Brain during Toxoplasma gondii Infection

The obligate intracellular parasite Toxoplasma gondii infects warm-blooded animals, including humans. We previously revealed through a whole-brain transcriptome analysis that infection with T. gondii in mice causes immune response-associated genes to be upregulated, for instance, chemokines and chemokine receptors such as CXC chemokine receptor 3 (CXCR3) and its ligand CXC chemokine ligand 10 (CXCL10). Here, we describe the effect of CXCR3 on responses against T. gondii infection in the mouse brain. In vivo assays using CXCR3-deficient mice showed that the absence of CXCR3 delayed the normal recovery of body weight and increased the brain parasite burden, suggesting that CXCR3 plays a role in the control of pathology in the brain, the site where chronic infection occurs. Therefore, to further analyze the function of CXCR3 in the brain, we profiled the gene expression patterns of primary astrocytes and microglia by RNA sequencing and subsequent analyses. CXCR3 deficiency impaired the normal upregulation of immune-related genes during T. gondii infection, in astrocytes and microglia alike. Collectively, our results suggest that the immune-related genes upregulated by CXCR3 perform a particular role in controlling pathology when the host is chronically infected with T. gondii in the brain.

Partners in Crime: Beta-Cells and Autoimmune Responses Complicit in Type 1 Diabetes Pathogenesis

Type 1 diabetes (T1D) is an autoimmune disease characterized by autoreactive T cell-mediated destruction of insulin-producing pancreatic beta-cells. Loss of beta-cells leads to insulin insufficiency and hyperglycemia, with patients eventually requiring lifelong insulin therapy to maintain normal glycemic control. Since T1D has been historically defined as a disease of immune system dysregulation, there has been little focus on the state and response of beta-cells and how they may also contribute to their own demise. Major hurdles to identifying a cure for T1D include a limited understanding of disease etiology and how functional and transcriptional beta-cell heterogeneity may be involved in disease progression. Recent studies indicate that the beta-cell response is not simply a passive aspect of T1D pathogenesis, but rather an interplay between the beta-cell and the immune system actively contributing to disease. Here, we comprehensively review the current literature describing beta-cell vulnerability, heterogeneity, and contributions to pathophysiology of T1D, how these responses are influenced by autoimmunity, and describe pathways that can potentially be exploited to delay T1D.

A model of the innate immune response to SARS-CoV-2 in the alveolar epithelium

We present a differential equation model of the innate immune response to SARS-CoV-2 within the alveolar epithelium. Critical determinants of the viral dynamics and host response, including type I and type II alveolar epithelial cells, interferons, chemokines, toxins and innate immune cells, are included. We estimate model parameters, compute the within-host basic reproductive number, and study the impacts of therapies, prophylactics, and host/pathogen variability on the course of the infection. Model simulations indicate that the innate immune response suppresses the infection and enables the alveolar epithelium to partially recover. While very robust antiviral therapy controls the infection and enables the epithelium to heal, moderate therapy is of limited benefit. Meanwhile interferon therapy is predicted to reduce viral load but exacerbate tissue damage. The deleterious effects of interferon therapy are especially apparent late in the infection. Individual variation in ACE2 expression, epithelial cell interferon production, and SARS-CoV-2 spike protein binding affinity are predicted to significantly impact prognosis.

GPR182 is an endothelium-specific atypical chemokine receptor that maintains hematopoietic stem cell homeostasis

G protein–coupled receptors (GPCRs) are important regulators of cellular and biological functions and are primary targets of therapeutic drugs. About 100 mammalian GPCRs are still considered orphan receptors because they lack a known endogenous ligand. We report the deorphanization of GPR182, which is expressed in endothelial cells of the microvasculature. We show that GPR182 is an atypical chemokine receptor, which binds CXCL10, 12, and 13. However, binding does not induce downstream signaling. Consistent with a scavenging function of GPR182, mice lacking GPR182 have increased plasma levels of chemokines. In line with the crucial role of CXCL12 in hematopoietic stem cell homeostasis, we found that loss of GPR182 results in increased egress of hematopoietic stem cells from the bone marrow.

G protein–coupled receptor 182 (GPR182) has been shown to be expressed in endothelial cells; however, its ligand and physiological role has remained elusive. We found GPR182 to be expressed in microvascular and lymphatic endothelial cells of most organs and to bind with nanomolar affinity the chemokines CXCL10, CXCL12, and CXCL13. In contrast to conventional chemokine receptors, binding of chemokines to GPR182 did not induce typical downstream signaling processes, including G_q- and G_i-mediated signaling or β-arrestin recruitment. GPR182 showed relatively high constitutive activity in regard to β-arrestin recruitment and rapidly internalized in a ligand-independent manner. In constitutive GPR182-deficient mice, as well as after induced endothelium-specific loss of GPR182, we found significant increases in the plasma levels of CXCL10, CXCL12, and CXCL13. Global and induced endothelium-specific GPR182-deficient mice showed a significant decrease in hematopoietic stem cells in the bone marrow as well as increased colony-forming units of hematopoietic progenitors in the blood and the spleen. Our data show that GPR182 is a new atypical chemokine receptor for CXCL10, CXCL12, and CXCL13, which is involved in the regulation of hematopoietic stem cell homeostasis.

