The primary role in biologic activity of the neutrophil chemokines IL-8 and GRO-alpha in cultured nasal epithelial cells

CXCL3: A key player in tumor microenvironment and inflammatory diseases

CXCL3 (C-X-C Motif Chemokine 3), a member of the C-X-C chemokine subfamily, operates as a potent chemoattractant for neutrophils, thereby orchestrating the recruitment and migration of leukocytes alongside eliciting an inflammatory response. Recent inquiries have shed light on the pivotal roles of CXCL3 in the context of carcinogenesis. In the tumor microenvironment, CXCL3 emanating from both tumor and stromal cells intricately modulates cellular behaviors through autocrine and paracrine actions, primarily via interaction with its receptor CXCR2. Activation of signaling cascades such as ERK/MAPK, AKT, and JAK2/STAT3 underscores CXCL3's propensity to favor tumorigenic processes. However, CXCL3 exhibits dualistic behaviors, as evidenced by its capacity to exert anti-tumor effects under specific conditions. Additionally, the involvement of CXCL3 extends to inflammatory disorders like eclampsia, obesity, and asthma. This review encapsulates the structural attributes, biological functionalities, and molecular underpinnings of CXCL3 across both tumorigenesis and inflammatory diseases.

A cohort-based study of host gene expression: tumor suppressor and innate immune/inflammatory pathways associated with the HIV reservoir size

The major barrier to an HIV cure is the HIV reservoir: latently-infected cells that persist despite effective antiretroviral therapy (ART). There have been few cohort-based studies evaluating host genomic or transcriptomic predictors of the HIV reservoir. We performed host RNA sequencing and HIV reservoir quantification (total DNA [tDNA], unspliced RNA [usRNA], intact DNA) from peripheral CD4+ T cells from 191 ART-suppressed people with HIV (PWH). After adjusting for nadir CD4+ count, timing of ART initiation, and genetic ancestry, we identified two host genes for which higher expression was significantly associated with smaller total DNA viral reservoir size, P3H3 and NBL1, both known tumor suppressor genes. We then identified 17 host genes for which lower expression was associated with higher residual transcription (HIV usRNA). These included novel associations with membrane channel (KCNJ2, GJB2), inflammasome (IL1A, CSF3, TNFAIP5, TNFAIP6, TNFAIP9, CXCL3, CXCL10), and innate immunity (TLR7) genes (FDR-adjusted q<0.05). Gene set enrichment analyses further identified significant associations of HIV usRNA with TLR4/microbial translocation (q = 0.006), IL-1/NRLP3 inflammasome (q = 0.008), and IL-10 (q = 0.037) signaling. Protein validation assays using ELISA and multiplex cytokine assays supported these observed inverse host gene correlations, with P3H3, IL-10, and TNF-α protein associations achieving statistical significance (p<0.05). Plasma IL-10 was also significantly inversely associated with HIV DNA (p = 0.016). HIV intact DNA was not associated with differential host gene expression, although this may have been due to a large number of undetectable values in our study. To our knowledge, this is the largest host transcriptomic study of the HIV reservoir. Our findings suggest that host gene expression may vary in response to the transcriptionally active reservoir and that changes in cellular proliferation genes may influence the size of the HIV reservoir. These findings add important data to the limited host genetic HIV reservoir studies to date.

Differences in expression of tumor suppressor, innate immune, inflammasome, and potassium/gap junction channel host genes significantly predict viral reservoir size during treated HIV infection

The major barrier to an HIV cure is the persistence of infected cells that evade host immune surveillance despite effective antiretroviral therapy (ART). Most prior host genetic HIV studies have focused on identifying DNA polymorphisms (e.g., CCR5Δ32 , MHC class I alleles) associated with viral load among untreated "elite controllers" (~1% of HIV+ individuals who are able to control virus without ART). However, there have been few studies evaluating host genetic predictors of viral control for the majority of people living with HIV (PLWH) on ART. We performed host RNA sequencing and HIV reservoir quantification (total DNA, unspliced RNA, intact DNA) from peripheral CD4+ T cells from 191 HIV+ ART-suppressed non-controllers. Multivariate models included covariates for timing of ART initiation, nadir CD4+ count, age, sex, and ancestry. Lower HIV total DNA (an estimate of the total reservoir) was associated with upregulation of tumor suppressor genes NBL1 (q=0.012) and P3H3 (q=0.012). Higher HIV unspliced RNA (an estimate of residual HIV transcription) was associated with downregulation of several host genes involving inflammasome ( IL1A, CSF3, TNFAIP5, TNFAIP6, TNFAIP9 , CXCL3, CXCL10 ) and innate immune ( TLR7 ) signaling, as well as novel associations with potassium ( KCNJ2 ) and gap junction ( GJB2 ) channels, all q<0.05. Gene set enrichment analyses identified significant associations with TLR4/microbial translocation (q=0.006), IL-1β/NRLP3 inflammasome (q=0.008), and IL-10 (q=0.037) signaling. HIV intact DNA (an estimate of the "replication-competent" reservoir) demonstrated trends with thrombin degradation ( PLGLB1 ) and glucose metabolism ( AGL ) genes, but data were (HIV intact DNA detected in only 42% of participants). Our findings demonstrate that among treated PLWH, that inflammation, innate immune responses, bacterial translocation, and tumor suppression/cell proliferation host signaling play a key role in the maintenance of the HIV reservoir during ART. Further data are needed to validate these findings, including functional genomic studies, and expanded epidemiologic studies in female, non-European cohorts.

