Role of CXCL10 in the progression of in situ to invasive carcinoma of the breast

Tumor immune microenvironment plays a crucial role in tumor progression. We performed immune profiling to compare immune-related gene expression between ductal carcinoma in situ (DCIS) and invasive carcinoma of the breast using nCounter PanCancer immune Profiling Panel and found that CXCL10 was the most significant gene that had the highest difference in expression between them. Effect of CXCL10 on breast cancer cell proliferation and invasion was examined in vitro, and expression of CXCL10 and its relationship with immune cell infiltration was assessed in breast cancer samples. CXCL10 induced cell proliferation, migration and epithelial-mesenchymal transition in MCF-7 and MDA-MB-231 breast cancer cell lines. We confirmed that CXCL10 mRNA expression was significantly higher in invasive carcinoma than in DCIS, especially in hormone receptor (HR)-negative tumors using a validation set. CXCL10 mRNA expression showed a positive correlation with tumor infiltrating lymphocyte (TIL) density in both DCIS and invasive carcinoma; CXCL10-positive tumors generally showed higher infiltration of CD8+ and FOXP3+TILs as well as PD-L1+ immune cells compared to CXCL10-negative tumors, albeit with different patterns according to HR status. In conclusion, our study showed that CXCL10 promotes tumor cell proliferation, invasion, and immune cell infiltration, implying its contribution in the progression of DCIS to invasive carcinoma of the breast.

Anti-tumor immunity in mismatch repair-deficient colorectal cancers requires type I IFN-driven CCL5 and CXCL10

Colorectal cancers (CRCs) deficient in DNA mismatch repair (dMMR) contain abundant CD8+ tumor-infiltrating lymphocytes (TILs) responding to the abundant neoantigens from their unstable genomes. Priming of such tumor-targeted TILs first requires recruitment of CD8+ T cells into the tumors, implying that this is an essential prerequisite of successful dMMR anti-tumor immunity. We have discovered that selective recruitment and activation of systemic CD8+ T cells into dMMR CRCs strictly depend on overexpression of CCL5 and CXCL10 due to endogenous activation of cGAS/STING and type I IFN signaling by damaged DNA. TIL infiltration into orthotopic dMMR CRCs is neoantigen-independent and followed by induction of a resident memory-like phenotype key to the anti-tumor response. CCL5 and CXCL10 could be up-regulated by common chemotherapies in all CRCs, indicating that facilitating CD8+ T cell recruitment underlies their efficacy. Induction of CCL5 and CXCL10 thus represents a tractable therapeutic strategy to induce TIL recruitment into CRCs, where local priming can be maximized even in neoantigen-poor CRCs.

CD163L1+CXCL10+ Macrophages are Enriched Within Colonic Lamina Propria of Diverticulitis Patients

BACKGROUND

Inflammation of diverticula, which are outpouchings of the colonic bowl wall, causes diverticulitis. Severe cases of diverticulitis require surgical intervention. Through RNA-seq analysis of intestinal tissues, we previously found that the innate immune response was deregulated in surgical diverticulitis patients. In that study, pro-inflammatory and macrophage markers were differentially expressed in the colons of diverticulitis versus control patients. Here we investigate CD163L1⁺ macrophages and the pro-inflammatory chemokine, CXCL10, in diverticulitis.

MATERIALS AND METHODS

We assessed tissue from an uninvolved area adjacent to a region of the sigmoid colon chronically affected by diverticulitis and performed Spearman's correlation on transcripts associated with macrophage signaling. We identified altered CD163L1 and CXCL10 gene expression levels that we confirmed by RT-qPCR analysis on an independent cohort of diverticulitis patients and controls. We used immunofluorescence microscopy to localize CD163L1⁺ macrophages and CXCL10 levels in intestinal tissue and ELISA to measure CXCL10 levels in patient serum.

RESULTS

We found a positive correlation between intestinal CD163L1 and CXCL10 gene expression and an increased number of CD163L1⁺ macrophages in the sigmoid colons of diverticulitis patients relative to controls (P = 0.036). Macrophages at the apices of colonic crypts expressed the chemokine CXCL10. Correspondingly, these diverticulitis patients also displayed heightened CXCL10 levels in their serum (P = 0.007).

CONCLUSIONS

We identified a novel population of CD163L1⁺CXCL10⁺ macrophages in the colonic crypts of diverticulitis patients and demonstrated increased expression of serum CXCL10 in these patients. CXCL10 may serve as a prognostic biomarker to aid in clinical decision making for diverticulitis patients.

The Pro-Inflammatory Chemokines CXCL9, CXCL10 and CXCL11 Are Upregulated Following SARS-CoV-2 Infection in an AKT-Dependent Manner

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible RNA virus that is the causative agent of the Coronavirus disease 2019 (COVID-19) pandemic. Patients with severe COVID-19 may develop acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) and require mechanical ventilation. Key features of SARS-CoV-2 induced pulmonary complications include an overexpression of pro-inflammatory chemokines and cytokines that contribute to a 'cytokine storm.' In the current study an inflammatory state in Calu-3 human lung epithelial cells was characterized in which significantly elevated transcripts of the immunostimulatory chemokines CXCL9, CXCL10, and CXCL11 were present. Additionally, an increase in gene expression of the cytokines IL-6, TNFα, and IFN-γ was observed. The transcription of CXCL9, CXCL10, IL-6, and IFN-γ was also induced in the lungs of human transgenic angiotensin converting enzyme 2 (ACE2) mice infected with SARS-CoV-2. To elucidate cell signaling pathways responsible for chemokine upregulation in SARS-CoV-2 infected cells, small molecule inhibitors targeting key signaling kinases were used. The induction of CXCL9, CXCL10, and CXCL11 gene expression in response to SARS-CoV-2 infection was markedly reduced by treatment with the AKT inhibitor GSK690693. Samples from COVID-19 positive individuals also displayed marked increases in CXCL9, CXCL10, and CXCL11 transcripts as well as transcripts in the AKT pathway. The current study elucidates potential pathway specific targets for reducing the induction of chemokines that may be contributing to SARS-CoV-2 pathogenesis via hyperinflammation.

CXCL10 potentiates immune checkpoint blockade therapy in homologous recombination-deficient tumors

Background: Homologous recombination deficiency (HRD) is a common molecular characteristic of genomic instability, and has been proven to be a biomarker for target therapy. However, until now, no research has explored the changes in the transcriptomics landscape of HRD tumors. Methods: The HRD score was established from SNP array data of breast cancer patients from the cancer genome atlas (TCGA) database. The transcriptome data of patients with different HRD scores were analyzed to identify biomarkers associated with HRD. The candidate biomarkers were validated in the gene expression omnibus (GEO) database and immunotherapy cohorts. Results: Based on data from the gene expression profile and clinical characteristics from 1310 breast cancer patients, including TCGA database and GEO database, we found that downstream targets of the cGAS-STING pathway, such as CXCL10, were upregulated in HRD tumors and could be used as a predictor of survival outcome in triple-negative breast cancer (TNBC) patients. Further comprehensive analysis of the tumor immune microenvironment (TIME) revealed that the expression of CXCL10 was positively correlated with neoantigen load and infiltrating immune cells. Finally, in vivo experimental data and clinical trial data confirmed that the expression of CXCL10 could be used as a biomarker for anti-PD-1/PD-L1 therapy. Conclusions: Together, our study not only revealed that CXCL10 is associated with HRD but also introduced a potential new perspective for identifying prognostic biomarkers of immunotherapy.

NK/ILC1 cells mediate neuroinflammation and brain pathology following congenital CMV infection

Congenital human cytomegalovirus (cHCMV) infection of the brain is associated with a wide range of neurocognitive sequelae. Using infection of newborn mice with mouse cytomegalovirus (MCMV) as a reliable model that recapitulates many aspects of cHCMV infection, including disseminated infection, CNS infection, altered neurodevelopment, and sensorineural hearing loss, we have previously shown that mitigation of inflammation prevented alterations in cerebellar development, suggesting that host inflammatory factors are key drivers of neurodevelopmental defects. Here, we show that MCMV infection causes a dramatic increase in the expression of the microglia-derived chemokines CXCL9/CXCL10, which recruit NK and ILC1 cells into the brain in a CXCR3-dependent manner. Surprisingly, brain-infiltrating innate immune cells not only were unable to control virus infection in the brain but also orchestrated pathological inflammatory responses, which lead to delays in cerebellar morphogenesis. Our results identify NK and ILC1 cells as the major mediators of immunopathology in response to virus infection in the developing CNS, which can be prevented by anti-IFN-γ antibodies.

Characterization of Type I Interferon-Associated Chemokines and Cytokines in Lacrimal Glands of Nonobese Diabetic Mice

Type I interferons (IFNs) are required for spontaneous lacrimal gland inflammation in the nonobese diabetic (NOD) mouse model of Sjögren’s disease, but the consequences of type I IFN signaling are not well-defined. Here, we use RNA sequencing to define cytokine and chemokine genes upregulated in lacrimal glands of NOD mice in a type I IFN-dependent manner. Interleukin (IL)-21 was the highest differentially expressed cytokine gene, and Il21 knockout NOD mice were relatively protected from lacrimal gland inflammation. We defined a set of chemokines upregulated early in disease including Cxcl9 and Cxcl10, which share a receptor, CXCR3. CXCR3⁺ T cells were enriched in lacrimal glands with a dominant proportion of CXCR3⁺ regulatory T cells. Together these data define the early cytokine and chemokine signals associated with type I IFN-signaling in the development of lacrimal gland inflammation in NOD mice providing insight into the role of type I IFN in autoimmunity development.

