The atypical chemokine receptor CXCR7/ACKR3 binds two endogenous chemokines, CXCL12 and CXCL11, and is upregulated in many cancers or following infection by several cancer-inducing viruses, including HHV-8. ACKR3 is a ligand-scavenging receptor and does not activate the canonical G protein pathways but was proposed to trigger β-arrestin-dependent signaling. Here, we identified the human herpesvirus 8-encoded CC chemokine vCCL2/vMIP-II as a third high-affinity ligand for ACKR3. vCCL2 acted as partial ACKR3 agonist, inducing β-arrestin recruitment to the receptor, subsequent reduction of its surface levels and its delivery to endosomes. In addition, ACKR3 reduced vCCL2-triggered MAP kinase and PI3K/Akt signaling through other chemokine receptors. Our data suggest that ACKR3 acts as a scavenger receptor for vCCL2, regulating its availability and activity toward human receptors, thereby likely controlling its function in HHV-8 infection. Our study provides new insights into the complex crosstalk between viral chemokines and host receptors as well as into the biology of ACKR3, this atypical and still enigmatic receptor.

Few studies have examined the migration pattern of natural killer (NK) cells, especially after radiation treatment for cancer. We investigated whether irradiation can modulate the expression of chemokines in cancer cells and the migration of NK cells to irradiated tumor cells.

The expression of chemokine receptors (CXCR3, CXCR4 and CXCR6) on interleukin-2 (IL-2)/IL-15-activated NK cells was assessed using flow cytometry. Related chemokine ligands (CXCL11, CXCL12 and CXCL16) in human breast cancer cell lines (MCF7, SKBR3 and MDA-MB231) irradiated at various doses were assessed using reverse transcription-polymerase chain reaction (RT-PCR), fluorescence-activated cell sorting (FACS) and enzyme-linked immunosorbent assay (ELISA). The cell-free culture supernatant was collected 96 h after irradiation of breast cancer cell lines for migration and blocking assays.

The activated NK cells expressed CXCR6. Expression of the CXCR6 ligand CXCL16 increased in a time- and dose-dependent manner in all analyzed cancer cell lines. CXCL16 expression was statistically significantly enhanced in all breast cancer cell lines on day 3 after 20 Gy irradiation. Activated NK cells migration correlated with CXCL16 concentration (R2 = 0.91; P <0.0001). Significantly enhanced migration of NK cells to irradiated cancer cells was observed for a dose of 20 Gy in MCF7 (P = 0.043) and SKBR3 (P = 0.043) cells, but not in MDA-MB231 (P = 0.225) cells. A blocking assay using a CXCR6 antibody showed a significant decrease in the migration of activated NK cells in all cancer cell lines.

Our data indicate that irradiation induces CXCL16 chemokine expression in cancer cells and enhances the migration of activated NK cells expressing CXCR6 to irradiated breast cancer cells. These results suggest that radiation would improve the anti-tumor effect of NK cells through enhanced migration of NK cells to tumor site for the treatment of patients with breast cancer.

Patients with definite systemic sclerosis (SSc) who lack fibrotic features can be stratified into an intermediate stage of disease severity between preclinical/early SSc (EaSSc) and fibrotic subsets (limited cutaneous SSc [lcSSc] and diffuse cutaneous SSc [dcSSc]). The aim of the present study was to molecularly characterize nonfibrotic SSc and EaSSc on the basis of a broad panel of serum markers of inflammation and tissue damage, in order to increase the knowledge of the pathophysiologic mechanisms underlying SSc progression before the development of fibrosis.

An 88-plex immunoassay was performed in serum samples from a discovery cohort composed of 21 patients with EaSSc (meeting the LeRoy and Medsger criteria), 15 with nonfibrotic SSc (meeting the American College of Rheumatology/European League Against Rheumatism 2013 classification criteria, without skin or lung fibrosis), and 11 healthy controls. Analyte concentrations that were consistently significantly different at the exploratory P value threshold of 0.1 were selected for replication analysis in a larger group composed of 47 patients with EaSSc, 48 with nonfibrotic SSc, and 43 healthy controls, as well as 51 patients with lcSSc and 35 with dcSSc. The value of the replicated molecules in predicting SSc progression (at a family-wise error rate of 0.05) was tested.