Author Summary

Although lifelong HIV antiretroviral therapy (ART) suppresses virus, the major barrier to an HIV cure is the persistence of infected cells that evade host immune surveillance despite effective ART, "the HIV reservoir." HIV eradication strategies have focused on eliminating residual virus to allow for HIV remission, but HIV cure trials to date have thus far failed to show a clinically meaningful reduction in the HIV reservoir. There is an urgent need for a better understanding of the host-viral dynamics during ART suppression to identify potential novel therapeutic targets for HIV cure. This is the first epidemiologic host gene expression study to demonstrate a significant link between HIV reservoir size and several well-known immunologic pathways (e.g., IL-1β, TLR7, TNF-α signaling pathways), as well as novel associations with potassium and gap junction channels (Kir2.1, connexin 26). Further data are needed to validate these findings, including functional genomic studies and expanded epidemiologic studies in female, non-European cohorts.

Increased Supply of Methionine During a Heat-Stress Challenge in Lactating Holstein Cows Alters Mammary Tissue mTOR Signaling and its Response to Lipopolysaccharide

The first objective was to investigate the effects of feeding rumen-protected methionine (RPM) during a heat stress (HS) challenge on abundance and phosphorylation of mechanistic target of rapamycin (mTOR)-related signaling proteins in mammary gland. The second objective was to investigate how HS and RPM may modulate the response of mammary gland explants to lipopolysaccharide (LPS) stimulation. Thirty-two multiparous, lactating Holstein cows (184 ± 59 DIM) were randomly assigned to 1 of 2 environmental treatment groups, and 1 of 2 dietary treatments [TMR with RPM (Smartamine M; Adisseo Inc.; 0.105% DM as top dress) or TMR without RPM (CON)] in a crossover design. There were 2 periods with 2 phases per period. In phase 1 (9 d), all cows were in thermoneutral conditions (TN) and fed ad libitum. During phase 2 (9 d), group 1 (n = 16) was exposed to HS using electric heat blankets while group 2 (n = 16) remained in TN but were pair-fed to HS counterparts to control for DMI decreases associated with HS. After a washout period (14 d), the study was repeated (period 2). Environmental treatments were inverted in period 2 (sequence), while dietary treatments remained the same. Mammary tissue was harvested via biopsy at the end of both periods. Tissue was used for protein abundance analysis and also for incubation with 0 or 3 μg/mL of LPS for 2 h and subsequently used for mRNA abundance. Data were analyzed using PROC MIXED in SAS. Analysis of protein abundance data included the effects of diet, environment and their interaction, and period and sequence to account for the crossover design. The explant data model also included the effect of LPS and its interaction with environment and diet. Abundance of phosphorylated mTOR and ratio of phosphorylated eukaryotic translation elongation factor 2 (p-EEF2) to total EEF2 in non-challenged tissue was greater with RPM supplementation (P = 0.04 for both) and in both cases tended to be greater with HS (P = 0.08 for both). Regardless of RPM supplementation, incubation with LPS upregulated mRNA abundance of IL8, IL6, IL1B, CXCL2, TNF, NFKB1 and TLR2 (P < 0.05). An environment × LPS interaction was observed for NFKB1 (P = 0.03); abundance was greater in LPS-treated explants from non-HS compared with HS cows. Abundance of CXCL2, NFKB1, NOS2, NOS1, and SOD2 was lower with HS (P < 0.05). While LPS did not alter abundance of mRNA associated with the antioxidant transcription factor NFE2L2 signaling (P = 0.59), explants from HS cows had lower abundance of NFE2L2 (P < 0.001) and CUL3 (P = 0.04). Overall, RPM supplementation may alter mTOR activation. Additionally, while HS reduced explant immune and antioxidant responses, RPM did not attenuate the inflammatory response induced by LPS in vitro.

Active bacterial modification of the host environment through RNA polymerase II inhibition

Unlike pathogens, which attack the host, commensal bacteria create a state of friendly coexistence. Here, we identified a mechanism of bacterial adaptation to the host niche, where they reside. Asymptomatic carrier strains were shown to inhibit RNA polymerase II (Pol II) in host cells by targeting Ser2 phosphorylation, a step required for productive mRNA elongation. Assisted by a rare, spontaneous loss-of-function mutant from a human carrier, the bacterial NlpD protein was identified as a Pol II inhibitor. After internalization by host cells, NlpD was shown to target constituents of the Pol II phosphorylation complex (RPB1 and PAF1C), attenuating host gene expression. Therapeutic efficacy of a recombinant NlpD protein was demonstrated in a urinary tract infection model, by reduced tissue pathology, accelerated bacterial clearance, and attenuated Pol II-dependent gene expression. The findings suggest an intriguing, evolutionarily conserved mechanism for bacterial modulation of host gene expression, with a remarkable therapeutic potential.

CXCL3 Signaling in the Tumor Microenvironment

Cancer progression is driven, to a large extent, by the action of immune cells that have been recruited to tumor sites through interactions between chemokines and their receptors. Chemokines of the CXC subfamily are secreted by both tumor and non-tumor cells within the microenvironment of the tumor, where they induce either antitumor or protumor activity that fosters either clearance or progression of the tumor, respectively. Understanding the nature of these interactions is important to envisage novel approaches targeting the essential components of the tumor microenvironment, increasing the odds for favorable patient outcomes. In this chapter we describe the involvement of the chemokine (C-X-C motif) ligand 3 (CXCL3) in the human tumor microenvironment and its effects on immune and non-immune cells. Because of the limited data on the CXCL3 signaling in the tumor microenvironment, we extend the review to other members of the CXC subfamily of chemokines. This review also addresses the future trends or directions for therapeutic interventions that target signaling pathways used by these molecules in the tumor microenvironment.

Characterization of mucosal cytokine profile in ulcerative colitis patients under conventional and anti-TNF-a treatment

OBJECTIVES

Cytokines play a pivotal role in inflammatory bowel disease (IBD). We investigated the expression of inflammatory and regulatory cytokines in inflamed and uninflamed mucosal samples of ulcerative colitis patients.

