scholarly journals Carbohydrate Moieties and Cytoenzymatic Characterization of Hemocytes in Whiteleg ShrimpLitopenaeus vannamei

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Norma Estrada ◽  
Edwin Velázquez ◽  
Carmen Rodríguez-Jaramillo ◽  
Felipe Ascencio
Keyword(s):  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Lectin Binding ◽  
Hydrolytic Enzymes ◽  
Nonspecific Esterase ◽  
Binding Assays ◽  
Foreign Material ◽  
Con A ◽  
Cellular Defense

Hemocytes represent one of the most important defense mechanisms against foreign material in Crustacea and are also involved in a variety of other physiological responses. Fluorescent lectin-binding assays and cytochemical reactions were used to identify specificity and distribution of carbohydrate moieties and presence of several hydrolytic enzymes, in hemocytes of whiteleg shrimpLitopenaeus vannamei. Two general classes of circulating hemocytes (granular and agranular) exist inL. vannamei, which express carbohydrates residues for FITC-conjugated lectins WGA, LEA, and PNA; UEA and Con-A were not observed. Enzymatic studies indicated that acid phosphatase, nonspecific esterase, and specific esterases were present; alkaline phosphatase was not observed. The enzymes and carbohydrates are useful tools in hemocyte classification and cellular defense mechanism studies.

scholarly journals Isolation and partial characterization of two antigenic glycoproteins from rye-grass (Lolium perenne) pollen

1981 ◽  
Vol 197 (3) ◽  
pp. 695-706 ◽  
Author(s):  
B J Howlett ◽  
A E Clarke
Keyword(s):  
Lolium Perenne ◽  
Concanavalin A ◽  
Sodium Dodecyl Sulphate ◽  
Lectin Binding ◽  
Sodium Dodecyl ◽  
Binding Assays ◽  
Pea Lectin ◽  
Rye Grass ◽  
Allergenic Activity

Two glycoproteins have been purified from a buffer extract of rye-grass (Lolium perenne) pollen. Both migrated as single bands on sodium dodecyl sulphate/polyacrylamide gels. Glycoprotein 1 (0.8 mg/g of pollen) had a apparent mol.wt. of 33 000 and contained 95% protein and 5% carbohydrate. The monosaccharides glucose, galactose, mannose, arabinose and N-acetylglucosamine were present in the proportions 3:3:1:2:1. Glycoprotein 2 (0.4 mg/g of pollen) had an apparent mol. wt. of 68000 and contained 88% protein and 12% carbohydrate. The monosaccharides glucose, galactose, mannose, fucose, xylose, arabinose and N-acetylglucosamine were present in the proportions 4:7:13:5:8:6:6. This glycoprotein bound concanavalin A and Lotus tetragonolobus (asparagus pea) lectin. Radioallergosorbent (RAST) inhibition tests showed that Glycoprotein 1 is an effective allergen, whereas Glycoprotein 2 has less allergenic activity. A method for performing both lectin-binding assays and RAST inhibition tests using microtitre trays is described.

Lectin-binding assays for the isoforms of human erythropoietin: comparison of urinary and four recombinant erythropoietins

1996 ◽  
Vol 150 (3) ◽  
pp. 401-412 ◽  
Author(s):  
P L Storring ◽  
R J Tiplady ◽  
R E Gaines Das ◽  
B Rafferty ◽  
Y G Mistry
Keyword(s):  
Recombinant Dna ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Chinese Hamster ◽  
Ovary Cell ◽  
Lower Content ◽  
Binding Assays ◽  
Con A ◽  
Human Erythropoietin