Systemic CXCL10 is a predictive biomarker of vitiligo lesional skin infiltration, PUVA, NB-UVB and corticosteroid treatment response and outcome

Vitiligo is an acquired pigmentary skin disorder that currently lacks standardized treatment and validated biomarkers to objectively evaluate disease state or therapeutic response. Although prior studies have linked vitiligo autoimmunity with CXCL10/CXCL9-mediated recruitment of leukocytes to the skin, only limited clinical data are available regarding CXCL10 as vitiligo biomarker. To evaluate the utility of systemic CXCL10 as a predictor of disease progression and treatment response on a large cohort of vitiligo patients. CXCL10 levels in lesional, perilesional, and unaffected skin of vitiligo patient (n = 30) and in the serum (n = 51) were measured by quantitative ELISA. CXCL10 expression, recruitment of leukocytes, and inflammatory infiltrates were evaluated by histochemical (n = 32) and immunofluorescence (n = 10) staining. Rigorous cross-sectional and longitudinal biostatistical analysis were employed to correlate CXCL10 levels with disease variables, treatment response, and outcome. We demonstrated that elevated CXCL10 level (2 pg/mm² and higher) in lesional skin correlates with increased leukocytic infiltrate, disease duration (< 2 year), and its higher level in the serum (50 pg/ml and higher). Changes in CXCL10 serum levels in patients treated with psoralen plus UVA (PUVA) phototherapy, narrowband UVB (NB-UVB) phototherapy, and systemic steroids (SS) correlated with changes in the intralesional CXCL10 levels in repigmented skin. NB-UVB and SS regimens provided most consistent CXCL10 mean change, suggesting that these regimens are most effective in harnessing CXCR3-mediated inflammatory response. Serum CXCL10 is a useful vitiligo biomarker, which predicts lesional skin leukocytic infiltration, and vitiligo treatment response and outcome.

Latent Cytomegalovirus-Driven Recruitment of Activated CD4+ T Cells Promotes Virus Reactivation

Human cytomegalovirus (HCMV) infection is not cleared by the initial immune response but persists for the lifetime of the host, in part due to its ability to establish a latent infection in cells of the myeloid lineage. HCMV has been shown to manipulate the secretion of cellular proteins during both lytic and latent infection; with changes caused by latent infection mainly investigated in CD34+ progenitor cells. Whilst CD34+ cells are generally bone marrow resident, their derivative CD14+ monocytes migrate to the periphery where they briefly circulate until extravasation into tissue sites. We have analyzed the effect of HCMV latent infection on the secretome of CD14+ monocytes, identifying an upregulation of both CCL8 and CXCL10 chemokines in the CD14+ latency-associated secretome. Unlike CD34+ cells, the CD14+ latency-associated secretome did not induce migration of resting immune cell subsets but did induce migration of activated NK and T cells expressing CXCR3 in a CXCL10 dependent manner. As reported in CD34+ latent infection, the CD14+ latency-associated secretome also suppressed the anti-viral activity of stimulated CD4+ T cells. Surprisingly, however, co-culture of activated autologous CD4+ T cells with latently infected monocytes resulted in reactivation of HCMV at levels comparable to those observed using M-CSF and IL-1β cytokines. We propose that these events represent a potential strategy to enable HCMV reactivation and local dissemination of the virus at peripheral tissue sites.

Polymorphisms in CXCR3 ligands predict early CXCL9 recovery and severe chronic GVHD

Chronic graft-versus-host disease (cGVHD) is a major cause of mortality and morbidity after allogeneic stem cell transplantation (alloSCT). The individual risk of severe cGVHD remains difficult to predict and may involve CXCR3 ligands. This study investigated the role of single-nucleotide polymorphisms (SNPs) of CXCL4, CXCL9, CXCL10, and CXCL11, and their day +28 serum levels, in cGVHD pathogenesis. Eighteen CXCR3 and CXCL4, CXCL9-11 SNPs as well as peri-transplant CXCL9-11 serum levels were analyzed in 688 patients without (training cohort; n = 287) or with statin-based endothelial protection cohort (n = 401). Clinical outcomes were correlated to serum levels and SNP status. Significant polymorphisms were further analyzed by luciferase reporter assays. Findings were validated in an independent cohort (n = 202). A combined genetic risk comprising four CXCR3 ligand SNPs was significantly associated with increased risk of severe cGVHD in both training cohort (hazard ratio (HR) 2.48, 95% confidence interval (CI) 1.33-4.64, P = 0.004) and validation cohort (HR 2.95, 95% CI 1.56-5.58, P = 0.001). In reporter assays, significantly reduced suppressive effects of calcineurin inhibitors in constructs with variant alleles of rs884304 (P < 0.001) and rs884004 (P < 0.001) were observed. CXCL9 serum levels at day +28 after alloSCT correlated with both genetic risk and risk of severe cGVHD (HR 1.38, 95% CI 1.10-1.73, P = 0.006). This study identifies patients with high genetic risk to develop severe cGVHD.

Expression and role of MIG/CXCR3 axis in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin lymphoma with a generally aggressive and heterogeneous clinical course. Chemokines are one of the complex components in the tumor microenvironment (TME), and they play a vital role in tumor progression and metastasis. There is no information about the monokine induced by gamma interferon (MIG)/CXC chemokine receptor 3 (CXCR3) axis in patients with MCL. In the present study, we discovered that CXCR3 was highly expressed in MCL tissues and some cell lines including Maver, Z138, and Jeko-1, and significantly associated with clinical factors reflecting high tumor burden in MCL patients. Moreover, elevated serum MIG at diagnosis showed a close relationship with advanced disease and poor prognosis in MCL patients. Additionally, the role of CXCR3 in promoting the proliferation and inhibiting the apoptosis of primary MCL cells and Jeko-1 cells was validated by in vitro experiments. Further research indicated that the MIG/CXCR3 axis mediated MCL cell migration to the TME through the PI3K/AKT signaling pathway. Therefore, the MIG/CXCR3 axis might be a potential target with fewer off-target side effects than other targets in MCL.

