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Cell Trafficking (cell + trafficking)
Kinds of Cell Trafficking Selected AbstractsSlamming the DOR on chemokine receptor signaling: Heterodimerization silences ligand-occupied CXCR4 and ,-opioid receptorsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2008Dale Hereld Abstract Dimerization has emerged as a common mechanism for regulating the function of G protein-coupled receptors (GPCR). Among these are chemokine receptors, which detect various chemokines and regulate a range of physiological process, including immune cell trafficking, cancer cell migration, and neuronal patterning. Homo- and heterodimerization in response to chemokine binding has been shown to be required for the initiation or alteration of signaling by a number of chemokine receptors. In this issue of the European Journal of Immunology, a new study indicates that the formation of heterodimers of chemokine receptor CXCR4 and the ,-opioid receptor (DOR) prevents each of them from actively signaling, suggesting a novel mechanism for silencing GPCR function. See accompanying article: http://dx.doi.org/10.1002/eji200737630 [source] Genomic variants of TLR1 , It takes (TLR-)two to tangoEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2007Abstract Toll-like receptors (TLR) are innate immune sensors of microbial cell wall products that initiate early host responses. The TLR2 receptor complex has been shown to contain heterodimers of TLR2 with either TLR1 or TLR6 enabling the host to detect different microbial molecules, such as lipopeptides of different chemical composition. In this issue of the European Journal of Immunology, an important role in the sensing of microbial products for I602S, a single nucleotide polymorphism (SNP) in human TLR1 has been identified. This result, in combination with another recently published report on this polymorphism elucidating a functional role in cell trafficking (surface expression of the receptor complex in individuals carrying the SNP was altered), provide genetic evidence affirming the important function of TLR1 as an essential co-receptor for TLR2. See accompanying article: http://dx.doi.org/10.1002/eji200737034 [source] Trypanosoma cruzi infection modulates intrathymic contents of extracellular matrix ligands and receptors and alters thymocyte migrationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2003Vinícius Cotta-de-Almeida Abstract Several T cell abnormalities have been described in the course of acute Trypanosoma cruzi infection in mice, including severe effects on the thymus. In the present study, looking at the expression of extracellular matrix ligands in the thymus, we observed that deposits of fibronectin and laminin increased progressively during the course of infection, reaching a maximum at the peak of parasitemia and thymic atrophy. Concomitantly, membrane expression of fibronectin and laminin receptors (VLA-4, VLA-5 and VLA-6) was also enhanced on thymocyte subsets of infected mice. These results correlated with changes in intrathymic thymocyte migration ability during the acute phase of infection, when a higher fibronectin-dependent transmigratory activity of CD4+CD8+ thymocytes was observed. Strikingly, we detected higher frequency of immature and high VLA-expressing CD4+CD8+ T cells in the peripheral lymphoid organs of infected mice at thepeak of parasitemia. These cells seemed to be thymus dependent, since significantly lower amounts of them were found in thymectomized mice, and some of them carry "prohibited" V, segments of the TCR. Our data suggest an imbalance in the intrathymic cell trafficking following acute T. cruzi infection, likely due to dysregulated extracellular matrix-dependent interactions. [source] Neurocutaneous syndrome with mental delay, autism, blockage in intracellular vescicular trafficking and melanosome defectsEUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2006S. Buoni We evaluated a 11-year-old male patient with mental delay, autism and brownish and whitish skin spots. The former resembled those of neurofibromatosis, the latter those of tuberous sclerosis. The patient received a complete clinical work-up to exclude neurofibromatosis, tuberous sclerosis, or any other known neurocutaneous disease, with biochemistry, chromosome analysis and analysis of skin specimens. Being all the other tests not significant, two main ultrastructural defects were observed. The first was a blockage in intracellular vescicular trafficking with sparing of the mitochondria; the second an aberrant presence of melanosomes in vacuoles of several cell lines and abnormal transfer of these organelles to keratinocytes. This patient