TY - JOUR. T1 - Prolactin suppression of leukocyte chemotaxis in vitro. AU - Harris, R. D.. AU - Kay, N. E.. AU - Seljeskog, E. L.. AU - Murray, K. J.. AU - Douglas, S. D.. PY - 1979/1/1. Y1 - 1979/1/1. N2 - Leukocyte chemotaxis in vitro was studied for cells from patients with pituitary adenomas. Leukocytes obtained preoperatively from two of three patients with elevated serum prolactin levels demonstrated chemotaxic alterations described in other malignant disease. Statistically significant suppression of chemotaxis occurred in the leukocytes of four of 12 specimens from normal donors at concentrations of 1000 ng/ml, and in four of eight specimens at 2000 ng/ml of prolactin in preincubation media. Thus prolactin concentration may influence the motility of leukocytes. The variable neoplastic behavior of morphologically similar pituitary adenomas may, in part, reflect a neurohormonally altered host response to the presence of these lesions.. AB - Leukocyte chemotaxis in vitro was studied for ...
TY - JOUR. T1 - Psoriasis and leukocyte chemotaxis. AU - Tagami, H.. AU - Iwatsuki, K.. AU - Takematsu, H.. PY - 1987/1/1. Y1 - 1987/1/1. N2 - Transepidermal migration of leukocytes, with resultant formation of microscopic or macroscopic sterile subcorneal pustules is a phenomenon characteristically noted in psoriasis and related sterile pustular dermatoses. It is natural to assume the presence of potent neutrophil chemotactic substances in the subcorneal portion of the lesional epidermis, because this location is the target of the in vivo leukocyte chemotaxis. In fact, crude psoriasis scale extracts show remarkably high neutrophil chemotactic and activating properties as compared with those of other non-psoriatic inflammatory dermatoses. We isolated a psoriatic leukotactic factor (PLF) having a molecular mass of around 12 kD, distinct from those common to other inflammatory changes involving the skin or those released by bacteria. Further analysis of PLF identified C5 cleavage fragments, ...
Methods Quiescent cultured RASMCs were pretreated with E2 or vehicle for 24 hours before tumor necrosis factor (TNF)-α was added. After 6 hours of treatment, total RNA was extracted from cells using TRIzol reagent, and SYBR green real-time RT-PCR was used to detect expression of CINC-2 mRNA. Conditioned media was collected and concentrated to measure CINC-2 protein level by ELISA. To assess neutrophil chemotactic activity of conditioned media, in vitro chemotaxis assays were performed using differentiated HL-60 cells in a 96-well modified Boyden chamber appropriate for the evaluation of leukocyte chemotaxis. The nonselective ER antagonist ICI-182780 was given to cells 2 hours prior to E2 incubation to study the mechanism of E2 effect. ...
The sequential and regulated recruitment of leukocytes into tissues by chemoattractants is essential for effective clearance of pathogens and healing. The Rho GTPases Cdc42, Rac, and Rho are important for establishing and maintaining migratory polarity. Most chemoattractants for phagocytes signal either through seven transmembrane G-protein-coupled receptors (GPCRs) or tyrosine kinase receptors. Y721 is the most important for chemotaxis because it recruits phospholipase-C-γ (PL C-γ) and the p85 subunit of class 1A PI3Ks, both of which are implicated in the initiation of chemotaxis. Several intracellular signaling complexes contribute to the polarization of phagocytes in response to chemoattractants, and they probably act together to allow optimal chemotaxis. Cdc42 is implicated in multiple types of cell polarity, including axon specification, yeast mating, and epithelial polarity. There are several PLC isoforms, of which PLCβ2 and PLCβ3 are activated by GPCR signaling in neutrophils, whereas PLCβ
Lymphocyte chemotaxis in inflammation. VIII. Demonstration of lymphocyte chemotactic lymphokines in PPD-induced delayed hypersensitivity skin reaction site in t
Chemotaxis is the primary mechanism by which cell movements are directed within multicellular organisms, and it is a major component of embryonic development, wound healing, and immune responses. Chemotaxis involves a complex cascade of events--formation of signaling complexes, receptor polarization, adhesion molecule activation, and cytoskeletal reorganization. Previous assay methods were limited in several ways that reduced users abilities to obtain quantitative data or to control conditions precisely. We describe a unique chemotactic assay that can incorporate multiple chemotactic gradients in different spatial and temporal combinations. In addition, this assay is easily adapted for live-cell imaging and fluorescent microscopy. With its relative simplicity, flexibility, and precision, this method is a key tool for the study of cellular chemotactic responses and the signaling processes underlying them. ...
