Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.4.3 (phospholipase C)
18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sheep and human erythrocytes, partially processed by Staphylococcus aureus or Clostridium perfringens, were susceptible to lysis in the presence of Propionibacterium acnes. P. acnes liberated a lipase that was detected on Tween 80 agar and also on phospholipase C-precipitated egg yolk agar. Such a lipase might have contributed in the process of an intensified cellular lysis. Similar reactions were attempted with Lactobacillus acidophilus, known to possess a nondiffusible lipase, and failed to produce any such reactions. The synergistic reactions, between P. acnes and C. perfringens, were compared with The classical CAMP reaction in an attempt to find a correlation with the established membrane composition of the erythrocytes involved. Synergistic reactions observed do seem to reflect the membrane composition. Such findings, besides being contributory to an understanding of the role of these organisms in the process of pathogenesis, are of importance in the elucidation of molecular organization of biomembranes. Detailed studies, involving a large number of representative anaerobic bacteria, may also help provide an avenue in anaerobic species identification.
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PMID:Synergistic lysis of erythrocytes by Propionibacterium acnes. 21 50

A new phenomenon of synergistic hemolysis by Clostridium perfringens alpha-toxin and the streptococcal CAMP factor on human and guinea pig erythrocytes is described. A possible mode of action of the CAMP factors is suggested. On human blood agar all of the tested isolates of group B streptococci gave an arrowhead-shaped zone of hemolysis; 74% of group A gave a crescent-shaped lytic zone, whereas all isolates of groups C and G and the remaining 26% of group A streptococci gave a bullet-shaped lytic zone. By comparison, in the CAMP test incubated aerobically and anaerobically, 70 and 91%, respectively, of streptococci other than group B gave positive, arrowhead-shaped lytic zones. If all intermediate positive reactions in the CAMP tests were read as negative after aerobic incubation, only 89% of group B streptococci would be properly identified. The synergistic hemolysis phenomenon, using an alpha-toxin-producing C. perfringens and human blood agar, provided a reliable test for presumptive identification of group B streptococci, with promising potential to differentiate in the same test group A streptococci from other groups.
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PMID:Synergistic hemolysis phenomenon shown by an alpha-toxin-producing Clostridium perfingens and streptococcal CAMP factor in presumptive streptococcal grouping. 21

The authors have modified the one-plate method for the detection of staphylococcal hemolysins. They recommend to use in this method a prepurified form of staphylococcal beta-toxin and of streptococcal CAMP-factor instead of the exclusively beta-tonin-producing strain of Staphylococcus aureus and instead of the intensively CAMP-test positive Streptococcus agalactiae strain, respectively. The authors determined concurrently staphylococcal hemolysins, using a three-plate method in which alpha-antitoxin was employed, to ensure a better evidence of alpha-toxin. A total of 494 staphylococcal strains were examined by both methods. Of this number, 446 Staphylococcus aureus strains were of diverse host origin and 48 were coagulase-negative staphylococcal strains. On the basis of the various hemolytically active staphylococcal toxins, the authors recommend the suggested modification of the one-plate method for their routine detection.
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PMID:Diagnostic utilization of hemolytically active exosubstances of certain gram-positive bacteria. I. Detection of staphylococcal hemolysins with prepurified preparations of staphylococcal beta-toxin and CAMP-factor of Streptococcus agalactiae. 39 88

The CAMP test was performed by employing Staphylococcus aureus beta-haemolysin (sphingomyelinase) and Clostridium perfringens alpha-toxin (lecithinase) for identification of group B streptococci on blood agar, using blood from different origin. Partial purification of Cl perfringens alpha-toxin was carried out by means of sheep erythrocytes. With the toxin preparations described positive CAMP reaction was obtained only on sheep blood agar. False positives with regard to group A streptococci could not be avoided by either of the methods.
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PMID:The CAMP test performed by using Staphylococcus aureus sphingomyelinase (beta-haemolysin) and Clostridium perfringens lecithinase. 627 70

