The neutrophil-activating protein (NAP-1) is also chemotactic for T lymphocytes

Human T cells expressing BEND3 on their surface represent a novel subpopulation that preferentially produces IL-6 and IL-8

BEN domain-containing protein 3 (BEND3) has no transmembrane region, is localized in the cytoplasm, and is involved in chromatin function and transcription. We here identified a novel subpopulation of human T cells that expressed BEND3 on their cell surface (BEND3⁺ T cells). BEND3⁺ T cells consisted of approximately 3% of T cells in the peripheral blood, were present in both CD4⁺ and CD8⁺ T cells, and were also observed in cord blood. The stimulation of BEND3⁺ T cells through the TCR/CD3 complex led to the production of various kinds of cytokines; however, the levels of IL-6 and IL-8 produced by BEND3⁺ T cells were higher than those by BEND3⁻ T cells. The proportion of BEND3⁺ T cells was also increased in some patients with inflammatory diseases. Taken together, these results indicate that BEND3⁺ T cells are a new subpopulation of T cells in terms of their cytokine profile. Further analyses on BEND3⁺ T cells may be of importance and useful in understanding human T cell immunology.

Effect of acupuncture on CXCL8 receptors in rats suffering from embryo implantation failure

To observe the effect of acupuncture on CXCL8 receptors (CXCR1 and CXCR2) in rat endometrium experiencing embryo implantation failure, 72 pregnant rats were randomly divided into four groups: normal group (N), embryo implantation failure group (M), acupuncture treatment group (A), and progestin treatment group (W). Then the rats in each group were equally randomized into a day-6 (D6) group, a day-8 (D8) group, and a day-10 (D10) group. The rats in group M, group A, and group W were treated with mifepristone-sesame oil solution on day 1, while the rats in group N were injected with the same amount of sesame oil. Meanwhile, "Housanli" and "Sanyinjiao" were selected for acupuncture. From day 1 to the time of death, the rats in group A were fastened up and then acupuncture was administered while the rats in group N and group M were only fixed, and the rats in group W were given progestin. The number of implanted embryos was calculated. The expression of CXCR1 and CXCR2 in rat endometrium was detected by immunohistochemistry, Western blotting and real-time PCR. Compared to group N, the average number of implanted embryos, the protein and mRNA expression of CXCR1 (D6, D8 and D10), and the protein and mRNA expression of CXCR2 (D8 and D10) in rat endometrium were significantly decreased in group M. Compared to group M, there was significant elevation in the average number of implanted embryos, the protein expression (D6, D8 and D10) and mRNA expression (D8) of CXCR1 in rat endometrium of group A, and the protein expression (D8 and D10) and mRNA expression (D8) of CXCR2 in rat endometrium of group W. These findings indicated that acupuncture can increase the number of implanted embryos in rats of embryo implantation failure, which may be relevant with up-regulation the expression of CXCR1 and CXCR2 at maternal-fetal interface of rats with embryo implantation failure.

Inflammation-induced lymphangiogenesis and lymphatic dysfunction

The lymphatic system is intimately linked to tissue fluid homeostasis and immune cell trafficking. These functions are paramount in the establishment and development of an inflammatory response. In the past decade, an increasing number of reports has revealed that marked changes, such as lymphangiogenesis and lymphatic contractile dysfunction occur in both vascular and nodal parts of the lymphatic system during inflammation, as well as other disease processes. This review provides a critical update on the role of the lymphatic system in disease process such as chronic inflammation and cancer and examines the changes in lymphatic functions the diseases cause and the influence these changes have on the progression of the diseases.

Haplotype analysis of interleukin-8 gene polymorphisms in chronic and aggressive periodontitis

Objectives. Periodontitis is an inflammatory disease characterized by connective tissue loss and alveolar bone destruction. Interleukin-8 (IL8) is important in the regulation of the immune response. The aim of this study was to analyze four polymorphisms in the IL8 gene in relation to chronic (CP) and aggressive (AgP) periodontitis. Methods. A total of 492 unrelated subjects were included in this case-control association study. Genomic DNA of 278 patients with CP, 58 patients with AgP, and 156 controls were genotyped, using the 5′ nuclease TaqMan assay, for IL8 (rs4073, rs2227307, rs2227306, and rs2227532) gene polymorphisms. Subgingival bacterial colonization was investigated by the DNA-microarray detection kit in a subgroup of subjects (N = 247). Results. Allele and genotype frequencies of all investigated IL8 polymorphisms were not significantly different between the subjects with CP and/or AgP and controls (P > 0.05). Nevertheless, the A(−251)/T(+396)/T(+781) and T(−251)/G(+396)/C(+781) haplotypes were significantly less frequent in patients with CP (2.0% versus 5.1%, P < 0.02, OR = 0.34, 95% CI: 0.15–0.78, resp., 2.0% versus 4.5%, P < 0.05, OR = 0.41, 95% CI: 0.18–0.97) than in controls. Conclusions. Although none of the investigated SNPs in the IL8 gene was individually associated with periodontitis, some haplotypes can be protective against CP in the Czech population.

Cytokines in terms of QSAR. Review, evaluation and comparative studies

Cytokines represent a class of chemical factors that act as mediators in the complex biological response of inflammation, potentially implicated in various diseases. Therefore, selective inhibition or antagonism of cytokines is a target of anti-inflammatory drug design. The QSAR (Quantitative Structure-Activity Relationships) analysis presented here attempts to identify the structural features and physicochemical properties that are significant for cytokine antagonists or inhibitors and in particular of i) interleukin-5 (IL-5), ii) interleukin-6 (IL-6) and iii) of the chemotactic cytokine (chemokine) interleukin-8 (IL-8). Firstly, a historical aspect of the limited published QSARs is discussed and then a 2D-QSAR analysis was carried out for 26 data sets of compounds using the C-QSAR program of Biobyte. In six cases hydrophobicity appeared to be important. Steric factors in the form of overall molar refractivity (CMR), molar refractivity of the substituent (MR), molar volume (MgVol), Taft's Es constant and the sterimol parameters B1 and B5 have a significant impact on biological activity in most of the derived equations whereas electronic parameters as σp, σm or Σσ appeared in five cases.