METHODS

Twenty-five ulcerative colitis patients were enrolled. Bioptic samples from inflamed and not inflamed intestinal areas were obtained. Multiplex analysis for inflammatory and regulatory cytokines was performed. Serum C-reactive protein (CRP) was assessed. Endoscopic Mayo score and histological simplified Geboes score were calculated.

RESULTS

Interleukin (IL)-1Ra, IL-6, IL-8, IL-17, induced Protein (IP)-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1a, MIP-1b resulted increased in ulcerative colitis inflamed vs ulcerative colitis not inflamed areas. No differences were registered between conventional and anti-tumor necrosis factor-a regimens. No difference with CRP levels was found. IL-7 resulted reduced in patients with endoscopic Mayo score ≥2. All the not inflamed samples had a Geboes score <2A, while all the inflamed specimens had a Geboes score ≥2B. IL-1Ra resulted increased in the group with a Geboes score ≥4.

CONCLUSIONS

Inflamed and adjacent not inflamed mucosal areas in ulcerative colitis patients share detailed inflammatory molecular pathways, but can be differentiated endoscopically and histologically on the basis of specific cytokines levels. This underlines the complexity of the mucosal cytokine network in ulcerative colitis and highlights the major limitations of a single proinflammatory target therapeutic strategy in IBD.

Enhancing responsiveness of human jejunal enteroids to host and microbial stimuli

KEY POINTS

Enteroids are a physiologically relevant model to examine the human intestine and its functions. Previously, the measurable cytokine response of human intestinal enteroids has been limited following exposure to host or microbial pro-inflammatory stimuli. Modifications to enteroid culture conditions facilitated robust human cytokine responses to pro-inflammatory stimuli. This new human enteroid culture methodology refines the ability to study microbiome:human intestinal epithelium interactions in the laboratory.

ABSTRACT

The intestinal epithelium is the primary interface between the host, the gut microbiome and its external environment. Since the intestinal epithelium contributes to innate immunity as a first line of defence, understanding how the epithelium responds to microbial and host stimuli is an important consideration in promoting homeostasis. Human intestinal enteroids (HIEs) are primary epithelial cell cultures that can provide insights into the biology of the intestinal epithelium and innate immune responses. One potential limitation of using HIEs for innate immune studies is the relative lack of responsiveness to factors that stimulate epithelial cytokine production. We report technical refinements, including removal of extracellular antioxidants, to facilitate enhanced cytokine responses in HIEs. Using this new method, we demonstrate that HIEs have distinct cytokine profiles in response to pro-inflammatory stimuli derived from host and microbial sources. Overall, we found that host-derived cytokines tumour necrosis factor and interleukin-1α stimulated reactive oxygen species and a large repertoire of cytokines. In contrast, microbial lipopolysaccharide, lipoteichoic acid and flagellin stimulated a limited number of cytokines and histamine did not stimulate the release of any cytokines. Importantly, HIE-secreted cytokines were functionally active, as denoted by the ability of human blood-derived neutrophil to migrate towards HIE supernatant containing interleukin-8. These findings establish that the immune responsiveness of HIEs depends on medium composition and stimuli. By refining the experimental culture medium and creating an environment conducive to epithelial cytokine responses by human enteroids, HIEs can facilitate exploration of many experimental questions pertaining to the role of the intestinal epithelium in innate immunity.

Distinct cachexia profiles in response to human pancreatic tumours in mouse limb and respiratory muscle

BACKGROUND

Cancer cachexia is a life-threatening metabolic syndrome that causes significant loss of skeletal muscle mass and significantly increases mortality in cancer patients. Currently, there is an urgent need for better understanding of the molecular pathophysiology of this disease so that effective therapies can be developed. The majority of pre-clinical studies evaluating skeletal muscle's response to cancer have focused on one or two pre-clinical models, and almost all have focused specifically on limb muscles. In the current study, we reveal key differences in the histology and transcriptomic signatures of a limb muscle and a respiratory muscle in orthotopic pancreatic cancer patient-derived xenograft (PDX) mice.

METHODS

To create four cohorts of PDX mice evaluated in this study, tumours resected from four pancreatic ductal adenocarcinoma patients were portioned and attached to the pancreas of immunodeficient NSG mice.

RESULTS

Body weight, muscle mass, and fat mass were significantly decreased in each PDX line. Histological assessment of cryosections taken from the tibialis anterior (TA) and diaphragm (DIA) revealed differential effects of tumour burden on their morphology. Subsequent genome-wide microarray analysis on TA and DIA also revealed key differences between their transcriptomes in response to cancer. Genes up-regulated in the DIA were enriched for extracellular matrix protein-encoding genes and genes related to the inflammatory response, while down-regulated genes were enriched for mitochondria related protein-encoding genes. Conversely, the TA showed up-regulation of canonical atrophy-associated pathways such as ubiquitin-mediated protein degradation and apoptosis, and down-regulation of genes encoding extracellular matrix proteins.

CONCLUSIONS

These data suggest that distinct biological processes may account for wasting in different skeletal muscles in response to the same tumour burden. Further investigation into these differences will be critical for the future development of effective clinical strategies to counter cancer cachexia.

Predictive markers of long-term recurrence in chronic rhinosinusitis with nasal polyps

BACKGROUND

In last years, many attempts were made to recognize chronic rhinosinusitis with nasal polyps (CRSwNP) phenotypes focusing on identifying relevant key pathogenic molecules. Polyps recurrence rate ranges from 4% to 60%, so it's clear that not all clinical and immunologic factors associated with recurrence are known.