Plasmacytoid Dendritic Cells Depletion and Elevation of IFN-γ Dependent Chemokines CXCL9 and CXCL10 in Children With Multisystem Inflammatory Syndrome

Background

SARS-CoV-2 occurs in the majority of children as COVID-19, without symptoms or with a paucisymptomatic respiratory syndrome, but a small proportion of children develop the systemic Multi Inflammatory Syndrome (MIS-C), characterized by persistent fever and systemic hyperinflammation, with some clinical features resembling Kawasaki Disease (KD).

Objective

With this study we aimed to shed new light on the pathogenesis of these two SARS-CoV-2-related clinical manifestations.

Methods

We investigated lymphocyte and dendritic cells subsets, chemokine/cytokine profiles and evaluated the neutrophil activity mediators, myeloperoxidase (MPO), and reactive oxygen species (ROS), in 10 children with COVID-19 and 9 with MIS-C at the time of hospital admission.

Results

Patients with MIS-C showed higher plasma levels of C reactive protein (CRP), MPO, IL-6, and of the pro-inflammatory chemokines CXCL8 and CCL2 than COVID-19 children. In addition, they displayed higher levels of the chemokines CXCL9 and CXCL10, mainly induced by IFN-γ. By contrast, we detected IFN-α in plasma of children with COVID-19, but not in patients with MIS-C. This observation was consistent with the increase of ISG15 and IFIT1 mRNAs in cells of COVID-19 patients, while ISG15 and IFIT1 mRNA were detected in MIS-C at levels comparable to healthy controls. Moreover, quantification of the number of plasmacytoid dendritic cells (pDCs), which constitute the main source of IFN-α, showed profound depletion of this subset in MIS-C, but not in COVID-19.

Conclusions

Our results show a pattern of immune response which is suggestive of type I interferon activation in COVID-19 children, probably related to a recent interaction with the virus, while in MIS-C the immune response is characterized by elevation of the inflammatory cytokines/chemokines IL-6, CCL2, and CXCL8 and of the chemokines CXCL9 and CXL10, which are markers of an active Th1 type immune response. We believe that these immunological events, together with neutrophil activation, might be crucial in inducing the multisystem and cardiovascular damage observed in MIS-C.

Diosmetin Ameliorates Nonalcoholic Steatohepatitis through Modulating Lipogenesis and Inflammatory Response in a STAT1/CXCL10-Dependent Manner

Nonalcoholic steatohepatitis (NASH) is an inflammatory lipotoxic disorder characterized by lipid accumulation and inflammation. Diosmetin (Dios), a flavonoid, has an active effect against nonalcoholic fatty liver disease, whereas its effect on NASH remains elusive. To investigate the effects of Dios on lipogenesis and inflammatory response and explore the molecular mechanisms of Dios on NASH, mice induced by high-fat diet (HFD), HepG2 cells stimulated by palmitic acid (PA), transcriptome sequencing, and molecular biological experiments were used. We show, by pathological analysis (HE, Oli Red O, and Masson staining) and biochemical parameters (TC, TG, LDL-C, ALT, and AST), Dios alleviated liver lipid accumulation and inflammatory injury. According to liver RNA-Seq analysis, CXCL10 and STAT1 were assumed to be the key target genes of Dios on NASH. Significantly, Dios regulated STAT1/CXCL10 signal pathway and further attenuated NASH via regulating the expression of LXRα/β, SREBP-1c, CHREBP, and NF-κB. In conclusion, Dios is proposed to alleviate NASH through suppression of lipogenesis and inflammatory response via a STAT1/CXCL10-dependent pathway.

Cross-linking of T cell to B cell lymphoma by the T cell bispecific antibody CD20-TCB induces IFNγ/CXCL10-dependent peripheral T cell recruitment in humanized murine model

Diffuse large B cell lymphomas (DLBCL) are a highly heterogeneous subtype of Non Hodgkin Lymphoma (NHL), accounting for about 25% of NHL. Despite an increased progression-free survival upon therapy, 40-50% of patients develop relapse/refractory disease, therefore there remains an important medical need. T cell recruiting therapies, such as the CD20xCD3 T cell bi-specific antibody CD20-TCB (RG6026 or glofitamab), represent a novel approach to target all stages of DLBCL, especially those that fail to respond to multiple lines of treatment. We aimed for a better understanding of the molecular features related to the mode of action (MoA) of CD20-TCB in inducing Target/T cell synapse formation and human T cell recruitment to the tumor. To directly evaluate the correlation between synapse, cytokine production and anti-tumor efficacy using CD20-TCB, we developed an innovative preclinical human DLBCL in vivo model that allowed tracking in vivo human T cell dynamics by multiphoton intravital microscopy (MP-IVM). By ex vivo and in vivo approaches, we revealed that CD20-TCB is inducing strong and stable synapses between human T cell and tumor cells, which are dependent on the dose of CD20-TCB and on LFA-1 activity but not on FAS-L. Moreover, despite CD20-TCB being a large molecule (194.342 kDa), we observed that intra-tumor CD20-TCB-mediated human T cell-tumor cell synapses occur within 1 hour upon CD20-TCB administration. These tight interactions, observed for at least 72 hours post TCB administration, result in tumor cell cytotoxicity, resident T cell proliferation and peripheral blood T cell recruitment into tumor. By blocking the IFNγ-CXCL10 axis, the recruitment of peripheral T cells was abrogated, partially affecting the efficacy of CD20-TCB treatment which rely only on resident T cell proliferation. Altogether these data reveal that CD20-TCB's anti-tumor activity relies on a triple effect: i) fast formation of stable T cell-tumor cell synapses which induce tumor cytotoxicity and cytokine production, ii) resident T cell proliferation and iii) recruitment of fresh peripheral T cells to the tumor core to allow a positive enhancement of the anti-tumor effect.

Infection of human Nasal Epithelial Cells with SARS-CoV-2 and a 382-nt deletion isolate lacking ORF8 reveals similar viral kinetics and host transcriptional profiles

The novel coronavirus SARS-CoV-2 is the causative agent of Coronavirus Disease 2019 (COVID-19), a global healthcare and economic catastrophe. Understanding of the host immune response to SARS-CoV-2 is still in its infancy. A 382-nt deletion strain lacking ORF8 (Δ382 herein) was isolated in Singapore in March 2020. Infection with Δ382 was associated with less severe disease in patients, compared to infection with wild-type SARS-CoV-2. Here, we established Nasal Epithelial cells (NECs) differentiated from healthy nasal-tissue derived stem cells as a suitable model for the ex-vivo study of SARS-CoV-2 mediated pathogenesis. Infection of NECs with either SARS-CoV-2 or Δ382 resulted in virus particles released exclusively from the apical side, with similar replication kinetics. Screening of a panel of 49 cytokines for basolateral secretion from infected NECs identified CXCL10 as the only cytokine significantly induced upon infection, at comparable levels in both wild-type and Δ382 infected cells. Transcriptome analysis revealed the temporal up-regulation of distinct gene subsets during infection, with anti-viral signaling pathways only detected at late time-points (72 hours post-infection, hpi). This immune response to SARS-CoV-2 was significantly attenuated when compared to infection with an influenza strain, H3N2, which elicited an inflammatory response within 8 hpi, and a greater magnitude of anti-viral gene up-regulation at late time-points. Remarkably, Δ382 induced a host transcriptional response nearly identical to that of wild-type SARS-CoV-2 at every post-infection time-point examined. In accordance with previous results, Δ382 infected cells showed an absence of transcripts mapping to ORF8, and conserved expression of other SARS-CoV-2 genes. Our findings shed light on the airway epithelial response to SARS-CoV-2 infection, and demonstrate a non-essential role for ORF8 in modulating host gene expression and cytokine production from infected cells.

Distinct Phenotypes of Islet Antigen-Specific CD4+ T Cells Among the 3 Subtypes of Type 1 Diabetes

CONTEXT

Type 1 diabetes (T1D) is classified into 3 subtypes: acute-onset (AT1D), slowly progressive (SP1D), and fulminant (FT1D). The differences in the type of cellular autoimmunity within each subtype remain largely undetermined.

OBJECTIVE

To determine the type and frequency of islet antigen-specific CD4+ T cells in each subtype of T1D.

PARTICIPANTS

Twenty patients with AT1D, 17 with SP1D, 18 with FT1D, and 17 persons without diabetes (ND).

METHODS

We performed an integrated assay to determine cellular immune responses and T-cell repertoires specific for islet antigens. This assay included an ex vivo assay involving a 48-hour stimulation of peripheral blood mononuclear cells with antigen peptides and an expansion assay involving intracytoplasmic cytokine analysis.

RESULTS

The results of the ex vivo assay indicated that glutamic acid decarboxylase 65 (GAD65)-specific interleukin-6 and interferon-inducible protein-10 (IP-10) responses and preproinsulin (PPI)-specific IP-10 responses were significantly upregulated in AT1D compared with those of ND. Furthermore, GAD65- and PPI-specific granulocyte colony-stimulating factor responses were significantly upregulated in FT1D. Expansion assay revealed that GAD65- and PPI-specific CD4+ T cells were skewed toward a type 1 helper T (Th1)- cell phenotype in AT1D, whereas GAD65-specific Th2 cells were prevalent in SP1D. GAD65-specific Th1 cells were more abundant in SP1D with human leukocyte antigen-DR9 than in SP1D without DR9. FT1D displayed significantly less type 1 regulatory T (Tr1) cells specific for all 4 antigens than ND.