Metabolic endotoxemia: a molecular link between obesity and cardiovascular risk

Obesity is associated with significantly increased cardiovascular (CV) risk and mortality. Several molecular mechanisms underlying this association have been implied, among which the intestinal barrier has gained a growing interest. In experimental models of obesity, significant alterations in the intestinal barrier lead to increased intestinal permeability, favoring translocation of microbiome-derived lipopolysaccharide to the bloodstream. This has been shown to result in a two- to threefold increase in its serum concentrations, a threshold named 'metabolic endotoxemia' (ME). ME may trigger toll-like receptor 4-mediated inflammatory activation, eliciting a chronic low-grade proinflammatory and pro-oxidative stress status, which may result in high CV risk and target-organ damage. In this review, we discuss the potential molecular implications of ME on several CV risk factors, such as obesity, insulin resistance, dyslipidemia, and oxidative stress, as well as its potential impact on the development of CV target-organ disease.

Stromal cells control soluble material and cellular transport in lymph nodes

Lymphocytes continuously patrol the secondary lymphoid organs (SLOs) of mammals in search for their cognate antigens. SLOs are composed of leucocytes (~95%) and lymphoid stromal cells (~5%) that form the structural framework of these organs. These sessile cells have been considered for decades as inert elements of the immune system. This simplistic view has dramatically changed in recent years, when it was discovered that these architectural cells are endowed with immuno-regulatory functions. Lymph nodes (LNs) are located at the interface between the blood and lymphatic systems, thus allowing tissue-derived antigen/antigen presenting cells (APCs) to gather with blood-derived lymphocytes. As a typical LN contains ~10 million of tightly packed cells, this accumulation of immune cells and information is probably not sufficient to foster the rare cellular interactions mandatory to the initiation of adaptative immune responses. Herein, I review some of the physicochemical elements of stromal cells that are used to transport and guide immune cells and soluble molecules within LNs.

Differential serum cytokine responses to inactivated and live attenuated seasonal influenza vaccines

Despite vaccine efforts, influenza outbreaks pose a significant threat to global public health. There are two commercially available seasonal influenza vaccines in the United States: the trivalent inactivated vaccine (TIV), delivered parenterally, and the live attenuated influenza vaccine (LAIV), delivered intranasally. Although both vaccines are generally efficacious, the immunologic mechanisms which contribute to protective immunity are incompletely understood. Thus, we investigated the protracted effects of TIV and LAIV on serum cytokine profiles at 14 and 28 days post-vaccination (when antibody titers are peak) in healthy adults over two influenza seasons. Vaccination with TIV was associated with a small, yet significant, decrease in the levels of both IL-8 and TNF-α at 14 and 28 days post-vaccination. LAIV, however, had no impact on serum cytokine levels. Similarly, analysis of serum antibody titers indicated that TIV recipients had a significantly higher sero-response rate compared to LAIV recipients, as has been previously shown. Finally, we examined the relationship between baseline serum cytokine levels and antibody responses to TIV (LAIV recipients were excluded due to the poor sero-response rate). Interestingly, in TIV recipients pre-vaccination levels of IL-8 were higher in sero-responders compared to non-responders. Collectively, these data suggest that cytokines may influence vaccine outcomes and indicate that parenteral immunization with TIV induces a sustained, systemic cytokine response which lasts for weeks.

Development and some applications of enzyme-linked immunosorbent assay system for murine macrophage inflammatory protein-2 (MIP-2)

We attempted to establish an enzyme-linked immunosorbent assay (ELISA) system by preparation of recombinant murine MIP-2 and its rabbit antibodies. A fusion construct of MIP-2 to protein A was used to enable easy purification as well as the generation of a sufficiently large antibody response. The specificity of antibody was confirmed by Western blotting analysis of 20-h conditioned medium from lipopolysaccharide (LPS)-stimulated RAW264.7 cells, a murine macrophage cell line; antibody gave a single band with a molecular weight of approximately 6000, which is identical to that of murine MIP-2 reported previously. Biotin–streptavidin sandwich ELISA could detect quantitatively MIP-2 at concentration range of 20 to 1000 pg/ml. In some applications of this ELISA system, time-related production of MIP-2 and inhibitory effect of dexamethasone on its production have been demonstrated in LPS-stimulated RAW264.7 cells. Thus, ELISA system established in this study is considered to be a useful tool to study MIP-2 response in various inflammation models in mice.

Neutrophil paralysis in Plasmodium vivax malaria

Background

The activation of innate immune responses by Plasmodium vivax results in activation of effector cells and an excessive production of pro-inflammatory cytokines that may culminate in deleterious effects. Here, we examined the activation and function of neutrophils during acute episodes of malaria.

Materials and Methods

Blood samples were collected from P. vivax-infected patients at admission (day 0) and 30–45 days after treatment with chloroquine and primaquine. Expression of activation markers and cytokine levels produced by highly purified monocytes and neutrophils were measured by the Cytometric Bead Assay. Phagocytic activity, superoxide production, chemotaxis and the presence of G protein-coupled receptor (GRK2) were also evaluated in neutrophils from malaria patients.

Principal Findings

Both monocytes and neutrophils from P. vivax-infected patients were highly activated. While monocytes were found to be the main source of cytokines in response to TLR ligands, neutrophils showed enhanced phagocytic activity and superoxide production. Interestingly, neutrophils from the malaria patients expressed high levels of GRK2, low levels of CXCR2, and displayed impaired chemotaxis towards IL-8 (CXCL8).

Conclusion

Activated neutrophils from malaria patients are a poor source of pro-inflammatory cytokines and display reduced chemotactic activity, suggesting a possible mechanism for an enhanced susceptibility to secondary bacterial infection during malaria.