The Notch signaling pathway is a well-conserved signaling pathway. As known so far Notch signaling is engaged in physiological processes in pulmonary hypertension (PAH). As shown recently, a significant increase of perivascular numbers of macrophages (CD68(+)) and monocytes (CD14(+)) can be observed in PAH. The aim of this study was to elucidate the role of the Notch signaling pathway in the migration of human monocytes.. Human monocytes were isolated from venous blood, taken from healthy donors. For the chemotactic assays modified 48-well microchemotaxis chambers were used. Cells migrated through a 5 µm pore sized cellulose membrane filter for 45 min in a humidified atmosphere against a gradient of the substances tested (fMLP, Jagged-1, DLL-4). Migration depth of the cells was quantified microscopically by measuring the distance [µm] from the surface of the filters to the leading front of the cells.. The Notch ligands DLL-4 and Jagged-1 significantly stimulated direct and indirect migration ...
Search and apply for the leading Front Office Clerk job offers. All Administration - Clerical jobs in one easy search. Page 7. jobisjob.com
To gain further insight into the effects of calcium influx on neutrophil chemotaxis, we depleted the calcium in the under-agarose chemotaxis models using a calcium-free solution and EGTA. We observed that the inhibitory effects of LPS on neutrophil chemotaxis were impaired in the presence of calcium-depleted medium (Fig. 3C). Moreover, using a calcium ionophore ionomycin to stimulate neutrophils, a sustained calcium influx was observed and chemoattractant-induced neutrophil chemotaxis was dramatically inhibited (SI Appendix, Fig. S7A). The sustained calcium influx appeared to be required for initiating stop signal of neutrophil chemotaxis. Previous reports displayed that intracellular calcium was necessary for neutrophil migration (19). Therefore, we further clarified the effects of calcium on neutrophil migration. Different chemoattractant-induced calcium mobilization patterns were found to be inconsistent (20, 21). We noted that different from stimulation of IL-8, a rapid increase in ...
TY - JOUR. T1 - Three forms of monocyte-derived neutrophil chemotactic factor (MDNCF) distinguished by different lengths of the amino-terminal sequence. AU - Teizo, Yoshimura. AU - Robinson, Elizabeth A.. AU - Appella, Ettore. AU - Matsushima, Kouji. AU - Showalter, Stephen D.. AU - Skeel, Alison. AU - Leonard, Edward J.. PY - 1989/1. Y1 - 1989/1. N2 - Human monocyte-derived neutrophil chemotactic factor (MDNCF) was purified from culture supernatant of lipopolysaccharide-stimulated human peripheral blood mononuclear leukocytes on a column of Sepharose-bound murine monoclonal anti-MDNCF. About 65% of the culture fluid chemotactic activity was bound to the column. The unbound 35% probably represents chemotactic activity of other cytokines in the culture fluid. More than 85% of the bound activity was eluted by pH 2.5 glycine buffer. When this material was applied to an HPLC-CM column, gradient elution produced four well-separated A280 peaks, each of which had chemotactic activity. N-terminal amino ...
