Chemotactic Index Research Articles

Research on chemotaxis response of Alternaria panax to amino acid of ginseng root exudates

Plate assay and spore germination method were used to study the chemotaxis response of Alternaria panax to arginine, glutamic acid, aspartic acid and threonine. The result showed that the optimum temperature of A. panax chemotaxis response to four amino acids were all 25 ℃. And chemotaxis responses of A. panax were different under conditions of different concentration and pH value. The chemotaxin reached to the highest under the condition of 2 mg•L⁻¹ and pH value was 7 for arginine, glutamic acid and threonine while 20 mg•L⁻¹ and pH value was 6 for aspartic acid . The data of chemotactic migration index (CMI) were 1.24, 1.38, 1.27, 1.31 and chemotactic growth rates(CGR) were 0.451 0, 0.353 0, 0.381 3, 0.228 8 and spores germination rates(SGR) were 57.33%，63%，56.67%，58% and the dry weight of mycelial (DWM) were 372.9, 348.5, 314.4, 390.2 mg•L⁻¹ respectively. It indicated that the low and middle concentration of amino acid had significant promoting effect on chemotaxis response of A. panax. As important substances generated in ginseng root, amino acids exhibited an efficient chemotactic effect on A. panax, and some even show inhibition effect under high concentration.

Signal Factors Secreted by 2D and Spheroid Mesenchymal Stem Cells and by Cocultures of Mesenchymal Stem Cells Derived Microvesicles and Retinal Photoreceptor Neurons.

We aim to identify levels of signal factors secreted by MSCs cultured in 2D monolayers (2D-MSCs), spheroids (spheroids MSCs), and cocultures of microvesicles (MVs) derived from 2D-MSCs or spheroid MSCs and retinal photoreceptor neurons. We seeded 2D-MSCs, spheroid MSCs, and cells derived from spheroids MSCs at equal numbers. MVs isolated from all 3 culture conditions were incubated with 661W cells. Levels of 51 signal factors in conditioned medium from those cultured conditions were quantified with bead-based assay. We found that IL-8, IL-6, and GROα were the top three most abundant signal factors. Moreover, compared to 2D-MSCs, levels of 11 cytokines and IL-2Rα were significantly increased in conditioned medium from spheroid MSCs. Finally, to test if enhanced expression of these factors reflects altered immunomodulating activities, we assessed the effect of 2D-MSC-MVs and 3D-MSC-MVs on CD14+ cell chemoattraction. Compared to 2D-MSC-MVs, 3D-MSC-MVs significantly decreased the chemotactic index of CD14+ cells. Our results suggest that spheroid culture conditions improve the ability of MSCs to selectively secrete signal factors. Moreover, 3D-MSC-MVs also possessed an enhanced capability to promote signal factors secretion compared to 2D-MSC-MVs and may possess enhanced immunomodulating activities and might be a better regenerative therapy for retinal degenerative diseases.

Termitarium-Inhabiting Bacillus spp. Enhanced Plant Growth and Bioactive Component in Turmeric (Curcuma longa L.).

Curcumin (diferuloyl methane) is the main bioactive component of turmeric (Curcuma longa L.) having remarkable multipotent medicinal and therapeutic applications. Two Bacilli isolated from termitarium soil and identified as Bacillus endophyticus TSH42 and Bacillus cereus TSH77 were used for bacterization of rhizome for raising C. longa ver. suguna for growth and enhancement. Both the strains showed remarkable PGP activities and also chemotactic in nature with high chemotactic index. Turmeric plants bacterized with strains B. endophyticus TSH42 and B. cereus TSH77 individually and in combination increased plant growth and turmeric production up to 18% in field trial in comparison to non-bacterized plants. High-performance liquid chromatography analysis was performed to determine the content of curcumin, which showed concentration of curcumin in un-inoculated turmeric as 3.66g which increased by 13.6% (4.16g) when combination of TSH42 and TSH77 was used.

A stochastic micro-machine inspired by bacterial chemotaxis

Inspired by bacterial chemotaxis, we propose and study the dynamics of a 3D hydrodynamical search-machine at micrometer scale. Chemotactic memory of the proposed system that is borrowed from bacteria, allows it to search the fluid medium and find the required target. As the motion in micron size length scale is dominated by random forces, we analyze the statistical properties of the model. Mean square displacements, orientational correlation functions and also the chemotactic index (CI) of the system are investigated in detail. Because of the chemotactic memory, the system shows superdiffusing displacements in all directions and the diffusion exponents are anisotropic for the directions along or perpendicular to a preferred direction given by the gradient of attractant molecules transmitted by the target.