Plasmodium vivax is responsible for approximately 60–80% of the malaria cases in the world, and contributes to significant social and economic instability in the developing countries of Latin America and Asia. The pathogenesis of P. vivax malaria is a consequence of host derived inflammatory mediators. Hence, a better understanding of the mechanisms involved in induction of systemic inflammation during P. vivax malaria is critical for the clinical management and prevention of severe disease. The innate immune receptors recognize Plasmodium sp. and initiate a broad spectrum of host defense mechanisms that mediate resistance to infection. However, the innate immune response is the classic “two-edged sword”, and clinical malaria is associated with high levels of circulating pro-inflammatory cytokines. Our findings show that both monocytes and neutrophils are highly activated during malaria. Monocytes produced high levels of IL-1β, IL-6 and TNF-α during acute malaria. On the other hand, neutrophils were a poor source of cytokines, but displayed an enhanced phagocytic activity and superoxide production. Unexpectedly, we noticed an impaired chemotaxis of neutrophils towards an IL-8 (CXCL8) gradient. We proposed that neutrophil paralysis is in part responsible for the enhanced susceptibility to bacterial infection observed in malaria patients.

Neutralization of IL-8 prevents the induction of dermatologic adverse events associated with the inhibition of epidermal growth factor receptor

Epidermal growth factor receptor (EGFR) inhibitors are widely used in the treatment of cancer. EGFR-targeted treatment is known to be associated with a high incidence of dermatological adverse reactions, including papulopustular rash, which can be dose-limiting and may affect compliance to treatment. Currently, the pathways involved in EGFR inhibitor-induced rash are poorly understood and few treatment options for this adverse event are available. Here, we developed a model for induction of papulopustular rash in healthy human volunteers by subcutaneous injection of the anti-EGFR monoclonal antibody zalutumumab. The injection sites and surrounding skin were evaluated by a dermatologist for the presence or absence of papulopustular rash and skin biopsies were taken to confirm the macroscopical findings by immunohistochemistry. Locally injected zalutumumab induced a papulopustular rash, characterized by acute follicular neutrophil-rich hair follicle inflammation, and thus mimicked adverse events induced by systemic administration of EGFR inhibitors. In this model, we tested the hypothesis that neutrophils, attracted by IL-8, play a central role in the observed rash. Indeed, concomitant local repeat dose treatment with HuMab-10F8, a neutralizing human antibody against IL-8, reduced the rash. Inhibition of IL-8 can therefore ameliorate dermatological adverse events induced by treatment with EGFR inhibitors.

Increases of vitreous monocyte chemotactic protein 1 and interleukin 8 levels in patients with concurrent hypertension and diabetic retinopathy

PURPOSE

To investigate whether concurrent hypertension affects vitreous cytokine levels in diabetic retinopathy.

METHODS

Vitreous samples from 41 patients with diabetic retinopathy with or without concurrent hypertension, who underwent vitrectomy, were collected. Vitreous cytokine concentrations were simultaneously measured using flow cytometry. Patients were stratified according to hypertension or other clinical conditions, and the differences in vitreous levels of monocyte chemotactic protein 1, interleukin 8, vascular endothelial growth factor, interferon-inducible protein 10, and monokine induced by interferon gamma were examined.

RESULTS

Vitreous levels of monocyte chemotactic protein 1 and interleukin 8 were significantly (P < 0.05) higher in hypertensive patients than in nonhypertensive patients and were significantly (P < 0.05) higher in active diabetic retinopathy than in inactive diabetic retinopathy. Vitreous levels of vascular endothelial growth factor, interferon-inducible protein 10, and monokine induced by interferon gamma were not affected by the coexistence of hypertension. In multivariate models, active diabetic retinopathy (P = 0.004 and P = 0.007), systolic blood pressure (P = 0.039 and P = 0.041), and hypertension (P = 0.032 and P = 0.035) were significant and independent predictors for increased vitreous monocyte chemotactic protein 1 and interleukin 8 levels.

CONCLUSION

Both monocyte chemotactic protein 1 and interleukin 8 levels were elevated in the vitreous of patients with diabetic retinopathy and concurrent hypertension. These findings may help to explain the epidemiologic and clinical evidence that systemic hypertension exacerbates diabetic retinopathy.

A study of elevated interleukin-8 (CXCL8) and detection of leukocyte migration inhibitory activity in patients allergic to beta-lactam antibiotics

BACKGROUND

The leukocyte migration test (LMT) is effective in identifying the causative drug in drug allergies. Both leukocyte migration activating activity (LMAA) and leukocyte migration inhibitory activity (LMIA) are involved in the development of drug allergies. However, no cytokines associated with LMIA have been identified to date. Because CXCL8 played an important role in neutrophil infiltration and activation, we performed the LMT and measured CXCL8 levels in patients with hypersensitivity to beta-lactam antibiotics (beta-lactams) and antipyretic analgesics (APAs) and investigated the pathogenic mechanism of hypersensitivity to these drugs.

METHODS

The LMT was performed according to an improved version of the agarose plate method and CXCL8 levels in the reacted solution that had been stored as described were measured using a solid-phase sandwich enzyme-linked immunosorbent assay.

RESULTS

Migration index (MI) values for the LMT were 77.7 ± 11.7 for patients with hypersensitivity to beta-lactams and 83.6 ± 1.9 for those with hypersensitivity to APAs. The CXCL8 concentrations were significantly higher in patients after beta-lactams administration (175.9 ± 71.2 ng/mL) than those without beta-lactams administration (48.3 ± 34.9 ng/mL). The CXCL8 concentrations were significantly lower in patients after APAs administration (41.7 ± 24.3 ng/mL) than those without APAs administration (63.1 ± 30.2 ng/mL).

CONCLUSIONS

Increased CXCL8 levels produced by beta-lactams administration were accompanied by LMIA. CXCL8 may be involved in LMIA and play a role in beta-lactam allergies. In contrast, the LMIA detected in patients with allergies to APAs may be a cytokine or chemokine other than CXCL8.