Based on the results of the explorative analysis, 16 molecules were selected for testing in the replication set. The results showed that CXCL10, CXCL11, tumor necrosis factor receptor type II (TNFRII), and chitinase 3-like protein 1 levels were significantly increased in patients with EaSSc and those with nonfibrotic SSc as compared to healthy controls. The disease in patients with high concentrations of CXCL10 and TNFRII was also characterized by a faster rate of progression from EaSSc and from nonfibrotic SSc to worse disease stages.

SSc patients with preclinical/early SSc and those with established, yet nonfibrotic, disease exhibit clear molecular alterations that are associated with faster rates of disease evolution. These data open novel avenues for disease interception in SSc.

The effects of senescence associated secretory phenotype (SASP) from therapy-induced senescent endothelial cells on tumor microenvironment (TME) remains to be clarified. Here, we investigated effects of ionizing radiation (IR)- and doxorubicin-induced senescent HUVEC on TME. MDA-MB-231 cancer cells treated with conditioned medium (CM) from senescent HUVEC or co-cultured with senescent HUVEC significantly increased cancer cell proliferation, migration, and invasion. We found that CXCL11 plays a principal role in the senescent CM-induced aggressive activities of MDA-MB-231 cells. When we treated HUVEC with a neutralizing anti-CXCL11 antibody or CXCL11 SiRNA, or treated MDA-MB-231 cells with CXCR3 SiRNA, we observed synergistic diminution of the ability of the HUVEC SASP to alter the migration and spheroid invasion of cancer cells. ERK activation was involved in the HUVEC SASP-induced aggressive activity of MDA-MB-231 cells. Finally, we observed the in vivo effect of CXCL11 from the senescent HUVEC in tumor-bearing mice. Together, our results demonstrate that SASP from endothelial cells experiencing therapy-induced senescence promotes the aggressive behavior of cancer cells, and that CXCL11 can potentially be targeted to prevent the adverse effects of therapy-induced senescent endothelial cells on the tumor microenvironment.

Keywords: CXCL11; Endothelial cells; Therapy-induced senescence; Tumor microenvironment.

Accumulating evidence reveals involvement of T lymphocytes and adaptive immunity in the chronic inflammation associated with infectious and noninfectious diseases of the heart, including coronary artery disease, Kawasaki disease, myocarditis, dilated cardiomyopathies, Chagas, hypertensive left ventricular (LV) hypertrophy, and nonischemic heart failure. Chemokine CXCL10 is elevated in cardiovascular diseases, along with increased cardiac infiltration of proinflammatory Th1 and cytotoxic T cells. CXCL10 is a chemoattractant for these T cells and polarizing factor for the proinflammatory phenotype. Thus, targeting the CXCL10 receptor CXCR3 is a promising therapeutic approach to treating cardiac inflammation. Due to biased signaling CXCR3 also couples to anti-inflammatory signaling and immunosuppressive regulatory T cell formation when activated by CXCL11. Numbers and functionality of regulatory T cells are reduced in patients with cardiac inflammation, supporting the utility of biased agonists or biologicals to simultaneously block the pro-inflammatory and activate the anti-inflammatory actions of CXCR3. Other immunotherapy strategies to boost regulatory T cell actions include intravenous immunoglobulin (IVIG) therapy, adoptive transfer, immunoadsorption, and low-dose interleukin-2/interleukin-2 antibody complexes. Pharmacological approaches include sphingosine 1-phosphate receptor 1 agonists and vitamin D supplementation. A combined strategy of switching CXCR3 signaling from pro- to anti-inflammatory and improving Treg functionality is predicted to synergistically lessen adverse cardiac remodeling.

BACKGROUND

Interferon beta has been approved for the treatment of multiple sclerosis (MS). It is believed that immunomodulatory rather than antiviral activity of interferon beta is responsible for disease amelioration. The impact of interferon beta on the chemoattraction of immune cells has not been fully addressed.

OBJECTIVE

To address the influence of interferon beta on the expression of chemokines and their receptors in a standardized setting.

METHODS

The expression of 14 chemokines and 14 chemokine receptor genes was determined by quantitative real-time polymerase chain reaction from fresh blood samples.

METHODS

Outpatient units in Germany. Patients Untreated and interferon beta-treated patients with MS who tested positive and negative for neutralizing antibodies (NABs) were recruited from August 24, 2006, through December 15, 2006, for the initial study and from March 12, 2007, through April 2, 2007, for the validation study.

METHODS

Gene expression and serum chemokine protein levels.