TY - JOUR. T1 - Antihistamine effect of supplemental ascorbic acid and neutrophil chemotaxis. AU - Johnston, Carol. AU - Martin, L. J.. AU - Cai, X.. PY - 1992/1/1. Y1 - 1992/1/1. N2 - Renewed interest in the antihistamine action of ascorbic acid has emerged with the recently recognized immunosuppressive role of histamine. We examined the antihistamine effect of acute and chronic vitamin C (VC) administration and its effect on neutrophil chemotaxis in healthy men and women. In the chronic study, 10 subjects ingested a placebo during weeks 1, 2, 5 and 6, and 2 g/day of VC during weeks 3 and 4. Fasting blood samples were collected after the initial 2-week period (baseline) and at the end of weeks 4 and 6. Plasma ascorbate rose significantly following VC administration compared to baseline and withdrawal values. Neutrophil chemotaxis rose 19% (NS) and VC administration, and fell 30% after VC withdrawal, but these changes were not correlated to plasma ascorbate levels (r = 0.01). Chemotaxis was ...
JS Parmar, D Bilton, ER Chilvers, DA Lomas; The Selective Chemotactic Effect of α1-Antitrypsin Polymers for Human Peripheral Blood Neutrophils. Clin Sci (Lond) 1 July 2002; 103 (s47): 56P. doi: https://doi.org/10.1042/cs103056P. Download citation file:. ...
Dendritic cells are believed to be crititcal in both initiating and modulating immune responses (32). Central to their role as immune sentinels is their ability to capture, process, and transport Ag to secondary lymphoid tissues where they serve as potent APCs capable of stimulating T cells in T cell areas. Trafficking of both T cells and dendritic cells to lymphoid organs followed by precise microenvironmental localization is necessary for efficient immune surveillance and is thought to be directed by chemokines (12). 6Ckine, a recently discovered CC chemokine (13, 14, 15), has been shown to be expressed by HEV in lymph nodes (16, 17), is capable of rapidly triggering integrin binding to vascular ligands (18), and is a potent chemoattractant for T lymphocytes (14, 15, 16, 17, 19), making it a leading candidate for mediating T cell homing. 6Ckine is also expressed by endothelial cells in lymphatic venules (17), the major route of dendritic cell entry into lymph nodes (33), suggesting that it may ...
The chemokinetic inhibitory factor (CIF) is a recently described B-cell derived lymphokine that mediates a chemokinetic inhibitory effect on human polymorphonuclear leukocyte (PMN) migration. In the present report the interaction of CIF with the neutrophil plasma membrane was studied. Normal human peripheral blood neutrophils and purified neutrophil plasma membranes selectively removed biologic activity from CIF-containing concentrates obtained during the purification procedure from conditioned medium. Removal was obtained at both 4 degrees C and 37 degrees C. Furthermore, HL-60 cells treated with dimethyl sulfoxide removed CIF activity (granulocyte-like cells) but HL-60 cells treated with 12-O-tetradecanoylphorbol-13-acetate (macrophage-like cells) did not. Purified human blood monocytes, cells from the macrophage-like U-937 cell line and cells from the basophilic leukemia cell line KU-812 did not remove CIF. These studies suggest that neutrophils express specific binding sites for ...
Human granulocytes were stimulated by means of a micropipette, with an orifice of about 0.2 micrometer in diameter, which contained fMet-Leu-Phe at a concentration of 10(−5) M. The cells were reorientated by extending lamellipodia towards the source of the attractant, often within less than 10 s. Any part of the granulocyte, from the front to the tip of the tail, could be stimulated to produce new lamellipodia. Usually, but not always, this response occurred at the side of the cell nearest to the micropipette. Cells stimulated from behind responded in one of the following ways: (1) Cells that maintained their polarity extended new lamellipodia at one side of the leading front and reorientated by moving in a U-turn towards the micropipette. Occasionally, the leading front was split because one part of the front tried to make a left-hand and the other a right-hand turn. (2) Formation of lamellipodia at the leading front was arrested and new lamellipodia were formed at the tail instead, ...