Effect of periodontal therapy on crevicular fluid interleukin-6 and interleukin-8 levels in chronic periodontitis

Purpose. The aim of this study was to analyse the levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) in gingival crevicular fluid (GCF) of patients with chronic periodontitis prior to and following surgical and/or nonsurgical periodontal therapy for a period of 32 weeks. Methods. GCF samples were obtained from 24 nondiseased and 72 diseased sites of 12 periodontal patients prior to as well as at 6, 16, and 32 weeks following non-surgical and surgical periodontal therapy. IL-6 and IL-8 levels were determined by enzyme-linked immunosorbent assay (ELISA). Results. Periodontal treatment improved all clinical parameters. Both treatment modalities resulted in similar IL-6 as well as IL-8 levels. Mean IL-6 and IL-8 concentrations were significantly higher in non-diseased compared to diseased sites and increased significantly following treatment in diseased sites. Mean total amounts of IL-6 and IL-8 (TAIL-6, TAIL-8) did not differ significantly between diseased and nondiseased sites, while following therapy TAIL-8 levels decreased significantly. Conclusions. The data suggest that periodontal therapy reduced the levels of IL-8 in GCF. However, a strong relationship between IL-6, IL-8 amounts in GCF and periodontal destruction and inflammation was not found.

Characterization of the interaction of interleukin-8 with hyaluronan, chondroitin sulfate, dermatan sulfate and their sulfated derivatives by spectroscopy and molecular modeling

The interactions between glycosaminoglycans (GAGs), important components of the extracellular matrix, and proteins such as growth factors and chemokines play critical roles in cellular regulation processes. Therefore, the design of GAG derivatives for the development of innovative materials with bio-like properties in terms of their interaction with regulatory proteins is of great interest for tissue engineering and regenerative medicine. Previous work on the chemokine interleukin-8 (IL-8) has focused on its interaction with heparin and heparan sulfate, which regulate chemokine function. However, the extracellular matrix contains other GAGs, such as hyaluronic acid (HA), dermatan sulfate (DS) and chondroitin sulfate (CS), which have so far not been characterized in terms of their distinct molecular recognition properties towards IL-8 in relation to their length and sulfation patterns. NMR and molecular modeling have been in great part the methods of choice to study the structural and recognition properties of GAGs and their protein complexes. However, separately these methods have challenges to cope with the high degree of similarity and flexibility that GAGs exhibit. In this work, we combine fluorescence spectroscopy, NMR experiments, docking and molecular dynamics simulations to study the configurational and recognition properties of IL-8 towards a series of HA and CS derivatives and DS. We analyze the effects of GAG length and sulfation patterns in binding strength and specificity, and the influence of GAG binding on IL-8 dimer formation. Our results highlight the importance of combining experimental and theoretical approaches to obtain a better understanding of the molecular recognition properties of GAG–protein systems.

Effects of Echinaforce® treatment on ex vivo-stimulated blood cells

The herb Echinacea purpurea, also called purple coneflower, is regarded as an immune modulator. This study examined changes in cytokine production in blood samples from 30 volunteers before and during 8-day oral administration with an ethanolic extract of fresh Echinacea purpurea (Echinaforce(®)). Daily blood samples were ex vivo stimulated by LPS/SEB or Zymosan and analysed for a series of cytokines and haematological and metabolic parameters. Treatment reduced the proinflammatory mediators TNF-α and IL-1β by up to 24% (p<0.05) and increased anti-inflammatory IL-10 levels by 13% (p<0.05) in comparison to baseline. This demonstrated a substantial overall anti-inflammatory effect of Echinaforce(®) for the whole group (n=28). Chemokines MCP-1 and IL-8 were upregulated by 15% in samples from subjects treated with Echinaforce(®) (p<0.05). An analysis of a subgroup of volunteers who showed low pre-treatment levels of the cytokines MCP-1, IL-8, IL-10 or IFN-γ (n=8) showed significant stimulation of these factors upon Echinaforce(®) treatment (30-49% increases; p<0.05), whereas the levels in subjects with higher pre-treatment levels remained unaffected. We chose the term "adapted immune-modulation" to describe this observation. Volunteers who reported high stress levels (n=7) and more than 2 colds per year experienced a significant transient increase in IFN-γ upon Echinaforce(®) treatment (>50%). Subjects with low cortisol levels (n=11) showed significant down-regulation of the acute-phase proteins IL1-β, IL-6, IL-12 and TNF-α by Echinaforce(®) (range, 13-25%), while subjects with higher cortisol levels showed no such down-regulation. This is the first ex vivo study to demonstrate adapted immune-modulation by an Echinacea preparation. While Echinaforce(®) did not affect leukocyte counts, we speculate that the underlying therapeutic mechanism is based on differential multi-level modulation of the responses of the different types of leukocytes. Echinaforce(®) thus regulates the production of chemokines and cytokines according to current immune status, such as responsiveness to exogenous stimuli, susceptibility to viral infection and exposure to stress.

Keratinocyte Growth Factor Stimulates Macrophage Inflammatory Protein 3α and Keratinocyte-derived Chemokine Secretion by Mouse Uterine Epithelial Cells

PROBLEM

communication between uterine epithelial cells and the underlying stromal fibroblasts is critical for proper endometrial function. Stromal fibroblast-derived growth factors have been shown to regulate epithelial immune functions. The purpose of this study was to determine whether keratinocyte growth factor (KGF) regulates uterine epithelial cell chemokine and antimicrobial secretion.

METHOD OF STUDY

uterine epithelial cells were isolated from Balb/c mice and cultured in either 96-well plates or transwell inserts. Epithelial cells were treated with KGF, epidermal growth factor (EGF), or hepatocyte growth factor (HGF). Macrophage inflammatory protein 3α (MIP3α) and keratinocyte-derived chemokine (KC) levels were measured by ELISA.

RESULTS

keratinocyte growth factor stimulated the secretion of MIP3α and KC. The effects on MIP3α by KGF were specific because EGF and HGF had no effect. In contrast, KGF, EGF, and HGF had similar effects on KC. Furthermore, KGF administered to the apical side of epithelial cells had no effect on MIP3α or KC secretion, indicating that the KGF receptor is located on the basolateral surface of uterine epithelial cells.