The Role of Chemokine Receptor CXCR3 and Its Ligands in Renal Cell Carcinoma

The major invasive subtype of kidney cancer is renal cell carcinoma (RCC). The essential components of cancer development are chronic inflammation and neoangiogenesis. It has been suggested that the chemokine ligand 9, -10, –11 (CXCL9–11) and chemokine receptor 3 (CXCR3) chemokines receptor expressed on monocytes, T and NK cells may be involved in the inhibition of angiogenesis. However, to date, little is known about the potential clinical significance of these chemokines and their receptor in renal cell carcinoma. Therefore, in this review, we described the role of CXCR3 and its ligands in pathogenesis of RCC. We performed an extensive search of the current literature in our investigation, using the MEDLINE/PubMed database. The changes of chemokines and their specific receptor in renal cell carcinoma were observed. Published studies revealed an increased expression of CXCR3 and elevated concentration of its ligands in RCC. The association between treatment of RCC and CXCL9–11/CXCR3 concentration and expression was also observed. Moreover, CXCR3 and its ligands levels were related to patient’s prognosis, risk of metastasis and tumor growth. This review describes the potential role of CXCR3 and its ligands in pathogenesis of RCC, as well as their potential immune-therapeutic significance. However, future studies should aim to confirm the clinical and prognostic role of CXCL9–11/CXCR3 in renal cell carcinoma.

CXC Chemokine/Receptor Axis Profile and Metastasis in Prostate Cancer

In this study, the effects of the CXC chemokine/receptor axis on lymph node and distant metastases of prostate cancer (PC) were analyzed. Further, mRNA expression data of metastatic PC were extracted from the Stand Up To Cancer–Prostate Cancer Foundation Dream Team database and differences between metastatic sites were comprehensively analyzed. CXC chemokine/receptor mRNA expression data of primary PC included in the Cancer Genome Atlas were used to analyze the relationships of CXC chemokine/receptor expression with lymph node metastasis and cancer progression. In metastatic PC, significantly higher expression of ELR⁺ CXC chemokines/receptors and significantly lower expression of ELR⁻ CXC chemokines/receptors were observed in bone metastases relative to lymph node metastases. In primary PC, significantly higher ELR⁻ CXC chemokine/receptor expression and significantly lower ELR⁺ CXC chemokine/receptor expression were observed in patients with lymph node metastasis relative to those without. Multivariate logistic regression analysis identified CXCL10 expression as an independent predictor of lymph node metastasis. Furthermore, the log-rank test results revealed that co-expression of CXCL10/CXCR3 was associated with postoperative recurrence. These findings demonstrate heterogeneous expression of CXC chemokine/receptor genes in primary PC as well as differences in expression patterns according to the metastatic site.

Cytokine profiling of extracellular vesicles isolated from plasma in myalgic encephalomyelitis/chronic fatigue syndrome: a pilot study

BACKGROUND

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating disease of unknown etiology lasting for a minimum of 6 months but usually for many years, with features including fatigue, cognitive impairment, myalgias, post-exertional malaise, and immune system dysfunction. Dysregulation of cytokine signaling could give rise to many of these symptoms. Cytokines are present in both plasma and extracellular vesicles, but little investigation of EVs in ME/CFS has been reported. Therefore, we aimed to characterize the content of extracellular vesicles (EVs) isolated from plasma (including circulating cytokine/chemokine profiling) from individuals with ME/CFS and healthy controls.

METHODS

We included 35 ME/CFS patients and 35 controls matched for age, sex and BMI. EVs were enriched from plasma by using a polymer-based precipitation method and characterized by Nanoparticle Tracking Analysis (NTA), Transmission Electron Microscopy (TEM) and immunoblotting. A 45-plex immunoassay was used to determine cytokine levels in both plasma and isolated EVs from a subset of 19 patients and controls. Linear regression, principal component analysis and inter-cytokine correlations were analyzed.

RESULTS

ME/CFS individuals had significantly higher levels of EVs that ranged from 30 to 130 nm in size as compared to controls, but the mean size for total extracellular vesicles did not differ between groups. The enrichment of typical EV markers CD63, CD81, TSG101 and HSP70 was confirmed by Western blot analysis and the morphology assessed by TEM showed a homogeneous population of vesicles in both groups. Comparison of cytokine concentrations in plasma and isolated EVs of cases and controls yielded no significant differences. Cytokine-cytokine correlations in plasma revealed a significant higher number of interactions in ME/CFS cases along with 13 inverse correlations that were mainly driven by the Interferon gamma-induced protein 10 (IP-10), whereas in the plasma of controls, no inverse relationships were found across any of the cytokines. Network analysis in EVs from controls showed 2.5 times more significant inter-cytokine interactions than in the ME/CFS group, and both groups presented a unique negative association.

CONCLUSIONS

Elevated levels of 30-130 nm EVs were found in plasma from ME/CFS patients and inter-cytokine correlations revealed unusual regulatory relationships among cytokines in the ME/CFS group that were different from the control group in both plasma and EVs. These disturbances in cytokine networks are further evidence of immune dysregulation in ME/CFS.

T cell and chemokine receptors differentially control CD8 T cell motility behavior in the infected airways immediately before and after virus clearance in a primary infection

In mice, experimental influenza virus infection stimulates CD8 T cell infiltration of the airways. Virus is cleared by day 9, and between days 8 and 9 there is an abrupt change in CD8 T cell motility behavior transitioning from low velocity and high confinement on day 8, to high velocity with continued high confinement on day 9. We hypothesized that loss of virus and/or antigen signals in the context of high chemokine levels drives the T cells into a rapid surveillance mode. Virus infection induces chemokine production, which may change when the virus is cleared. We therefore sought to examine this period of rapid changes to the T cell environment in the tissue and seek evidence on the roles of peptide-MHC and chemokine receptor interactions. Experiments were performed to block G protein coupled receptor (GPCR) signaling with Pertussis toxin (Ptx). Ptx treatment generally reduced cell velocities and mildly increased confinement suggesting chemokine mediated arrest (velocity <2 μm/min) (Friedman RS, 2005), except on day 8 when velocity increased and confinement was relieved. Blocking specific peptide-MHC with monoclonal antibody unexpectedly decreased velocities on days 7 through 9, suggesting TCR/peptide-MHC interactions promote cell mobility in the tissue. Together, these results suggest the T cells are engaged with antigen bearing and chemokine producing cells that affect motility in ways that vary with the day after infection. The increase in velocities on day 9 were reversed by addition of specific peptide, consistent with the idea that antigen signals become limiting on day 9 compared to earlier time points. Thus, antigen and chemokine signals act to alternately promote and restrict CD8 T cell motility until the point of virus clearance, suggesting the switch in motility behavior on day 9 may be due to a combination of limiting antigen in the presence of high chemokine signals as the virus is cleared.