presented with a unique clinical picture distinct from neurofibromatosis or tuberous sclerosis or any other known neurocutaneous disease. The ultrastructural abnormalities suggested a defect in cell trafficking involving several cell lines and compartments. [source] Mast cells and eicosanoid mediators: a system of reciprocal paracrine and autocrine regulationIMMUNOLOGICAL REVIEWS, Issue 1 2007Joshua A. Boyce Summary:, When activated by specific antigen, complement, or other transmembrane stimuli, mast cells (MCs) generate three eicosanoids: prostaglandin (PG)D2, leukotriene (LT)B4, and LTC4, the parent molecule of the cysteinyl leukotrienes (cysLTs). These diverse lipid mediators, which are generated from a single cell membrane-associated precursor, arachidonic acid, can initiate, amplify, or dampen inflammatory responses and influence the magnitude, duration, and nature of subsequent immune responses. PGD2 and cysLTs, which were originally recognized for their bronchoconstricting and vasoactive properties, also serve diverse and pivotal functions in effector cell trafficking, antigen presentation, leukocyte activation, matrix deposition, and fibrosis. LTB4 is a powerful chemoattractant for neutrophils and certain lymphocyte subsets. Thus, MCs can contribute to each of these processes through eicosanoid generation. Additionally, MCs express G-protein-coupled receptors specific for cysLTs, LTB4, and another eicosanoid, PGE2. Each of these receptors can regulate MC functions in vivo by autocrine and paracrine mechanisms. This review focuses on the biologic functions for MC-associated eicosanoids, the regulation of their production, and the mechanisms by which eicosanoids may regulate MC function in host defense and disease. [source] Lymphatics at the crossroads of angiogenesis and lymphangiogenesisJOURNAL OF ANATOMY, Issue 6 2004Claudio Scavelli Abstract The lymphatic system is implicated in interstitial fluid balance regulation, immune cell trafficking, oedema and cancer metastasis. However, the sequence of events that initiate and coordinate lymphatic vessel development (lymphangiogenesis) remains obscure. In effect, the understanding of physiological regulation of lymphatic vasculature has been overshadowed by the greater emphasis focused on angiogenesis, and delayed by a lack of specific markers, thereby limiting this field to no more than a descriptive characterization. Recently, new insights into lymphangiogenesis research have been due to the discovery of lymphatic-specific markers and growth factors of vascular endothelial growth factor (VEGF) family, such as VEGF-C and VEGF-D. Studies using transgenic mice overexpressing VEGF-C and VEGF-D have demonstrated a crucial role for these factors in tumour lymphangiogenesis. Knowledge of lymphatic development has now been redefined at the molecular level, providing an interesting target for innovative therapies. This review highlights the recent insights and advances into the field of lymphatic vascular research, outlining the most important aspects of the embryo development, structure, specific markers and methods applied for studying lymphangiogenesis. Finally, molecular mechanisms involved in the regulation of lymphangiogenesis are described. [source] Review article: lymphatic system and associated adipose tissue in the development of inflammatory bowel diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2010P.-Y. Von Der Weid Summary Background, The lymphatic system plays critical roles in tissue fluid homoeostasis, immune defence and metabolic maintenance. Lymphatic vessels transport lymph, proteins, immune cells and digested lipids, allowing fluid and proteins to be returned to the blood stream, lipids to be stored and metabolized and antigens to be sampled in lymph nodes. Lymphatic drainage is mainly driven by rhythmic constrictions intrinsic to the vessels and critically modulated by fluid pressure and inflammatory mediators. Aim, To collect and discuss the compelling available information linking the lymphatic system, adiposity and inflammation. Methods, A literature search was performed through PubMed focusing on lymphatic system, inflammation, immune cells and fat transport and function in the context of IBD. Results, Evidence collected allows us to propose the following working model. Compromised lymph drainage, reported in IBD, leads to oedema, lymphangiogenesis, impaired immune cell trafficking and lymph leakage. Lymph factor(s) stimulate adipose tissue to proliferate and produce cytokines, which affect immune cell functions and exacerbate inflammation. Conclusions, Understanding the lymphatic system's role in immune cell trafficking and immune responses, contribution