Harbord, M W N, Marks, D J B, Forbes, A, Bloom, S L, Day, R M and Segal, A W (2006) Impaired neutrophil chemotaxis in Crohns disease relates to reduced production of chemokines and can be augmented by granulocyte-colony stimulating factor. Alimentary Pharmacology and Therapeutics, 24 (4). pp. 651-660. ISSN 0269-2813 Full text not available from this repository. (Request a copy ...
Thank you for your interest in spreading the word about Clinical Science.. NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.. ...
In article ,9411040146.AA25636 at eliris.med.yale.edu,, lolis at ELIRIS.MED.YALE.EDU (elias lolis) wrote: , Does anyone have any strong opinions on what the most effective apparatus is , for doing neutrophil chemotaxis assays? The Boyden-chamber seems to be , heavily used but there appear to be other systems that do the job. Specifically, , does anyone know the relative advantages/disadvantages of using the 48-well , microchamber from Neuroprobe or any of the products sold by Costar. I am , a protein biochemist who will shortly set up to do these chemotaxis assays , (Ive never done them before) and any help or references would be appreciated. , , Elias Dear Elias, The Costar transwells are small, relatively cheap, disposable items. It is possible to culture cells on the filters and observe penetration through the monolayer. They are simple to set up but use a lot of solutions and require you to cut out each filter from the frame by hand, which is quite a pain. I dont know if Costar has ...
To date, we have not tested the fixation of cells in gel inside the observation area of µ-Slide Chemotaxis. From tube formation assays, we generally know that fixation, permeabilization, blocking, and staining of cells on Matrigel™ is possible. Therefore, it should also be possible to do immunostainings in the 3D chemotaxis assay. In this case, we recommend removing the liquid from one reservoir and successively filling the second reservoir with the different solutions. We can assume that the incubation time should be increased by a factor of 4, in order to give the solutions sufficient time to diffuse into the observation area. The filling of liquids should be carefully done, in order not to push out the gel from the observation area.. ...
Abstract: In recent years, it has been drawn a lot of attention to the question of whether logistic kinetics is sufficient to enforce the global existence of classical solutions or to prevent finite-time blow-up in various chemotaxis models. However, for several important chemotaxis models, only in the space two dimensional setting, it has been shown that logistic kinetics is sufficient to enforce the global existence of classical solutions (see [8] and [28]). The current paper is to give a confirmed answer to the above question for the following parabolic-elliptic chemotaxis system with singular sensitivity and logistic source in any space dimensional setting, \begin{equation} \begin{cases} u_t=\Delta u-\chi\nabla\cdot (\frac{u}{v} \nabla v)+u(a(x,t)-b(x,t) u),\quad x\in \Omega\cr 0=\Delta v-\mu v+\nu u,\quad x\in \Omega \quad \cr \frac{\partial u}{\partial n}=\frac{\partial v}{\partial n}=0,\quad x\in\partial\Omega, \end{cases} \end{equation} where $\Omega \subset \mathbb{R}^n$ is a bounded ...
Proposed path for GC chemotaxis induced by netrin binding with DCC receptors.Solid arrows indicate the prevalent direction of chemical reactions, the dashed arr
Learn more about 1-aminomethyl-cyclohexyl-diethyl-amine. We enable science by offering product choice, services, process excellence and our people make it happen.
Neutrophils play a critical role in host defense against invading pathogens. Chemotaxis, the directed migration of cells, allows neutrophil to seek out the sites of inflammation and infection. Neutrophil chemotaxis as well as other type of cell migration are considered as cycles composed of highly orchestrated steps. Recently the underlying signaling mechanisms of neutrophil chemotaxis are better understood with the studies in knockout mice and neutrophil-like cell lines: a number of signaling molecules in neutrophil chemotaxis have been identified, and a feedback loop-based model of "frontness" and "backness" pathways has been proposed to explain the establishment of neutrophil polarity and chemotaxis. However, the signaling mechanisms that control actin cytoskeleton reorganization and interaction between the cells and the substratum on which cells migrate are still not fully understood. In my first research project, we have identified a signaling pathway, mediated by non-receptor tyrosine ...