RESULTS

CCL1, CCL2, CCL7, CXCL10, CXCL11, and CCR1 gene expression was strongly upregulated in interferon beta-treated, NAB-negative MS patients. In contrast, gene expression in interferon beta-treated, NAB-positive MS patients did not differ from untreated control donor individuals. Antibody titers inversely correlated with chemokine and chemokine receptor gene expression. Accordingly, serum chemokine protein levels of interferon beta-treated, NAB-negative MS patients were significantly higher than in untreated or interferon beta-treated, NAB-positive MS patients.

CONCLUSIONS

We demonstrate that interferon beta strongly upregulates a set of chemokines and CCR1 in peripheral immune cells. The peripheral upregulation of these chemokines may reduce the chemoattraction of immune cells to the central nervous system and thus add to the therapeutic effects of interferon beta.

Tumor-infiltrating T-cells are strongly associated with prognosis in colorectal cancer, but the mechanisms governing intratumoral lymphocyte recruitment are unclear. We investigated the clinical relevance and functional contribution of interferon-regulated CXC-chemokines CXCL9, CXCL10, and CXCL11, described as T-cells attractants. Their expression was significantly elevated in tumors as compared to normal colon in 163 patients with colon cancer, represented an independent positive predictor of post-operative survival, and was highly significantly correlated with the presence of tumor-infiltrating cytotoxic CD8+ T-cells and CD4+ TH1-effector cells. The regulation of chemokine expression was investigated in established cell lines and in tissue explants from resected tumor specimen (n=22). All colorectal cancer cell lines tested, as well as stroma or endothelial cells, produced CXC-chemokines in response to cytokine stimulation. Moreover, resected tumor explants could be stimulated to produce CXC-chemokines, even in cases with initially low CXC-levels. Lastly, a causative role of chemokine expression was evaluated with an orthotopic mouse model, based on isogenic rectal CT26 cancer cells, engineered to express CXCL10. The orthotopic model demonstrated a protective and anti-metastatic role of intratumoral CXCL10 expression, mediated mainly by adaptive immunity.

Recently an outbreak that emerged in Wuhan, China in December 2019, spread to the whole world in a short time and killed >1,410,000 people. It was determined that a new type of beta coronavirus called severe acute respiratory disease coronavirus type 2 (SARS-CoV-2) was causative agent of this outbreak and the disease caused by the virus was named as coronavirus disease 19 (COVID19). Despite the information obtained from the viral genome structure, many aspects of the virus-host interactions during infection is still unknown. In this study we aimed to identify SARS-CoV-2 encoded microRNAs and their cellular targets. We applied a computational method to predict miRNAs encoded by SARS-CoV-2 along with their putative targets in humans. Targets of predicted miRNAs were clustered into groups based on their biological processes, molecular function, and cellular compartments using GO and PANTHER. By using KEGG pathway enrichment analysis top pathways were identified. Finally, we have constructed an integrative pathway network analysis with target genes. We identified 40 SARS-CoV-2 miRNAs and their regulated targets. Our analysis showed that targeted genes including NFKB1, NFKBIE, JAK1-2, STAT3-4, STAT5B, STAT6, SOCS1-6, IL2, IL8, IL10, IL17, TGFBR1-2, SMAD2-4, HDAC1-6 and JARID1A-C, JARID2 play important roles in NFKB, JAK/STAT and TGFB signaling pathways as well as cells' epigenetic regulation pathways. Our results may help to understand virus-host interaction and the role of viral miRNAs during SARS-CoV-2 infection. As there is no current drug and effective treatment available for COVID19, it may also help to develop new treatment strategies.