to fat transport, distribution, metabolism and implication in the pathogenesis of chronic intestinal inflammation may provide the basis for new therapeutic strategies and improved quality-of-life. [source] Oxidative stress due to anesthesia and surgical trauma: Importance of early enteral nutritionMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2009Katerina Kotzampassi Abstract Anesthesia and surgical trauma are considered major oxidative and nitrosative stress effectors resulting in the development of SIRS. In this study we evaluated the usefulness of early enteral nutrition after surgical trauma. Sixty male Wistar rats were subjected to midline laparotomy and feeding-gastrostomy. Twenty of these rats served as controls after recovering from the operation stress. The remaining rats received, through gastrostomy, enteral nutrition or placebo-feeding for 24 h. Oxidative stress markers and CC chemokine production were evaluated in rat serum and liver tissue. The operation itself was found to increase nitric oxide (NO) and malondialdehyde (MDA) and to decrease superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as liver tissue energy charge (EC) in relation to controls. The rats receiving enteral feeding exhibited statistically significantly lower levels of NO and MDA, and higher levels of SOD, GSH-Px, and liver EC, in relation to placebo feeding rats. The operation significantly increased the chemokines monocyte chemoattractant protein (MCP)-1 and regulated upon activation, normal T-cell expressed, and secreted (RANTES) in rat serum, while enteral nutrition caused a further significant increase in chemokine levels in serum. mRNA chemokine expression in liver was increased in a similar pattern. These findings indicate that early enteral feeding might play an important role after surgery ameliorating oxidative stress, affecting positively the hepatic EC and regulating, via chemokine production, cell trafficking, and healing process. [source] Molecular imaging for pediatric lung diseasesPEDIATRIC PULMONOLOGY, Issue 4 2004Jean-Christophe Richard MD Abstract Molecular imaging is a rapidly developing multidisciplinary field that combines advances in contrast agent development, instrumentation, and molecular/cell biology to follow cellular and sub-cellular events in intact organisms. Platforms for molecular imaging include radionuclide-based methods, optical methods, and magnetic resonance. To date, molecular imaging studies of the lungs have been used to monitor the effectiveness of gene transfer, neutrophilic inflammation, and cell trafficking. Eventually, the goal will be to translate these new techniques to clinical settings such as cystic fibrosis. Pediatr Pulmonol. 2004; 37:286,296. © 2004 Wiely-Liss, Inc. [source] ORIGINAL ARTICLE: Cytokine Array Comparisons of Plasma from Cycling Fertile Women on Cycle Day 5 and OvulationAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2009Kota Hatta Problem, To identify plasma immuno-regulatory molecules up or down regulated between the follicular phase and ovulation of the human menstrual cycle. Method of study, RayBio® cytokine arrays were used to screen 174 immuno-regulatory molecules in plasma collected during the follicular phase at menstrual cycle day 5 and at ovulation from five healthy, non-smoking, fertile women of reproductive age not using hormonal contraception. Results, A total of 23 differentially expressed molecules were found: 10 molecules were differentially up-regulated and 13 down-regulated at ovulation compared with that at the follicular phase (, = 0.05, false discovery rate of 0.45). Conclusion, Circulating immuno-regulatory molecules fluctuate over the menstrual cycle in healthy women. The combination of differentially expressed molecules suggests roles in cyclical regulation of angiogenesis and immune cell trafficking. [source] Gene expression profiling in autoantibody-positive patients with arthralgia predicts development of arthritis,ARTHRITIS & RHEUMATISM, Issue 3 2010Lisa G. M. van Baarsen Objective To identify molecular features associated with the development of rheumatoid arthritis (RA), to understand the pathophysiology of preclinical development of RA, and to assign predictive biomarkers. Methods The study group comprised 109 anti,citrullinated protein antibody (ACPA), and/or rheumatoid factor,positive patients with arthralgia who did not have arthritis but were at risk of RA, and 25 patients with RA. The gene expression profiles of blood samples obtained from these patients were determined by DNA microarray analysis and quantitative polymerase chain reaction. Results In 20 of the 109 patients with arthralgia who were at risk of