In addition to the steepness of the gradient, the context in which a cell perceives a chemoattractant gradient can have a profound effect on their response to the chemotactic stimulus. For example, both our group (Heit et al., 2005) and others (Ferguson et al., 2007) have demonstrated that neutrophil chemotaxis to fMLP is profoundly impacted by the makeup of the substratum upon which the cell is crawling. For example, ligands for LFA-1, MAC-1 and VLA-4 need to be present to get a full chemotactic response to fMLP (Heit et al., 2005). Moreover, Ferguson et al. have demonstrated profound differences in the chemotaxis of neutrophils to fMLP on glass verses protein substrata (Ferguson et al., 2007). These profound differences in the behavior of neutrophils, based on the substratum they are crawling upon, demonstrate that careful selection of the substratum is an important factor when selecting or designing chemotactic assays, especially in mammalian systems. In this regard, we have used a ...
Chemokinesis is chemically prompted kinesis, a motile response of unicellular prokaryotic or eukaryotic organisms to chemicals that cause the cell to make some kind of change in their migratory/swimming behaviour. Changes involve an increase or decrease of speed, alterations of amplitude or frequency of motile character, or direction of migration. However, in contrast to chemotaxis, chemokinesis has a random, non-vectorial moiety, in general. Due to the random character, techniques dedicated to evaluate chemokinesis are partly different from methods used in chemotaxis research. One of the most valuable ways to measure chemokinesis is computer-assisted (see, e.g., Image J) checker-board analysis, which provides data about migration of identical cells, whereas, in Protozoa (e.g., Tetrahymena), techniques based on measurement of opalescence were also developed. Becker EL (1977). "Stimulated neutrophil locomotion: chemokinesis and chemotaxis". Arch Pathol Lab Med. 101 (10): 509-13. PMID 199132. ...
El Annan J, Goyal S, Zhang Q, Freeman GJ, Sharpe AH, Dana R. Regulation of T-cell chemotaxis by programmed death-ligand 1 (PD-L1) in dry eye-associated corneal inflammation. Invest Ophthalmol Vis Sci. 2010;51 (7) :3418-23.
The heterogeneity of the H460 large cell lung cancer cell line was investigated by selecting for chemokinetic cells from a CON population that demonstrated both chemokinesis and chemotaxis. Using Boyden chambers, cells that migrated under chemokinetic conditions were collected and their numbers expanded. Time-lapsed microscopy under isotropic conditions showed that KINE cells moved faster and changed directions more frequently than CON confirming their chemokinetic character. KINE cells which lacked stable focal adhesion were also less adhesive to culture plates compared to CON cells which had focal adhesions at the leading edge shown by phospho-Paxillin-tyr118 antibody labeling. Weak substrate adhesion in KINE cells may account for motile characteristics of rapid and random movement [16-19]. Furthermore, the selection for increased chemokinesis did not compromise the ability of KINE cells to chemotax. KINE cells were also significantly more invasive compared to CON.. These results underscore ...
Lamb, DJ, Modjtahedi, H, Plant, NJ and Ferns, GAA (2004) EGF mediates monocyte chemotaxis and macrophage proliferation and EGF receptor is expressed in atherosclerotic plaques ...
TY - JOUR. T1 - Chemokines in ischemia and reperfusion. AU - Frangogiannis, Nikolaos G.. PY - 2007/5. Y1 - 2007/5. N2 - Chemokine signaling plays an important role in the post-ischemic inflammatory response. Overlapping pathways involving reactive oxygen intermediates, Toll-like receptor (TLR) activation, the complement cascade and the nuclear factor (NF)-κB system induce both CXC and CC chemokines in ischemic tissues. Reperfusion accentuates chemokine expression promoting an intense inflammatory reaction. ELR-containing CXC chemokines regulate neutrophil infiltration in the ischemic area, whereas CXCR3 ligands may mediate recruitment of ThI cells. CC chemokines, on the other hand, induce mononuclear cell infiltration and macrophage activation. Evidence suggests that chemokine signaling mediates actions beyond leukocyte chemotaxis and activation, regulating angiogenesis and fibrous tissue deposition. Effective repair of ischemic tissue is dependent on a well-orchestrated cellular response and ...