Abstract Assays have been developed for the isoforms of erythropoietin (EPO) based on their binding to eight different lectins. These assays were used to compare the isoform compositions of two preparations of human urinary EPO (uEPO) and four preparations of recombinant DNA-derived human EPO (rEPO), which had been shown to differ in their biological and immunological properties and in their isoform composition as judged by isoelectric focusing and electrophoresis. Agarose-bound Ricinus communis agglutinin I (RCA), Erythrina cristagalli agglutinin (ECA), Maackia amurensis leukoagglutinin (MAL), Sambucus nigra agglutinin (SNA), Lycopersicon esculentum agglutinin (LEA), concanavalin A (Con A), Phaseolus vulgaris agglutinin-L4 (L-PHA) and Agaricus bisporus agglutinin (ABA) were used to bind EPO isoforms possessing: N-glycans containing non-sialylated outer Galβ1–4GlcNAc (RCA and ECA), NeuAcα2-3Galβ1–4GlcNAc (MAL), NeuAcα2–6Gal (SNA), or repeating Galβ1–4GlcNAc sequences (LEA); biantennary N-glycans (Con A); tetraantennary and 2,6-branched triantennary N-glycans (L-PHA); and O-glycans containing NeuAcα2–6GalNAc (SNA) and Galβ1–3GalNAc (ABA). Free EPO was measured by mouse spleen cell bioassay or immunoassay. Estimates from most lectin-binding assays were reproducible between assays and batches of lectin-agarose, although batches of MAL- and ABA-agarose, and to a lesser extent LEA-agarose, differed in their EPO-binding. Lectin-binding assays showed differences between the isoform compositions of all EPOs, including the two Chinese hamster ovary cell-derived rEPOs, with RCA-and ECA-binding assays being the most discriminating. Lectin-binding estimates provided evidence that uEPO differs from these rEPOs in its lower content of isoforms with biantennary N-glycans and higher content of those with multiantennary N-glycans, and in its lower content of isoforms with N-glycans possessing repeating Galβ1–4GlcNAc sequences and of those with O-glycans containing Galβ1–3GalNAc. Lectin-binding estimates also indicated that, contrary to some reports, uEPO possesses Galβ1–3GalNAc-containing O-glycans but not NeuAcα2–6GalNAc-containing O-glycans or NeuAcα2–6Gal-containing N-glycans. Most groups of lectin-bound EPO isoforms did not differ in their relative bioactivities and immunoreactivities. However, estimates for ABA-bound EPO isoforms suggested that O-glycans might influence the bioactivity of EPO differently to its immunoreactivity. Furthermore, the bioactivities of some ECA-bound EPO isoforms were higher, and those of some of the MAL-bound EPO isoforms lower, than their immunoreactivities, consistent with the reported enhancement of EPO in vitro bioactivity by desialylation. Journal of Endocrinology (1996) 150, 401–412

scholarly journals Functional Characterization of Hexacorallia Phagocytic Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Grace A. Snyder ◽  
Shir Eliachar ◽  
Michael T. Connelly ◽  
Shani Talice ◽  
Uzi Hadad ◽  
...  
Keyword(s):  
Cell Biology ◽  
Defense Mechanism ◽  
Immune Cell ◽  
Functional Characterization ◽  
Microbial Pathogens ◽  
Pocillopora Damicornis ◽  
Phagocytic Cells ◽  
Cellular Defense ◽  
Cellular Markers

Phagocytosis is the cellular defense mechanism used to eliminate antigens derived from dysregulated or damaged cells, and microbial pathogens. Phagocytosis is therefore a pillar of innate immunity, whereby foreign particles are engulfed and degraded in lysolitic vesicles. In hexacorallians, phagocytic mechanisms are poorly understood, though putative anthozoan phagocytic cells (amoebocytes) have been identified histologically. We identify and characterize phagocytes from the coral Pocillopora damicornis and the sea anemone Nematostella vectensis. Using fluorescence-activated cell sorting and microscopy, we show that distinct populations of phagocytic cells engulf bacteria, fungal antigens, and beads. In addition to pathogenic antigens, we show that phagocytic cells engulf self, damaged cells. We show that target antigens localize to low pH phagolysosomes, and that degradation is occurring within them. Inhibiting actin filament rearrangement interferes with efficient particle phagocytosis but does not affect small molecule pinocytosis. We also demonstrate that cellular markers for lysolitic vesicles and reactive oxygen species (ROS) correlate with hexacorallian phagocytes. These results establish a foundation for improving our understanding of hexacorallian immune cell biology.

Structure and macromolecular composition of the zebrafish egg chorion

Zygote ◽  
1996 ◽  
Vol 4 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Daniele Bonsignorio ◽  
Lucia Perego ◽  
Luca Del Giacco ◽  
Franco Cotelli
Keyword(s):  
Danio Rerio ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Binding Assays ◽  
Sambucus Nigra ◽  
Con A ◽  
Reducing Conditions ◽  
Sds Page ◽  
Galanthus Nivalis ◽  
Macromolecular Composition

SummaryThe chorion is the acellular envelope surrounding mature eggs of teleostean fish. The macromolecular composition of the zebrafish (Danio rerio) egg chorion, organised as a three-layered structure, has been analysed. SDS-PAGE analysis, under reducing conditions, of isolated and purified chorions revealed a reproducible pattern of four major polypeptides (116, 97, 50 and 43kDa) and several minor bands. Lectin binding assays showed that both the 116 kDa and 50kDa proteins were recognised by concanavalin agglutinin (Con A), Galanthus nivalis agglutinin (GNA), Sambucus nigra bark agglutinin (SNA) and Ricinus communis agglutinin (RCA 120), suggesting that these polypeptides are N-linked glycoproteins. By contrast, neither the 97 kDa nor the 43 kDa polypeptides were stained by these lectins, indicating that these polypeptides are not glycosylated. Amino acid analysis also showed significant differences in the average content of some amino acids, for example serine and proline, when compared with previous reports.

