Search results for "Chemotactic Factors"
showing 9 items of 9 documents
Hawthorn extract inhibits human isolated neutrophil functions.
2008
Hawthorn extract is a popular herbal medicine given as adjunctive treatment for chronic heart failure. In contrast to the cardiac properties of hawthorn extract, its anti-inflammatory effect has been scarcely investigated. This study examines the effects of a dry extract of leaves and flowers of Crataegus laevigata on various functional outputs of human neutrophils in vitro. Incubation of human neutrophils obtained from peripheral blood of healthy donors with C. laevigata extract (0.75-250 microg/ml) inhibited N-formyl-Met-Leu-Phe (FMLP)-induced superoxide anion generation, elastase release and chemotactic migration with potency values of 43.6, 21.9, and 31.6 microg/ml, respectively. By con…
Natural Proteolytic Processing of Hemofiltrate Cc Chemokine 1 Generates a Potent Cc Chemokine Receptor (Ccr)1 and Ccr5 Agonist with Anti-HIV Properti…
2000
Hemofiltrate CC chemokine (HCC)-1 is a recently described human chemokine that is constitutively expressed in numerous tissues and is present at high concentrations in normal plasma. Using a cell line expressing CC chemokine receptor (CCR)5 as a bioassay, we isolated from human hemofiltrate an HCC-1 variant lacking the first eight amino acids. HCC-1[9–74] was a potent agonist of CCR1, CCR3, and CCR5 and promoted calcium flux and chemotaxis of T lymphoblasts, monocytes, and eosinophils. It also blocked entry of HIV-1 strains using CCR5 as coreceptor. Limited tryptic digestion of HCC-1 generated the active variant. Conditioned media from several tumor cell lines activated HCC-1 with a high ef…
Migration of Leukocytes into Filters Coated Homogeneously with Immune Complexes, Antigens, Lectins or Tripeptides
1980
Cellulose nitrate filters were incubated in solutions of albumin, a chemotactically active tripeptide (f-Met-Leu-Phe), immune complexes or lectins and afterwards washed with buffer. They showed a dose-dependent increased leukocyte migration, when tested in typical Boyden chambers in comparison to filters treated only with buffer. The tripeptide, the immune complexes and the lectins were stimulatory at very low concentrations and acted inhibitory at high concentrations. Treating filters with formaldehyde or glutardialdehyde had no clear stimulatory effect. These findings extend earlier observations obtained with casein. They show that cells move very effectively on solid substrata in the abs…
Mouse langerhans cells differentially express an activated T cell-attracting CC chemokine.
1999
Epidermal Langerhans cells represent an immature population of dendritic cells, not yet able to prime naive T cells. Following in vitro culture Langerhans cells mature into potent immunostimulatory cells. We constructed a representative cDNA library of in vitro matured murine Langerhans cells. Applying a differential screening procedure 112 differentially expressed cDNA clones were isolated. Thirty-six clones represented cDNA fragments of the same gene, identifying it to be the most actively expressed gene induced in maturing Langerhans cells. A full-length cDNA was sequenced completely. The open reading frame codes for a protein of 92 amino acids containing a leader peptide of 24 amino aci…
CiC3-1a-Mediated Chemotaxis in the Deuterostome Invertebrate Ciona intestinalis (Urochordata)
2003
Abstract Deuterostome invertebrates possess complement genes, and in limited instances complement-mediated functions have been reported in these organisms. However, the organization of the complement pathway(s), as well as the functions exerted by the cloned gene products, are largely unknown. To address the issue of the presence of an inflammatory pathway in ascidians, we expressed in Escherichia coli the fragment of Ciona intestinalis C3-1 corresponding to mammalian complement C3a (rCiC3-1a) and assessed its chemotactic activity on C. intestinalis hemocytes. We found that the migration of C. intestinalis hemocytes toward rCiC3-1a was dose dependent, peaking at 500 nM, and was specific for…
Immune escape mechanism: defective resting and stimulated leukocyte-endothelium interaction in hepatocellular carcinoma of the rat.
2004
Hepatocellular carcinoma represents an increasing therapeutic challenge due to its high incidence and early metastasis. Numerous studies have demonstrated the influence of the vascular system on tumor growth and development. In addition, the role of leukocyte-endothelium interaction in tumor vessels is of particular significance with regard to immunological tumor therapy. In this study we used an experimental in vivo animal model that allows a quantitative analysis on vessel morphology, microcirculation, and leukocyte-endothelium interaction. The vessel architecture in tumor tissue was found to be extremely heterogeneous, with a consecutively variable blood flow velocity. Following superfus…
An asymmetric electrospun membrane for the controlled release of ciprofloxacin and FGF-2: Evaluation of antimicrobial and chemoattractant properties.
2021
Here, an asymmetric double-layer membrane has been designed and fabricated by electrospinning as a tool for a potential wound healing application. A hydrophobic layer has been produced by using a polyurethane-polycaprolactone (PU-PCL) copolymer and loaded with the antibacterial ciprofloxacin whereas an ion responsive hydrophilic layer has been produced by using an octyl derivative of gellan gum (GG-C8) and polyvinyl alcohol (PVA) and loaded with the growth factor FGF-2. This study investigated how the properties of this asymmetric membrane loaded with actives, were influenced by the ionotropic crosslinking of the hydrophilic layer. In particular, the treatment in DPBS and the crosslinking i…
Phospholipase A2 and arachidonic acid: a common link in the generation of the eosinophil chemotactic factor (ECF) from human PMN by various stimuli.
1980
An eosinophil chemotactic factor (ECF) of low molecular weight can be generated and released from human polymorphonuclear neutrophils by the calcium ionophore, phagocytosis of zymosan particles, arachidonic acid, and phospholipase A2. Since the activation of cells by the ionophore and during the phagocytic event leads to phospholipid turnover, with the subsequent generation of arachidonic acid, it is reasonable that phospholipase A2 represents the common link for ECF production. The kinetics of ECF release by phospholipase A2 is similar to the pattern observed with the various stimuli. After a rapid rise in activity a decline occurred at later times of secretion, suggesting a mechanism of i…
Proteomics of Galápagos Marine Iguanas Links Function of Femoral Gland Proteins to the Immune System
2020
Femoral glands secrete a wax-like substance on the inner side of lizard hind legs, which is thought to function as a mode of chemical communication. Though the minor volatile fraction is well studied, the major protein fraction remains enigmatic. Here, we use proteomics to analyze proteins in femoral gland secretions of the Galápagos marine iguana. Although we found no evidence for proteins and peptides involved in chemical communication, we found several immune-regulatory proteins which also demonstrate anti-microbial functions. Accordingly, we show that femoral gland proteins and peptides function as a barrier against microbial infection and may prevent the rapid degradation of volatile s…