CONCLUSIONS

The phenotypes of islet antigen-specific CD4+ T cells differed among the three T1D subtypes. These distinct T-cell phenotypes may be associated with the manner of progressive β-cell destruction.

A dynamic COVID-19 immune signature includes associations with poor prognosis

Improved understanding and management of COVID-19, a potentially life-threatening disease, could greatly reduce the threat posed by its etiologic agent, SARS-CoV-2. Toward this end, we have identified a core peripheral blood immune signature across 63 hospital-treated patients with COVID-19 who were otherwise highly heterogeneous. The signature includes discrete changes in B and myelomonocytic cell composition, profoundly altered T cell phenotypes, selective cytokine/chemokine upregulation and SARS-CoV-2-specific antibodies. Some signature traits identify links with other settings of immunoprotection and immunopathology; others, including basophil and plasmacytoid dendritic cell depletion, correlate strongly with disease severity; while a third set of traits, including a triad of IP-10, interleukin-10 and interleukin-6, anticipate subsequent clinical progression. Hence, contingent upon independent validation in other COVID-19 cohorts, individual traits within this signature may collectively and individually guide treatment options; offer insights into COVID-19 pathogenesis; and aid early, risk-based patient stratification that is particularly beneficial in phasic diseases such as COVID-19.

The therapeutic potential of resveratrol in a mouse model of melanoma lung metastasis

Resveratrol is an anticancer phytochemical polyphenol isolated from a natural origin, without any significant side effects. Resveratrol was investigated in immunocompetent mice with regards to its possible effect on lung cancer metastasis. Cytotoxicity was assessed in three melanoma cell lines (B16F10, B6, and A375) by administration of 20 and 40 μM resveratrol. B16F10 cells were transfected with pT-tdTomato vector to express red fluorescent protein (RFP). RFP-B16F10 cells were injected IV into 3 groups of 20 C57BL/6 mice (ten for tests and others for survival). The three groups include PBS, no treatment, and resveratrol 40 mg/kg IP (4X/week for 3 weeks). Lung tissues were analyzed by TUNEL assay, Western blot, and immunohistochemistry. The in vitro growth of all melanoma cell lines was significantly suppressed by 40 μM resveratrol for 3 days. The mean survival rate of mice was enhanced and the lung tumor growth was inhibited by in vivo IP injection of 40 mg/kg resveratrol. Increased CXCL10 and IFN-γ levels and decreased angiogenesis and less tumor infiltration by Tregs were found in the lung tumors. In conclusion, lung metastasis of melanoma was effectively inhibited by resveratrol treatment.

Human Fallopian Tube Epithelial Cell Culture Model To Study Host Responses to Chlamydia trachomatis Infection

Chlamydia trachomatis infection of the human fallopian tubes can lead to damaging inflammation and scarring, ultimately resulting in infertility. To study the human cellular responses to chlamydial infection, researchers have frequently used transformed cell lines that can have limited translational relevance. We developed a primary human fallopian tube epithelial cell model based on a method previously established for culture of primary human bronchial epithelial cells. After protease digestion and physical dissociation of excised fallopian tubes, epithelial cell precursors were expanded in growth factor-containing medium. Expanded cells were cryopreserved to generate a biobank of cells from multiple donors and cultured at an air-liquid interface. Culture conditions stimulated cellular differentiation into polarized mucin-secreting and multiciliated cells, recapitulating the architecture of human fallopian tube epithelium. The polarized and differentiated cells were infected with a clinical isolate of C. trachomatis, and inclusions containing chlamydial developmental forms were visualized by fluorescence and electron microscopy. Apical secretions from infected cells contained increased amounts of proteins associated with chlamydial growth and replication, including transferrin receptor protein 1, the amino acid transporters SLC3A2 and SLC1A5, and the T-cell chemoattractants CXCL10, CXCL11, and RANTES. Flow cytometry revealed that chlamydial infection induced cell surface expression of T-cell homing and activation proteins, including ICAM-1, VCAM-1, HLA class I and II, and interferon gamma receptor. This human fallopian tube epithelial cell culture model is an important tool with translational potential for studying cellular responses to Chlamydia and other sexually transmitted pathogens.

Human Chorionic Gonadotropin modulates CXCL10 Expression through Histone Methylation in human decidua

The process of implantation, trophoblast invasion and placentation demand continuous adaptation and modifications between the trophoblast (embryonic) and the decidua (maternal). Within the decidua, the maternal immune system undergoes continued changes, as the pregnancy progress, in terms of the cell population, phenotype and production of immune factors, cytokines and chemokines. Human chorionic gonadotropin (hCG) is one of the earliest hormones produced by the blastocyst and has potent immune modulatory effects, especially in relation to T cells. We hypothesized that trophoblast-derived hCG modulates the immune population present at the maternal fetal interface by modifying the cytokine profile produced by the stromal/decidual cells. Using in vitro models from decidual samples we demonstrate that hCG inhibits CXCL10 expression by inducing H3K27me3 histone methylation, which binds to Region 4 of the CXCL10 promoter, thereby suppressing its expression. hCG-induced histone methylation is mediated through EZH2, a functional member of the PRC2 complex. Regulation of CXCL10 expression has a major impact on the capacity of endometrial stromal cells to recruit CD8 cells. We demonstrate the existence of a cross talk between the placenta (hCG) and the decidua (CXCL10) in the control of immune cell recruitment. Alterations in this immune regulatory function, such as during infection, will have detrimental effects on the success of the pregnancy.

A Four-Chemokine Signature Is Associated with a T-cell-Inflamed Phenotype in Primary and Metastatic Pancreatic Cancer

PURPOSE

The molecular drivers of antitumor immunity in pancreatic ductal adenocarcinoma (PDAC) are poorly understood, posing a major obstacle for the identification of patients potentially amenable for immune-checkpoint blockade or other novel strategies. Here, we explore the association of chemokine expression with effector T-cell infiltration in PDAC.

EXPERIMENTAL DESIGN

Discovery cohorts comprised 113 primary resected PDAC and 107 PDAC liver metastases. Validation cohorts comprised 182 PDAC from The Cancer Genome Atlas and 92 PDACs from the Australian International Cancer Genome Consortium. We explored associations between immune cell counts by immunohistochemistry, chemokine expression, and transcriptional hallmarks of antitumor immunity by RNA sequencing (RNA-seq), and mutational burden by whole-genome sequencing.

RESULTS

Among all known human chemokines, a coregulated set of four (CCL4, CCL5, CXCL9, and CXCL10) was strongly associated with CD8⁺ T-cell infiltration (P < 0.001). Expression of this "4-chemokine signature" positively correlated with transcriptional metrics of T-cell activation (ZAP70, ITK, and IL2RB), cytolytic activity (GZMA and PRF1), and immunosuppression (PDL1, PD1, CTLA4, TIM3, TIGIT, LAG3, FASLG, and IDO1). Furthermore, the 4-chemokine signature marked tumors with increased T-cell activation scores (MHC I presentation, T-cell/APC costimulation) and elevated expression of innate immune sensing pathways involved in T-cell priming (STING and NLRP3 inflammasome pathways, BATF3-driven dendritic cells). Importantly, expression of this 4-chemokine signature was consistently indicative of a T-cell-inflamed phenotype across primary PDAC and PDAC liver metastases.

CONCLUSIONS

A conserved 4-chemokine signature marks resectable and metastatic PDAC tumors with an active antitumor phenotype. This could have implications for the appropriate selection of PDAC patients in immunotherapy trials.

ILF3 contributes to the establishment of the antiviral type I interferon program

Upon detection of viral infections, cells activate the expression of type I interferons (IFNs) and pro-inflammatory cytokines to control viral dissemination. As part of their antiviral response, cells also trigger the translational shutoff response which prevents translation of viral mRNAs and cellular mRNAs in a non-selective manner. Intriguingly, mRNAs encoding for antiviral factors bypass this translational shutoff, suggesting the presence of additional regulatory mechanisms enabling expression of the self-defence genes. Here, we identified the dsRNA binding protein ILF3 as an essential host factor required for efficient translation of the central antiviral cytokine, IFNB1, and a subset of interferon-stimulated genes. By combining polysome profiling and next-generation sequencing, ILF3 was also found to be necessary to establish the dsRNA-induced transcriptional and translational programs. We propose a central role for the host factor ILF3 in enhancing expression of the antiviral defence mRNAs in cellular conditions where cap-dependent translation is compromised.

IL-18/IL-37/IP-10 signalling complex as a potential biomarker for discriminating active and latent TB

Background

Currently, there are serious limitations in the direct diagnosis of active tuberculosis (ATB). We evaluated the levels of the IL-18/IL-37/IP-10 signalling complex proteins in Mycobacterium tuberculosis (M.tb)-specific antigen-stimulated QuantiFERON® Gold In-Tube (QFT) cultures and in serum samples from ATB patients, healthy individuals with latent M.tb infection (LTBI) and healthy controls (HC) to examine whether combined analyses of these proteins were useful in the differentiation of M.tb states.

Methods

The concentrations of IL-18, IL-18BP, IFN-γ, IL-37 and IP-10 in the serum and QFT supernatants were measured using specific enzyme-linked immunosorbent assay (ELISA) kits. Free IL-18 levels were calculated using the law of mass action.