Lectin Binding Studies on RNA Tumor Virus-Infected Cells

1975 ◽  
Vol 33 ◽  
pp. 326-327
Author(s):  
D. C. Hixson
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Culture Conditions ◽  
3T3 Cells ◽  
Binding Studies ◽  
Con A ◽  
Microscopic Studies ◽  
Tumor Virus ◽  
Infected Cells ◽  
Cell Culture Conditions

The abilities of plant lectins to preferentially agglutinate malignant cells and to bind to specific monosaccharide or oligosaccharide sequences of glycoproteins and glycolipids make them a new and important biochemical probe for investigating alterations in plasma membrane structure which may result from malignant transformation. Electron and light microscopic studies have demonstrated clustered binding sites on surfaces of SV40-infected or tryp- sinized 3T3 cells when labeled with concanavalin A (con A). No clustering of con A binding sites was observed in normal 3T3 cells. It has been proposed that topological rearrangement of lectin binding sites into clusters enables con A to agglutinate SV40-infected or trypsinized 3T3 cells (1). However, observations by other investigators have not been consistent with this proposal (2) perhaps due to differences in reagents used, cell culture conditions, or labeling techniques. The present work was undertaken to study the lectin binding properties of normal and RNA tumor virus-infected cells and their associated viruses using lectins and ferritin-conjugated lectins of five different specificities.

Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts

2019 ◽  
Vol 4 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Alison E. Fowler ◽  
Rebecca E. Irwin ◽  
Lynn S. Adler
Keyword(s):  
Defense Mechanisms ◽  
Poor Quality ◽  
Future Research ◽  
Immune Priming ◽  
Social Bees ◽  
Bee Health ◽  
Landscape Scales ◽  
And Function ◽  
Solitary Species

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.

The Use of the Defense Mechanism Test to Aid in Understanding the Personality of Senior Executives and the Implications for Their Careers

2009 ◽  
Vol 30 (1) ◽  
pp. 73-96 ◽  
Author(s):  
Olya Khaleelee
Keyword(s):  
Crisis Intervention ◽  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Senior Executives ◽  
Ideal Types ◽  
The Individual ◽  
Test Profiles ◽  
Real Test

This paper describes the use of the Defense Mechanism Test as an aid in helping to assess senior executives in four areas: for selection, development, career strategy, and crisis intervention. The origins of this test, developed to measure the defense mechanisms used to protect the individual from stress, are described. The paper shows how it was used to predict the capacity of trainee fighter pilots to withstand stress and its later application to other stressful occupations. Finally, some ideal types of the test are shown followed by four real test profiles, two of them with their associated histories.

A Study of Memory and Psychological Defense Mechanism in Julian Barnes’s The Sense of an Ending

2019 ◽  
Author(s):  
Hossein Aliakbari Harehdasht ◽  
Zahra Ekbatäni
Keyword(s):  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Human Mind ◽  
The Novel ◽  
Psychological Defense ◽  
Julian Barnes ◽  
Self Image

In The Sense of an Ending, Julian Barnes portrays the mysterious workings of the human mind as it distorts facts towards the end of a self-image that one can live with. The protagonist in the novel deploys certain psychological defense mechanisms in order to protect himself from feelings of anxiety, only to experience even more profound anxiety due to his excessive use of them. The significance of the present paper lies in its novel view of the book. So far, the critique on the novel has mainly been focused on the workings of time on memory; however, the present paper investigates how psychological defense mechanisms blur the protagonist’s perception of reality and distort his memories. This paper also attempts to attract scholarly interest in the study of psychological defense mechanisms in the study of The Sense of an Ending which has so far been to the best of our knowledge overlooked

Antifungal Proteins from Plant Latex

2020 ◽  
Vol 21 (5) ◽  
pp. 497-506
Author(s):  
Mayck Silva Barbosa ◽  
Bruna da Silva Souza ◽  
Ana Clara Silva Sales ◽  
Jhoana D’arc Lopes de Sousa ◽  
Francisca Dayane Soares da Silva ◽  
...  
Keyword(s):  
Cell Walls ◽  
Defense Mechanisms ◽  
Hydrolytic Enzymes ◽  
Fungal Species ◽  
Biologically Active ◽  
Protein Classification ◽  
Fungal Cell ◽  
Antifungal Proteins ◽  
Plant Latex

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants’ defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.

Role of Histamine and Leucotaxin in Function of Cellular Defense Mechanism

1956 ◽  
Vol 184 (2) ◽  
pp. 296-300 ◽  
Author(s):  
László Kátó ◽  
Béla Gözsy
Keyword(s):  
Fluid Flow ◽  
Tissue Damage ◽  
Inflammatory Process ◽  
Defense Mechanism ◽  
Volatile Oils ◽  
Time Intervals ◽  
Cellular Defense ◽  
Intradermal Administration ◽  
Flow Through

Experiments are presented to the effect that in an inflammatory process histamine and leucotaxin appear successively at different and orderly time intervals, thus assuring an increased fluid flow through the capillary wall. Histamine is released not only in the inflammatory process but also by intradermal administration of such substances (volatile oils or their components) which induce neither the triple response of Th. Lewis nor any tissue damage. This could be explained by the fact that in the tissues histamine is ‘present’ but leucotaxin is ‘formed.’

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