Keywords: ACE-2, angiotensin-converting enzyme 2; AKT1, AKT serine/threonine kinase 1; BCL2, BCL2 apoptosis regulator; CDK1, cyclin dependent kinase 1; CDKL2, cyclin dependent kinase like 2; COVID19, new type corona virus disease; CTNNB1, catenin beta 1; CXCL1, C-X-C motif chemokine ligand 1; CXCL10, C-X-C motif chemokine ligand 10; CXCL11, C-X-C motif chemokine ligand 11; CXCL16, C-X-C motif chemokine ligand 16; CXCL9, C-X-C motif chemokine ligand 9; E2F1, E2F transcription factor 1; EIF4A1, eukaryotic translation initiation factor 4A1; GRB2, growth factor receptor bound protein 2; HDAC1, histone deacetylase 1; HDAC2, histone deacetylase 2; HDAC3, histone deacetylase 3; HIF1A, hypoxia inducible factor 1 subunit alpha; ICTV, International Committee on Taxonomy of Viruses; IFNGR2, interferon gamma receptor 2; IKBKE, inhibitor of nuclear factor kappa B kinase subunit epsilon; IL10, interleukin 10; IL13, interleukin 13; IL15, interleukin 15; IL16, interleukin 16; IL17A, interleukin 17 A; IL2, interleukin 2; IL21, interleukin 21; IL22, interleukin 22; IL24, interleukin 24; IL25, interleukin 25; IL33, interleukin 33; IL5, interleukin 5; IL7, interleukin 7; IL8, interleukin 8; JAK/STAT; JAK1, Janus kinase 1; JAK2, Janus kinase 2; JARID1A, lysine demethylase 5A; JARID1B, lysine demethylase 5B; JARID1C, lysine demethylase 5C; JARID2, Jumonji and AT-rich interaction domain containing 2; KEGG, Kyoto Encyclopedia of Genes and Genomes; MAPK1, mitogen-activated protein kinase 1; MAPK3, mitogen-activated protein kinase 3; MAPK4, mitogen-activated protein kinase 4; MAPK6, mitogen-activated protein kinase 6; MAPK7, mitogen-activated protein kinase 7; NFKB; NFKB1, nuclear factor kappa B subunit 1; NFKBIE, NFKB inhibitor epsilon; NOS3, nitric oxide synthase 3; PANTHER, protein analysis through evolutionary relationships; PIK3CA, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; PTEN, phosphatase and tensin homolog; RB1, RB transcriptional corepressor 1; RHOA, ras homolog family member A; SARS-CoV-2; SARS-CoV-2, severe acute respiratory disease coronavirus type 2; SMAD2, SMAD family member 2; SMAD3, SMAD family member 3; SMAD4, SMAD family member 4; SOCS1, suppressor of cytokine signaling 1; SOCS3, suppressor of cytokine signaling 3; SOCS4, suppressor of cytokine signaling 4; SOCS5, suppressor of cytokine signaling 5; SOCS6, suppressor of cytokine signaling 6; SOS1, SOS Ras/Rac guanine nucleotide exchange factor 1; SP1, Sp1 transcription factor; STAT3, signal transducer and activator of transcription 3; STAT4, signal transducer and activator of transcription 4; STAT5B, signal transducer and activator of transcription 5B; STAT6, signal transducer and activator of transcription 6; SUMO1, small ubiquitin like modifier 1; SUMO2, small ubiquitin like modifier 2; TBP, TATA-box binding protein; TGFB; TGFBR1, transforming growth factor beta receptor 1; TGFBR2, transforming growth factor beta receptor 2; TMPRSS11A, transmembrane serine protease 11A; TMPRSS4, transmembrane serine protease 4; TNFRSF21, TNF receptor superfamily member 21; WHO, World Health Organization; miRNA.

Human rhinoviruses (HRVs) are the commonest cause of the common cold. While HRV is less pathogenic than other respiratory viruses, it is frequently associated with exacerbation of chronic respiratory diseases such as rhinosinusitis and asthma. Nasal epithelial cells are the first sites of viral contact, immune initiation, and airway interconnectivity, but there are limited studies on HRV infection of nasal epithelial cells. Hence, we established a model of HRV infection of in vitro-differentiated human nasal epithelial cells (hNECs) derived from multiple individuals. Through HRV infection of hNECs, we found that HRV mainly targeted ciliated cells and preferentially induced type I and III interferon antiviral pathways. Quantitative polymerase chain reaction analysis of inflammatory genes suggested predominant type 1 immunity signaling and recruitment, with secreted CXCL9, IP-10, CXCL11, and RANTES as likely initiators of airway inflammatory responses. Additionally, we further explored HRV bidirectional release from the hNECs and identified 11 associated genes. Other HRV interactions were also identified through a systematic comparison with influenza A virus infection of hNECs. Overall, this in vitro hNEC HRV infection model provides a platform for repeatable and controlled studies of different individuals, thus providing novel insights into the roles of human nasal epithelium in HRV interaction and immune initiation.