RA, arthritis developed after a median of 7 months. Gene expression profiling of blood cells revealed heterogeneity among the at-risk patients, based on differential expression of immune-related genes. This report is the first to describe gene signatures relevant to the development of arthritis. Signatures significantly associated with arthritis development were involved in interferon (IFN),mediated immunity, hematopoiesis, and chemokine/cytokine activity. Logistic regression analysis revealed that the odds ratio (OR) for developing arthritis within 12 months was 21.0 (95% confidence interval [95% CI] 2.8,156.1 [P = 0.003]) for the subgroup characterized by increased expression of genes involved in IFN-mediated immunity and/or cytokine/chemokine-activity. Genes involved in B cell immunology were associated with protection against progression to arthritis (OR 0.38, 95% CI 0.21,0.70 [P = 0.002]). These processes were reminiscent of those in patients with RA, implying that the preclinical phase of disease is associated with features of established disease. Conclusion The results of this study indicate that IFN-mediated immunity, hematopoiesis, and cell trafficking specify processes relevant to the progression of arthritis independent of ACPA positivity. These findings strongly suggest that certain gene signatures have value for predicting the progression to arthritis, which will pave the way to preventive medicine. [source] Induction of prolonged infiltration of T lymphocytes and transient T lymphocyte,dependent collagen deposition in mouse lungs following adenoviral gene transfer of CCL18ARTHRITIS & RHEUMATISM, Issue 8 2006Irina G. Luzina Objective Levels of CCL18 are elevated in patients with scleroderma lung disease and other fibrotic pulmonary diseases associated with T lymphocyte involvement. We sought to determine whether CCL18 alone can induce pulmonary T lymphocytic infiltration and fibrosis in mouse lungs. Methods An adenovirus vector was constructed and used for CCL18 delivery to mouse lungs in vivo. Immunohistochemical, flow cytometric, and enzyme-linked immunosorbent assay analyses were used to assess the resulting changes. Results Overexpression of CCL18 led to massive perivascular and peribronchial infiltration of T lymphocytes. Although the expression of CCL18 peaked on day 7, the infiltration persisted up to day 64 after infection. The infiltrates were negative for proliferating cell nuclear antigen and TUNEL, suggesting the role of cell trafficking, rather than proliferation and apoptosis, in the infiltration dynamics. Patchy destruction of the alveolar architecture and collagen accumulation in association with the infiltrates were also noticed. These changes were infiltration-dependent, rather than CCL18-dependent, since treatment with antilymphocyte serum completely abrogated the CCL18-induced changes. The infiltrates consisted almost exclusively of T lymphocytes that were minimally activated, with a minimal increase in the expression of CD69 and no changes in the expression of CD25, Fas, FasL, or CD40L. There was no increase in total pulmonary levels of profibrotic cytokines transforming growth factor ,1 (TGF,1) or interleukin-13, although active TGF,1 was present locally in association with the infiltrates and areas of distorted alveolar architecture. Prestimulation of primary T lymphocytes with CCL18 in vitro caused an up-regulation of TGF,1 and collagen production in T lymphocyte/fibroblast cocultures. Conclusion CCL18 promotes selective, long-term pulmonary infiltration of T lymphocytes and infiltration-dependent accumulation of collagen through a TGF,1-dependent mechanism. [source] Functional roles of N -glycans in cell signaling and cell adhesion in cancerCANCER SCIENCE, Issue 7 2008Yan-Yang Zhao Glycosylation is one of the most common post-translational modification reactions and nearly half of all known proteins in eukaryotes are glycosylated. In fact, changes in oligosaccharide structures are associated with many physiological and pathological events, including cell growth, migration, differentiation, tumor invasion, host,pathogen interactions, cell trafficking, and transmembrane signaling. Emerging roles of glycan functions have been highly attractive to scientists in various fields of life science as they open a field, "Functional Glycomics", that is a comprehensive study of the glycan structures in relation to functions. In particular, the N-glycans of signaling molecules including receptors or adhesion molecules are considered to be involved in cellular functions. This review will focus on the roles of glycosyltransferases involved in the biosynthesis of N-glycan branching and identification of cell