A team of researchers from the University of Manitoba in collaboration with local clinical scientists in Winnipeg, Canada, have developed a new method for rapid neutrophil chemotaxis test directly from a small drop of whole ...
The outcomes of this study are especially favorable considering the study population, which included older patients (68% over the age of 60 years) and a high proportion of matched unrelated donors (50%) and HLA-mismatched donors (16%); the anticipated incidence of acute GVHD in similar patients is typically more than 50%.31-33 The patients in our study also had major coexisting illnesses, with an intermediate or high comorbidity index26 in almost half the patients. At our institution, by day 180 among patients receiving tacrolimus and methotrexate for prophylaxis after reduced-intensity conditioned HSCT, the rates of acute GVHD are 38.5% for grade II to IV disease and 21.9% for grade III or IV disease. During the same time period in our study, the use of a combination of maraviroc, tacrolimus, and methotrexate resulted in cumulative incidence rates of 23.6% for grade II to IV disease and 5.9% for grade III or IV disease. Results of this study also compare favorably with other studies of ...
Sphingosine-1-phosphate (S1P) is the endogenous ligand for the sphingosine-1-phophate receptors (S1P1-5) and triggers a number of cellular responses through their stimulation. S1P and its interaction with the S1P receptors play a significant role in a variety of biological processes including vascular stabilization, heart development, lymphocyte homing, and cancer angiogenesis. Agonism of S1P1, especially, has been shown to play an important role in lymphocyte trafficking from the thymus and secondary lymphoid organs, inducing immunosuppression, which has been established as a novel mechanism of treatment for immune diseases and vascular diseases. Sphingosine-1 -phosphate (SlP) has been demonstrated to induce many cellular effects, including those that result in platelet aggregation, cell proliferation, cell morphology, tumor cell invasion, endothelial cell and leukocyte chemotaxis, endothelial cell in vitro angiogenesis, and lymphocyte trafficking. SlP receptors are therefore good targets for a ...
Shop Leukocyte cell-derived chemotaxin ELISA Kit, Recombinant Protein and Leukocyte cell-derived chemotaxin Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
Blocking of monocyte migration induced by supernatant of RA SCL stimulated with TNF-α. Monocyte migration induced by supernatants of RA SCLs (RA6/1 and RA8/3)
Primobolan side effects is a selective agonist of beta2-adrenergic receptors. At therapeutic doses it acts on beta2-adrenergic receptors of smooth muscles of the bronchi, providing pronounced bronchodilator effect, prevents and relieves bronchospasm, increases lung capacity. It prevents the release of histamine, slow reacting substances from mast cells and neutrophil chemotactic factors. It is a small …. Read more ...
Primobolan side effects is a selective agonist of beta2-adrenergic receptors. At therapeutic doses it acts on beta2-adrenergic receptors of smooth muscles of the bronchi, providing pronounced bronchodilator effect, prevents and relieves bronchospasm, increases lung capacity. It prevents the release of histamine, slow reacting substances from mast cells and neutrophil chemotactic factors. It is a small …. Read more ...
Used to investigate chemotaxis of fast or slow migrating adherent cells and non-adherent cells in gel matrices Chemotaxis measurement in real-time Stable gra...
E. Coli (and many other bacteria) rely heavily upon chemotaxis in order to find areas of food and keep out of areas of harmful substances. One of the im...
LC] D. Lauffenburger and P. Calcano, Competition between two microbial populations in a non-mixed environment: Effect of cell random motility, Biotech. and Bioengrg. 25, 2103-2125 (1983 ...