In Vitro effects of tamoxifen on equine neutrophils

Neutrophils participate in innate immunity as the first line of host defense against microorganisms. However, exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous preliminary studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apoptosis of blood and BALF neutrophils, reduction of BALF neutrophils, and improvement in animals' clinical status. The aim of this study was to evaluate the in vitro effect of TX on functional tests in equine peripheral blood neutrophils. Chemotaxis, respiratory burst production and phagocytosis assays were performed on neutrophils isolated from peripheral blood samples from 10 healthy horses. Results showed that IL-8 stimulated cells decrease their chemotactic index when treated with TX (1 and 10μM). Respiratory burst production was also dampened after treatment with TX. In conclusion, these results confirm that tamoxifen has a direct action on equine peripheral blood neutrophils. However, more in vivo and in vitro studies are required to fully understand the mechanisms of action of TX on neutrophils, in order to elucidate if it can be used as treatment in disorders such as allergic asthma in humans and horses.

Calcitonin gene-related peptide is a key factor in the homing of transplanted human MSCs to sites of spinal cord injury.

Mesenchymal stem cells (MSCs) can be used to treat many diseases, including spinal cord injury (SCI). Treatment relies mostly on the precise navigation of cells to the injury site for rebuilding the damaged spinal cord. However, the key factors guiding MSCs to the epicenter of SCI remain unknown. Here, we demonstrated that calcitonin gene-related peptide (CGRP), a neural peptide synthesized in spinal cord, can dramatically aid the homing of human umbilical cord mesenchymal stem cells (HUMSCs) in spinal cord-transected SCI rats. First, HUMSCs exhibited chemotactic responses in vitro to CGRP. By time-lapse video analysis, increased chemotactic index (CMI), forward migration index (FMI) and speed contributed to this observed migration. Then, through enzyme immunoassay, higher CGRP concentrations at the lesion site were observed after injury. The release of CGRP directed HUMSCs to the injury site, which was suppressed by CGRP 8–37, a CGRP antagonist. We also verified that the PI3K/Akt and p38MAPK signaling pathways played a critical role in the CGRP-induced chemotactic migration of HUMSCs. Collectively, our data reveal that CGRP is a key chemokine that helps HUMSCs migrate to the lesion site and thereby can be used as a model molecule to study MSCs homing after SCI.

Fermentation products of <i>Cordyceps militaris</i> enhance performance and modulate immune response of weaned piglets

The aim of this study was to investigate the effect of supplementation of Cordyceps militaris fermentation products (CMF) on growth performance and immunocompetence of piglets. The study involved three groups of animals, which were supplemented with CMF (500, 1000 and 1500 μg/kg feed), and a control group. CMF supplementation significantly increased growth performance in weaned piglets. Bodyweight gain, average daily gain and feed intake in animals supplemented with 1000 μg CMF/kg feed were significantly higher in comparison with the control group. In addition, CMF supplementation only significantly increased the synthesis of Th1 cytokines, as indicated by the levels of IL-2 and IFN-γ. The piglets fed with the CMF supplement displayed an increased cellular immune response. Indeed, alveolar macrophages isolated from piglets supplemented with 1000 and 1500 μg CMF/kg feed had significantly higher chemotactic and phagocytic indices than those isolated from piglets that received the control feed or feed supplemented with 500 μg CMF/kg. In relation to the absence of effect on Th2 cytokines, the CMF supplement had no effect on hog cholera antibody titre. In summary, feed supplementation with CMF improves growth performance and enhances cell-mediated immunity. CMF supplementation may thus be useful at weaning to counteract physiological and immunological stress during this period. Keywords: Cellular immunity, growth performance, humoral immunity, Th1/Th2 cytokines

Interferon Regulatory Factor 6 Has a Protective Role in the Host Response to Endotoxic Shock.