Functional differences of three CXCL10 homologues in the giant spiny frog Quasipaa spinosa

Chemokines are a superfamily of structurally related chemotactic cytokines exerting significant roles in acting as a bridge between the innate and adaptive immune responses. In this study, we identified three CXC motif chemokine 10 (CXCL10) homologues (QsCXCL10-1, QsCXCL10-2 and QsCXCL10-3) from giant spiny frog Quasipaa spinosa. All three deduced QsCXCL10 proteins contained four conserved cysteine residues as found in other known CXC chemokines. Phylogenetic analysis showed that QsCXCL10-1, 2, 3 and other CXCL10s in amphibian were grouped together to form a separate clade. These three QsCXCL10s were highly expressed in spleen and blood. Upon infection with Staphylococcus aureus or Aeromonas hydrophila, the expressions of QsCXCL10s were markedly increased in spleen and blood during biotic stresses. Meanwhile, the QsCXCL10s transcription in liver could also be up-regulated under abiotic stresses such as cold and heat stresses. The recombinant proteins of frog CXCL10 homologues were produced and purified in E. coli and possessed similar but differential bioactivities. Both rCXCL10-1 and rCXCL10-2 had strong effects on the up-regulation of pro-inflammatory cytokines (TNF-α, IL-1β and IL-8) in vivo, whereas rCXCL10-3 induced a weak expression of these cytokines. Moreover, the rCXCL10-1 and rCXCL10-2 could strongly promote splenocyte proliferation and induce lymphocytes migration, while rCXCL10-3 had limited effects on these biological processes. All three frog chemokines triggered their functional activities by engaging CXC motif chemokine receptor 3 (CXCR3). Taken together, these results revealed that the three QsCXCL10s had similar but differential functional activities in mediating immune responses and host defenses, which might contribute to a better understanding of the functional evolution of CXCL10 in vertebrates.

Chemokine receptor CXCR3 is required for lethal brain pathology but not pathogen clearance during cryptococcal meningoencephalitis

Cryptococcal meningoencephalitis (CM) is the major cause of infection-related neurological death, typically seen in immunocompromised patients. However, T cell-driven inflammatory response has been increasingly implicated in lethal central nervous system (CNS) immunopathology in human patients and murine models. Here, we report marked up-regulation of the chemokine receptor CXCR3 axis in human patients and mice with CM. CXCR3 deletion in mice improves survival, diminishes neurological deficits, and limits neuronal damage without suppressing fungal clearance. CD4+ T cell accumulation and TH1 skewing are reduced in the CNS but not spleens of infected CXCR3-/- mice. Adoptive transfer of WT, but not CXCR3-/- CD4+ T cells, into CXCR3-/- mice phenocopies the pathology of infected WT mice. Collectively, we found that CXCR3+CD4+ T cells drive lethal CNS pathology but are not required for fungal clearance during CM. The CXCR3 pathway shows potential as a therapeutic target or for biomarker discovery to limit CNS inflammatory damages.

Chemokines and their receptors as biomarkers in esophageal cancer

Esophageal cancer (EC) is one of the most lethal malignancies of the digestive tract and remains to be improved poor prognosis. Two histological subtypes, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), are major characteristics of EC. Deep understanding about both subtypes is essential to overcome EC. Here, we focus on chemokines and their receptors as biomarkers and their current applications for the prognosis in EC. We reviewed relevant articles identified using PubMed database for the chemokines and their receptors in EC analyzed by immunohistochemistry. The primary objective is to summarize evidences for them as prognostic biomarkers in EC. A total of twenty-one articles were reviewed after exclusion. Most studies have been done in ESCC, and less in EAC. CXCL12 and its receptor CXCR4 have been shown in both subtypes as biomarkers. CXCR7, CXCL8 and its receptor CXCR2, and CCL21 and its receptor CCR7 have been examined in ESCC. Although it was a small number of reports, CXCL10, CCL4, and CCL5 have been indicated to have anti-tumor effects in ESCC. Chemokines and their receptors have the potential to be the biomarkers in EC. Comparative studies between ESCC and EAC will reveal the similarity and difference in these two subtypes of EC. These studies may indicate whether these molecules play important roles in both subtypes or are unique to one or another.

CXCL-10: a new candidate for melanoma therapy?

BACKGROUND

Melanoma is a malignancy that stems from melanocytes and is defined as the most dangerous skin malignancy in terms of metastasis and mortality rates. CXC motif chemokine 10 (CXCL10), also known as interferon gamma-induced protein-10 (IP-10), is a small cytokine-like protein secreted by a wide variety of cell types. CXCL10 is a ligand of the CXC chemokine receptor-3 (CXCR3) and is predominantly expressed by T helper cells (Th cells), cytotoxic T lymphocytes (CTLs), dendritic cells, macrophages, natural killer cells (NKs), as well as some epithelial and cancer cells. Similar to other chemokines, CXCL10 plays a role in immunomodulation, inflammation, hematopoiesis, chemotaxis and leukocyte trafficking.

CONCLUSIONS

Recent studies indicate that the CXCL10/CXCR3 axis may act as a double-edged sword in terms of pro- and anti-cancer activities in a variety of tissues and cells, especially in melanoma cells and their microenvironments. Most of these activities arise from the CXCR3 splice variants CXCR3-A, CXCR3-B and CXCR3-Alt. In this review, we discuss the pro- and anti-cancer properties of CXCL10 in various types of tissues and cells, particularly melanoma cells, including its potential as a therapeutic target.