Rectal cancer is a common type of colorectal cancer with high mortality and morbidity. The objective of this study was to identify gene signatures and uncover the potential mechanisms during rectal cancer samples. The gene expression profiles of GSE87211 data set were downloaded from GEO (Gene Expression Omnibus) database. The GSE87211 data set contained 2363 samples, including 203 rectal cancer samples and 160 matched mucosa control samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted, and protein-protein interaction network of differentially expressed genes (DEGs) was performed by Cytoscape. Then, Gene Expression Profiling Interactive Analysis (GEPIA) was applied to get the hub genes expression level and survival analysis between rectum adenocarcinoma (READ) tissues and normal tissues. In total, 846 DEGs were identified, including 402 upregulated genes and 444 downregulated genes. GO analysis showed that upregulated DEGs were enriched in inflammatory response, signal transduction, cell adhesion, immune response, and positive regulation of cell proliferation. KEGG pathway analysis showed that upregulated DEGs were enriched in cytokine-cytokine receptor interaction, Pi3K-Akt signaling pathway, and chemokine signaling pathway. The top 20 hub genes contained IL8, CXCR1, SSTR2, SST, CXCR2, GALR1, GAL, CXCL1, SSTR1, NPY1R, NPY, AGT, PPY, PPBP, CXCL2, CXCL6, CXCL11, CXCL3, GNG4, and GNGT1, and only four genes significantly increased expression levels with obvious changes of survival analysis in READ tissues based on GEPIA. Our study indicated that identified DEGs might promote our understanding of molecular mechanisms, which might be used as molecular targets or diagnostic biomarkers for the treatment of rectal cancer.

CXCR3 is a chemokine receptor with three ligands; CXCL9, CXCL10, and CXCL11. CXCL11 binds CXCR3 with a higher affinity than the other ligands leading to receptor internalization. Long ago we reported that one of these chemokines, CXCL10, not only attracts CXCR3+ CD4+ and CD8+ effector T cells to sites of inflammation, but also direct their polarization into highly potent effector T cells. Later we showed that CXCL11 directs the linage development of T-regulatory-1 cells (Tr1). We also observed that CXCL11 and CXCL10 induce different signaling cascades via CXCR3. Collectively this suggests that CXCR3 ligands differentially regulate the biological function of T cells via biased signaling. It is generally accepted that tumor cells evolved to express several chemokine receptors and secrete their ligands. Vast majority of these chemokines support tumor growth by different mechanisms that are discussed. We suggest that CXCL10 and possibly CXCL9 differ from other chemokines by their ability to restrain tumor growth and enhance anti-tumor immunity. Along with this an accumulating number of studies showed in various human cancers a clear association between poor prognosis and low expression of CXCL10 at tumor sites, and vice versa. Finally, we discuss the possibility that CXCL9 and CXCL10 may differ in their biological function via biased signaling and its possible relevance to cancer immunotherapy. The current mini review focuses on exploring the role of CXCR3 ligands in directing the biological properties of CD4+ and CD8+ T cells in the context of cancer and autoimmunity. We believe that the combined role of these chemokines in attracting T cells and also directing their biological properties makes them key drivers of immune function.

Keywords: CXCL10; CXCL9; CXCR3; EAE; cancer; chemokines; tolerance.

Platelet-derived SDF-1α (stromal cell derived factor-α) mediates inflammation, immune defence and repair mechanisms at site of tissue injury. This review summarizes the relative expression of CXC chemokine receptor 4 (CXCR4) and CXCR7 in platelets, their dynamic trafficking in presence of ligands like chemokine C-X-C-motif ligand 11 (CXCL11), CXCL12 and MIF (macrophage migration inhibitory factor); how these receptors differentially mediate the functional and survival response to the chemokines CXCL11, CXCL12 and MIF. We further elaborate and emphasize the prognostic significance of platelet surface expression of CXCR4-CXCR7 in the context of coronary artery disease (CAD). SDF-1α/CXCL12, CXCL11, MIF effects mediated through CXCR4 and CXCR7 may play a regulatory role at the site of vascular and tissue inflammation, immune defence and repair where activated platelets reach as forerunners and function as critical players.