surface receptors as their target proteins. We also suggest that the modulation of N-glycans of those receptors alters their important functions such as cell signaling and cell adhesion which are implicated in cancer invasion and metastasis. (Cancer Sci 2008; 99: 1304,1310) [source] Imaging of cell trafficking and metastases of paediatric rhabdomyosarcomaCELL PROLIFERATION, Issue 2 2008G. Seitz Objective:,The aim of this study was to establish a preclinical mouse model to study metastases of paediatric rhabdomyosarcoma at the macroscopic and cellular levels, with different imaging methods. Experimental Design:,The alveolar rhabdomyosarcoma cell line Rh30 was stably transfected with the red fluorescent protein (DsRed2) then was xenotransplanted (intravenous injection [n = 8], and footpad injection [n = 8]) into nude mice (NMRI nu/nu). Macroscopic imaging of metastases was performed using DsRed2-fluorescence and flat-panel volumetric computed tomography scan. In a further series of animals (n = 8), in vivo cell trafficking of rhabdomyosarcoma cells using cellular imaging with an Olympus OV100 variable-magnification small-animal imaging system was used. Results:,Metastases in the pelvis, thoracic wall and skin were visualized by fluorescence imaging. Pelvic metastases were found after tail vein injection and at other metastatic sites after footpad injection. Flat-panel volumetric computed tomography scan data allowed highly specific analysis of contrast between tumour and surrounding tissue. Correlation between fluorescence and flat-panel volumetric computed tomography scan imaging data was observed. Single-cell imaging visualized tumour cells in the vessels and demonstrated the arrest of tumour cells at vessel junctions followed by extravasation of the tumour cells. Conclusion:,We established a model for visualization of experimental metastatic invasion and describe relevant tools for imaging childhood rhabdomyosarcoma metastases at the macroscopic and cellular levels. Imaging of cell trafficking visualized the behaviour of tumour cells and development of metastases by accumulation and extravasation of rhabdomyosarcoma cells. [source] Technoreview: Molecular imaging of host,pathogen interactions in intact small animalsCELLULAR MICROBIOLOGY, Issue 4 2004David Piwnica-Worms Summary Characterization and non-invasive measurement of host,pathogen interactions in living cells, animal models and humans at the cellular and molecular levels is now possible using remote imaging detectors. Positron emission tomography scanners, highly sensitive cooled charge-coupled device cameras for bioluminescence and fluorescence imaging as well as high-magnetic-field magnetic resonance imaging scanners can be used to study such diverse processes as pathogen tropism, pathogen life cycle, signal transduction, host response, cell trafficking and gene transfer. In many cases, images from more than one modality can be fused, allowing structure,function and multifunction relationships to be studied on a tissue-restricted or regional basis. These new instruments, when used in conjunction with targeted contrast agents, reporter substrates and radiopharmaceuticals, enable ,molecular imaging' with enormous potential for elucidating host,pathogen interactions in intact animal models. [source] In vivo imaging of microglial cell traffickingACTA OPHTHALMOLOGICA, Issue 2009M PAQUES Purpose Microglial cells (MCs) are active sensors of neural tissues that are rapidly mobilized upon disruption of homeostasis. OUr goal was to observe in vivo the migration of MCs, which has not been done yet. Methods Following acute laser damage, the behavior of MCs in the retina of adult Cx3cr1gfp/+ and gfp/gfp mice was observed noninvasively using time-lapse confocal scanning laser ophthalmoscopy. Observation were done at various time-points up to 8 days after laser damage. Results Focal damage elicite prompt migratory response of MCs within 200 to 400 µm around laser burns. This migratory response was preceded in all case by dendritic reorientation. Convergent and nonconvergent migration were observed. Such migratory activity persisted several days after laser damage. At day 8, the microglia network was restored and microglial locomotion had ceased. Conclusion To our knowledge, this is the first observation of microglial locomotion in vivo. A Morphological evidence of microglial activation starts with dendritic reorganization. Migrating cells were only of the dendritic type (i.e. not ameboid). There appears to be a notable heterogeneity in the locomotor response of MCs. MCs within and around scars remain highly motile and mobile several days after laser damage. [source] | |||||||||||||