Human granulocyte-macrophage colony-stimulating factor (GM-CSF) modulates the function of mature neutrophils by priming for enhanced chemotaxis and oxidative metabolism in response to N-formyl-methionyl-leucyl-phenylalanine (f-Met-Leu-Phe). Our studies establish a relationship between f-Met-Leu-Phe receptor number and affinity and neutrophil chemotaxis and oxidative metabolism. A brief (5- to 15-min) exposure to physiologic concentrations of GM-CSF (10 pM to 100 pM) enhances f-Met-Leu-Phe-induced neutrophil chemotaxis by 85%, correlating with a rapid threefold increase (46,000/cell to 150,000/cell) in high-affinity neutrophil f-Met-Leu-Phe receptors. More prolonged incubation (1 to 2 hr) of neutrophils with GM-CSF is accompanied by a change to low-affinity f-Met-Leu-Phe receptors (Kd = 29 nM to Kd = 99 nM) concomitant with priming for enhanced neutrophil oxidative metabolism. Moreover, enhanced chemotactic responses to f-Met-Leu-Phe are no longer evident after more prolonged incubation of ...
The presence of neutrophils in the synovial joint of patients with rheumatoid arthritis (RA) is thought to be due to the activity of chemotactic factors released by activated cells in the joint. We have shown in this report, for the first time, the abundance of one such factor, interleukin 8 (IL 8), in the synovial fluid of patients both with RA and other non-RA joint diseases, and the spontaneous production of IL 8 mRNA by RA synovial cells in culture. There was no correlation between the levels of chemotactic activity and IL 8 protein, suggesting that other factors with similar neutrophil chemotactic activity are also present in the synovial fluid exudate. In support of this concept neither the level of chemotactic activity nor IL 8 protein levels correlated with neutrophil or leukocyte infiltration, indicating that the mechanism of migration into the inflammatory environment of the joint is complex. Such migration is likely to be due to a number of chemotactic signals in addition to IL 8, which may
By the use of chambers containing two compartments with an interposed micropore filter, chemotaxis of polymorphonuclear leukocytes (PMNs) in vitro was studied employing various agents that fixed serum complement (C). Antigen-antibody complexes, zymosan, and aggregated human gamma globulin, in the presence of fresh rabbit, guinea pig, or mouse serum resulted in the migration of PMNs through the micropore filter. Pepsin-degraded rabbit antibody or unaltered duck serum containing antibody did not exhibit such activity after addition of antigen. Heating of the serum before treatment or the presence of EDTA prevented the generation of the chemotactic factor. The chemotactic factor could not be generated in whole serum from rabbits genetically deficient in C. However, the defect in this rabbit serum could be corrected by addition of rabbit or human C6. Serum of B10.D2 mice deficient in hemolytic C also yielded poor chemotactic activity. Interaction of the first four reacting components of guinea ...
By the use of chambers containing two compartments with an interposed micropore filter, chemotaxis of polymorphonuclear leukocytes (PMNs) in vitro was studied employing various agents that fixed serum complement (C). Antigen-antibody complexes, zymosan, and aggregated human gamma globulin, in the presence of fresh rabbit, guinea pig, or mouse serum resulted in the migration of PMNs through the micropore filter. Pepsin-degraded rabbit antibody or unaltered duck serum containing antibody did not exhibit such activity after addition of antigen. Heating of the serum before treatment or the presence of EDTA prevented the generation of the chemotactic factor. The chemotactic factor could not be generated in whole serum from rabbits genetically deficient in C. However, the defect in this rabbit serum could be corrected by addition of rabbit or human C6. Serum of B10·D2 mice deficient in hemolytic C also yielded poor chemotactic activity.. Interaction of the first four reacting components of ...
