Hemocyte surface phenoloxidase (PO) and immune response to Lipopolysaccharide (LPS) in Ceratitis capitata

Charalambidis, Nektarios D.; Foukas, Lazaros C.; Zervas, Christos G.; Marmaras, Vassilis J.

doi:10.1016/s0965-1748(96)00053-7

Cited by 30 publications

(31 citation statements)

References 18 publications

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“…Lipopolysaccharides are known to trigger the exocytosis of the nonself recognition molecule p47 through a protein tyrosine phosphorylation pathway in insect haemocytes [35]. Lipopolysaccharide-dependent exocytosis of a proPO serine proteinase activator is also mediated by protein tyrosine phosphorylation [36]. The present study provides the basis for further characterisation of the molecular components of TS (as well as intracellular components) and possible associations with differential in vitro reactions by haemocytes to microbial compounds.…”

Section: Discussionmentioning

confidence: 73%

Flow cytometric analysis of crayfish haemocytes activated by lipopolysaccharides

Cárdenas

Dankert

Jenkins

2004

Fish & Shellfish Immunology

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Lipopolysaccharides (LPS) from Gram-negative bacteria are strong stimulators of white river crayfish, Procambarus zonangulus, haemocytes in vitro. Following haemocyte treatment with LPS and with LPS from rough mutant R5 (LPS Rc) from Salmonella minnesota, flow cytometric analysis revealed a conspicuous and reproducible decrease in cell size as compared to control haemocytes. These LPS molecules also caused a reduction in haemocyte viability as assessed by flow cytometry with the fluorescent dyes calcein-AM and ethidium homodimer. The onset of cell size reduction was gradual and occurred prior to cell death. Haemocytes treated with LPS from S. minnesota without the Lipid A moiety (detoxified LPS) decreased in size without a reduction of viability. The action of LPS on crayfish haemocytes appeared to be related to the activation of the prophenoloxidase system because phenoloxidase (PO)-specific activity in the supernatants from control and detoxified LPS-treated cells was significantly lower than that from LPS and LPS-Rc treated cells (P % 0:05). Furthermore, addition of trypsin inhibitor to the LPS treatments caused noticeable delays in cell size and viability changes. These patterns of cellular activation by LPS formulations indicated that crayfish haemocytes react differently to the polysaccharide and lipid A moieties of LPS, where lipid A is cytotoxic and the polysaccharide portion is stimulatory. These effects concur with the general pattern of mammalian cell activation by LPS, thereby indicating common innate immune recognition mechanisms to bacterial antigens between cells from mammals and invertebrates. These definitive molecular approaches used to verify and identify mechanisms of invertebrate haemocyte responses to LPS could be applied with other glycoconjugates, soluble mediators, or xenobiotic compounds.

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Section: Discussionmentioning

confidence: 73%

Flow cytometric analysis of crayfish haemocytes activated by lipopolysaccharides

Cárdenas

Dankert

Jenkins

2004

Fish & Shellfish Immunology

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“…The idea that LPS can stimulate cellular defense reactions is well established in mammalian immunology (Weinstein et al, 1991), as well as in several invertebrate species, including mussels (Tunkijjanukij et al, 1997), annelid worms (Beschin et al, 1998), crustaceans (Lorenzon et al, 1997) and sea urchins (Smith et al, 1995). LPS-binding proteins have been detected in hemolymph from a variety of insect species, such as the silkworm, B. mori (Koizumi et al, 1997), the American cockroach, Periplaneta americana (Jomori et al, 1990), the bloodsucking bug, Triatoma infestans (Hypsa and Grubhoffer, 1995), and the fruitfly, Ceratitis capitata (Charalambidis et al, 1996). We infer that recognition of LPS as a component of certain bacterial cell surfaces is a general mechanism of cellular host defense systems.…”

Section: Discussionmentioning

confidence: 99%

Insect cellular reactions to the lipopolysaccharide component of the bacterium Serratia marcescens are mediated by eicosanoids