Interferon Regulatory Factor (IRF) 6, a member of the IRF family, is essential for epidermal and orofacial embryonic development. Irf6 is strongly expressed in keratinocytes, in which it regulates epidermal proliferation, differentiation, and migration. A recent role for Irf6 in Toll-like receptor 2-dependent chemokine gene expression was also reported in an epithelial cell line. However, a function for Irf6 in innate immune cells was not previously reported. In the present study, we investigated the expression and function of Irf6 in bone marrow-derived neutrophils and macrophages. We show here, using a conditional knockout of Irf6 in lysosymeM expressing cells, that Irf6 is required for resistance to LPS-induced endotoxic shock. In addition, Irf6-deficient bone marrow-derived neutrophils exhibited increased chemotactic index and velocity compared with wild-type cells in vitro. TLR4-specific KC and IL6 secretions were upregulated in Irf6-deficient bone marrow-derived macrophages in vitro. These cells also exhibited an increased level of phosphorylated IkBa. Collectively, our findings suggest a role for Irf6 in the resistance to endotoxic shock due to NFk-B-mediated alteration of cytokine production.

Emergent Collective Chemotaxis without Single-Cell Gradient Sensing.

Many eukaryotic cells chemotax, sensing and following chemical gradients. However, experiments show that even under conditions when single cells cannot chemotax, small clusters may still follow a gradient. This behavior is observed in neural crest cells, in lymphocytes, and during border cell migration in Drosophila, but its origin remains puzzling. Here, we propose a new mechanism underlying this "collective guidance," and study a model based on this mechanism both analytically and computationally. Our approach posits that contact inhibition of locomotion, where cells polarize away from cell-cell contact, is regulated by the chemoattractant. Individual cells must measure the mean attractant value, but need not measure its gradient, to give rise to directional motility for a cell cluster. We present analytic formulas for how the cluster velocity and chemotactic index depend on the number and organization of cells in the cluster. The presence of strong orientation effects provides a simple test for our theory of collective guidance.

Eosinophil chemotaxis assay in nasal polyps by using a novel optical device EZ-TAXIScan: Role of CC-chemokine receptor 3

BackgroundThe chemokine receptor, CC-chemokine receptor 3 (CCR3), and its major ligands, eotaxin, RANTES, and MCP-4, are involved in eosinophil chemotaxis. It is thought that CCR3 plays an important role in the recruitment and activation of eosinophils in nasal polyposis. We examined nasal polyp extract-induced eosinophil chemotaxis and the effect of a CCR3 antagonist using EZ-TAXIScan, a novel real-time chemotaxis assay device. MethodsNasal polyps were obtained from chronic rhinosinusitis (CRS) patients during surgery. The polyps were homogenized and eotaxin levels in the extracts were measured. Eosinophils were purified from human peripheral blood by the CD16 negative selection method. Nasal polyp extract-induced eosinophil chemotaxis, with or without CCR3 antagonist, was assessed by EZ-TAXIScan. ResultsThere was a significant positive correlation between the eosinophil counts in nasal polyp and eotaxin levels in the nasal polyp extracts. Using EZ-TAXIScan, eosinophil chemotactic responses were observed following stimulation with nasal polyp extracts. There was a significant positive correlation between the chemotactic index toward the nasal polyp extracts and their eotaxin levels. Nasal polyp extract-induced chemotaxis was completely inhibited by CCR3 antagonist but not by chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) antagonist which inhibited PGD2-induced eosinophil chemotaxis. ConclusionsThe CCR3 pathway may play an important role in the pathogenesis of eosinophil recruitment in nasal polyps through selective eosinophil chemotaxis.

Microfluidic-Based Live-Cell Analysis of NK Cell Migration In Vitro.

Effector functions and cellular properties of natural killer (NK) cells are regulated by cellular and extracellular factors shaped by the microenvironments. NK cells express specific chemokine and non-chemokine receptors to aid preferential migrations or localizations in tissues. Good understanding of how NK-cell migratory properties are regulated in physiological and pathological microenvironments will provide further insights into the development of NK cell-based therapeutic approaches. In contrast to the commonly used conventional in vitro migration assays such as Trans-well assays that measure movements of a population of the migratory cells, microfluidic-based devices support live-cell imaging of cell migrations under a well-defined chemical gradient(s) at microscale. Subsequent analyses at single-cell level provide quantitative measurements of cell-migration parameters such as speed and Chemotactic Index, and permit distinguishing chemotaxis, chemokinesis, and chemo-repulsion. Our recent work established the use of a Y-shaped microfluidic device to study NK cell migrations in vitro. In this chapter, we described the detailed method of acquiring and analyzing NK cell migration in the microfluidic devices.