CONCLUSION

we demonstrate that KGF plays a role in uterine epithelial cell secretion of MIP3α and KC, key immune mediators involved in the protection of mucosal surfaces in the female reproductive tract.

Size dependent induction of proinflammatory cytokines and cytotoxicity of particulate beta-tricalciumphosphate in vitro

Cellular responses to particulate calcium phosphate ceramics can lead to inflammatory reactions under certain conditions that depend on particle composition, size and morphology. In this context, the potential influence of varying sizes of particulate beta-tricalciumphosphate (beta-TCP) on the induction of inflammation and cytotoxicity remains to be determined. The present work investigates the effects of beta-TCP particles of five different sizes (1, 3, 13, 32 and 40 μm) on human peripheral blood mononuclear cells (PBMC) in vitro concerning the release of TNF-alpha, IL-1beta and IL-8 after six and 18 h of incubation (ELISA) as well as intracellular TNF-alpha, IFN-gamma, IL-1alpha, IL-1beta and IL-8 levels within distinct PBMC subpopulations after 12 h (FACS). Potential cytotoxic effects were determined by assaying lactate dehydrogenase (LDH) and morphological analyses (electron microscopy). Beta-TCP 1 μm did not induce any cytokine after 6 h but slightly increases TNF-alpha, IL-1beta and IL-8 release after 18 h. Larger particles (32 and 40 μm) consistently caused higher levels of cytokine release by increasing the fraction of cytokine producing monocytes. They also caused higher levels of LDH release as did smaller, phagocytosable particles. These data suggest a less inflammatory and cytotoxic profile of beta-TCP devices with a smaller primary particle size when compared to larger particles.

Different characteristics of human herpesvirus 6 encephalitis between primary infection and viral reactivation

BACKGROUND

Pathogenesis of human herpesvirus 6 (HHV-6) encephalitis, in particular difference between HHV-6 encephalitis at the time of primary infection and reactivation remains unclear.

OBJECTIVES

To elucidate the mechanism of HHV-6 encephalitis at the time of primary infection and reactivation.

STUDY DESIGN

Twenty-two HHV-6 encephalitis patients at the time of primary infection, 6 febrile convulsion (FC) patients caused by HHV-6 infection, and 14 FC patients without HHV-6 infection (non HHV-6 FC) were enrolled. Additionally, 7 stem cell transplant recipients with HHV-6 encephalitis and eight adult controls were also enrolled in this study. Cerebrospinal fluid (CSF) HHV-6 DNA copy numbers and biomarkers levels were compared.

RESULTS

Low copy number of CSF HHV-6 DNA was detected in 7 of the 22 patients with HHV-6 encephalitis in primary infection, whereas all seven CSF samples collected from post-transplant HHV-6 encephalitis patients contained high viral DNA copy numbers (P<0.001). CSF concentrations of IL-6 (P=0.032), IL-8 (P=0.014), MMP-9 (P=0.004), and TIMP-1 (P=0.002) were significantly higher in patients with HHV-6 encephalitis in primary infection than non-HHV-6 FC. CSF IL-6 (P=0.008), IL-8 (P=0.015), and IL-10 (P=0.019) concentrations were significantly higher in patients with post-transplant HHV-6 encephalitis than adult controls.

CONCLUSION

The present study suggests that the characteristics of HHV-6 encephalitis are different between HHV-6 encephalitis at the time of primary infection and reactivation in transplant recipients.

Novel roles for hypoxia and prostaglandin E2 in the regulation of IL-8 during endometrial repair

The endometrium has a remarkable capacity for efficient repair; however, factors involved remain undefined. Premenstrual progesterone withdrawal leads to increased prostaglandin (PG) production and local hypoxia. Here we determined human endometrial expression of interleukin-8 (IL-8) and the roles of PGE(2) and hypoxia in its regulation. Endometrial biopsy specimens (n = 51) were collected. Endometrial cells and explants were exposed to 100 nmol/L of PGE(2) or 0.5% O(2). The endometrial IL-8 concentration peaked during menstruation (P < 0.001) and had a significant proangiogenic effect. IL-8 was increased by PGE(2) and hypoxia in secretory but not proliferative explants, which suggests that exposure to progesterone is essential. In vitro progesterone withdrawal induced significant IL-8 up-regulation in proliferative explants primed with progestins, but only in the presence of hypoxia. Epithelial cells treated simultaneously with PGE(2) and hypoxia demonstrated synergistic increases in IL-8. Inhibition of HIF-1 by short hairpin RNA abolished hypoxic IL-8 induction, and inhibition of NF-κB by an adenoviral dominant negative inhibitor decreased PGE(2)-induced IL-8 expression (P > 0.05). Increased menstrual IL-8 is consistent with a role in repair. Progesterone withdrawal, hypoxia, and PGE(2) regulate endometrial IL-8 by acting via HIF-1 and NF-κB. Hence, progesterone withdrawal may activate two distinct pathways to initiate endometrial repair.

Gut microbiota, lipopolysaccharides, and innate immunity in the pathogenesis of obesity and cardiovascular risk

Compelling evidence supports the concepts that gut microbiota actively promotes weight gain and fat accumulation and sustains, indirectly, a condition of low-grade inflammation, thus enhancing the cardiovascular risk. Fewer Bacteroidetes and more Firmicutes seem to characterize the gut microbiota of obese people as compared with that of lean individuals. This difference translates into an increased efficiency of microbiota of obese individuals in harvesting energy from otherwise indigestible carbohydrates. Furthermore, the microbiota also seems able to favor fat accumulation. Indeed, studies performed in germ-free animals have demonstrated that conventionalization of sterile intestine with gut microbiota is associated with an enhanced expression of various lipogenic genes in different tissues, i.e., hepatic, adipose, and muscle tissues. Finally, the microbiota favors systemic exposure to the lipopolysaccharides (LPSs), large glycolipids derived from the outer membrane of Gram-negative bacteria. LPSs can cause a condition of "metabolic endotoxemia" characterized by low-grade inflammation, insulin resistance, and augmented cardiovascular risk. LPSs are a powerful trigger for the innate immune system response. Upon binding to the Toll-like receptor 4 and its coreceptors, LPSs trigger a cascade of responses ultimately resulting in the release of proinflammatory molecules that interfere with modulation of glucose and insulin metabolism, promote development and rupture of the atherosclerotic plaque, and favor progression of fatty liver disease to steatohepatitis. This review gives a comprehensive breakdown of the interaction among gut microbiota, LPSs, and the innate immune system in the development of obesity and promotion of an individual's cardiovascular risk.

