Lytic action of lysozyme on candida albicans

Kamaya, T.

doi:10.1007/bf02051947

Cited by 45 publications

(26 citation statements)

References 34 publications

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“…It is not killed effectively by defensins under anaerobic conditions or in the presence of various mitochondrial inhibitors (15). Although relatively few other examples of the regulation of susceptibility to PMN components by microbial energetics or metabolism have been reported (42,43), this phenomenon is described with regard to several colicins and bacteriocins (e.g., references [44][45][46] and serum complement (47).…”

Section: Discussionmentioning

confidence: 99%

Interaction of human defensins with Escherichia coli. Mechanism of bactericidal activity.

Lehrer¹,

Barton²,

Daher³

et al. 1989

J. Clin. Invest.

672

516

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Defensins are smalL cysteine-rich antimicrobial peptides that are abundant in human, rabbit, and guinea pig neutrophils (PMN). Three defensins (human neutrophil peptide defensin constitute between 30 and 50% of the total protein in azurophil granules of human PMN. We examined the mechanism of HNP-mediated bactericidal activity against Escherichia coli ML-35 (i-, y-, z+) and its pBR322-transformed derivative, E. coli ML-35p. Under conditions that supported bactericidal activity, HNP-1 sequentially permeabilized the outer membrane (OM) and inner membrane (IM) of E. coli. Coincident with these events, bacterial synthesis of DNA, RNA, and protein ceased and the colony count fell. Although these events were closely coupled under standard assay conditions, OM permeabilization was partially dissociated from IM permeabilization when experiments were performed with E. coli that had been plasmolyzed by mannitol. Under such conditions, the rate and extent of bacterial death more closely paralleled loss of IM integrity than OM permeabilization. Electron microscopy of E. coli that had been killed by defensins revealed the presence of striking electron-dense deposits in the periplasmic space and affixed to the OM.Overall, these studies show that HNP-mediated bactericidal activity against E. coli ML-35 is associated with sequential permeabilization of the OM and IM, and that inner membrane permeabilization appears to be the lethal event.

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Section: Discussionmentioning

confidence: 99%

Interaction of human defensins with Escherichia coli. Mechanism of bactericidal activity.

Lehrer¹,

Barton²,

Daher³

et al. 1989

J. Clin. Invest.

672

516

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“…Although our experimental conditions were quite different from those employed by Olson et al, we also found that mitochondrial metabolism sensitizes C. albicans to the cytotoxic effects of protamine. It has also been reported thatlysozyme can kill C. albicans in hypotonic solutions that contain small amounts of glucose (31) or other nu- Table III. trients (32), perhaps indicating a requirement for active target-cell metabolism under these conditions as well.…”

Section: Methodsmentioning

confidence: 99%

Modulation of the in vitro candidacidal activity of human neutrophil defensins by target cell metabolism and divalent cations.

Lehrer

Ganz²,

Szklarek³

et al. 1988

J. Clin. Invest.

217

145

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We tested the in vitro susceptibility of Candida albicans to three defensins from human neutrophilic granulocytes (HNP-1, 2, and 3), a homologous defensin from rabbit leukocytes (NP-1), and four unrelated cationic peptides. Although the primary amino acid sequences of HNP-1, 2, and 3 are identical except for a single amino-terminal amino acid alteration, HNP-1 and HNP-2 killed C. albicans but HNP-3 did not. C. albicans blastoconidia were protected from HNP-I when incubations were performed in the absence of oxygen or in the presence of inhibitors that blocked both of its mitochondrial respiratory pathways. Neither anaerobiosis nor mitochondrial inhibitors substantially protected C. albicans exposed to NP-1, poly-L-arginine, poly-L-lysine, or mellitin. Human neutrophilic granulocyte defensin-mediated candidacidal activity was inhibited by both Mg2+ and Can, and was unaffected by Fe2". In contrast, Fe2" inhibited the candidacidal activity of NP-i and all of the model cationic peptides, whereas Mg2+ inhibited none of them. These data demonstrate that susceptibility of C. albicans to human defensins depends both on the ionic environment and on the metabolic state of the target cell. The latter finding suggests that leukocyte-mediated microbicidal mechanisms may manifest oxygen dependence for reasons unrelated to the production of reactive oxygen intermediates by the leukocyte.

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“…28 Besides moderate activity against gram-negative bacteria, 29 G. mellonella lysozyme was also shown to exhibit antifungal activity in vitro, 4 similar to that of human lysozyme against the pathogenic yeasts Candida albicans and Coccidioides immitis. 30,31 The effect of commercially available hen-egg-white lysozyme on virulent or non-virulent strains of M. anisopliae is illustrated in Figure 1. A recent analysis of the G. mellonella immunity-related transcriptome resulted in identification of four lysozyme homologues and an additional i-type lysozyme whose precise functions in antifungal immunity remain to be elucidated (Vogel, et al unpublished).…”

Section: Andreas Vilcinskasmentioning

confidence: 99%

Coevolution between pathogen-derived proteinases and proteinase inhibitors of host insects

Vilcinskas¹

2010

Virulence

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Virulence is thought to coevolve as a result of reciprocal selection between pathogens and their hosts. This paper focuses on coevolution between microbial proteinases operating as virulence factors and host defense molecules of insects. Owing to shorter generation times and smaller genomes, microbes exhibit a high evolutionary adaptability in comparison with their hosts. Indeed, the latter can only compete with pathogens if they evolve mechanisms providing a comparable genetic plasticity. Gene or domain duplication and shuffling by recombination is the driving force behind the countermeasures in host defense effectors. Recent literature provides evidence for both diversifications of fungal proteinases involved in pathogenesis and expansion host proteinase inhibitors subsets contributing to insect innate immunity. For example, the pathogen-associated spectrum of proteolytic enzymes encompasses thermolysin-like metalloproteinases that putatively promoted the evolution of corresponding host inhibitors of these virulence factors which complement the insect repertoire of antimicrobial defense molecules. Beyond mutual diversification of effector molecules coevolution resulted also in sophisticated molecular adaptations of host insects such as sensing and feedback-loop regulation of microbial metalloproteinases and corresponding countermeasures of pathogens providing evasion of host immunity induced by these virulence factors

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Lytic action of lysozyme on candida albicans

Cited by 45 publications

References 34 publications

Interaction of human defensins with Escherichia coli. Mechanism of bactericidal activity.

Interaction of human defensins with Escherichia coli. Mechanism of bactericidal activity.

Modulation of the in vitro candidacidal activity of human neutrophil defensins by target cell metabolism and divalent cations.

Coevolution between pathogen-derived proteinases and proteinase inhibitors of host insects

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