Efficacy of polysaccharide from Alcaligenes xylosoxidans MSA3 administration as protection against γ-radiation in female rats.

Damage to normal tissues is a consequence of both therapeutic and accidental exposures to ionizing radiation. A water-soluble heteropolysaccharide called AXEPS, composed of glucose, galactose, rhamnose and glucouronic acid in a molar ratio of nearly 1.0:1.6:0.4:2.3, respectively, was isolated from culture medium of strain Alcaligenes xylosoxidans MSA3 by ethanol precipitation followed by freeze-drying. Chemical analysis, Fourier-transform infrared (FTIR) and chromatographic studies revealed that the molecular weight was 1.6 × 104 g mol−1. This study was designed to investigate the radioprotective and biological effects of AXEPS in alleviating the toxicity of ionizing radiation in female albino rats. A total of 32 female albino rats were divided into four groups. In the control group, rats were administered vehicle by tube for four weeks. The second group was administered AXEPS (100 mg/kg) orally by gavage for four weeks. Animals in the third group were exposed to whole-body γ-rays (5 Gy) and remained for 2 weeks without treatment. The fourth group received AXEPS (100 mg/kg) orally by gavage for two weeks before being exposed to whole-body γ-rays (5 Gy), then 24 h post γ-rays, they received AXEPS (100 mg/kg) in a treatment continuing till the end of the experiment (15 days after the whole–body γ-irradiation). Oral administration of AXEPS (100 mg/kg) significantly reversed the oxidative stress effects of radiation, as evidenced by the decrease in DNA damage in the bone marrow. Assessment of apoptosis and cell proliferation markers revealed that caspase-3 significantly increased in the irradiated group. Moreover, a significant decrease in the hematological constituents of peripheral blood, the chemotactic index and CD8+ T cells were observed in animals in the irradiation-only group, whereas an increase in the lymphocyte index was observed in animals in that group. In contrast, AXEPS treatment prevented these alterations. From our results, we conclude that AXEPS is a potent antioxidant and treatment agent for protection from γ-rays.

A haptotaxis assay for leukocytes based on surface-bound chemokine gradients.

The migration of leukocytes in response to chemokine gradients is an important process in the homeostasis of the human immune system and inflammation. In vivo the migration takes place on the surface of the endothelium to which the chemokine gradient is immobilized via interaction with glycosaminoglycans. To study leukocyte migration in response to surface-bound chemokines, we generated chemokine gradients by a simple stamping method: agarose stamps were soaked with chemokine solution to form continuous chemokine gradients by diffusion. These gradients could be easily transferred to a petri dish surface by stamping. We show that neutrophil granulocytes recognize these gradients and migrate toward increasing chemokine concentrations dependent on the slope of the gradient. Single-cell responses were recorded, and statistical analyses of cell behavior and migration were performed. For analysis of chemotaxis/haptotaxis, we propose a chemotactic precision index that is broadly applicable, valid, and allows for a straightforward and rapid quantification of the precision by which cells follow the direction of a given gradient. The presented technique is very simple, cost-efficient, and can be broadly applied for generating defined and reproducible immobilized gradients of almost any protein on surfaces, and it is a valuable tool to study haptotaxis.

Activation of the NOTCH signaling pathway stimulates migration of human b-lymphocytes

The NOTCH signaling pathway is required for embryonic development, cell differentiation, and for maintenance of tissue homeostasis and stem cell function. Consequently, dysfunction is associated with several genetic diseases or cancer development. Engagement in inflammatory disorders is under investigation. We explored whether the NOTCH ligands Jagged-1 and Delta-like-4 might affect migration of human B-lymphocytes in vitro. B-lymphocytes were isolated from EDTA-anticoagulated venous blood of healthy volunteers. For migration assays 5µm pore sized nitrocellulose membrane filters and a modified 48well microchemotaxis chamber were used. After an incubation period of 90 min., the distances cells migrated were measured microscopically. The “Chemotactic Index” was defined as the ratio between the distance cells migrated towards the NOTCH ligands and that towards control medium. Additionally, migration behavior was investigated after preincubation of cells with the γ-secretase inhibitor DAPT and ADAM17. We report for the first time that the NOTCH ligands Jagged-1 and Delta-like-4 significantly stimulate the migration of human B-lymphocytes in vitro. The observed effects were comparable to the maximal effects elicited by the chemoattractant fMLP. Furthermore, preincubation of cells with DAPT and ADAM17 diminished migration. Checkerboard assays showed that B-lymphocytes migrate both, in a chemokinetic and chemotactic manner in response to the NOTCH ligands tested. In conclusion this study shows that activation of the NOTCH signaling pathway can stimulate migration of B-lymphocytes and thus may serve as a new target in inflammatory pulmonary diseases.