OBJECTIVE

We investigate the inflammatory profile in patients with long term recurrent and non-recurrent CRSwNPs and if a specific profile is associated with recurrence, comparing eosinophilic, neutrophilic and lymphocytic infiltration, as well as IL-5 and IL-8 expression to long term recurrence rate.

METHODS

This prospective study included 44 adult patients with CRSwNP treated with endoscopic sinus surgery between 2008 and 2010. Long term follow-up data (8-10 years) indicated that among 44 patients, 18 (40.1%) experienced long term recurrence of nasal polyposis needing maximal medical treatment or revision surgery. We realized two groups: one with patients who didn't present long term recurrence (26 patients) and another with patients who presented long term recurrence (18 patients) and in both groups eosinophilic, neutrophilic and lymphocytic infiltration and IL-5 and IL-8 expression were measured.

RESULTS

The parameters that reached statistical significance (p < 0.05) comparing the two groups were eosinophilic infiltration and IL-5 expression, whereas neutrophilic and lymphocytic infiltration, as IL-8 expression didn't show any significant difference. Asthma and aspirin intolerance seemed significantly more frequent in patients with recurrence, while allergy presented not statistically significant difference between two groups.

CONCLUSIONS

We can conclude that high eosinophilic infiltration and high IL-5 expression in CRSwNP correlate with higher rate of long term recurrence, while neutrophilic and lymphocytic infiltration, and IL-8 expression don't correlate with it. These findings provide the opportunity to improve our ability to predict the prognosis of surgical intervention, although it is still needed to explore the optimal predictor of outcome in CRSwNP.

Obesity and Type 2 Diabetes mellitus induce lipopolysaccharide tolerance in rat neutrophils

Obesity and diabetes implicate in various health complications and increased mortality caused by infection. Innate immune system is broadly affected by these diseases, leading the patients to an immunosuppressive state. A mechanism that leads innate immune cells to a less capacity of killing microorganism is the impaired TLR4 activation. TLR4 recognizes a component of the outer membrane of Gram-negative bacteria, lipopolysaccharide (LPS), and when activated increases the production of inflammatory substances. Neutrophils are components of the innate immune system and are the first responders to an invading agent. The correct activation of TLR4 in these cells is required for the initiation of the inflammatory process and elimination of the microorganisms. The aim of this study was to evaluate the influence of type 2 diabetes and obesity in the TLR4 pathway in rat neutrophils. Two experimental models were used: Goto-Kakizaki rats and high-fat-diet induced obese Wistar rats. To evaluate neutrophil response to LPS, intratracheal LPS instillation was used. Neutrophils from obese and diabetic animals exhibited tolerance to LPS, mainly by the impaired production of cytokines and chemokines and the low content of phospho-NFκB and phospho-IKBα. Neutrophils from both experimental models had increased cell death, impaired in vivo migration and myeloperoxidase activity.

Activation of GPR30 stimulates GTP-binding of Gαi1 protein to sustain activation of Erk1/2 in inhibition of prostate cancer cell growth and modulates metastatic properties

Previously, we reported that GPR30 activation by the receptor-specific, non-estrogenic ligand G-1 inhibited in vitro and in vivo growth of prostate cancer (PCa) cells via sustained Erk1/2 activation. Mechanism underlying the sustained Erk1/2 activation for PCa cell growth inhibition remains unclear. Here we report that G-1, through GPR30, activated Gαi1 proteins to sustain Erk1/2 activation but failed to activate adenylyl cyclase (AC) for cAMP production in PCa cells. The chemical-induced activation of AC-cAMP-PKA signaling attenuated Erk1/2 activity and blocked the cell growth inhibitory effects of G-1. Furthermore, PCa predominantly expressed Gαi1 proteins. Silencing of Gαi1 expression blocked the inhibitory effects of G-1 on PCa cell growth. By gene expression profiling, GPR30 activation by G-1 interfered expression of cell cycle regulators and machinery elements to modulate PCa cell growth and the RACGAP1 interactome to control metastatic properties. In this regard, we demonstrated that G-1 inhibited PCa cell migration and invasion with reduced formations of filopodia and stress fibers through a GPR30-dependent pathway. Taken together, our findings revealed the underlying mechanism for sustaining Erk1/2 activation upon GPR30 activation by G-1 in PCa cells and the GPR30-mediated pathways in controlling PCa cell growth and metastatic properties.

Expression Profile of Immune-Associated Genes in Nasal Polyps

Objectives:

We performed this study to investigate the expression profile of immune-associated genes and to probe the role of related genes in the immune pathogenesis of nasal polyps.

Methods:

Microarray analysis was used to find the expression profile of 491 immune-associated genes in nasal polyps. In validation studies, immunohistochemical staining and Western blot analysis were used to detect interleukin (IL)–17 and IL-17 receptor (IL-17R) in nasal polyps and controls.

Results:

Eighty-seven genes were differentially expressed in the immune-associated gene profile of nasal polyps, and 15 genes showed differential expression in both chips. In nasal polyp tissues, IL-17 was expressed mainly in the cytoplasm of plasma cells and to a lesser degree in the prickle cell layer of the epithelium and the acinus of the serous gland. In turbinates, IL-17 was also expressed in the same location, but the expression of IL-17 in nasal polyps and that in turbinates differed significantly (p > .05). Both IL-17 and IL-17R displayed specific bands in nasal polyps and turbinates, but the bands of IL-17 and IL-17R in nasal polyps were stronger than those in turbinates.

Conclusions:

The differentially expressed genes in immune-associated gene chips will provide clues about, and a theoretical foundation for, the pathogenesis of nasal polyps. Furthermore, IL-17 may play an important role in the occurrence of nasal polyps by overexpression.