Effective Treatments for Bladder Cancer Affecting CXCL9/CXCL10/CXCL11/CXCR3 Axis: A Review

Bladder cancer (BC) originates mainly from the epithelial compartment of the bladder, which is defined as transitional cell carcinoma or urothelial cell carcinoma. About 70% of patients with BC will survive five years from diagnosis. Previous studies revealed that the immune system and its mediators, particularly chemokines, play a crucial role in modulating responses against BC. Chemokines, which serve as chemoattractants for leukocytes, are small proteins that can initiate inflammatory and anti-inflammatory immune responses and also are associated with many aspects of both regulation and progression of mentioned responses. Additionally, these immune mediators can interfere with the other tumor-related processes, including tumor proliferation, neovascularization, and metastases. Among these chemokines, CXC chemokines, including CXCL9, CXCL10, and CXCL11, are recognized as the main ligands of C-X-C motif chemokine receptor 3 (CXCR3) and contribute to related immune responses after therapeutic strategies for BC. Evidence suggests that the production of these chemokines can have two important implications. First, these mediators can trigger the accumulation of CD8+ T cells that can contribute to the elimination of the tumor. Secondly, the production of these chemokines by tumor tissue may trigger the migration and activation of immune cells including myeloid-derived suppressor cells and regulatory T cells, which act in favor of the tumor and its progress. Therefore, in this review, we describe the latest therapeutic approaches based on targeting this axis's components and subsequent immune phenomenon.

Role of Chemokines and Chemokine Receptors in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune diseases and a prototypic inflammatory disease, affecting the small joints of the hands and feet. Chemokines and chemokine receptors play a critical role in RA pathogenesis via immune cells recruitment. Several chemokines and chemokine receptors are abundant in the peripheral blood and in the local inflamed joints of RA. Furthermore, synthetic and biologics disease modifying anti rheumatic drugs have been reported to affect chemokines expression. Thus, many studies have focused on targeting chemokines and chemokine receptors, where some have shown positive promising results. However, most of the chemokine blockers in human trials of RA treatment displayed some failures that can be attributed to several reasons in their structures and binding affinities. Nevertheless, targeting chemokines will continue to be under development, in order to improve their therapeutic potentials in RA and other autoimmune diseases. In this review we provide an up-to-date knowledge regarding the role of chemokines and chemokine receptors in RA with an emphasis on their activities on immune cells. We also discussed the effects of drugs targeting those molecules in RA. This knowledge might provide impetus for developing new therapeutic modalities to treat this chronic disease.

The CC and CXC chemokines: major regulators of tumor progression and the tumor microenvironment

Chemokines are a family of soluble cytokines that act as chemoattractants to guide the migration of cells, in particular of immune cells. However, chemokines are also involved in cell proliferation, differentiation, and survival. Chemokines are associated with a variety of human diseases including chronic inflammation, immune dysfunction, cancer, and metastasis. This review discusses the expression of CC and CXC chemokines in the tumor microenvironment and their supportive and inhibitory roles in tumor progression, angiogenesis, metastasis, and tumor immunity. We also specially focus on the diverse roles of CXC chemokines (CXCL9-11, CXCL4 and its variant CXCL4L1) and their two chemokine receptor CXCR3 isoforms, CXCR3-A and CXCR3-B. These two distinct isoforms have divergent roles in tumors, either promoting (CXCR3-A) or inhibiting (CXCR3-B) tumor progression. Their effects are mediated not only directly in tumor cells but also indirectly via the regulation of angiogenesis and tumor immunity. A full comprehension of their mechanisms of action is critical to further validate these chemokines and their receptors as biomarkers or therapeutic targets in cancer.

Cutting Edge: CXCR3 Escapes X Chromosome Inactivation in T Cells during Infection: Potential Implications for Sex Differences in Immune Responses

CXCR3, an X-linked gene, is subject to X chromosome inactivation (XCI), but it is unclear whether CXCR3 escapes XCI in immune cells. We determined whether CXCR3 escapes XCI in vivo, evaluated the contribution of allelic CXCR3 expression to the phenotypic properties of T cells during experimental infection with Leishmania, and examined the potential implications to sex differences in immune responses. We used a bicistronic CXCR3 dual-reporter mouse, with each CXCR3 allele linked to a green or red fluorescent reporter without affecting endogenous CXCR3 expression. Our results show that CXCR3 escapes XCI, biallelic CXCR3-expressing T cells produce more CXCR3 protein than monoallelic CXCR3-expressing cells, and biallelic CXCR3-expressing T cells produce more IFN-γ, IL-2, and CD69 compared with T cells that express CXCR3 from one allele during Leishmania mexicana infection. These results demonstrate that XCI escape by CXCR3 potentially contributes to the sex-associated bias observed during infection.

The Distinct Roles of CXCR3 Variants and Their Ligands in the Tumor Microenvironment

First thought to orchestrate exclusively leukocyte trafficking, chemokines are now acknowledged for their multiple roles in the regulation of cell proliferation, differentiation, and survival. Dysregulation of their normal functions contributes to various pathologies, including inflammatory diseases and cancer. The two chemokine receptor 3 variants CXCR3-A and CXCR3-B, together with their cognate chemokines (CXCL11, CXCL10, CXCL9, CXCL4, and CXCL4L1), are involved in the control but also in the development of many tumors. CXCR3-A drives the infiltration of leukocytes to the tumor bed to modulate tumor progression (paracrine axis). Conversely, tumor-driven changes in the expression of the CXCR3 variants and their ligands promote cancer progression (autocrine axis). This review summarizes the anti- and pro-tumoral activities of the CXCR3 variants and their associated chemokines with a focus on the understanding of their distinct biological roles in the tumor microenvironment.