Inhibitory effect of plant phenolics on fMLP-induced intracellular calcium rise and chemiluminescence of human polymorphonuclear leukocytes and their chemotactic activity in vitro

Context: Polymorphonuclear leukocytes (PMNs) produce oxidants, contributing to systemic oxidative stress. Diets rich in plant polyphenols seem to decrease the risk of oxidative stress-induced disorders including cardiovascular disease.Objective: The objective of this study was to examine the in vitro effect of each of the 14 polyphenols on PMNs chemotaxis, intracellular calcium response, oxidants production.Materials and methods: Blood samples and PMNs suspensions were obtained from 60 healthy non-smoking donors and incubated with a selected polyphenol (0.5–10 µM) or a control solvent. We assessed resting and fMLP-dependent changes of intracellular calcium concentration ([Ca2+]i) in PMNs with the Fura-2AM method and measured fMLP-induced luminol enhanced whole blood chemiluminescence (fMLP-LBCL). Polyphenol chemoattractant activity for PMNs was tested with Boyden chambers.Results: Polyphenols had no effect on resting [Ca2+]i. Unaffected by other compounds, fMLP-dependent increase of [Ca2+]i was inhibited by quercetin and catechol (5 µM) by 32 ± 14 and 12 ± 10% (p < 0.04), respectively. Seven of the 14 tested substances (5 µM) influenced fMLP-LBCL by decreasing it. Catechol, quercetin, and gallic acid acted most potently reducing fMLP-LBCL by 49 ± 5, 42 ± 15, and 28 ± 18% (p < 0.05), respectively. 3,4-Dihydroxyhydrocinnamic, 3,4-dihydroxyphenylacetic, 4-hydroxybenzoic acid, and catechin (5 µM) revealed distinct (p < 0.02) chemoattractant activity with a chemotactic index of 1.9 ± 0.8, 1.8 ± 0.7, 1.6 ± 0.6, 1.4 ± 0.2, respectively.Conclusion and discussion: Catechol, quercetin, and gallic acid at concentrations commensurate in human plasma strongly suppressed the oxidative response of PMNs. Regarding quercetin and catechol, this could result from an inhibition of [Ca2+]i response.

Vitamin C Supplementation and Immune System: a Metaregression Analysis on leukocyte chemotactic responsiveness

BackgroundVitamin C is an important antioxidant. Study conducted revealed that vitamin C can alter certain cellular immune functions and humoral factors both in vivo and in vitro. The aim of this study was to evaluate, through a meta‐analysis of clinical studies, the association between Vitamin C supplementation and leukocyte chemotaxis.MethodsArticles published until December 2014 were identified by searching the database Pubmed, using the string “Vitamins”, limited to “clinical trials” and “humans”. 18091 records were retrieved. Out of them, studies with detailed information of supplementation of Vitamin C and chemotactic index were retrained for the analysis. A meta‐regression model for leukocyte chemotaxis has been estimated using Generalized Least Squares, accounting for within‐study correlation (assuming a Continuous Auto‐Regressive of first order structure) and weights proportional to study variance and study size. Effect of dose has been estimated as Cumulative Effect (dose in mg per day over the days of study duration).Results4 studies (42 patients) followed for an average time of 33 days were included in the meta‐analysis for leukocyte chemotaxis evaluation. A non‐significant dose‐response relationship has been found between Vitamin C supplementation and Chemotactic index. Num. Studies Effect S.E. p‐value Dose on leukocyte chemotaxis 4 ‐0.0000024 0.000019 0.901 ConclusionThe results suggest that Vitamin C supplementation may not have beneficial effects on leukocyte chemotaxis. However, given the high variability in study estimates, further researches are necessary to confirm the present conclusion.