Results

Increased concentrations of total and free IL-18, IL-18BP, IFN-γ and IP-10 in the sera of ATB patients were detected. These increases were not counterbalanced by the overproduction of IL-37. Complex co-expression of serum IL-18BP and IL-37, IP-10 and IFN-γ was identified as the highest discriminative biomarker set for the diagnosis of ATB.

Conclusions

Our results suggest that the IL-18 signalling complex might be exploited by M. tuberculosis to expand the clinical manifestations of pulmonary TB. Therefore, direct analysis of the serum components of the IL-18/IL-37 signalling complex and IP-10 may be applicable in designing novel diagnostic tests for ATB.

Empowering therapeutic antibodies with IFN-α for cancer immunotherapy

Type 1 IFNs stimulate secretion of IP-10 (CXCL10) which is a critical chemokine to recruit effector T cells to the tumor microenvironment and IP-10 knockout mice exhibit a phenotype with compromised effector T cell generation and trafficking. Type 1 IFNs also induce MHC class 1 upregulation on tumor cells which can enhance anti-tumor CD8 T cell effector response in the tumor microenvironment. Although type 1 IFNs show great promise in potentiating anti-tumor immune response, systemic delivery of type 1 IFNs is associated with toxicity thereby limiting clinical application. In this study, we fused tumor targeting antibodies with IFN-α and showed that the fusion proteins can be produced with high yields and purity. IFN fusions selectively induced IP-10 secretion from antigen positive tumor cells, which was critical in recruiting the effector T cells to the tumor microenvironment. Further, we found that treatment with the anti-PDL1-IFN- α fusion at concentrations as low as 1 pM exhibited potent activity in mediating OT1 CD8+ T cell killing against OVA expressing tumor cells, while control IFN fusion did not exhibit any activity at the same concentration. Furthermore, the IFN-α fusion antibody was well tolerated in vivo and demonstrated anti-tumor efficacy in an anti-PD-L1 resistant syngeneic mouse tumor model. One of the potential mechanisms for the enhanced CD8 T cell killing by anti-PD-L1 IFN fusion was up-regulation of MHC class I/tumor antigen complex. Our data supports the hypothesis of targeting type 1 IFN to the tumor microenvironment may enhance effector T cell functions for anti-tumor immune response.

PREDICTIVE VALUE OF SERUM IL-17A AND IP-10 FOR EVALUATION OF LIVER FIBROSIS PROGRESSION IN PATIENTS WITH HBV/HIV CO-INFECTION

The problem of HBV and HCV infections in addition to the HIV-infection in sub-Saharan African countries remains important due to the high prevalence and mortality after fast progressing fibrogenesis and development of hepatocellular carcinoma. Despite of the large number of investigations on diagnostics and prediction of the disease course, the exact role of the proinflammatory influence of IP-10 and IL-17A on the fibrogenesis during HIV/HBV-co-infection is still unknown. The aim of the study was to investigate IP-10 and IL-17A concentration in blood serum among HIV/HBV patients to consider their potential role in improvement of diagnostics of liver fibrosis progression. 53 HIV/HBV patients of Lewanika General Hospital (West Zambia) and 21 healthy blood donors were checked for serological markers, liver biopsy and IP-10, IL-17A in blood serum. The obtained results were analyzed by statistical package SPSS 12.0. Mean IP-10 was 753,6 pg/ml among HIV/HBV co-infected patients with F3-4 and it was reliably higher than in F1-2 patients and healthy responders (р=0,005). This group had also higher level of IL-17A (37,54 pg/ml) than comparison groups (р=0,032). We found out strong correlation between increasing IP-10 (r=0,6), IL-17A (r=0,52) and fibrotic severity (р<0,05). High IP-10, IL-17A amount increases the risk of F3-4 formation in HIV/HBV patients.

Inflammation induced by influenza virus impairs human innate immune control of pneumococcus

Colonization of the upper respiratory tract by pneumococcus is important both as a determinant of disease and for transmission into the population. The immunological mechanisms that contain pneumococcus during colonization are well studied in mice but remain unclear in humans. Loss of this control of pneumococcus following infection with influenza virus is associated with secondary bacterial pneumonia. We used a human challenge model with type 6B pneumococcus to show that acquisition of pneumococcus induced early degranulation of resident neutrophils and recruitment of monocytes to the nose. Monocyte function was associated with the clearance of pneumococcus. Prior nasal infection with live attenuated influenza virus induced inflammation, impaired innate immune function and altered genome-wide nasal gene responses to the carriage of pneumococcus. Levels of the cytokine CXCL10, promoted by viral infection, at the time pneumococcus was encountered were positively associated with bacterial load.

Study of 2009 H1N1 Pandemic Influenza Virus as a Possible Causative Agent of Diabetes

CONTEXT

Recent studies have suggested that influenza A virus (IAV) might be involved in the etiology of diabetes.

OBJECTIVE AND METHODS

To address this question, we tested the ability of H1N1 pandemic IAV to infect, replicate, and damage human β cells/pancreatic islets in vitro and induce pancreatic damage and/or glucose metabolism alterations in chemical and autoimmune models of β cell damage in vivo. Moreover, we looked for direct and/or indirect evidence of correlation between IAV infection and autoimmunity/diabetes in humans.

RESULTS

Human H1N1 A/California/2009-derived viruses infected human pancreatic islets in vitro, inducing a proinflammatory response associated with substantial increases of CXCL9 and CXCL10 release. In vivo, infected mice showed a clear susceptibility to the virus, with its localization also found in extrapulmonary organs, including the pancreas. Infection was able to induce mild modifications of glycemia in C57B6 mice after chemical damage of islets but did not modulate the autoimmune damage of islets in NOD mice. One of 69 nasopharyngeal swabs collected from patients at the onset of type 1 diabetes yielded positive results for IAV. Pancreas sections from 17 organ donors available from the Network for Pancreatic Organ Donors With Diabetes showed the persistence of CXCL10-positive cells in islet autoimmunity-positive subjects; however, extremely rare cells stained for viral RNA and not preferentially in autoimmune subjects.

CONCLUSION

Influenza H1N1 pdm strains are able to infect and replicate in mammalian pancreatic cells both in vitro and in vivo but did not cause any functional impairment consistent with diabetes.

Endogenous IL-10 maintains immune tolerance but IL-10 gene transfer exacerbates autoimmune cholangitis

The immunomodulatory effect of IL-10 as an immunosuppressive and anti-inflammatory cytokine is well known. Taking advantage of our established mouse model of autoimmune cholangitis using 2-octynoic acid conjugated ovalbumin (2-OA-OVA) induction, we compared liver pathology, immune cell populations and antimitochondrial antibodies between IL-10 knockout and wild type mice immunized with 2-OA-OVA. At 10 weeks post immunization, portal inflammation and fibrosis were more severe in 2-OA-OVA immunized IL-10 knockout mice than in wild type mice. This was accompanied by significant higher levels of collagen I and III expression, T, NK and NKT subsets in liver and IgG anti-mitochondrial autoantibodies (AMAs) compared to 2-OA-OVA immunized wild type mice, suggesting that endogenous IL-10 is necessary for the maintenance of immune tolerance in primary biliary cholangitis (PBC). Further, we investigated whether administration of exogenous IL-10 could prevent PBC by administration of IL-10 expressing recombinant adeno-associated virus (AAV-IL-10) either 3 days before or 3 weeks after the establishment of liver pathology. Interestingly, administration of AAV-IL-10 resulted in increased liver inflammation and fibrosis, accompanied by increases in IFN-γ in liver CD4⁺ T cell, granzyme B, FasL, and CD107a in liver CD8⁺ T and NKT cells, and granzyme B and FasL in liver NK cells of AAV-IL-10 administered mice compared with control mice. Furthermore, administration of AAV-IL-10 significantly increased levels of proinflammatory cytokines and chemokines (IFN-γ, TNF-α, CXCL9 and CXCL10) and collagen I and III production in naïve mice, together with increase in immune cell infiltration and collagen deposition in the liver, suggesting a role of IL-10 in fibrosis. In conclusion, our data demonstrate that endogenous IL-10 is critical in the maintenance of immune tolerance but exogenous administration of IL-10 exacerbates liver inflammation and fibrosis. Furthermore, the distinctive presence of inflammatory immune cell populations and collagen expression in AAV-IL-10 treated naïve mice cautions against the clinical use of exogenous IL-10 in patients with autoimmune cholangitis.

Boosting effect of IL-7 in interferon gamma release assays to diagnose Mycobacterium tuberculosis infection

Background

A quarter of the world’s population is estimated to be infected with Myobacterium tuberculosis (Mtb). Infection is detected by immune response to M. tuberculosis antigens using either tuberculin skin test (TST) and interferon gamma release (IGRA’s), tests which have low sensitivity in immunocompromised. IL-7 is an important cytokine for T-cell function with potential to augment cytokine release in in-vitro assays. This study aimed to determine whether the addition of IL-7 in interferon-gamma release assays (IGRAs) improves its diagnostic performance of Mtb infection.

Methods

44 cases with confirmed TB and 45 household contacts without TB were recruited and 1ml of blood was stimulated in two separate IGRA’s tube set: one set of standard Quantiferon TB gold tubes mitogen, TB antigen and TB Nil; one set of customized Quantiferon TB gold tubes with added IL-7. Following IFN-γ and IP-10 release was determined using ELISA.