The NET, the trap and the pathogen: neutrophil extracellular traps in cutaneous immunity

Neutrophil extracellular traps (NETs), large chromatin structures casted with various proteins, are externalized by neutrophils upon induction by both self- and non-self-stimuli. It has become clear that NETs are potent triggers of inflammation in autoimmune skin diseases. Moreover, the ability of NETs to trap pathogens suggests a crucial role in innate host defense. However, the outcome of the encounter between pathogens and NETs remains highly controversial. Here, we discuss recent insights into the morphology and formation of NETs, their role in skin inflammation and how NETs might contribute to host protection in skin infection.

Characterization of Serum Cytokine Profile in Predominantly Colonic Inflammatory Bowel Disease to Delineate Ulcerative and Crohn's Colitides

BACKGROUND

As accessible diagnostic approaches fail to differentiate between ulcerative colitis (UC) and Crohn’s colitis (CC) in one-third of patients with predominantly colonic inflammatory bowel disease (IBD), leading to inappropriate therapy, we aim to investigate the serum cytokine levels in these patients in search of molecular biometric markers delineating UC from CC.

METHODS

We measured 38 cytokines, chemokines, and growth factors using magnetic-bead-based multiplex immunoassay in 25 UC patients, 28 CC patients, and 30 controls. Our results are compared with those from a review of current literature regarding advances in serum cytokine profiles and associated challenges preventing their use for diagnostic/prognostic purposes.

RESULTS

Univariate analysis showed statistically significant increases of eotaxin, GRO, and TNF-α in UC patients compared to controls (Ctrl); interferon γ, interleukin (IL)-6, and IL-7 in CC group compared to Ctrl; and IL-8 in both UC and CC versus Ctrl. No cytokines were found to be different between UC and CC. A generalized linear model identified combinations of cytokines, allowing the identification of UC and CC patients, with area under the curve (AUC) = 0.936, as determined with receiver operating characteristic (ROC) analysis.

CONCLUSIONS

The current knowledge available about circulating cytokines in IBD is often contradictory. The development of an evidence-based tool using cytokines for diagnostic accuracy is still preliminary.

Effects of IL-17 on expression of GRO-α and IL-8 in fibroblasts from nasal polyps

Recent studies indicated that interleukin (IL)-17, growth-related oncogene (GRO)-α and IL-8 play an important role in the pathogenesis of nasal polyps. However, the effects of the increased amount of IL-17 and the production of GRO-α and IL-8 in human nasal polyp fibroblasts are not completely understood. This study aimed to determine the effects of the increased IL-17 on the changes of GRO-α and IL-8 expression in human nasal polyp fibroblasts and further investigate the mechanism of neutrophil infiltration in nasal polyps. Nasal polyp fibroblasts were isolated from six cases of human nasal polyps, and the cells were stimulated with five different concentrations of IL-17. Real-time fluorescence quantitative polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of GRO-α and IL-8. The mRNA of GRO-α and IL-8 was expressed in unstimulated controls and remarkably increased by stimulation with IL-17. Moreover, the levels of GRO-α and IL-8 produced by fibroblasts were increased gradually with the increases in IL-17 concentrations. The present study showed that nasal fibroblasts can produce GRO-α and IL-8, and their production is remarkably enhanced by IL-17 stimulation, thereby clarifying the mechanism of the IL-17 mediated neutrophil infiltration in nasal polyps. These findings might provide a rationale for using IL-17 inhibitors as a treatment for nasal inflammatory diseases such as nasal polyps.

Differential roles of CXCL2 and CXCL3 and their receptors in regulating normal and asthmatic airway smooth muscle cell migration

Structural cell migration plays a central role in the pathophysiology of several diseases, including asthma. Previously, we established that IL-17-induced (CXCL1, CXCL2, and CXCL3) production promoted airway smooth muscle cell (ASMC) migration, and consequently we sought to investigate the molecular mechanism of CXC-induced ASMC migration. Recombinant human CXCL1, CXCL2, and CXCL3 were used to assess migration of human primary ASMCs from normal and asthmatic subjects using a modified Boyden chamber. Neutralizing Abs or small interfering RNA (siRNA) knockdown and pharmacological inhibitors of PI3K, ERK1/2, and p38 MAPK pathways were used to investigate the receptors and the signaling pathways involved in CXC-induced ASMC migration, respectively. We established the ability of CXCL2 and CXCL3, but not CXCL1, to induce ASMC migration at the tested concentrations using normal ASMCs. We found CXCL2-induced ASMC migration to be dependent on p38 MAPK and CXCR2, whereas CXCL3-induced migration was dependent on p38 and ERK1/2 MAPK pathways via CXCR1 and CXCR2. While investigating the effect of CXCL2 and CXCL3 on asthmatic ASMC migration, we found that they induced greater migration of asthmatic ASMCs compared with normal ones. Interestingly, unlike normal ASMCs, CXCL2- and CXCL3-induced asthmatic ASMC migration was mainly mediated by the PI3K pathway through CXCR1. In conclusion, our results establish a new role of CXCR1 in ASMC migration and demonstrate the diverse mechanisms by which CXCL2 and CXCL3 mediate normal and asthmatic ASMC migration, suggesting that they may play a role in the pathogenesis of airway remodeling in asthma.

Autocrine-regulated airway smooth muscle cell migration is dependent on IL-17-induced growth-related oncogenes

BACKGROUND

Airway smooth muscle cell (ASMC) migration is one of the proposed mechanisms underlying the increased airway smooth muscle mass seen in airway remodeling of patients with severe asthma. IL-17-related cytokines are a new subgroup of inflammatory mediators that have been suggested to play a role in regulating smooth muscle function. We hypothesized that IL-17-induced chemokine production from smooth muscle cells can contribute to migration of additional smooth muscle cells in the airways of asthmatic patients.