The Role of CXCR3 in Neurological Diseases

BACKGROUND

Neurological diseases have become an obvious challenge due to insufficient therapeutic intervention. Therefore, novel drugs for various neurological disorders are in desperate need. Recently, compelling evidence has demonstrated that chemokine receptor CXCR3, which is a G protein-coupled receptor in the CXC chemokine receptor family, may play a pivotal role in the development of neurological diseases. The aim of this review is to provide evidence for the potential of CXCR3 as a therapeutic target for neurological diseases.

METHODS

English journal articles that focused on the invovlement of CXCR3 in neurological diseases were searched via PubMed up to May 2017. Moreover, reference lists from identified articles were included for overviews.

RESULTS

The expression level of CXCR3 in T cells was significantly elevated in several neurological diseases, including multiple sclerosis (MS), glioma, Alzheimer's disease (AD), chronic pain, human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and bipolar disorder. CXCR3 antagonists showed therapeutic effects in these neurological diseases.

CONCLUSION

These studies provided hard evidence that CXCR3 plays a vital role in the pathogenesis of MS, glioma, AD, chronic pain, HAM/TSP and bipolar disorder. CXCR3 is a crucial molecule in neuroinflammatory and neurodegenerative diseases. It regulates the activation of infiltrating cells and resident immune cells. However, the exact functions of CXCR3 in neurological diseases are inconclusive. Thus, it is important to understand the topic of chemokines and the scope of their activity in neurological diseases.

CCL2 and CXCL10 are associated with poor outcome after intracerebral hemorrhage

OBJECTIVE

Intracerebral hemorrhage carries a high mortality and survivors are frequently left with significant disability. Immunological mechanisms may play an important role in hemorrhage-induced brain injury, however, research linking these mechanisms with clinical outcome remains limited. We aim to identify serum inflammatory mediators that are associated with outcome after intracerebral hemorrhage in order to translate data from experimental models to a patient cohort and identify potential targets worthy of reverse translation.

METHODS

A prospective cohort study at two comprehensive stroke centers enrolled patients with spontaneous intracerebral hemorrhage. Peripheral blood was collected at 6, 24, and 72 h from onset. Functional outcome was assessed at 90 days using the modified Rankin Scale (mRS). Serum inflammatory mediators were measured using multiplex ELISA. Multivariable modeling identified serum biomarkers independently associated with functional outcome at 90 days.

RESULTS

115 patients completed the study. At 6 h after onset, patients with elevated CCL2 had worse mRS score at day 90 (OR 4.07, 95% CI 1.27-13.10, P = 0.02) after adjusting for age, gender, ICH volume, IVH, infratentorial location and NIHSS score. At 24 and 72 h after onset, elevation in CXCL10 was independently associated with worse 90 days mRS score (24 h: OR 8.08, 95% CI 2.69-24.30, P < 0.001; 72 h: OR 3.89, 95% CI 1.12-13.49, P = 0.03).

INTERPRETATION

Acute and subacute elevations in specific immune factors are associated with poor outcome, highlighting potential pathways that may contribute to ongoing brain injury in patients with intracerebral hemorrhage.

Mechanisms regulating expansion of CD8+ T cells during HIV-1 infection

Abnormal immune activation and expansion of CD8+ T cells, especially of memory and effector phenotypes, take place during HIV-1 infection, and these abnormal features persist during administration of antiretroviral therapy (ART) to infected patients. The molecular mechanisms for CD8+ T-cell expansion remain poorly characterized. In this article, we review the literature addressing features of CD8+ T-cell immune pathology and present an integrated view on the mechanisms leading to abnormal CD8+ T-cell expansion during HIV-1 infection. The expression of molecules important for directing the homing of CD8+ T cells between the circulation and lymphoid tissues, in particular CCR5 and CXCR3, is increased in CD8+ T cells in circulation and in inflamed tissues during HIV-1 infection; these disturbances in the homing capacity of CD8+ T cells have been linked to increased CD8+ T-cell proliferation. The production of IL-15, a cytokine responsible for physiological proliferation of CD8+ T cells, is increased in lymphoid tissues during HIV-1 infection as result of microbial translocation and severe inflammation. IL-15, and additional inflammatory cytokines, may lead to deregulated proliferation of CD8+ T cells and explain the accumulation of CD8+ T cells in circulation. The decreased capacity of CD8+ T cells to localize to gut-associated lymphoid tissue also contributes to the accumulation of these cells in blood. Control of inflammation, through ART administration during primary HIV-1 infection or therapies aimed at controlling inflammation during HIV-1 infection, is pivotal to prevent abnormal expansion of CD8+ T cells during HIV-1 infection.

Chronic inflammatory lesions of the placenta are associated with an up-regulation of amniotic fluid CXCR3: A marker of allograft rejection

OBJECTIVE

The objective of this study is to determine whether the amniotic fluid (AF) concentration of soluble CXCR3 and its ligands CXCL9 and CXCL10 changes in patients whose placentas show evidence of chronic chorioamnionitis or other placental lesions consistent with maternal anti-fetal rejection.

METHODS

This retrospective case-control study included 425 women with (1) preterm delivery (n=92); (2) term in labor (n=68); and (3) term not in labor (n=265). Amniotic fluid CXCR3, CXCL9 and CXCL10 concentrations were determined by ELISA.

RESULTS

(1) Amniotic fluid concentrations of CXCR3 and its ligands CXCL9 and CXCL10 are higher in patients with preterm labor and maternal anti-fetal rejection lesions than in those without these lesions [CXCR3: preterm labor and delivery with maternal anti-fetal rejection placental lesions (median, 17.24 ng/mL; IQR, 6.79-26.68) vs. preterm labor and delivery without these placental lesions (median 8.79 ng/mL; IQR, 4.98-14.7; P=0.028)]; (2) patients with preterm labor and chronic chorioamnionitis had higher AF concentrations of CXCL9 and CXCL10, but not CXCR3, than those without this lesion [CXCR3: preterm labor with chronic chorioamnionitis (median, 17.02 ng/mL; IQR, 5.57-26.68) vs. preterm labor without chronic chorioamnionitis (median, 10.37 ng/mL; IQR 5.01-17.81; P=0.283)]; (3) patients with preterm labor had a significantly higher AF concentration of CXCR3 than those in labor at term regardless of the presence or absence of placental lesions.