Results

We found that the addition of IL-7 led to significantly higher release of IFN-γ in individuals with active TB from 4.2IU/ml (IQR 1.4–6.9IU/ml) to 5.1IU/ml (IQR 1.5–8.1IU/ml, p = 0.0057), and we found an indication of a lower release of both IFN-γ and IP-10 in participants with negative tests.

Conclusions

In TB cases addition of IL-7 in IGRA tubes augments IFN-γ but not IP-10 release, and seems to lower the response in controls. Whether IL-7 boosted IGRA holds potential over standard IGRA needs to be confirmed in larger studies in high and low TB incidence countries.

Chemokines and Chemokine Receptors as Therapeutic Targets in Inflammatory Bowel Disease; Pitfalls and Promise

The principal targets for anti-chemokine therapy in inflammatory bowel disease (IBD) have been the receptors CCR9 and CXCR3 and their respective ligands CCL25 and CXCL10. More recently CCR6 and its ligand CCL20 have also received attention, the expression of the latter in enterocytes being manipulated through Smad7 signalling. These pathways, selected based on their fundamental role in regulating mucosal immunity, have led to the development of several therapeutic candidates that have been tested in early phase clinical trials with variable clinical efficacy. In this article, we appraise the status of chemokine-directed therapy in IBD, review recent developments, and nominate future areas for therapeutic focus.

Immune response biomarkers in human and veterinary research

Biomarkers are increasingly utilised in biological research and clinical practice for diagnosis of disease, monitoring of therapeutic prognosis, or as end points in clinical studies. Cytokines are small molecules that orchestrate immune responses and as such have great potential as biomarkers for both human and veterinary fields. Given the ease of sampling in the blood, and their high prevalence in clinical applications we will focus on protein detection as an area for biomarker discovery. This is facilitated by new technological developments such as digital ELISA that have led to significant increases in sensitivity. Two highly relevant examples include type I interferons, namely IFNα, that is now directly quantifiable by digital ELISA from biological samples. The application of this approach to the study of the unique bat interferon response may reveal novel findings with applications in both human and veterinary research. As a second example we will describe the use of CXCL10 as a disease biomarker in Tuberculosis, highlighting findings from human and mouse studies that should be considered in veterinary research. In summary, we describe how cytokines may be applied as novel biomarkers and illustrate two key examples where human and veterinary research may complement each other in line with the One Health objectives.

Nitrosporeusine analogue ameliorates Chandipura virus induced inflammatory response in CNS via NFκb inactivation in microglia

Chandipura Virus (CHPV), a negative-stranded RNA virus belonging to the Rhabdoviridae family, has been previously reported to bring neuronal apoptosis by activating several factors leading to neurodegeneration. Following virus infection of the central nervous system, microglia, the ontogenetic and functional equivalents of macrophages in somatic tissues gets activated and starts secreting chemokines, thereby recruiting peripheral leukocytes into the brain parenchyma. In the present study, we have systemically examined the effect of CHPV on microglia and the activation of cellular signalling pathways leading to chemokine expression upon CHPV infection. Protein and mRNA expression profiles of chemokine genes revealed that CHPV infection strongly induces the expression of CXC chemokine ligand 10 (CXCL10) and CC chemokine ligand 5 (CCL5) in microglia. CHPV infection triggered the activation of signalling pathways mediated by mitogen-activated protein kinases, including p38, JNK 1 and 2, and nuclear factor κB (NF-kappaB). CHPV-induced expression of CXCL10 and CCL5 was achieved by the activation of p38 and NF-kappaB pathways. Considering the important role of inflammation in neurodegeneration, we have targeted NF-kappaB using a newly synthesised natural product nitrosporeusine analogue and showed incapability of microglial supernatant of inducing apoptosis in neurons after treatment.

Chronic ethanol consumption: role of TLR3/TRIF-dependent signaling

Chronic ethanol consumption stimulates neuroimmune signaling in the brain, and Toll-like receptor (TLR) activation plays a key role in ethanol-induced inflammation. However, it is unknown which of the TLR signaling pathways, the myeloid differentiation primary response gene 88 (MyD88) dependent or the TIR-domain-containing adapter-inducing interferon-β (TRIF) dependent, is activated in response to chronic ethanol. We used voluntary (every-other-day) chronic ethanol consumption in adult C57BL/6J mice and measured expression of TLRs and their signaling molecules immediately following consumption and 24 hours after removing alcohol. We focused on the prefrontal cortex where neuroimmune changes are the most robust and also investigated the nucleus accumbens and amygdala. Tlr mRNA and components of the TRIF-dependent pathway (mRNA and protein) were increased in the prefrontal cortex 24 hours after ethanol and Cxcl10 expression increased 0 hour after ethanol. Expression of Tlr3 and TRIF-related components increased in the nucleus accumbens, but slightly decreased in the amygdala. In addition, we demonstrate that the IKKε/TBK1 inhibitor Amlexanox decreases immune activation of TRIF-dependent pathway in the brain and reduces ethanol consumption, suggesting the TRIF-dependent pathway regulates drinking. Our results support the importance of TLR3 and the TRIF-dependent pathway in ethanol-induced neuroimmune signaling and suggest that this pathway could be a target in the treatment of alcohol use disorders.

CXCL9, CXCL10, CXCL11/CXCR3 axis for immune activation - A target for novel cancer therapy

Chemokines are proteins which induce chemotaxis, promote differentiation of immune cells, and cause tissue extravasation. Given these properties, their role in anti-tumor immune response in the cancer environment is of great interest. Although immunotherapy has shown clinical benefit for some cancer patients, other patients do not respond. One of the mechanisms of resistance to checkpoint inhibitors may be chemokine signaling. The CXCL9, -10, -11/CXCR3 axis regulates immune cell migration, differentiation, and activation, leading to tumor suppression (paracrine axis). However, there are some reports that show involvements of this axis in tumor growth and metastasis (autocrine axis). Thus, a better understanding of CXCL9, -10, -11/CXCR3 axis is necessary to develop effective cancer control. In this article, we summarize recent evidence regarding CXCL9, CXCL10, CXCL11/CXCR3 axis in the immune system and discuss their potential role in cancer treatment.

CCL2 recruits T cells into the brain in a CCR2-independent manner

CCL2 is a chemokine that can be induced during neuroinflammation to recruit immune cells, but its role in the central nervous system (CNS) is unclear. Our aim was to better understand its role. We induced CCL2 in CNS of naive CCL2-deficient mice using intrathecally administered replication-defective adenovirus and examined cell infiltration by flow cytometry. CCL2 expression induced pronounced and unexpected recruitment of regulatory and IFNγ-producing T cells to CNS from blood, possibly related to defective egress of monocytes from CCL2-deficient bone marrow. Infiltration also occurred in mice lacking CCR2, a receptor for CCL2. Expression of another receptor for CCL2, CCR4, and CXCR3, a receptor for CXCL10, which was also induced, were both increased in CCL2-treated CNS. CCR4 was expressed by neurons and astrocytes as well as CD4 T cells, and CXCR3 was expressed by CD4 and CD8 T cells. Chemokine-recruited T cells did not lead to CNS pathology. Our findings show a role for CCL2 in recruitment of CD4 T cells to the CNS and show that redundancy among chemokine receptors ensures optimal response.

The prognostic importance of CXCR3 chemokine during organizing pneumonia on the risk of chronic lung allograft dysfunction after lung transplantation

RATIONALE

Since the pathogenesis of chronic lung allograft dysfunction (CLAD) remains poorly defined with no known effective therapies, the identification and study of key events which increase CLAD risk is a critical step towards improving outcomes. We hypothesized that bronchoalveolar lavage fluid (BALF) CXCR3 ligand concentrations would be augmented during organizing pneumonia (OP) and that episodes of OP with marked chemokine elevations would be associated with significantly higher CLAD risk.

METHODS

All transbronchial biopsies (TBBX) from patients who received lung transplantation between 2000 to 2010 were reviewed. BALF concentrations of the CXCR3 ligands (CXCL9, CXCL10 and CXCL11) were compared between episodes of OP and "healthy" biopsies using linear mixed-effects models. The association between CXCR3 ligand concentrations during OP and CLAD risk was evaluated using proportional hazards models with time-dependent covariates.

RESULTS

There were 1894 bronchoscopies with TBBX evaluated from 441 lung transplant recipients with 169 (9%) episodes of OP and 907 (49%) non-OP histopathologic injuries. 62 (37%) episodes of OP were observed during routine surveillance bronchoscopy. Eight hundred thirty-eight (44%) TBBXs had no histopathology and were classified as "healthy" biopsies. There were marked elevations in BALF CXCR3 ligand concentrations during OP compared with "healthy" biopsies. In multivariable models adjusted for other injury patterns, OP did not significantly increase the risk of CLAD when BAL CXCR3 chemokine concentrations were not taken into account. However, OP with elevated CXCR3 ligands markedly increased CLAD risk in a dose-response manner. An episode of OP with CXCR3 concentrations greater than the 25th, 50th and 75th percentiles had HRs for CLAD of 1.5 (95% CI 1.0-2.3), 1.9 (95% CI 1.2-2.8) and 2.2 (95% CI 1.4-3.4), respectively.

CONCLUSIONS

This study identifies OP, a relatively uncommon histopathologic finding after lung transplantation, as a major risk factor for CLAD development when considered in the context of increased allograft expression of interferon-γ inducible ELR- CXC chemokines. We further demonstrate for the first time, the prognostic importance of BALF CXCR3 ligand concentrations during OP on subsequent CLAD risk.