OBJECTIVE

We sought to investigate the effect of IL-17 on smooth muscle-derived chemokines and to examine the mechanisms involved in their production and contribution to the increase in airway smooth muscle migration.

METHODS

The effect of IL-17-induced supernatants on human ASMC migration was investigated. IL-17-induced growth-related oncogene (GRO) production and mRNA expression was assessed by using ELISA and RT-PCR, respectively. The direct effect of GROs on ASMC migration and the involvement of the CXCR2 receptor were also examined.

RESULTS

IL-17-induced supernatants promoted ASMC migration. After IL-17 stimulation, GROs were the most abundant chemokines produced from ASMCs, and blocking their effect by using neutralizing antibodies significantly inhibited ASMC migration. In addition, a combination of recombinant human GRO-α, GRO-β, and GRO-γ was able to promote significant migration of ASMCs that was mediated through the CXCR2 receptor.

CONCLUSION

These findings suggest that IL-17-induced GROs can be an important mediator of ASMC migration and therefore might contribute to the pathogenesis of airway remodeling in asthmatic patients.

Granulocyte chemotactic protein 2 (gcp-2/cxcl6) complements interleukin-8 in periodontal disease

BACKGROUND AND OBJECTIVE

Mucosal inflammatory responses are orchestrated largely by pro-inflammatory chemokines. The chemokine granulocyte chemotactic protein 2 (CXCL6) is involved in neutrophil recruitment and migration. Previous studies have shown that granulocyte chemotactic protein 2 is up-regulated during mucosal inflammation (e.g. in inflammatory bowel disease), similarly to the functionally and structurally related chemokine interleukin-8. Nevertheless, unlike interleukin-8, a role of granulocyte chemotactic protein 2 in gingival inflammation has not been yet demonstrated. In this study we aimed to evaluate the expression of the chemokine granulocyte chemotactic protein 2 in clinically healthy vs. diseased gingival tissues and to explore possible correlations with clinical and microbiological markers of periodontitis.

MATERIAL AND METHODS

Gene expression in 184 'diseased' and 63 'healthy' gingival tissue specimens from 90 patients with periodontitis was analyzed using Affymetrix U133Plus2.0 arrays. The expression of granulocyte chemotactic protein 2 was further confirmed by real-time reverse transcription-polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay, while the localization of granulocyte chemotactic protein 2 in gingival tissues was analyzed by immunohistochemistry. Plaque samples from the adjacent periodontal pockets were collected and evaluated for 11 species of periodontal bacteria using checkerboard DNA-DNA hybridizations.

RESULTS

Among all known chemokines, GCP-2 expression was the most up-regulated (3.8-fold, p < 1.1 x 10(-16)), in 'diseased' vs. 'healthy' tissue as compared to a 2.6-fold increased expression of interleukin-8 mRNA (p < 1.2 x 10(-15)). Increased expression of granulocyte chemotactic protein 2 correlated with higher levels of 'red' and 'orange' complex pathogens and with increased probing depth, but not with attachment loss. Immunohistochemistry showed that granulocyte chemotactic protein 2 was expressed in gingival vascular endothelium.

CONCLUSION

The level of expression of granulocyte chemotactic protein 2 correlates with the severity of periodontitis and appears to act as a hitherto unrecognized functional adjunct to interleukin-8 in diseased gingival tissues.

Anti-inflammatory effects of ciprofloxacin in S. aureus Newman induced nasal inflammation in vitro

Objectives

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the nasal mucosa. Recent studies suggest that S. aureus enterotoxins may play an etiologic role in the development of CRS. Apart from surgery and repeated courses of steroids, macrolide antibiotics have been reported to exert anti-inflammatory effects in CRS. Similar effects have been reported for fluoroquinolones on various cell types. Since these effects have poorly been characterized in CRS, we examined anti-inflammatory effects of ciprofloxacin on human nasal epithelial cells (HNECs).

Methods

Inflammation was induced in HNECs cultured from nasal turbinate mucosa with supernatants of S. aureus Newman for 12 hours. Subsequently, HNECs were coincubated with S. aureus Newman and ciprofloxacin (1.5 × 10^-5 M), clarithromycin (10^-6 M) or prednisolone (10^-5 M) for another 12 hours. IL-8 synthesis was quantified after 12 and 24 hours by ELISA.

Results

Stimulation with S. aureus Newman supernatants was associated with an increase of IL-8 synthesis after 12 hours in all experiments. During the second 12 hours, IL-8 synthesis decreased and this effect was independent from any stimulus or inhibitor. However, coincubation of HNECs with ciprofloxacin was associated with a more extensive decrease of IL-8 synthesis. Similarly, addition of clarithromycin was associated with a reduction of IL-8 synthesis although this effect was not significant. Coincubation with prednisolone resulted in a significant reduction of IL-8 levels.

Conclusion

Ciprofloxacin exerts anti-inflammatory effects in S. aureus Newman driven nasal inflammation. Inhibitory effects were comparable to those of prednisolone and clarithromycin.

PAR-2 activation regulates IL-8 and GRO-alpha synthesis by NF-kappaB, but not RANTES, IL-6, eotaxin or TARC expression in nasal epithelium

BACKGROUND

The effects of protease-activated receptor-2 (PAR-2) stimulation on inflammation mechanisms of chronic rhinosinusitis (CRS) are still unknown.