Bacteremic pneumonia with some pneumococcal capsular serotypes, including serotype 3 (ST3), has been associated with a higher risk of death, whereas others, such as ST8, are associated with a lower risk. To provide a molecular basis for understanding such differences, we used oligo cDNA microarrays to analyze and compare the gene expression profiles of the lungs of Balb/c mice infected intranasally with either ST3, strain A66.1, or ST8, strain ATCC 6308 (6308). Compared to uninfected controls, infection with either A66.1 or 6308 led to inoculum-dependent expression of IFN-γ inducible CXC chemokines among other pro-inflammatory genes. To investigate the role that IFN-γ inducible chemokines CXCL9, CXCL10 and CXCL11 play in A66.1- and 6308-induced pneumonia, we examined the effect of the absence of their common receptor, CXCR3, on intranasal infection in CXCR3(-/-) (Balb/c) mice. Compared to wild type (WT) mice, virulence of A66.1 but not 6308 was attenuated in CXCR3(-/-) mice. A66.1-infected CXCR3(-/-) mice had fewer lung neutrophils and more alveolar macrophages 48 h after infection and fewer blood CFU 72 h after infection. Histopathological examination of lung sections revealed less inflammation among A66.1-infected CXCR3(-/-) than WT mice. The reduced virulence of A66.1 in CXCR3(-/-) mice suggests that inhibition of the functional activity of IFN-γ inducible chemokines modulates the host response to A66.1, in turn suggesting a novel approach to improve vaccine-mediated protection against ST3 pneumonia.

To decipher early promoters of the local microenvironment for Th2-type immunity, we wanted to identify gene patterns that were induced by Leishmania major in the infected skin of susceptible, Th2-prone BALB/c, but not of resistant, Th1-prone C57BL/6 mice. We found a marked up-regulation of the chemokine I-TAC (Cxcl11) during the first 2 d of infection in the epidermis of susceptible but not of resistant mice. Accordingly, local injection of I-TAC (2×1 μg) in resistant mice on the first day of infection resulted in a Th2-driven, sustained deterioration of disease and dramatically enhanced parasite levels. On the cellular level, I-TAC decreased IL-12 production by dendritic cells (DCs) in skin-draining lymph nodes and by DCs in vitro. Thus, we demonstrate for the first time that epidermis-derived I-TAC triggers a sustained Th2-response that determines the outcome of a complex immunological process.

Accumulating evidence suggests that metabolic master regulators, including mTOR, regulate adaptive and innate immune responses. Resident mesenchymal tissue components are increasingly recognized as key effector cells in inflammation. Whether mTOR also controls the inflammatory response in fibroblasts is insufficiently studied. Here, we show that TNF signaling co-opts the mTOR pathway to shift synovial fibroblast (FLS) inflammation toward an IFN response. mTOR pathway activation is associated with decreased NF-κB-mediated gene expression (e.g., PTGS2, IL-6, and IL-8) but increased STAT1-dependent gene expression (e.g., CXCL11 and TNFSF13B). We further demonstrate how metabolic inputs, such as amino acids, impinge on TNF-mTORC1 signaling to differentially regulate pro-inflammatory signaling circuits. Our results define a critical role for mTOR in the regulation of the pro-inflammatory response in FLSs and unfold its pathogenic involvement in TNF-driven diseases, such as rheumatoid arthritis (RA).

The CXC chemokines, monokine induced by interferon (IFN)-gamma (MIG) (CXCL9), IFN-gamma-induced protein 10 (IP-10) (CXCL10) and IFN-inducible T cell alpha chemoattractant (I-TAC) (CXCL11), are known to attract CXCR3- (CXCR3A and CXCR3B) T lymphocytes. We investigated MIG, IP-10 and I-TAC mRNAs expression by semi-quantitative multiplex reverse transcription-polymerase chain reaction (RT-PCR) in liver biopsies obtained from patients with a first diagnosis of primary biliary cirrhosis [(PBC) = 20] compared to patients with normal liver biopsy [normal controls (NCs) = 20]. Chemokine production was assessed by enzyme-linked immunosorbent assay (ELISA) in serum. Measurements were repeated 6 months after ursodeoxycholic acid (UDCA) treatment in PBC patients. CXCR3A and CXCR3B mRNAs expression was examined in immunomagnetically sorted CD3(+) peripheral blood lymphocytes (PBL) pre- and post-treatment by RT-PCR. Flow cytometry was used to evaluate the expression of CXCR3(+) PBLs of NCs and PBC patients. A marked mRNA expression of MIG and IP-10 was found in PBC patients. I-TAC mRNA was not detected. In serum of PBC patients there was a significant increase of MIG and IP-10 compared to NCs. Interestingly, there was a significant reduction of these proteins in patients' serum after UDCA treatment. I-TAC was not statistically different between groups. CXCR3A mRNA expression was found in PBLs from PBC patients as well as in NCs. CXCR3B mRNA was expressed in four of 20 (19%) NCs and 20 of 20 PBC patients. Flow cytometry revealed a significantly lower CXCR3 expression in NCs (13·5%) than in PBC (37·2%), which was reduced (28·1%, P < 0·01) after UDCA administration. These data suggest a possible role for CXCR3-binding chemokines and their receptor in the aetiopathogenetic recruitment of lymphocytes in PBC and a new mechanism of action for UDCA.