Repurposed JAK1/JAK2 Inhibitor Reverses Established Autoimmune Insulitis in NOD Mice

Recent advances in immunotherapeutics have not yet changed the routine management of autoimmune type 1 diabetes. There is an opportunity to repurpose therapeutics used to treat other diseases to treat type 1 diabetes, especially when there is evidence for overlapping mechanisms. Janus kinase (JAK) 1/JAK2 inhibitors are in development or clinical use for indications including rheumatoid arthritis. There is good evidence for activation of the JAK1/JAK2 and signal transducer and activator of transcription (STAT) 1 pathway in human type 1 diabetes and in mouse models, especially in β-cells. We tested the hypothesis that using these drugs to block the JAK-STAT pathway would prevent autoimmune diabetes. The JAK1/JAK2 inhibitor AZD1480 blocked the effect of cytokines on mouse and human β-cells by inhibiting MHC class I upregulation. This prevented the direct interaction between CD8⁺ T cells and β-cells, and reduced immune cell infiltration into islets. NOD mice treated with AZD1480 were protected from autoimmune diabetes, and diabetes was reversed in newly diagnosed NOD mice. This provides mechanistic groundwork for repurposing clinically approved JAK1/JAK2 inhibitors for type 1 diabetes.

Resisting fatal attraction: a glioma oncometabolite prevents CD8+ T cell recruitment

Immunotherapy has emerged as a potent approach for treating aggressive cancers, such as non-small-cell lung tumors and metastatic melanoma. Clinical trials are now in progress for patients with malignant gliomas; however, a better understanding of how these tumors escape immune surveillance is required to enhance antitumor immune responses. With gliomas, the recruitment of CD8+ T cells to the tumor is impaired, in part preventing containment or elimination of the tumor. In this issue of the JCI, Kohanbash and colleagues present an elegant dissection of how gliomas exploit an enzymatic activity acquired through a common mutation to abrogate the migration of CD8+ T cells to the tumor. They show that the oncometabolite 2-hydroxyglutarate (2HG), generated by mutated forms of isocitrate dehydrogenase (IDH1 and IDH2), reduces the expression of STAT1, thereby limiting the production of the chemokines CXCL9 and CXCL10. As a result, IDH1-mutated tumors are less effectively infiltrated by CD8+ T cells, contributing to tumor escape. Finally, in mice harboring syngeneic gliomas, an inhibitor of 2HG synthesis complemented vaccination to ameliorate tumor control. Understanding how to increase immune infiltration of gliomas represents a key first step in achieving tumor destruction through immunotherapy.

Antibody Neutralization of CXCL10 in Vivo Is Dependent on Binding to Free and Not Endothelial-bound Chemokine: IMPLICATIONS FOR THE DESIGN OF A NEW GENERATION OF ANTI-CHEMOKINE THERAPEUTIC ANTIBODIES

To improve our understanding of properties that confer successful inhibition of chemokines in vivo, we analyzed anti-murine CXCL10 monoclonal antibodies (mAb) having different characteristics. 1B6 displayed potent inhibition of cell recruitment in vitro with an IC50 of 0.5 nm but demonstrated little efficacy in various animal models of human disease. On the contrary, 1F11 showed efficacy in several models of inflammation yet was less potent at inhibiting chemotaxis in vitro with an IC50 of 21 nm Furthermore, we observed that 1B6 displayed a rapid dose-dependent clearance (t½ 10-60 h) in contrast to 1F11, which presented a dose-proportional pharmacokinetic profile and a half-life of 12 days. Moreover, 1B6 recognized glycosaminoglycan (GAG)-bound CXCL10, resulting in target-mediated clearance, which was corroborated using CXCL10-deficient mice. In contrast to 1B6, 1F11 inhibited the interaction of CXCL10 with GAGs, did not recognize GAG-bound CXCL10, and did not display target-mediated drug disposition. Confirming previous animal studies, 1B6 was poor at reversing glycemia in a model of type 1 diabetes, whereas 1F11 induced early and prolonged control of diabetes. Furthermore, when using 1A4, a subsequently generated anti-mCXCL10 mAb that shares the property with 1F11 of being unable to recognize CXCL10 immobilized on GAG, we observed a similar superior control of diabetes as compared with 1B6. We therefore concluded that targeting chemokines with antibodies such as 1B6 that recognize the more abundant GAG-bound form of the chemokine may not be the optimal strategy to achieve disease control.

Identification of a fish specific chemokine CXCL_F2 in large yellow croaker (Larimichthys crocea) reveals its primitive chemotactic function

Chemokines are a superfamily of cytokines regulating immune cell migration under both inflammatory and normal physiological conditions. Currently, a number of fish specific CXC chemokines, named as CXCL_F1-5, have been identified in several species. However, understanding of their functional characteristics is still limited. In this study, we identified a fish specific chemokine CXCL_F2 (LycCXCL_F2) from large yellow croaker (Larimichthys crocea). The open reading frame (ORF) of LycCXCL_F2 is 348 nucleotides long, encoding a protein of 115 amino acids (aa). The deduced LycCXCL_F2 protein contains a 20-aa signal peptide and a 95-aa mature polypeptide. Phylogenetic analysis showed that LycCXCL_F2 fell into a major clade formed by CXCL_F2 sequences and was separated from CXCL_F1 and CXCL_F3-5 subgroups. LycCXCL_F2 mRNA transcript was constitutively expressed in various tissues, with the highest levels in spleen and head kidney. After stimulation with inactivated trivalent bacterial vaccines, LycCXCL_F2 mRNA transcription was significantly increased in both spleen and head kidney. Moreover, recombinant LycCXCL_F2 protein exhibited obvious chemotaxis to monocytes, lymphocytes and eosnophils of PBLs isolated from large yellow croaker, but could not induce the respiratory burst of macrophages. These results indicate that this fish specific CXC chemokine LycCXCL_F2 possesses primitive chemotactic activity and may play a role in immune response in large yellow croaker.

Gremlin-1 Overexpression in Mouse Lung Reduces Silica-Induced Lymphocyte Recruitment - A Link to Idiopathic Pulmonary Fibrosis through Negative Correlation with CXCL10 Chemokine

Idiopathic pulmonary fibrosis (IPF) is characterized by activation and injury of epithelial cells, the accumulation of connective tissue and changes in the inflammatory microenvironment. The bone morphogenetic protein (BMP) inhibitor protein gremlin-1 is associated with the progression of fibrosis both in human and mouse lung. We generated a transgenic mouse model expressing gremlin-1 in type II lung epithelial cells using the surfactant protein C (SPC) promoter and the Cre-LoxP system. Gremlin-1 protein expression was detected specifically in the lung after birth and did not result in any signs of respiratory insufficiency. Exposure to silicon dioxide resulted in reduced amounts of lymphocyte aggregates in transgenic lungs while no alteration in the fibrotic response was observed. Microarray gene expression profiling and analyses of bronchoalveolar lavage fluid cytokines indicated a reduced lymphocytic response and a downregulation of interferon-induced gene program. Consistent with reduced Th1 response, there was a downregulation of the mRNA and protein expression of the anti-fibrotic chemokine CXCL10, which has been linked to IPF. In human IPF patient samples we also established a strong negative correlation in the mRNA expression levels of gremlin-1 and CXCL10. Our results suggest that in addition to regulation of epithelial-mesenchymal crosstalk during tissue injury, gremlin-1 modulates inflammatory cell recruitment and anti-fibrotic chemokine production in the lung.

Folate-Modified Chitosan Nanoparticles Coated Interferon-Inducible Protein-10 Gene Enhance Cytotoxic T Lymphocytes' Responses to Hepatocellular Carcinoma

Adoptive therapy using tumor antigen-specific cytotoxic T lymphocytes (CTLs) is a promising approach for treatment of human cancers. Due to immune suppression in cancer patients, it is difficult for tumor antigen-specific CTLs to arrive at tumor tissues. Interferon-inducible protein-10 (IP-10) is a powerful chemokine that effectively attracts CTLs to tumor tissues and improves their anti-tumor activity. Increase over expression of IP-10 in tumor tissues can efficiently promote efficacy of adoptive therapy. Folate-modified chitosan nanoparticles coating the human IP-10 gene (FA-CS-hIP-10) were therefore developed in this study. The FA-CS-hIP-10 nanoparticles were specifically bound to folate receptors on hepatoma cells and promoted the expression of IP-10, to improve the activity of pMAGE-A1(278-286) specific CTLs. Combination of the FA-CS-hIP-10 and pMAGE-A1(278-286) specific CD8+ CTLs efficiently increased secretion of IFN-γ, inhibited tumor growth and extended survival of nude mice with subcutaneously transplanted human hepatocellular carcinoma. Our results demonstrated that the mechanism behind this novel therapeutic approach involved inhibition of angiogenesis and proliferation, and also promoted apoptosis of tumor cells. Our study provides a potentially novel approach for treatment of human hepatocellular carcinoma by improving the activity of tumor antigen-specific CTLs.