METHODS

PAR-2 receptor expression was investigated by immunohistochemistry and Taqman mRNA analysis in the mucosa of different rhinosinusitis entities. In primary nasal epithelial cell cultures, the function of PAR-2 and its ability to produce CXC, CC chemokines, and IL-6 were measured by calcium mobilization and stimulation tests. Inhibition tests were performed using cortisone, serine protease inhibitors, cysteine protease inhibitors, Pertussis toxin (PTX) and nuclear transcription factor (NF-kappaB) inhibition (BAY 11-7085). Signal transduction pathways were analysed by electromobility shift assays (EMSA) and NF-kappaB binding studies.

RESULTS

The expression of PAR-2 was found to be increased in CRS specimens. The activation of PAR by trypsin or PAR-2-specific activating peptide (AP) caused an increase in cytosolic calcium, as well as the release of the CXC chemokines IL-8 and growth-related oncogene (GRO)-alpha, but not the release of CC chemokines or IL-6. AP-induced CXC chemokine was sensitive to PTX and activation of NF-kappaB was inhibited by BAY11-7085. Furthermore, a serine protease inhibitor significantly inhibited chemokine synthesis stimulated by trypsin and culture supernatants of staphylococci, whereas steroids and cysteine protease inhibitors had little effect.

CONCLUSION

PAR-2 plays a role in serine protease-mediated regulation - staphylococcal and non-staphylococcal origin - of IL-8 and GRO-alpha in nasal epithelial cells, but not in the regulation of CC chemokines. PAR-2 may therefore be involved in the pathophysiology of CRS and NP at different sites of activation, namely (i) proteases, (ii) the PAR-2 receptor itself or (iii) the application of novel agents that block NF-kappaB/IkappaB-alpha signalling.

Proinflammatory impact of Staphylococcus epidermidis on the nasal epithelium quantified by IL-8 and GRO-alpha responses in primary human nasal epithelial cells

BACKGROUND

Bacterial etiology of chronic rhinosinusitis (CRS) still remains controversial. Whereas Staphylococcus aureus enterotoxins have been detected in CRS, the impact of Staphylococcus epidermidis, a major commensal inhabitant of the nose, has not been studied. Among others, serine and cysteine proteases have been identified as factors of virulence in S. epidermidis.

METHODS

S. epidermidis was examined in tissue biopsies of 30 CRS patients (16 with nasal polyposis) using standard procedures. Primary human nasal epithelial cells from inferior nasal turbinates (HNECs), from nasal polyps (NPECs) and A549 airway epithelial cells were stimulated with S. epidermidis supernatants DSM20044 or ATCC35984 and the IL-8 and GRO-alpha response was quantified by ELISA. Protease-triggered chemokine responses and involvement of NF-kappaB were investigated by addition of protease or NF-kappaB inhibitors. Activation of NF-kappaB was demonstrated by quantitative DNA binding assay.

RESULTS

S. epidermidis was the most frequently isolated bacteria in the majority of CRS patients. HNECs and NPECs revealed no different IL-6 and IL-8 synthesis following stimulation with DSM20044 or ATCC35984. Stimulation of HNECs and A549 cells with S. epidermidis supernatants resulted in increased IL-8 and GRO-alpha expression which could be suppressed by the serine protease inhibitor AEBSF and the NF-kappaB inhibitor BAY 11 but not by the cysteine protease inhibitor E64. Results obtained for A549 cells were similar to HNECs.

CONCLUSION

S. epidermidis was present in the majority of CRS specimens. Proinflammatory impact of S. epidermidis supernatants on nasal epithelial cells was demonstrated by serine protease-triggered and NF-kappaB-dependent chemokine responses.

Primary role of growth-related oncogene-alpha and granulocyte chemotactic protein-2 as neutrophil chemoattractants in chronic rhinosinusitis

BACKGROUND

The aetiology of chronic rhinosinusitis (CRS) remains unclear. The purpose of this study was to investigate neutrophil-attracting chemokine patterns in CRS without nasal polyposis.

METHODS

The biological activity of the chemokines was identified using a two-step high-performance liquid chromatography (HPLC) technique combined with a bioassay in extracts from 55 CRS patients, and in the turbinate mucosa (TM) of patients (N=51) undergoing septumplasty. The biologic activity of each chemokine was assessed using blocking antibodies to chemokines. Immunolocalization of detected neutrophil chemokines was performed by quantitative evaluation of immunohistochemistry. Besides, PCR analysis was performed to quantify neutrophil chemokine mRNA.

RESULTS

In CRS, the chemokines primarily detected by two-step HPLC were growth-related oncogene-alpha (GRO-alpha) and the granulocyte chemotactic protein-2 (GCP-2). Blocking of GCP-2 and GRO-alphad each resulted in chemotaxis inhibition rates of 43.3% and 35.9%, respectively, whereas anti-IL-8 and anti-ENA-78 had no effect. Both GCP-2 and GRO-alphad were generally synthesized by the surface epithelium and mucosal glands while GRO-alpha in particular was synthesized by endothelial cells, as shown by immunohistochemistry. The concentrations of the chemokines IL-8 and epithelial cell-derived neutrophil attractant-78 (ENA-78) were low in CRS and TM.

CONCLUSION

It appears that both GRO-alpha and GCP-2 contribute to neutrophil chemotaxis in CRS, whereas IL-8 and ENA-78 appear to be of secondary importance for the chemotaxis of neutrophils in this condition. The expression of chemokines in mucosal gland cells is the main phenomenon involved in constitutive neutrophil chemotaxis in the TM.

