A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

Expression of cell adhesion molecules and lymphocyte-endothelium interaction under simulated hypogravity in vitro

Using histochemical staining and FACS-analysis we have studied the basal and TNF-alpha induced expression of E-selectin, ICAM-1 and VCAM-1 in human umbilical vein endothelial cells (ECs) exposed to simulated hypogravity. Control ECs did not contain detectable amounts of E-selectin or VCAM-1 but were ICAM-1 positive. As soon as after 6-8 hrs of clinorotation at 5 RPM the cellular content of ICAM- 1 increased. Moreover, hypogravity potentiated the effect of inflammatory cytokines (TNF-alpha and IL-1) on ICAM-1 expression. No increase in E-selectin or VCAM-1 expression was observed in ECs exposed to hypogravity itself. However, hypogravity reduced E-selectin and VCAM-1 expression in cell cultures activated by cytokines, more visible at their low (5-10 U/ml) concentrations. Both, control and clinorotated ECs poorly supported spontaneous lymphocyte adhesion; the adhesion of PMA-activated leukocytes was 15-20-fold higher. The interaction of unstimulated lymphocytes with cytokine-activated endothelium was more noticeable but significantly lower in cultures exposed to hypogravity. Activated blood cells interacted with endothelium more effectively, particularly, under hypogravity. Obtained results suggest that EC adhesion molecule expression and endothelium-lymphocyte interaction are altered under simulated hypogravity conditions in direction of increase of endotlielial adhesiveness for activated blood cells.     

Interferon production by primary culture of human endothelial cells

Endothelial cells of human umbilical vein are capable of producing interferon upon induction with Newcastle disease virus, influenza virus, and poly I: poly C, but not staphylococcal enterotoxin A. All the interferons produced belonged to the alpha-type. After treatment with influenza virus the endothelial cells produce two subtypes of alpha-interferon: acid-labile and acid-stable.     

Coculture of human endothelium and smooth muscle cells: functional heterogeneity of endothelial cells from zones with different susceptibility to atherosclerosis

Using co-culture technique and 3H-thymidine radioautography we have studied effects of human aortic endothelial cells (EC), isolated separately from zones of low (LP) and high (HP) probability of atherosclerosis of grossly normal and atherosclerotic aortas, on 3H-thymidine incorporation by human intimal smooth muscle cells (SMCs). It was found that EC activity depended on a zone of probability, from which the cells were isolated, and on the degree of atherosclerotic lesion. The first-passage ECs from grossly normal LP zones inhibited 3H-thymidine incorporation, compared to control, incubated without Ecs, SMCs (63.5 +/- 27.5%). Cells from HP zones of the same vessels were less active or stimulated SMC proliferation (99.4 +/- 42.9%). EC cultures obtained from both LP and HP zones of atherosclerotic vessels had, as a rule, no effect or increased 3H-thymidine incorporation by SMCs (100.3 +/- 19.8 and 124.1 +/- 20.1%). In contrast to morphologically heterogeneous primary and first-passage cultures obtained from high seeding density, EC monolayers obtained with a split 1:10 were composed predominantly of small mononuclear cells. These cultures effectively inhibited SMC DNA synthesis independently of a zone of probability and a degree of atherosclerotic lesion of aorta (60.4 +/- 10.0 and 51.5 +/- 12.7%). The obtained data suggest that EC morphological heterogeneity is accompanied by functional changes of cells and may be involved in atherosclerotic plaque formation.     

COL4A1 mutations cause ocular dysgenesis, neuronal localization defects, and myopathy in mice and Walker-Warburg syndrome in humans

Muscle-eye-brain disease (MEB) and Walker Warburg Syndrome (WWS) belong to a spectrum of autosomal recessive diseases characterized by ocular dysgenesis, neuronal migration defects, and congenital muscular dystrophy. Until now, the pathophysiology of MEB/WWS has been attributed to alteration in dystroglycan post-translational modification. Here, we provide evidence that mutations in a gene coding for a major basement membrane protein, collagen IV alpha 1 (COL4A1), are a novel cause of MEB/WWS. Using a combination of histological, molecular, and biochemical approaches, we show that heterozygous Col4a1 mutant mice have ocular dysgenesis, neuronal localization defects, and myopathy characteristic of MEB/WWS. Importantly, we identified putative heterozygous mutations in COL4A1 in two MEB/WWS patients. Both mutations occur within conserved amino acids of the triple-helix-forming domain of the protein, and at least one mutation interferes with secretion of the mutant proteins, resulting instead in intracellular accumulation. Expression and posttranslational modification of dystroglycan is unaltered in Col4a1 mutant mice indicating that COL4A1 mutations represent a distinct pathogenic mechanism underlying MEB/WWS. These findings implicate a novel gene and a novel mechanism in the etiology of MEB/WWS and expand the clinical spectrum of COL4A1-associated disorders.     

Mechano-chemical control of human endothelium orientation and size

Human umbilical vein endothelial cells (EC) were grown on elastic silicone membranes subjected to cyclic stretch, simulating arterial wall motion. Stretching conditions (20% amplitude, 52 cycle/min) stimulated stress fiber formation and their orientation transversely to the strain direction. Cell bodies aligned along the same axis after the actin cytoskeleton. EC orientation response was inhibited by the adenylate cyclase activator, forskolin (10(-5) M), which caused stress fiber disassembly and the redistribution of F-actin to the cortical cytoplasm. Preoriented EC depleted of stress fibers by forskolin treatment retained their aligned state. Thus, stress fibers are essential for the process of EC orientation induced by repeated strain, but not for the maintenance of EC orientation. The monolayer formed by EC grown to confluence in conditions of intermittent strain consisted of uniform elongated cells and was resistant to deformation. In contrast, the monolayer assembled in stationary conditions was less compliant and exposed local denudations on initiation of stretching. When stretched in the presence of 10(-5) M forskolin it rapidly (3-4 h) reestablished integrity but gained a heterogeneous appearance since denuded areas were covered by giant cells. The protective effect of forskolin was because of the stimulation of EC spreading. This feature of forskolin was demonstrated while studying its action on EC spreading and repair of a scratched EC monolayer in conventional culture. Thus mechanical deformation and adenylate cyclase activity may be important factors in the control of endothelium morphology in human arteries.     

Clinical aspects of control in therapy with platelet inhibitors]

46 patients with ischaemic heart disease were treated with Micristin (20-40 mg/kg) or a combination of Micristin and Propranolol (80-120 mg/die). The values of bleeding time, the platelet factor 4 in lysate of thrombocytes or in plasma of patients as well as the soluble fibrin monomer complexes were investigated. They showed no obvious correlation to the clinical findings.     

AmylPepPred: Amyloidogenic Peptide Prediction tool

We present an efficient computational architecture designed using supervised machine learning model to predict amyloid fibril forming protein segments, named AmylPepPred. The proposed prediction model is based on bio-physio-chemical properties of primary sequences and auto-correlation function of their amino acid indices. AmylPepPred provides a user friendly web interface for the researchers to easily observe the fibril forming and non-fibril forming hexmers in a given protein sequence. We expect that this stratagem will be highly encouraging in discovering fibril forming regions in proteins thereby benefit in finding therapeutic agents that specifically aim these sequences for the inhibition and cure of amyloid illnesses.

Availability

AmylPepPred is available freely for academic use at www.zoommicro.in/amylpeppred