Involvement and prognosis value of CD8(+) T cells in giant cell arteritis

CD8(+) T cells participate in the pathogenesis of some vasculitides. However, little is known about their role in Giant Cell Arteritis (GCA). This study was conducted to investigate CD8(+) T cell involvement in the pathogenesis of GCA. Analyses were performed at diagnosis and after 3 months of glucocorticoid treatment in 34 GCA patients and 26 age-matched healthy volunteers. Percentages of CD8(+) T-cell subsets, spectratype analysis of the TCR Vβ families of CD8(+) T cells, levels of cytokines and chemokines and immunohistochemistry of temporal artery biopsies (TAB) were assessed. Among total CD8(+) T cells, percentages of circulating cytotoxic CD8 T lymphocytes (CTL, CD3(+)CD8(+)perforin(+)granzymeB(+)), Tc17 (CD3(+)CD8(+)IL-17(+)), CD63(+)CD8(+) T cells and levels of soluble granzymes A and B were higher in patients than in controls, whereas the percentage of Tc1 cells (CD3(+)CD8(+)IFN-γ(+)) was similar. Moreover, CD8(+) T cells displayed a restricted TCR repertoire in GCA patients. Percentages of circulating CTL, Tc17 and soluble levels of granzymes A and B decreased after treatment. CXCR3 expression on CD8(+) T cells and its serum ligands (CXCL9, -10, -11) were higher in patients. Analyses of TAB revealed high expression of CXCL9 and -10 associated with infiltration by CXCR3(+)CD8(+) T cells expressing granzyme B and TiA1. The intensity of the CD8 T-cell infiltrate in TAB was predictive of the severity of the disease. This study demonstrates the implication and the prognostic value of CD8(+) T-cells in GCA and suggests that CD8(+) T-cells are recruited within the vascular wall through an interaction between CXCR3 and its ligands.

Antiviral Activities of Different Interferon Types and Subtypes against Hepatitis E Virus Replication

Hepatitis E virus (HEV) is the causative agent of hepatitis E in humans and a member of the genusOrthohepevirusin the familyHepeviridae HEV infections are the common cause of acute hepatitis but can also take chronic courses. Ribavirin is the treatment of choice for most patients, and type I interferon (IFN) has been evaluated in a few infected transplant patientsin vivo In this study, the antiviral effects of different exogenously administered interferons were investigated by using state-of-the-art subgenomic replicon and full-length HEV genome cell culture models. Hepatitis C virus (HCV) subgenomic replicons based on the genotype 2a JFH1 isolate served as the reference. The experiments revealed that HEV RNA replication was inhibited by the application of all types of IFN, including IFN-α (type I), IFN-γ (type II), and IFN-λ3 (type III), but to a far lesser extent than HCV replication. Simultaneous determination of interferon-stimulated gene (ISG) expression levels for all IFN types demonstrated efficient downregulation by HEV. Furthermore, different IFN-α subtypes were also able to block viral replication in combination with ribavirin. The IFN-α subtypes 2a and 2b exerted the strongest antiviral activity against HEV. In conclusion, these data demonstrate for the first time moderate anti-HEV activities of types II and III IFNs and different IFN-α subtypes. As HEV employed a potent anti-interferon mechanism by restricting ISG expression, exogenous application of IFNs as immunotherapy should be carefully assessed.

Hepatitis C virus infection induces elevation of CXCL10 in human brain microvascular endothelial cells

Hepatitis C virus (HCV) primarily infects liver tissues, while pathogenesis of extrahepatic tissues has been reported. About 50% of patients with HCV infection suffer from neurological disease. The underlying molecular mechanisms remain unclear. In the present study, we aimed to investigate the induction of CXC chemokine ligand 10 (CXCL10) in human brain microvascular endothelial cells (HBMECs) by HCV infection. CXCL10 and its receptor CXCR3 were constitutively expressed in HBMECs. HCV infection induced CXCL10 elevation in HBMECs. The elevation of CXCL10 in HBMECs was eliminated when HCV infection was blocked by neutralizing antibodies. NF-κB is a positive regulator for CXCL10 transcription. HCV infection led to an increased phosphorylation of NF-κB (ser536) in HBMECs, and CXCL10 induced by HCV was slightly decreased when an inhibitor of NF-κB was added. IL1 beta and IFN gama were also upregulated in HCV infected HBMECs, and could be depressed by inhibitor of NF-κB. Thus, HCV infection leads to upregulated expression of CXCL10 in HBMECs, which is probably via the phosphorylation of NF-κB. The findings of this study provide potential mechanisms and novel targets for HCV induced neuroinflammation. J. Med. Virol. 88:1596-1603, 2016. © 2016 Wiley Periodicals, Inc.

Donor interleukin-22 and host type I interferon signaling pathway participate in intestinal graft-versus-host disease via STAT1 activation and CXCL10

Acute graft-versus-host disease (aGVHD) remains a major complication following allogeneic hematopoietic cell transplantation, limiting the success of this therapy. We previously reported that interleukin-22 (IL-22) participates to aGVHD development, but the underlying mechanisms of its contribution remain poorly understood. In this study, we analyzed the mechanism of the pathological function of IL-22 in intestinal aGVHD. Ex-vivo colon culture experiments indicated that IL-22 was able to induce Th1-like inflammation via signal transducer and activator of transcription factor-1 (STAT1) and CXCL10 induction in the presence of type I interferon (IFN). To evaluate a potential synergy between IL-22 and type I IFN in aGVHD, we transplanted recipient mice, either wild-type (WT) or type I IFN receptor deficient (IFNAR(-/-)), with bone marrow cells and WT or IL-22 deficient (IL-22(-/-)) T cells. We observed a decreased GVHD severity in IFNAR(-/-) recipient of IL-22(-/-) T cells, which was associated with a lower level of STAT1 activation and reduced CXCL10 expression in the large intestine. Finally, immunohistochemistry staining of STAT1 performed on gastrointestinal biopsies of 20 transplanted patients showed exacerbated STAT1 activation in gastrointestinal tissues of patients with aGVHD as compared with those without aGVHD. Thus, interfering with both IL-22 and type I IFN signaling may provide a novel approach to limit aGVHD.

Enzymes for Pancreatic Islet Isolation Impact Chemokine-Production and Polarization of Insulin-Producing β-Cells with Reduced Functional Survival of Immunoisolated Rat Islet-Allografts as a Consequence

The primary aim of this study was to determine whether normal variations in enzyme-activities of collagenases applied for rat-islet isolation impact longevity of encapsulated islet grafts. Also we studied the functional and immunological properties of rat islets isolated with different enzyme preparations to determine whether this impacts these parameters. Rat-islets were isolated from the pancreas with two different collagenases with commonly accepted collagenase, neutral protease, and clostripain activities. Islets had a similar and acceptable glucose-induced insulin-release profile but a profound statistical significant difference in production of the chemokines IP-10 and Gro-α. The islets were studied with nanotomy which is an EM-based technology for unbiased study of ultrastructural features of islets such as cell-cell contacts, endocrine-cell condition, ER stress, mitochondrial conditions, and cell polarization. The islet-batch with higher chemokine-production had a lower amount of polarized insulin-producing β-cells. All islets had more intercellular spaces and less interconnected areas with tight cell-cell junctions when compared to islets in the pancreas. Islet-graft function was studied by implanting encapsulated and free islet grafts in rat recipients. Alginate-based encapsulated grafts isolated with the enzyme-lot inducing higher chemokine production and lower polarization survived for a two-fold shorter period of time. The lower survival-time of the encapsulated grafts was correlated with a higher influx of inflammatory cells at 7 days after implantation. Islets from the same two batches transplanted as free unencapsulated-graft, did not show any difference in survival or function in vivo. Lack of insight in factors contributing to the current lab-to-lab variation in longevity of encapsulated islet-grafts is considered to be a threat for clinical application. Our data suggest that seemingly minor variations in activity of enzymes applied for islet-isolation might contribute to longevity-variations of immunoisolated islet-grafts.

AAV-IL-22 modifies liver chemokine activity and ameliorates portal inflammation in murine autoimmune cholangitis

There remain significant obstacles in developing biologics to treat primary biliary cholangitis (PBC). Although a number of agents have been studied both in murine models and human patients, the results have been relatively disappointing. IL-22 is a member of the IL-10 family and has multiple theoretical reasons for predicting successful usage in PBC. We have taken advantage of an IL-22 expressing adeno-associated virus (AAV-IL-22) to address the potential role of IL-22 in not only protecting mice from autoimmune cholangitis, but also in treating animals with established portal inflammation. Using our established mouse model of 2-OA-OVA immunization, including α-galactosylceramide (α-GalCer) stimulation, we treated mice both before and after the onset of clinical disease with AAV-IL-22. Firstly, AAV-IL-22 treatment given prior to 2-OA-OVA and α-GalCer exposure, i.e. before the onset of disease, significantly reduces the portal inflammatory response, production of Th1 cytokines and appearance of liver fibrosis. It also reduced the liver lymphotropic chemokines CCL5, CCL19, CXCL9, and CXCL10. Secondly, and more importantly, therapeutic use of AAV-IL-22, administered after the onset of disease, achieved a greater hurdle and significantly improved portal pathology. Further the improvements in inflammation were negatively correlated with levels of CCL5 and CXCL10 and positively correlated with levels of IL-22. In conclusion, we submit that the clinical use of IL-22 has a potential role in modulating the inflammatory portal process in patients with PBC.