CONCLUSION

Our findings support a role for maternal anti-fetal rejection in a subset of patients with preterm labor.

Single-Cell Tracking Reveals a Role for Pre-Existing CCR5+ Memory Th1 Cells in the Control of Rhinovirus-A39 After Experimental Challenge in Humans

Background

Little is known about T cells that respond to human rhinovirus in vivo, due to timing of infection, viral diversity, and complex T-cell specificities. We tracked circulating CD4+ T cells with identical epitope specificities that responded to intranasal challenge with rhinovirus (RV)-A39, and we assessed T-cell signatures in the nose.

Methods

Cells were monitored using a mixture of 2 capsid-specific major histocompatibility complex II tetramers over a 7-week period, before and after RV-A39 challenge, in 16 human leukocyte antigen-DR4+ subjects who participated in a trial of Bifidobacterium lactis (Bl-04) supplementation.

Results

Pre-existing tetramer+ T cells were linked to delayed viral shedding, enriched for activated CCR5+ Th1 effectors, and included a minor interleukin-21+ T follicular helper cell subset. After RV challenge, expansion and activation of virus-specific CCR5+ Th1 effectors was restricted to subjects who had a rise in neutralizing antibodies, and tetramer-negative CCR5+ effector memory types were comodulated. In the nose, CXCR3-CCR5+ T cells present during acute infection were activated effector memory type, whereas CXCR3+ cells were central memory type, and cognate chemokine ligands were elevated over baseline. Probiotic had no T-cell effects.

Conclusions

We conclude that virus-specific CCR5+ effector memory CD4+ T cells primed by previous exposure to related viruses contribute to the control of rhinovirus.

Overview of the Mechanisms that May Contribute to the Non-Redundant Activities of Interferon-Inducible CXC Chemokine Receptor 3 Ligands

The inflammatory chemokines CXCL9, CXCL10, and CXCL11 are predominantly induced by interferon (IFN)-γ and share an exclusive chemokine receptor named CXC chemokine receptor 3 (CXCR3). With a prototype function of directing temporal and spatial migration of activated T cells and natural killer cells, and inhibitory effects on angiogenesis, these CXCR3 ligands have been implicated in infection, acute inflammation, autoinflammation and autoimmunity, as well as in cancer. Intense former research efforts led to recent and ongoing clinical trials using CXCR3 and CXCR3 ligand targeting molecules. Scientific evidence has claimed mutual redundancy, ligand dominance, collaboration or even antagonism, depending on the (patho)physiological context. Most research on their in vivo activity, however, illustrates that CXCL9, CXCL10, and CXCL11 each contribute to the activation and trafficking of CXCR3 expressing cells in a non-redundant manner. When looking into detail, one can unravel a multistep machinery behind final CXCR3 ligand functions. Not only can specific cell types secrete individual CXCR3 interacting chemokines in response to certain stimuli, but also the receptor and glycosaminoglycan interactions, major associated intracellular pathways and susceptibility to processing by particular enzymes, among others, seem ligand-specific. Here, we overview major aspects of the molecular properties and regulatory mechanisms of IFN-induced CXCR3 ligands, and propose that their in vivo non-redundancy is a reflection of the unprecedented degree of versatility that seems inherent to the IFN-related CXCR3 chemokine system.

Differential expression profile of CXCR3 splicing variants is associated with thyroid neoplasia. Potential role in papillary thyroid carcinoma oncogenesis?

Papillary thyroid cancer (PTC) is the most prevalent endocrine neoplasia. The increased incidence of PTC in patients with thyroiditis and the frequent immune infiltrate found in PTC suggest that inflammation might be a risk factor for PTC development. The CXCR3-ligand system is involved in thyroid inflammation and CXCR3 has been found upregulated in many tumors, suggesting its pro-tumorigenic role under the inflammatory microenvironment. CXCR3 ligands (CXCL4, CXCL9, CXCL10 and CXCL11) trigger antagonistic responses partly due to the presence of two splice variants, CXCR3A and CXCR3B. Whereas CXCR3A promotes cell proliferation, CXCR3B induces apoptosis. However, the relation between CXCR3 variant expression with chronic inflammation and PTC development remains unknown. Here, we characterized the expression pattern of CXCR3 variants and their ligands in benign tumors and PTC. We found that CXCR3A and CXCL10 mRNA levels were increased in non-metastatic PTC when compared to non-neoplastic tissue. This increment was also observed in a PTC epithelial cell line (TPC-1). Although elevated protein levels of both isoforms were detected in benign and malignant tumors, the CXCR3A expression remained greater than CXCR3B and promoted proliferation in Nthy-ori-3-1 cells. In non-metastatic PTC, inflammation was conditioning for the CXCR3 ligands increased availability. Consistently, CXCL10 was strongly induced by interferon gamma in normal and tumor thyrocytes.

Our results suggest that persistent inflammation upregulates CXCL10 expression favoring tumor development via enhanced CXCR3A-CXCL10 signaling. These findings may help to further understand the contribution of inflammation as a risk factor in PTC development and set the basis for potential therapeutic studies.