BACKGROUND

Regulatory T cells (Tregs) effectively ameliorate graft-versus-host disease (GVHD). The mechanisms underlying Treg therapeutic effect on GVHD are not fully elucidated. This study investigates whether Treg prevention of GVH tissue damage is associated with blocking CD8 effector T-cell tissue invasion, a question not yet addressed in humans.

METHODS

Tissue-infiltrating T cells and histopathology scores were detected using an in vitro human GVHD skin explant model, together with immunohistochemistry, cytometric bead array, functional adhesion and migration assays, flow cytometry, and quantitative real-time polymerase chain reaction.

RESULTS

Treg intervention during priming significantly decreased effector T-cell infiltration into target tissue (P<0.01) resulting in a striking reduction in the histopathology score of tissue injury (P<0.0001). These results were coupled with reduced CXCR3 and cutaneous lymphocyte antigen expression by effector T cells, together with decreased CXCL10 and CXCL11 expression in target tissue. Treg intervention also impaired the functional interaction of CXCR3 and cutaneous lymphocyte antigen with their specific ligands (P<0.01) and suppressed the secretion of CXCL9, CXCL10, and interferon-γ (P<0.01, P<0.05, and P<0.001, respectively). Late addition of Tregs into the effector phase abolished their ability to suppress effector T-cell tissue invasion, resulting in a total loss of their ability to ameliorate GVH tissue damage.

CONCLUSIONS

Preventing effector T-cell tissue invasion is a critical mechanistic event leading to Treg attenuation of GVH tissue damage. This therapeutic effect is associated with a failure of CD8 T cells to increase tissue homing receptors after allo-stimulation, together with a breakdown of interferon-γ-induced chemoattractant expression in the target tissue.

OBJECTIVE

Chemokines are small soluble molecules which mediate leukocyte migration and may be involved in the pathophysiology of preterm labor. We aimed to determine if serum concentrations of selected chemokines are changed in preterm labor and delivery.

METHODS

A novel array-based enzyme-linked immunosorbent assay was used to quantitate serum levels of nine chemokines from a single sample: MDC/CCL22, TARC/CCL17, ITAC/CXCL11, I-309/CCL1, IP-10/CXCL10, MIP-1alpha/CCL3, -1beta/CCL4, -3alpha/CCL20 and -3beta/CCL19. Women in preterm labor who delivered (n = 17), women at preterm pregnancy not in labor (n = 13) and women in labor at term (n = 8) participated.

RESULTS

In the preterm delivery group of patients, the MIP-3beta/CCL19 concentration was in mean (+/-S.D.) 70.4+/-31.7 pg/mL, which was significantly lower than that in preterm gravidas not in labor of 123+/-34 pg/mL (p < 0.001) and those in labor at term of 118+/-25.6 pg/mL (p < 0.01). The other measured chemokines did not differ significantly.

CONCLUSIONS

Of a small number of examined chemokines, we were able to show that one of them, MIP-3beta/CCL19 was significantly lower in women with preterm labor and delivery. Whether or not this chemokine has a potential as biochemical marker of preterm delivery remains to be determined.

BACKGROUND

Chemokine (C-X-C motif) ligand (CXCL)9 and CXCL11 play an important role in the initial phases of autoimmune thyroiditis (AT); however, their serum levels in patients with Graves' disease (GD) have never been evaluated in relation to thyroid function and treatment.

METHODS

To evaluate CXCL9 and CXCL11 serum levels in GD and to relate these parameters to the clinical phenotype, we measured CXCL9 and CXCL11 serum levels in 91 GD patients; 91 AT, 34 nontoxic multinodular goiters (MNGs), 31 toxic nodular goiters (TNGs), respectively; and 91 healthy controls (age- and sex-matched).