In vitro anti-influenza A H1N1 effect of extract of Bupleuri Radix

This study investigated the effect of the extract of Bupleuri Radix (BRE) on the infection of Madin-Darby Canine Kidney (MDCK) cells by anti-H1N1 virus. The effect of BRE on RANTES (the chemokine regulated on activation, normal T cells expressed and secreted) secretion in H1N1-infected A549 cells (human bronchial epithelial cells) was evaluated via quantative measurement of the changes in the cytopathic effects and by the ultraviolet (UV) absorbance at 600 nm. It was found that BRE was toxic to MDCK cells at a higher concentration while had a marked inhibitory effect on cell pathological changes at a lower concentration. Results also showed that BRE possessed more than 50% suppressing effect on RANTES secretion in H1N1-infected A549 cells at a concentration of 100 and 200 μg/ml. Our findings show that BRE has a significant protective effect on MDCK cells infected in a dose-dependent manner with an excellent suppressing effect on RANTES secretion, suggesting that BRE can be developed as an antivirus agent.

Mycobacterium tuberculosis activates human macrophage peroxisome proliferator-activated receptor gamma linking mannose receptor recognition to regulation of immune responses

Mycobacterium tuberculosis enhances its survival in macrophages by suppressing immune responses in part through its complex cell wall structures. Peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear receptor superfamily member, is a transcriptional factor that regulates inflammation and has high expression in alternatively activated alveolar macrophages and macrophage-derived foam cells, both cell types relevant to tuberculosis pathogenesis. In this study, we show that virulent M. tuberculosis and its cell wall mannose-capped lipoarabinomannan induce PPARgamma expression through a macrophage mannose receptor-dependent pathway. When activated, PPARgamma promotes IL-8 and cyclooxygenase 2 expression, a process modulated by a PPARgamma agonist or antagonist. Upstream, MAPK-p38 mediates cytosolic phospholipase A(2) activation, which is required for PPARgamma ligand production. The induced IL-8 response mediated by mannose-capped lipoarabinomannan and the mannose receptor is independent of TLR2 and NF-kappaB activation. In contrast, the attenuated Mycobacterium bovis bacillus Calmette-Guérin induces less PPARgamma and preferentially uses the NF-kappaB-mediated pathway to induce IL-8 production. Finally, PPARgamma knockdown in human macrophages enhances TNF production and controls the intracellular growth of M. tuberculosis. These data identify a new molecular pathway that links engagement of the mannose receptor, an important pattern recognition receptor for M. tuberculosis, with PPARgamma activation, which regulates the macrophage inflammatory response, thereby playing a role in tuberculosis pathogenesis.

Association of interleukin-8 gene polymorphisms and haplotypes with oral lichen planus in a Chinese population

Interleukin-8 (IL-8), a CXC chemokine with multiple biological functions, plays an important role in the pathogenesis of oral lichen planus (OLP). The aim of this study was to investigate the association of single nucleotide polymorphisms (SNPs) of IL-8 gene with OLP in a Chinese population. Four SNPs of the IL-8 gene at positions -845 T/C (rs2227532), -738 T/A, -251 A/T (rs4073) and +781 C/T (rs2227306) were analyzed in 109 patients with OLP and 101 normal controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The data revealed that the -251 AA genotype and -251 A allele frequency was significantly lower in the erosive OLP (eOLP) group than in the control group (P = 0.012 and P = 0.031, respectively). Haplotype analysis revealed that the -251 A/+781 C haplotype frequency was lower in the eOLP group than in the control group (P = 0.029) while the -251 T/+781 C haplotype frequency was higher in the eOLP patients than in the healthy controls (P = 0.028). The study suggests that the IL-8 polymorphisms may be associated with the severity of OLP in this Chinese cohort.

Mammalian target of rapamycin (mTOR) and S6 kinase down-regulate phospholipase D2 basal expression and function

The mammalian target of rapamycin (mTOR) and S6 kinase (S6K) pathway is essential for cell differentiation, growth, and survival. Phospholipase D2 (PLD2) plays a key role in mTOR/S6K mitogenic signaling. However, the impact of PLD on mTOR/S6K gene expression is not known. Here we show that interleukin-8 (IL-8) increases mRNA expression levels for PLD2, mTOR, and S6K, with PLD2 preceding mTOR/S6K in time. Silencing of PLD2 gene expression abrogated IL-8-induced mTOR/S6K mRNA expression, whereas silencing of mTOR or S6K gene expression resulted in large (>3-fold and >5-fold, respectively) increased levels of PLD2 RNA, which was paralleled by increases in protein expression and lipase activity. Treatment of cells with 0.5 nm rapamycin induced a similar trend. These results suggest that, under basal conditions, PLD2 expression and concomitant activity is negatively regulated by the mTOR/S6K signaling pathway. Down-regulation of PLD2 was confirmed in differentiated HL-60 leukocytes overexpressing an mTOR-wild type, but not an mTOR kinase-dead construct. At the cellular level, overexpression of mTOR-wild type resulted in lower basal cell migration, which was reversed by treatment with IL-8. We propose that IL-8 reverses an mTOR/S6K-led down-regulation of PLD2 expression and enables PLD2 to fully function as a facilitator for cell migration.