Abstract B11: A microfluidic platform to evaluate soluble signaling in the metastasis microenvironment

Abstract Cancer mortality varies widely across different cancer types, but over 90% of cancer deaths, regardless of tumor origin, are caused by metastasis. Recent work to elucidate the mechanisms of metastasis has focused on the early stages of metastasis, specifically migration within a primary tumor and intravasation into vessels of the circulatory system. What is still relatively unknown is how these circulating cancer cells extravasate from the vessels to form micrometastases in distant organs. Chemokine gradients have long been associated with cell migration in embryogenesis and have also been implicated in promoting migration of cancer cells in vitro. This study was designed to investigate how competing gradients of chemotactic cytokines produced by cells in the metastatic niche communicate with cancer cells trapped in the vasculature to promote extravasation and colonization of new tumors. A microfluidic channel having five inlets and outlets was fabricated from polydimethylsiloxane (PDMS) bound to glass, and metastatic breast cancer cells (MDA-MB-231-4175 cell line, ATCC) were seeded into the device. Following cell attachment, a syringe pump supplied cells with a constant gradient of either epidermal growth factor (EGF) or stromal cell-derived factor 1 (SDF-1)-two known breast cancer chemoattractants-in serum-free media. Cells in the device were imaged regularly for 8 hours, and the timelapse data was used to quantify velocity, directionality, and chemotactic index of the cells. Following single-chemokine gradient studies, EGF and SDF-1 gradients of equal strength but opposite direction were introduced to the chip simultaneously. Cells in the device were again imaged for 8 hours, and velocity, directionality, and chemotactic index of cells in the competing gradients were quantified. To study chemokine gradients involved specifically in hematogenous metastasis, an extravasation microenvironment was built inside a microfluidic channel similar to the device previously described. Evenly spaced PDMS posts extending the height of the channel separated the channel into 5 lanes. A collagen gel was polymerized in two lanes to simulate niche extracellular matrix and to provide structural support for endothelial cells grown to confluence in the shape of a vessel. The shape of the EGF diffusion gradient formed across the endothelial monolayer was characterized using fluorescein isothiocyanate (FITC)–dextran as a diffusion marker. These experiments test the ability of both EGF and SDF-1 to promote directional migration of MDA-MB-231-4175 both individually and when applied in opposition, allowing us to test the hypotheses that chemotaxis of metastatic breast cancer cells can be controlled by chemokine gradients and that cells can sense and respond to multiple gradients simultaneously. In regard to hematogenous metastasis, characterization of an EGF gradient across an endothelial monolayer in both the absence and presence of cancer cells will assess the function of endothelial cell tight junctions in establishing chemokine gradients in the metastasis microenvironment. Combined, these studies will evaluate the hypotheses that: (1) Metastatic cancer cells trapped in the vasculature must initiate communication by modifying tight junctions between endothelial cells and (2) Once chemokines are free to diffuse into the vessel, extravasation and colonization are influenced by communication via a variety of competing chemokines that the cancer cells can sense and respond to simultaneously. Which chemokines ultimately “win” the competition and succeed in attracting cancer cells to colonize a target organ is the driving question of this research and will be the focus of future work. Citation Format: Laura Blaha, Chentian Zhang, Byungwoo Ryu, Rhoda Alani, Mario Cabodi, Joyce Wong. A microfluidic platform to evaluate soluble signaling in the metastasis microenvironment. [abstract]. In: Abstracts: AACR Special Conference on Cellular Heterogeneity in the Tumor Microenvironment; 2014 Feb 26-Mar 1; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(1 Suppl):Abstract nr B11. doi:10.1158/1538-7445.CHTME14-B11

Increased of exhaled breath condensate neutrophil chemotaxis in acute exacerbation of COPD