Extracellular Histones Induce Chemokine Production in Whole Blood Ex Vivo and Leukocyte Recruitment In Vivo

The innate immune system relies to a great deal on the interaction of pattern recognition receptors with pathogen- or damage-associated molecular pattern molecules. Extracellular histones belong to the latter group and their release has been described to contribute to the induction of systemic inflammatory reactions. However, little is known about their functions in the early immune response to an invading pathogen. Here we show that extracellular histones specifically target monocytes in human blood and this evokes the mobilization of the chemotactic chemokines CXCL9 and CXCL10 from these cells. The chemokine induction involves the toll-like receptor 4/myeloid differentiation factor 2 complex on monocytes, and is under the control of interferon-γ. Consequently, subcutaneous challenge with extracellular histones results in elevated levels of CXCL10 in a murine air pouch model and an influx of leukocytes to the site of injection in a TLR4 dependent manner. When analyzing tissue biopsies from patients with necrotizing fasciitis caused by Streptococcus pyogenes, extracellular histone H4 and CXCL10 are immunostained in necrotic, but not healthy tissue. Collectively, these results show for the first time that extracellular histones have an important function as chemoattractants as their local release triggers the recruitment of immune cells to the site of infection.

The detrimental effects of extracellular histones under pathological conditions have lately attracted considerable attention. However, little is known about their functions as damage-associated molecular pattern molecules. Our study shows for the first time that extracellular histones trigger the induction of chemotactic chemokines from monocytes. As this interaction is dependent on a pattern recognition receptor, namely toll-like receptor 4, our data indeed point to an important role of extracellular histones in danger signaling. Notably, CXCL9 and CXCL10 are chemoattractants, and the recruitment of immune cells to the site of histone injection in a subcutaneous mouse model supports the concept that low levels of extracellular histones constitute a part of the host response.

Association between CXCL10 and DPP4 Gene Polymorphisms and a Complementary Role for Unfavorable IL28B Genotype in Prediction of Treatment Response in Thai Patients with Chronic Hepatitis C Virus Infection

Pretreatment serum levels of interferon-γ-inducible protein-10 (IP-10, CXCL10) and dipeptidyl peptidase-4 (DPP IV) predict treatment response in chronic hepatitis C (CHC). The association between functional genetic polymorphisms of CXCL10 and DPP4 and treatment outcome has not previously been studied. This study aimed to determine the association between genetic variations of CXCL10 and DPP4 and the outcome of treatment with pegylated interferon-α (PEG-IFN-α) based therapy in Thai patients with CHC. 602 Thai patients with CHC treated using a PEG-IFN-α based regimen were genotyped for CXCL10 rs56061981 G>A and IL28B rs12979860 C>T. In addition, in patients infected with CHC genotype 1, DPP4 (rs13015258 A>C, rs17848916 T>C, rs41268649 G>A, and rs 17574 T>C) were genotyped. Correlations between single nucleotide polymorphisms, genotype, and treatment response were analyzed. The rate of sustained virologic response (SVR) was higher for the CC genotype of IL28B rs12979860 polymorphisms than for non-CC in both genotype 1 (60.6% vs. 29.4%, P < 0.001) and non-genotype 1 (69.4% vs. 49.1%, P < 0.05) CHC. SVR was not associated with the CXCL10 gene variant in all viral genotypes or DPP4 gene polymorphisms in viral genotype1. Multivariate analysis revealed IL28B rs12979860 CC genotype (OR = 3.12; 95% CI, 1.72-5.67; P < 0.001), hepatitis C virus RNA < 400,000 IU/ml (OR = 2.21; 95% CI, 1.22-3.99, P < 0.05), age < 45 years (OR = 2.03; 95% CI, 1.11-3.68; P < 0.05), and liver fibrosis stage 0-1 (OR = 1.64; 95% CI, 1.01-2.65, P < 0.05) were independent factors for SVR. Unfavorable IL28B rs12979860 CT or TT genotypes with the CXCL10 rs56061981 non-GG genotype were associated with a higher SVR than GG genotype (66.7% vs. 33.0%, P = 0.004) in viral genotype 1. In Thai CHC genotype 1 infected patients with an unfavorable IL28B rs12979860 CT/TT genotype, the complementary CXCL10 polymorphism strongly enhances prediction of treatment response.

Glucocorticoid dexamethasone down-regulates basal and vitamin D3 induced cathelicidin expression in human monocytes and bronchial epithelial cell line

Glucocorticoids (GCs) have been extensively used as the mainstream treatment for chronic inflammatory disorders. The persistent use of steroids in the past decades and the association with secondary infections warrants for detailed investigation into their effects on the innate immune system and the therapeutic outcome. In this study, we analyse the effect of GCs on antimicrobial polypeptide (AMP) expression. We hypothesize that GC related side effects, including secondary infections are a result of compromised innate immune responses. Here, we show that treatment with dexamethasone (Dex) inhibits basal mRNA expression of the following AMPs; human cathelicidin, human beta defensin 1, lysozyme and secretory leukocyte peptidase 1 in the THP-1 monocytic cell-line (THP-1 monocytes). Furthermore, pre-treatment with Dex inhibits vitamin D3 induced cathelicidin expression in THP-1 monocytes, primary monocytes and in the human bronchial epithelial cell line BCi NS 1.1. We also demonstrate that treatment with the glucocorticoid receptor (GR) inhibitor RU486 counteracts Dex mediated down-regulation of basal and vitamin D3 induced cathelicidin expression in THP-1 monocytes. Moreover, we confirmed the anti-inflammatory effect of Dex. Pre-treatment with Dex inhibits dsRNA mimic poly IC induction of the inflammatory chemokine IP10 (CXCL10) and cytokine IL1B mRNA expression in THP-1 monocytes. These results suggest that GCs inhibit innate immune responses, in addition to exerting beneficial anti-inflammatory effects.

Role of CXCL10 in cryoglobulinemia

Interferon (IFN)-γ-induced protein 10 (IP-10/CXCL10) and its receptor, C-X-C motif receptor 3, appear to contribute to the pathogenesis of hepatitis C virus (HCV)-related mixed cryoglobulinaemia (MC) (HCV+MC). The secretion of CXCL10 by cluster of differentiation (CD) CD4+, CD8+, and natural killer-T cells is dependent on IFN-γ, which is itself mediated by the interleukin-12 cytokine family. Under the influence of IFN-γ, CXCL10 is secreted by several cell types including lymphocytes, hepatocytes, endothelial cells, fibroblasts, etc. In tissues, recruited T helper 1 lymphocytes may be responsible for enhanced IFN-γ and tumour necrosis factor-α production, which in turn stimulates CXCL10 secretion from the cells, therefore creating an amplification feedback loop, and perpetuating the autoimmune process. High levels of CXCL10 in circulation have been found in HCV+MC, especially in patients with clinically active vasculitis. Furthermore, HCV+MC patients with autoimmune thyroiditis (AT) have higher levels than those without AT. Further studies are needed to investigate interactions between chemokines and cytokines in the pathogenesis, and to evaluate whether CXCL10 is a novel therapeutic target in HCV-related MC.

Common variants of chemokine receptor gene CXCR3 and its ligands CXCL10 and CXCL11 associated with vascular permeability of dengue infection in peninsular Malaysia

Dengue causes significantly more human disease than any other arboviruses. It causes a spectrum of illness, ranging from mild self-limited fever, to severe and fatal dengue hemorrhagic fever, as evidenced by vascular leakage and multifactorial hemostatic abnormalities. There is no specific treatment available till date. Evidence shows that chemokines CXCL10, CXCL11 and their receptor CXCR3 are involved in severity of dengue, but their genetic association with the susceptibility of vascular leakage during dengue infection has not been reported. We genotyped 14 common variants of these candidate genes in 176 patients infected with dengue. rs4859584 and rs8878 (CXCL10) were significantly associated with vascular permeability of dengue infection (P < 0.05); while variants of CXCL11 showed moderate significance of association (P = 0.0527). Haplotype blocks were constructed for genes CXCL10 and CXCL11 (5 and 7 common variants respectively). Haplotype association tests performed revealed that, “CCCCA” of gene CXCL10 and “AGTTTAC” of CXCL11 were found to be significantly associated with vascular leakage (P = 0.0154 and 0.0366 respectively). In summary, our association study further strengthens the evidence of the involvement of CXCL10 and CXCL11 in the pathogenesis of dengue infection.

CXCL10-induced migration of adoptively transferred human natural killer cells toward solid tumors causes regression of tumor growth in vivo

Adoptive infusion of natural killer (NK) cells is being increasingly explored as a therapy in patients with cancer, although clinical responses are thus far limited to patients with hematological malignancies. Inadequate homing of infused NK cells to the tumor site represents a key factor that may explain the poor anti-tumor effect of NK cell therapy against solid tumors. One of the major players in the regulation of lymphocyte chemotaxis is the chemokine receptor chemokine (C-X-C motif) receptor 3 (CXCR3) which is expressed on activated NK cells and induces NK cell migration toward gradients of the chemokine (C-X-C motif) ligand (CXCL9, 10 and 11). Here, we show that ex vivo expansion of human NK cells results in a tenfold increased expression of the CXCR3 receptor compared with resting NK cells (p = 0.04). Consequently, these NK cells displayed an improved migratory capacity toward solid tumors, which was dependent on tumor-derived CXCL10. In xenograft models, adoptively transferred NK cells showed increased migration toward CXCL10-transfected melanoma tumors compared with CXCL10-negative wild-type tumors, resulting in significantly reduced tumor burden and increased survival (median survival 41 vs. 32 days, p = 0.03). Furthermore, administration of interferon-gamma locally in the tumor stimulated the production of CXCL10 in subcutaneous melanoma tumors resulting in increased infiltration of adoptively transferred CXCR3-positive expanded NK cells. Our findings demonstrate the importance of CXCL10-induced chemoattraction in the anti-tumor response of adoptively transferred expanded NK cells against solid melanoma tumors.