Toll-like receptor-induced reactivity and strongly potentiated IL-8 production in granulocytes mobilized for transfusion purposes

Transfusion of granulocytes from granulocyte-colony stimulating factor (G-CSF)/dexamethasone (dexa)-treated donors can be beneficial for neutropenic recipients that are refractory to antimicrobial therapy. G-CSF/dexa treatment not only increases the number of circulating neutrophils but also affects their gene expression. Because of the intended transfusion of these granulocytes into patients who are severely ill, it is of importance to establish to what extent mobilization affects the cellular behavior of neutrophils. Here, we studied the effects of mobilization on Toll-like receptor (TLR)-mediated responses. Mobilized granulocytes displayed increased gene and protein expression of TLR2, TLR4, TLR5, and TLR8. Although mobilized granulocytes displayed normal priming of nicotinamide adenine dinucleotide phosphate oxidase activity and a slight increase in adhesion in response to TLR stimulation, these cells produced massive amounts of interleukin-8 (IL-8), in particular to TLR2 and TLR8 stimulation. The increase in IL-8 release occurred despite reduced IL-8 mRNA levels in the donor granulocytes after in vivo G-CSF/dexa treatment, indicating that the enhanced TLR-induced IL-8 production was largely determined by posttranscriptional regulation. In summary, granulocytes mobilized for transfusion purposes show enhanced TLR responsiveness in cytokine production, which is anticipated to be beneficial for the function of these cells on transfusion into patients.

Crosstalk between perivascular adipose tissue and blood vessels

Crosstalk between cells in the blood vessel wall is vital to normal vascular function and is perturbed in diseases such as atherosclerosis and hypertension. Perivascular adipocytes reside at the adventitial border of blood vessels but until recently were virtually ignored in studies of vascular function. However, perivascular adipocytes have been demonstrated to be powerful endocrine cells capable of responding to metabolic cues and transducing signals to adjacent blood vessels. Accordingly, crosstalk between perivascular adipose tissue (PVAT) and blood vessels is now being intensely examined. Emerging evidence suggests that PVAT regulates vascular function through numerous mechanisms, but evidence to date suggests modulation of three key aspects that are the focus of this review: inflammation, vasoreactivity, and smooth muscle cell proliferation.

G protein-coupled receptor 43 is essential for neutrophil recruitment during intestinal inflammation

Molecular danger signals attract neutrophilic granulocytes (polymorphonuclear leukocytes (PMNs)) to sites of infection. The G protein-coupled receptor (GPR) 43 recognizes propionate and butyrate and is abundantly expressed on PMNs. The functional role of GPR43 activation for in vivo orchestration of immune response is unclear. We examined dextrane sodium sulfate (DSS)-induced acute and chronic intestinal inflammatory response in wild-type and Gpr43-deficient mice. The severity of colonic inflammation was assessed by clinical signs, histological scoring, and cytokine production. Chemotaxis of wild-type and Gpr43-deficient PMNs was assessed through transwell cell chemotactic assay. A reduced invasion of PMNs and increased mortality due to septic complications were observed in acute DSS colitis. In chronic DSS colitis, Gpr43(-/-) animals showed diminished PMN intestinal migration, but protection against inflammatory tissue destruction. No significant difference in PMN migration and cytokine secretion was detected in a sterile inflammatory model. Ex vivo experiments show that GPR43-induced migration is dependent on activation of the protein kinase p38alpha, and that this signal acts in cooperation with the chemotactic cytokine keratinocyte chemoattractant. Interestingly, shedding of L-selectin in response to propionate and butyrate was compromised in Gpr43(-/-) mice. These results indicate a critical role for GPR43-mediated recruitment of PMNs in containing intestinal bacterial translocation, yet also emphasize the bipotential role of PMNs in mediating tissue destruction in chronic intestinal inflammation.

Asthma during pregnancy alters immune cell profile and airway epithelial chemokine release

OBJECTIVE

Pregnancy can influence the course of maternal asthma, but the mechanisms are presently unknown. The aim of the present study was to access maternal immune cell profiles in the presence and absence of asthma and to determine the effect of pregnancy-derived factors on epithelial cell function.

METHODS

Cells from the human bronchial epithelial cell line BEAS-2B were treated with plasma from pregnant or nonpregnant asthmatic and nonasthmatic subjects. Cell culture supernatants were collected after 24 h and assayed for IL-6, IL-8, eotaxin, RANTES and sICAM-1 protein using ELISA. Maternal immune cell count and peripheral blood chemotactic response to plasma from pregnant and non-pregnant asthmatic subjects were also assessed.

RESULTS

The presence of maternal asthma during pregnancy was associated with increased monocyte and neutrophil numbers, increased BEAS-2B cell production of IL-8 and sICAM-1 (P < 0.05) and increased chemotactic capacity relative to pregnant women without asthma.

CONCLUSION

The results of this study suggest that circulating pregnancy-related factors enhance chemotactic mediators in epithelial cells in the presence of asthma. This may be one mechanism that contributes to pregnancy-induced changes in asthma.

Induction of IL-8 expression by bacterial flagellin is mediated through lipid raft formation and intracellular TLR5 activation in A549 cells

We investigated the mechanism for the induction of a chemokine, IL-8, by bacterial flagellins in the human alveolar type II epithelial cell line, A549. Bacterial flagellin induced expression of IL-8 mRNA and protein in dose- and time-dependent manners. IL-8 expression was inhibited by nystatin (a lipid rafts inhibitor) but not by chlorpromazine (a clathrin-coated pits inhibitor). Interestingly, Toll-like receptor 5 (TLR5) recognizing flagellins was found in the intracellular compartment of A549 but rarely on the cell surface. Flagellin-induced IL-8 expression appears to be mediated through TLR5 as determined by in vitro transient transfection experiment in HEK-293 cells expressing TLR5 using a reporter gene construct containing IL-8 promoter. IL-8 expression was attenuated by inhibitors for protein kinase C (PKC) and mitogen-activated protein (MAP) kinases. Furthermore, NF-kappaB and NF-IL6 transcription factors played an important role in the flagellin-induced IL-8 gene expression in A549 cells. Collectively, these results suggest that flagellin-induced IL-8 expression requires formation of lipid rafts, intracellular TLR activation, and subsequent activation of PKC and MAP kinases leading to the activation of the transcription factors NF-kappaB and NF-IL6 in human alveolar type II epithelial cells.