Bedick

Pardy

Howard³

et al. 2000

Journal of Insect Physiology

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Nodulation, which begins with the formation of cellular microaggregates, is the predominant cellular defense reaction to bacterial infections in insects. We suggested that these reactions to bacterial infections are mediated by eicosanoids. The lipopolysaccharide (LPS) component of some bacterial cells stimulates defense reactions in mammals and insects. Here, we report on experiments designed to test the hypothesis that eicosanoids mediate microaggregation reactions to LPS. Injections of LPS (purified from the bacterium, Serratia marcescens) into larvae of the tenebrionid beetle, Zophobas atratus, stimulated microaggregation reactions in a dose-dependent manner. Treatments with eicosanoid-biosynthesis inhibitors immediately prior to LPS challenge sharply reduced the microaggregation responses. Separate treatments with specific inhibitors of phospholipase A 2 , cyclooxygenase and lipoxygenase reduced microaggregation, supporting our view that microaggregate formation involves lipoxygenase and cyclooxygenase products. The inhibitory influence of dexamethasone was apparent within 30 min after injection, and microaggregation was significantly reduced, relative to control insects, over the following 90 min. The dexamethasone effects were reversed by treating LPS-injected insects with the eicosanoid precursor, arachidonic acid. These findings indicate that cellular defense reactions to a specific component of bacterial cells are mediated by eicosanoids, and open up new possibilities for dissecting detailed hemocytic actions in insect immune reactions to bacterial infections.

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“…The di#erent PO enzymatic activity of membrane-bound and soluble PO has also been reported for the helminth, Fasciola gigantia, where PO is also believed to be involved in the pathogen defence mechanisms (Nellaiappan et al, 1989). A haemocyte surface PO might be important in the crayfish cellular defence against bacteria since it has been shown that cell-surface PO is a prerequisite for LPS internalisation in Ceratitis capitata haemocytes (Charalambidis et al, 1996).…”

mentioning

confidence: 89%

“…This enzyme is present within circulating haemocytes (Smith & Söderhäll, 1991;Cárdenas & Dankert, 1997;Perazzolo & Barracco, 1997) and in haemolymph (Ashida, 1971;Andersson et al, 1989). PO is also localised on haemocyte cell surfaces (Charalambidis et al, 1996). Phenoloxidases associated with *Correspondence author.…”

Section: Introductionmentioning

confidence: 99%

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Cresolase, catecholase and laccase activities in haemocytes of the red swamp crayfish

Cárdenas

Dankert

2000

Fish & Shellfish Immunology

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Phenoloxidase activity in crayfish haemocyte lysates and extracts of haemocyte membranes were studied using native PAGE and SDS-PAGE gels and staining for cresolase, catecholase and laccase activities. The activation of the proenzyme, prophenoloxidase to phenoloxidase, in native PAGE was demonstrated following exposure to SDS. By staining samples separated in SDS-PAGE followed by renaturation, a high molecular mass phenoloxidase activity was identified in both the soluble and membrane fractions of haemocyte preparations. The membrane-associated activity appeared at only relatively high molecular mass (>300 kDa), and could easily be eluted from membranes using detergents or NaCl. Further, this membrane-associated activity has a catecholase activity but not the cresolase activity seen in the soluble preparations. In addition, several other phenoloxidase enzymes were identified with di#erent relative mobilities (250, 80, 72 and 10 kDa). Crayfish haemocytes also contained laccase activity, thought to be restricted to cuticle sclerotisation in the integument. Laccase activity in haemocytes might aid in the formation of capsule used to contain pathogens. Academic Press

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Hemocyte surface phenoloxidase (PO) and immune response to Lipopolysaccharide (LPS) in Ceratitis capitata

Cited by 30 publications

References 18 publications

Flow cytometric analysis of crayfish haemocytes activated by lipopolysaccharides

Flow cytometric analysis of crayfish haemocytes activated by lipopolysaccharides

Insect cellular reactions to the lipopolysaccharide component of the bacterium Serratia marcescens are mediated by eicosanoids

Cresolase, catecholase and laccase activities in haemocytes of the red swamp crayfish

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