Probiotic bacteria Bifidobacterium animalis MB5 and Lactobacillus rhamnosus GG protect intestinal Caco-2 cells from the inflammation-associated response induced by enterotoxigenic Escherichia coli K88

Probiotic bacteria may provide protection against intestinal damage induced by pathogens, but the underlying mechanisms are still largely unknown. We investigated whether Bifidobacterium animalis MB5 and Lactobacillus rhamnosus GG (LGG) protected intestinal Caco-2 cells from the inflammation-associated response induced by enterotoxigenic Escherichia coli (ETEC) K88, by inhibiting pathogen attachment to the cells, which is the first step of ETEC pathogenicity, and regulating neutrophil recruitment, a crucial component of inflammation. A partial reduction of ETEC adhesion was exerted by probiotics and their culture supernatant fractions either undigested or digested with proteases. ETEC viability was unaffected by the presence of B. animalis, LGG or their supernatant fractions in the culture medium, indicating an absence of probiotic bactericidal activity. Probiotics and their supernatant fractions, either undigested or digested with proteases, strongly inhibited the neutrophil transmigration caused by ETEC. Both B. animalis and LGG counteracted the pathogen-induced up regulation of IL-8, growth-related oncogene-alpha and epithelial neutrophil-activating peptide-78 gene expression, which are chemokines essential for neutrophil migration. Moreover, the probiotics prevented the ETEC-induced increased expression of IL-1beta and TNF-alpha and decrease of transforming growth factor-alpha, which are regulators of chemokine expression. These results indicate that B. animalis MB5 and LGG protect intestinal cells from the inflammation-associated response caused by ETEC K88 by partly reducing pathogen adhesion and by counteracting neutrophil migration, probably through the regulation of chemokine and cytokine expression.

Divergent roles of murine neutrophil chemokines in hemorrhage induced priming for acute lung injury

Neutrophil associated lung injury is identified with a variety of local and systemic priming insults. In vitro studies have shown that TNF-alpha mediated suppression of neutrophil apoptosis is due to the secretion of interleukin-8 (IL-8), a human chemokine shown to alter neutrophil chemotaxis. Our initial in vitro antibody neutralization studies with neutrophil chemotactic proteins, keratinocyte-derived chemokine (KC) and macrophage inflammatory protein-2alpha (MIP-2alpha), mouse IL-8 homologues, indicate that MIP-2alpha but not KC appears to mediate TNF-alpha suppression of mouse neutrophil apoptosis. Therefore, we hypothesized that in vivo neutralization of KC or MIP-2alpha during an initial priming insult would produce differential effects on the extent of lung injury by restoring normal neutrophil apoptotic function. To assess this, mice were hemorrhaged followed with septic challenge at 24 h. Antibody against KC or MIP-2alpha or a nonspecific IgG was given during resuscitation immediately following hemorrhage. Anti-MIP-2alpha treatment resulted in a significant reduction in lung tissue IL-6 and myeloperoxidase levels. Percentage of neutrophil apoptosis increased significantly in the anti-KC group. Tissue and plasma KC and MIP-2alpha were reduced in their respective treatment groups. These data suggest that KC and MIP-2alpha differ in their mediation of neutrophil function (apoptosis and chemotaxis) and contribution to the pathogenesis of lung injury following hemorrhage subsequent to sepsis.

Interleukin-8 in non-small cell lung carcinoma: relation with angiogenic pattern and p53 alterations

Progression of solid tumors, including NSCLC, is associated with increase in MVC (microvessel count), as a measure of tumor angiogenesis resulting from an imbalance between angiogenic factors and inhibitors. However, since tumor angiogenesis is a multi-step process under the control of various molecules, the mechanism of angiogenesis has not been fully clarified. Interleukin (IL)-8 has been shown to have a potential angiogenic effect in vitro and in vivo, and is overexpressed in several human solid cancers. Among the various angiogenic factors, vascular endothelial growth factor (VEGF) has been shown to correlate with a high MVC and with adverse prognosis in several human cancers, including NSCLC. Alterations of p53 suppressor gene are the most common genetic changes found in malignant tumors; several studies examined the link between aberrant p53 and angiogenesis in lung cancer, but only a few studies report data regarding a relation between p53 mutations and IL-8 expression. In this study we observed a correlation between IL-8 mRNA expression, intratumoral MVC and VEGF mRNA expression levels; furthermore, an aberrant p53 status was related to IL-8 expression. However, in our samples IL-8 levels did not significantly affect prognosis of NSCLC; more studies are required to elucidate the precise role of IL-8 in a large series of patients with non-small cell lung carcinoma.

Biologically active neutrophil chemokine pattern in tonsillitis

To gain an insight into the mechanisms of chronic and acute inflammation, the production of neutrophil chemokines in different types of tonsillitis - hyperplastic tonsillitis (HT), recurrent tonsillitis (RT) and peritonsillar abscesses (PA) - was investigated. The chemokines interleukin-8 (IL-8), growth-related oncogene-alpha (GRO-alpha), epithelial cell-derived neutrophil attractant-78 (ENA-78) and granulocyte chemotactic protein-2 (GCP-2) were detected and shown to have different biological activities. With respect to the biological properties of CXC chemokines, the biological activity of the chemokines was identified using a three-step high-performance liquid chromatography (HPLC) technique, a bioassay involving measurement of neutrophil chemotaxis in a single Boyden chamber in tissue of HT, RT and PA. Using reverse transcription-polymerase chain reaction (RT-PCR), the chemokine concentrations were determined in the different tonsillitis entities. The chemokine pattern was dominated in PA by IL-8 and GRO-alpha and in RT by GRO-alpha. Hyperplastic tonsils of patients without a history of infection generated about five times lower IL-8 than PA. A protein concentration of GCP-2 was induced in PA and RT, whereas ENA-78 remained the same in all entities. In conclusion, it would appear that IL-8 was up-regulated in acute inflammation, whereas GRO-alpha dominated in chronic inflammation. ENA-78 seems not to play a pivotal role in inflammatory processes in tonsils. GCP-2 may serve as a substitute chemokine in certain inflammatory conditions as its quantity of mRNA and protein was higher in RT and PA than in HT.