Potential role of CXCL10/CXCR3 signaling in the development of morphine tolerance in periaqueductal gray

Tolerance to morphine antinociception hinders its long-term use in clinical practice. Interaction between neuron and microglia has been proved to play critical role in the mechanism of morphine tolerance, while CXCL10/CXCR3 signaling has been implicated in neuron-glia signaling and morphine analgesia. This study aims to investigate whether CXCL10/CXCR3 signaling in periaqueductal gray (PAG) contributes to the development of morphine tolerance by modulating neuron-microglia interaction. The results showed that the expressions of CXCR3 and CXCL10 were gradually increased in parallel with repeated morphine administration and activation of microglia. CXCR3 was co-localized with neuronal marker NeuN, while CXCL10 was derived from microglia. Microglia inhibitor minocycline significantly attenuated the expression of CXCL10, besides, both minocycline and CXCR3 inhibitor alleviated the development of morphine tolerance. Taken together, our study provided the evidence that CXCL10/CXCR3 signaling in PAG is involved in the development of morphine analgesic tolerance via neuron-microglia interaction.

Differences between chronic lymphocytic leukaemia and small lymphocytic lymphoma cells by proteomic profiling and SNP microarray analysis

The majority of malignant cells in chronic lymphocytic leukaemia (CLL) circulate in the peripheral blood whereas small lymphocytic lymphoma (SLL) cells reside in tissues. The aim of this study was to detect differences in chemokine receptor expression, DNA single nucleotide polymorphism (SNP) microarray analysis and proteomic profiling to help elucidate why the cells remain in their respective environments. We identified by flow cytometric studies of chemokine receptors and DNA SNP microarray analysis significant differences between cells from CLL and SLL patients. Proteomic analysis revealed two potential markers (m/z 3091 and 8707) to distinguish the two disorders. There was a significantly greater expression of leucocyte trafficking receptor CXCR3 (CD183) and migration and homing receptor CXCR4 (CD184), and significantly lower expression of cell adhesion molecule integrin α₄ chain (CD49d), on CLL cells, compared with SLL cells. Conversely, SNP microarrays revealed greater numbers of copy-neutral loss of heterozygosity chromosomal aberrations, as well as gross chromosomal aberrations, in the SLL group, compared with the CLL group. These findings revealed that there was a significantly greater expression of trafficking, migration and homing receptors and significantly lower expression of adhesion molecules on CLL cells than on SLL cells, and that SLL may be a more progressive disease than CLL, with a more complex genotype.

Tissue-specific regulation of CXCL9/10/11 chemokines in keratinocytes: Implications for oral inflammatory disease

The IFN-γ-inducible chemokines CXCL9, CXCL10, and CXCL11 play a key role in many inflammatory conditions, particularly those mediated by T cells. Therefore, the production of these chemokines in peripheral tissues could be instrumental in the pathophysiology of tissue-specific immunological diseases such as oral lichen planus (OLP). In the present study, we assessed the production of keratinocyte-derived CXCL9/10/11 under basal and inflammatory conditions and investigated whether these chemokines were involved in the pathogenesis of OLP. We used semi-quantitative PCR, ELISA, chemotaxis assays, and fluorescence-activated cell sorting (FACS) to assess the expression and functional role of CXCL9/10/11 in oral keratinocytes (three strains of normal human oral keratinocytes (NHOK), and the H357 oral cancer cell line) in the presence or absence of IFN-γ. CXCL9/10/11 were also assessed in tissues from normal patients and those with oral lichen planus (OLP). The time course study in oral keratinocytes treated with IFN-γ showed that expression of CXCL9/10/11 chemokines was significantly enhanced by IFN-γ in a time-dependent manner. In particular, CXCL10, a prominent chemokine that was overexpressed by IFN-γ-stimulated NHOK, was able to effectively recruit CD4 lymphocytes, mainly CD4+CD45RA- cells. Significantly higher levels of CXCL9/10/11 were found in tissues from patients with OLP compared to normal oral mucosa. Taken together, the results demonstrate that normal oral keratinocytes produce chemotactic molecules that mediate T cell recruitment. This study furthers understanding of chemokine production in oral keratinocytes and their role in the pathophysiology of oral mucosa, with particular relevance to OLP.

Activity of chemokines in prostate and renal tumors and their potential role as future therapeutic targets

Chemokines are a class of low-molecular-weight proteins that induce chemotaxis and are implicated in the modulation of angiogenesis. The imbalance among angiogenic and antiangiogenic chemokines can promote the development of several conditions, including chronic inflammation, dysplastic transformation and cancer. In this review, we describe the activity and clinical significance of chemokines in prostate and renal tumors and provide an update on ongoing studies in this setting.

Phenotypically resembling myeloid derived suppressor cells are increased in children with HIV and exposed/infected with Mycobacterium tuberculosis

Increased disease susceptibility during early life has been linked to immune immaturity, regulatory T-cell/TH2 immune biasing and hyporesponsiveness. The contribution of myeloid derived suppressor cells (MDSCs) remains uninvestigated. Here, we assessed peripheral MDSC in HIV-infected and -uninfected children with tuberculosis (TB) disease before, during and after TB treatment, along with matched household contacts (HHCs), HIV-exposed, -infected and -uninfected children without recent TB exposure. Serum analytes and enzymes associated with MDSC accumulation/activation/function were measured by colorimetric- and fluorescence arrays. Peripheral frequencies of cells phenotypically resembling MDSCs were significantly increased in HIV-exposed uninfected (HEU) and M.tb-infected children, but peaked in children with TB disease and remained high following treatment. MDSC in HIV-infected (HI) children were similar to unexposed uninfected controls; however, HAART-mediated MDSC restoration to control levels could not be disregarded. Increased MDSC frequencies in HHC coincided with enhanced indoleamine-pyrrole-2,3-dioxygenase (IDO), whereas increased MDSC in TB cases were linked to heightened IDO and arginase-1. Increased MDSC were paralleled by reduced plasma IP-10 and thrombospondin-2 levels in HEU and significantly increased plasma IL-6 in HI HHC. Current investigations into MDSC-targeted treatment strategies, together with functional analyses of MDSCs, could endorse these cells as novel innate immune regulatory mechanism of infant HIV/TB susceptibility.