Bromelain, a mixture of proteases derived from pineapple stem, has been reported to have therapeutic benefits in a variety of inflammatory diseases, including murine inflammatory bowel disease. The purpose of this work was to understand potential mechanisms for this anti-inflammatory activity. Exposure to bromelain in vitro has been shown to remove a number of cell surface molecules that are vital to leukocyte trafficking, including CD128a/CXCR1 and CD128b/CXCR2 that serve as receptors for the neutrophil chemoattractant IL-8 and its murine homologues. We hypothesized that specific proteolytic removal of CD128 molecules by bromelain would inhibit neutrophil migration to IL-8 and thus decrease acute responses to inflammatory stimuli. Using an in vitro chemotaxis assay, we demonstrated a 40% reduction in migration of bromelain- vs. sham-treated human neutrophils in response to rhIL-8. Migration to the bacterial peptide analog fMLP was unaffected, indicating that bromelain does not induce a global ...
C1q, the first component of the classical pathway of the complement system, interacts with various cell types and triggers a variety of cell-specific cellular responses, such as oxidative burst, chemotaxis, phagocytosis, etc. Different biological responses are attributed to the interaction of C1q with more than one putative cell-surface C1q receptor/C1q-binding protein. Previously, it has been shown that C1q-mediated oxidative burst by neutrophils is not linked to G-protein-coupled fMet-Leu-Phe-mediated response. In the present study, we have investigated neutrophil migration brought about by C1q and tried to identify the signal-transduction pathways involved in the chemotactic response. We found that C1q stimulated neutrophil migration in a dose-dependent manner, primarily by enhancing chemotaxis (directed movement) rather than chemokinesis (random movement). This C1q-induced chemotaxis could be abolished by an inhibitor of G-proteins (pertussis toxin) and PtdIns(3,4,5)P3 kinase (wortmannin and ...
Advances in the management of renal failure necessitate a new look at the uremic patient. Infection is the leading cause of death in acute renal failure and the second most common cause of death in chronic uremia. The uremic patient must be regarded as an altered host more susceptible to infection. Some contributing factors are alterations of the skin and mucous membrane barriers, as well as lymphocyte and leukocyte dysfunction. Lymphocytes produce less interferon and also, when stimulated by phytohemagglutinin, show decreased metabolic activity in uremic serums. Leukocyte Chemotaxis is decreased. Other factors await more scientific investigation. Another important source ...
Chemotaxis (from chemo- + taxis) is the movement of an organism in response to a chemical stimulus. Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food (e.g., glucose) by swimming toward the highest concentration of food molecules, or to flee from poisons (e.g., phenol). In multicellular organisms, chemotaxis is critical to early development (e.g., movement of sperm towards the egg during fertilization) and subsequent phases of development (e.g., migration of neurons or lymphocytes) as well as in normal function. In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis. Positive chemotaxis occurs if the movement is toward a higher concentration of the chemical in question; negative chemotaxis if the movement is in the opposite direction. Chemically prompted kinesis (randomly directed or ...
BioAssay record AID 297157 submitted by ChEMBL: Inhibition of CXCL8-induced cell migration in human PMN cells at 0.01 uM by chemotaxis assay.
In contrast to other isolation techniques, neutrophils enriched by spontaneous sedimentation were found to be intact both in terms of their function and relative numbers within the
Immune and inflammatory responses require leukocytes to migrate within and through the vasculature, a process that is facilitated by their capacity to switch to a polarized morphology with an asymmetric distribution of receptors. We report that neutrophil polarization within activated venules served to organize a protruding domain that engaged activated platelets present in the bloodstream. The selectin ligand PSGL-1 transduced signals emanating from these interactions, resulting in the redistribution of receptors that drive neutrophil migration. Consequently, neutrophils unable to polarize or to transduce signals through PSGL-1 displayed aberrant crawling, and blockade of this domain protected mice against thromboinflammatory injury. These results reveal that recruited neutrophils scan for activated platelets, and they suggest that the neutrophils bipolarity allows the integration of signals present at both the endothelium and the circulation before inflammation proceeds.