BackgroundNeutrophils have been involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Underlying mechanisms of neutrophil accumulation in the airways of stable and exacerbated COPD patients are poorly understood. The aim of this study was to assess exhaled breath condensate (EBC) neutrophil chemotactic activity, the level of two chemoattractants for neutrophils (GRO-α and LTB4) during the course of an acute exacerbation of COPD (AECOPD).Methods50 ex smoking COPD patients (33 with acute exacerbation and 17 in stable disease) and 20 matched ex smoking healthy controls were compared. EBC was collected by using a commercially available condenser (EcoScreen®). EBC neutrophil chemotactic activity (NCA) was assessed by using Boyden microchambers. Chemotactic index (CI) was used to evaluate cell migration. LTB4 and GROα levels were measured by a specific enzyme immunoassay in EBC.ResultsStable COPD and outpatients with AECOPD, but not hospitalized with AECOPD, had raised EBC NCA compared to healthy subjects (p < 0.05 and p < 0.01 respectively). In outpatients with AECOPD EBC NCA significantly decreased 6 weeks after the exacerbation. Overall EBC NCA was weakly correlated with sputum neutrophil counts (r = 0.26, p < 0.05).EBC LTB4 levels were increased in all groups of COPD compared to healthy subjects while GRO-α was only raised in patients with AECOPD. Furthermore, EBC LTB4 and GRO-α significantly decreased after recovery of the acute exacerbation. Increasing concentrations (0.1 to 10 μg/mL) of anti- human GRO-α monoclonal antibody had no effect on EBC neutrophil chemotactic activity of 10 exacerbated COPD patients.ConclusionsEBC NCA rose during acute exacerbation of COPD in ambulatory patients and decreased at recovery. While LTB4 seems to play a role both in stable and in exacerbated phase of the disease, the role of GRO-α as a chemotactic factor during AECOPD is not clearly established and needs further investigation.

Therapeutic effect of anti-C-X-C motif chemokine 10 (CXCL10) antibody on C protein-induced myositis mouse.

IntroductionC-X-C motif chemokine 10 (CXCL10) is a chemokine that plays a critical role in the infiltration of T cells in autoimmune diseases and is reported to be expressed in muscle tissue of polymyositis. To determine the therapeutic efficacy of CXCL10 blockade, we investigated the role of CXCL10 and the effect of anti-CXCL10 antibody treatment in C protein-induced myositis (CIM), an animal model of polymyositis.MethodsCIM was induced with human skeletal muscle C protein fragment in female C57BL/6 mice. Immunohistochemistry of CXCL10 and C-X-C motif chemokine receptor 3 (CXCR3) and measurement of serum CXCL10 were performed. Cell surface markers and interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) in CIM lymph node cells was investigated by flow cytometry. Mice with CIM were treated with anti-CXCL10 antibody or control antibody (anti-RVG1) and the inflammation in muscle tissue was assessed.ResultsImmunohistochemistry showed increased expression of CXCL10 and CXCR3 in the inflammatory lesions of muscle in CIM. Especially, CD8+ T cells invading myofiber expressed CXCR3. Serum level of CXCL10 was increased in CIM compared to the level in normal mice (normal mouse, 14.3 ± 5.3 pg/ml vs. CIM, 368.5 ± 135.6 pg/ml, P < 0.001). CXCR3 positivity in CD8+ T cells was increased compared to that of CD4+ T cells in the lymph node cells of CIM (CXCR3+ among CD8+ T cell, 65.9 ± 2.1% vs. CXCR3+ among CD4+ T cell, 23.5 ± 4.7%, P <0.001). Moreover, IFN-γ+ cells were increased among CXCR3+CD8+ T cells compared to CXCR3–CD8+ T cells (CXCR3+CD8+ T cell, 28.0 ± 4.2% vs. CXCR3-CD8+ T cell, 9.5 ± 1.5%, P = 0.016). Migration of lymph node cells was increased in response to CXCL10 (chemotactic index was 1.91 ± 0.45). CIM mice treated with anti-CXCL10 antibody showed a lower inflammation score in muscles than those with anti-RVG1 (median, anti-CXCL10 treatment group, 0.625 vs. anti-RVG1 treatment group, 1.25, P = 0.007).ConclusionsCXCL10/CXCR3 expression was increased in the inflammation of CIM model and its blockade suppressed inflammation in muscle.

S114 Simvastatin improves neutrophil migratory targeting in COPD: in vitro studies supporting Statin use as a potential adjuvant therapy

IntroductionStatin use in COPD is associated with a reduction in all cause mortality, with greatest reductions seen in patients with the highest inflammatory burden. However, the mechanism for these effects...