RESULTS

Mean CXCL9 and CXCL11 levels were higher in GD in comparison with controls, euthyroid AT, MNG, or TNG (p < 0.05, ANOVA; CXCL9: 274 ± 265, 76 ± 33, 132 ± 78, 87 ± 48, and 112 ± 56 pg/mL; CXCL11: 140 ± 92, 64 ± 20, 108 ± 48, 76 ± 33, 91 ± 41 pg/mL, respectively). Hyperthyroid GD patients had significantly higher CXCL9 or CXCL11 than euthyroid or hypothyroid GD patients. GD patients with untreated hyperthyroidism had higher CXCL9 or CXCL11 than hyperthyroid or euthyroid GD patients under methimazole (MMI) treatment. Comparable CXCL9 and CXCL11 levels were observed in newly diagnosed untreated hyperthyroid GD versus untreated patients with relapse of hyperthyroidism after a previous MMI course.

CONCLUSIONS

Serum CXCL9 and CXCL11 levels are associated with the active phase of GD both in newly diagnosed and relapsing hyperthyroid patients. The reduction of serum CXCL9 and CXCL11 levels in treated patients with GD may be related to the immunomodulatory effects of MMI.

Variation between inbred mice of susceptibility to experimental Trypanosoma cruzi infection has frequently been described, but the immunogenetic background is poorly understood. The outcross of the susceptible parental mouse strains C57BL/6 (B6) and DBA/2 (D2), B6D2F1 (F1) mice, is highly resistant to this parasite. In the present study we show by quantitative PCR that the increase of tissue parasitism during the early phase of infection is comparable up to day 11 between susceptible B6 and resistant F1 mice. A reduction of splenic parasite burdens occurs thereafter in both strains but is comparatively retarded in susceptible mice. Splenic microarchitecture is progressively disrupted with loss of follicles and B lymphocytes in B6 mice, but not in F1 mice. By genotyping of additional backcross offspring we corroborate our earlier findings that susceptibility maps to three loci on Chromosomes 5, 13 and 17. Analysis of gene expression of spleen cells from infected B6 and F1 mice with microarrays identifies about 0.3% of transcripts that are differentially expressed. Assuming that differential susceptibility is mediated by altered gene expression, we propose that the following differentially expressed transcripts from these loci are strong candidates for the observed phenotypic variation: H2-Ealpha, H2-D1, Ng23, Msh5 and Tubb5 from Chromosome 17; and Cxcl11, Bmp2k and Spp1 from Chromosome 5. Our results indicate that innate mechanisms are not of primary relevance to resistance of F1 mice to T. cruzi infection, and that differential susceptibility to experimental infection with this protozoan pathogen is not paralleled by extensive variation of the transcriptome.

This review presents a hypothetical model of the development of a venous leg ulcer. The primary pathology is venous hypertension that leads to increased capillary permeability, resulting in extravasation of erythrocytes. Macrophages produce proinflammatory cytokines, which enhance the expression of adhesion molecules in the endothelium of postcapillary venules and increase the recruitment of leukocytes to the pericapillary interstitium. Extravasated T lymphocytes stimulated by cytokines, which are produced by activated macrophages, differentiate toward the Th1 phenotype. In the case of excessive extracapillary passage of erythrocytes or impaired transport of ferric ions by macrophages, the accumulation of iron in the dermis can occur. In tissues with a high concentration of iron, T lymphocytes proliferate instead of undergoing apoptosis. This is possible due to the internalization of the INF-gR2 chain of the interferon-g receptor, the downregulation of inducible nitric oxide synthase expression in macrophages and the inactivation of the active site of caspases. Stimulated by interferon-g skin keratinocytes produce chemokines: CXCL9, CXCL10 and CXCL11, which attract T lymphocytes. Finally, positive feedback loops develop resulting in the migration of T lymphocytes toward the epidermis and in high local concentrations of interferon-g and keratinocyte-derived chemokines. T lymphocytes invading epidermis produce interferon-g and Fas ligand. High concentrations of interferon-g result in the overexpression of Fas by keratinocytes. Matrix metalloproteinases shed Fas ligand from T lymphocytes. The combined effect of Fas ligand and interferon-g on Fas-overexpressing keratinocytes results in their abundant apoptosis and dermo-epidermal detachment, which is clinically manifested as blister-like lesions that progress to chronic ulcerations.