Macrophage inflammatory protein-1beta and interleukin-8 associated with idiopathic steroid-sensitive nephrotic syndrome

BACKGROUND

The cytokines associated with idiopathic steroid-sensitive nephrotic syndrome (ISSNS) have not been identified definitively, because previous studies had variable sampling and population heterogeneity. To clarify the cytokines involved, serum cytokine levels were measured using uniform sampling in a homogeneous population.

METHODS

Five children meeting the following criteria were included: (i) ISSNS; (ii) selectivity index <0.1; (iii) paired sera obtained in the nephrotic phase before steroid treatment (STx; group A) and in the remission phase under STx (group B); (iv) no infection; and (v) no immunosuppressant. Control groups were as follows: group C, four children with ISSNS in the remission phase without STx; group D, five with normal urinalysis; group E, five with symptomatic secondary nephrotic syndrome before STx. Cytokine levels were measured using bead-based assay.

RESULTS

Serum macrophage inflammatory protein-1beta (MIP-1beta) levels were higher in group B compared to group A, and group C was lower than groups A and B. Serum interleukin-8 (IL-8) levels were higher in group A than in groups B and C, and groups B and C did not differ. With regard to both cytokine levels, there were no differences between groups C and D, and groups A and E.

CONCLUSION

Serum MIP-1beta and IL-8 are associated with the clinical status of ISSNS in children. A relationship between MIP-1beta and ISSNS has not been previously reported. The mechanism by which MIP-1beta and IL-8 affect ISSNS is unclear. Nevertheless, the present findings are an interesting starting point for further investigations into the pathophysiology of ISSNS in children.

Chemotactic properties and absence of the formyl peptide receptor in ferret (Mustela putorius furo) neutrophils

This study describes a chemotaxis assay of ferret polymorphonuclear cells (PMNs). The optimal conditions for this chemotaxis assay were investigated for three chemoattractants: zymosan activated serum (ZAS), recombinant human interleukin-8 (rhIL-8) and N-formyl-Met-Leu- Phe (fMLF). In this study, ferret polymorphonuclear cells (PMNs) reacted to ZAS and rhIL-8, but not fMLF. The optimal concentration of ZAS and rhIL-8 were 5% and 100 ng/ml, respectively. The optimal incubation time of each reagent was 60 min. Due to the lack of response shown from fMLF, the existence of formyl peptide receptors (FPR) on ferret PMNs was investigated by evaluating FPR binding using flow cytometry. The receptor was not detected, implying that ferret neutrophils may lack FPR. This study confirms the fundamental experimental conditions for ferret PMNs chemotaxis and elucidates new findings concerning FPR in ferret neutrophils.

Prokineticin 1 modulates IL-8 expression via the calcineurin/NFAT signaling pathway

Prokineticins and their receptors are expressed in various cellular compartments in human endometrium, with prokineticin 1 (PROK1) showing a dynamic pattern of expression across the menstrual cycle and during pregnancy. Previous studies suggest that PROK1 can play an important role in implantation and early pregnancy by inducing vascular remodeling and increasing vascular permeability. Here we demonstrate that PROK1 induces the expression of IL-8, a chemokine with angiogenic properties, in endometrial epithelial Ishikawa cells stably expressing prokineticin receptor 1 and in human first trimester decidua. We also show that IL-8 promoter activity is induced by PROK1 and that this requires the presence of AP1 and NFAT motifs. The role of calcineurin/NFAT signaling pathway is confirmed by the use of specific chemical inhibitors. Additionally, PROK1 induces the expression of the regulator of calcineurin 1 isoform 4 (RCAN1-4) via the calcineurin/NFAT pathway. A modulatory role for RCAN1-4 is demonstrated by RCAN1-4 overexpression which results in the inhibition of PROK1-induced IL-8 expression whereas reduction in RCAN1-4 endogenous expression results in an increase in PROK1-induced IL-8 production. Our findings show that in endometrial cells PROK1 can activate the calcineurin/NFAT pathway to induce IL-8 expression and that this is negatively modulated by the induction of expression of RCAN1-4.

Orf virus-encoded chemokine-binding protein is a potent inhibitor of inflammatory monocyte recruitment in a mouse skin model

The parapoxvirus orf virus causes pustular dermatitis in sheep and is transmissible to humans. The virus encodes a secreted chemokine-binding protein (CBP). We examined the ability of this protein to inhibit migration of murine monocytes in response to CC inflammatory chemokines, using chemotaxis assays, and its effects on monocyte recruitment into the skin, using a mouse model in which inflammation was induced with bacterial lipopolysaccharide. CBP was shown to bind murine chemokines CCL2, CCL3 and CCL5 with high affinity by surface plasmon resonance and it completely inhibited chemokine-induced migration of monocytes at a CBP:chemokine molar ratio of 4:1. In the mouse, low levels of CBP potently inhibited the recruitment of Gr-1+/CD11b+ monocytes to the site of inflammation in the skin but had little effect on neutrophil recruitment, suggesting that this factor plays a role in disrupting chemokine-induced recruitment of specific immune cell types to infection sites.

Human immunodeficiency virus type 1-anchored CD40 ligand induces secretion of the chemokine interleukin-8 by human primary macrophages

CD40 ligand (CD40L) is mainly expressed in activated CD4(+)T cells and interacts with CD40 on antigen-presenting cells to regulate both humoral and cellular immune responses. We previously reported that CD40L is acquired by emerging HIV-1 particles. Here we demonstrate that both wild-type and a non-functional mutated form of CD40L are incorporated within HIV-1. Importantly, we show that wild-type CD40L remains functional since CD40L-bearing virions mediate NF-kappaB activation in a CD40-expressing reporter cell line and induce secretion of the chemokine IL-8 by monocyte-derived macrophages. These results suggest a possible means exploited by HIV-1 to attract susceptible target cells to the site of infection, a process that might promote viral dissemination.