Usefulness of the synergistic haemolysis (CAMP-like) test in the identification of Aeromonas hydrophila, Aeromonas sobria, and Aeromonas caviae was evaluated, using beta-toxin producing Staphylococcus aureus ATCC 25923 and alpha-toxin producing Clostridium perfringens ATCC 13124 as sphingomyelinase producing indicator strains. The tests were done on Columbia Blood Agar Base supplemented with 5% sheep blood (CBA; Difco Laboratories, Detroit, MI, USA). When cultured aerobically, 77% of A. hydrophila isolates, 75% of A. sobria isolates, and 23% of A. caviae isolates elicited synergistic haemolysis of sheep erythrocytes with the beta-toxin producing strain of S. aureus. Anaerobically, using the same indicator strain, synergistic haemolysis was given by 91%, 51% and 82% of A. hydrophila, A. sobria, and A. caviae, respectively. When alpha-toxin producing C. perfringens was used in the test instead of beta-toxin producing S. aureus, 100%, 86%, and 93% of A. hydrophila, A. sobria, and A. caviae isolates, respectively, showed synergistic haemolysis of sheep erythrocytes. Due to the high number of the tested isolates of A. hydrophila, A. sobria, and A. caviae giving a positive synergistic haemolysis reaction in both atmospheric conditions of culture, this test cannot be used to identify any of the three Aeromonas spp. The use of alpha-toxin producing C. perfringens did not improve discriminatory power of the test. Because the nature of the product of Aeromonas spp. responsible for the lytic phenomenon is not known, the use of Aeromonas factor and synergistic haemolysis terms was proposed rather than CAMP (reaction, test) or CAMP (-like) factor.
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PMID:Evaluation of the synergistic haemolysis (CAMP-like) test in the identification of motile, mesophilic Aeromonas species. 924 99

Antimicrobial peptides, human beta-defensins (hBD-1/-2), and LL-37 (a peptide of human cathelicidin CAP18) are predominately expressed at epithelial tissues, where they participate in the innate host defense by killing invading microorganisms. In this study, to investigate the interactions between epithelial cell-derived antimicrobial peptides and mast cells, we evaluated the effects of hBD-1/-2 and LL-37 on mast cell functions using rat peritoneal mast cells. hBD-2 and LL-37 but not hBD-1 induced histamine release and intracellular Ca(2+) mobilization, and hBD-2 was more potent than LL-37. Interestingly, histamine release and intracellular Ca(2+) mobilization elicited by hBD-2 and LL-37 were markedly suppressed by BAPTA-AM (an intracellular Ca(2+) chelating agent), pertussis toxin and U-73122 (a phospholipase C inhibitor). In addition, among the peptides examined, only hBD-2 significantly induced PGD(2) production, which was abolished by indomethacin (cyclooxygenase-1/-2 inhibitor) but not NS-398 (cyclooxygenase-2 inhibitor), suggesting that hBD-2-induced PGD(2) production is mediated by cyclooxygenase-1. Likewise, the PGD(2) production was suppressed by pertussis toxin and U-73122. These observations suggest that hBD-2 and LL-37 stimulate mast cells to mobilize intracellular Ca(2+) and release histamine or generate PGD(2) in a G protein-phospholipase C-dependent manner. Thus, hBD-2 and LL-37 may have modulatory effects on inflammatory reactions.
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PMID:Evaluation of the effects of peptide antibiotics human beta-defensins-1/-2 and LL-37 on histamine release and prostaglandin D(2) production from mast cells. 1129 31

The mast cell is one of the major effector cells in inflammatory reactions and can be found in most tissues throughout the body. During inflammation, an increase in the number of mast cells in the local milieu occurs, and such accumulation requires directed migration of this cell population. As it has previously been reported that the human cathelicidin-derived antibacterial peptide, LL-37, stimulates the degranulation of mast cells, we hypothesized that LL-37 could be a mast cell chemotaxin. The present study shows that LL-37 is a potent chemotactic factor for mast cells. The chemotactic response was dose-dependent and bell-shaped, reaching an optimal concentration of 5 microg/ml. In addition, checkerboard analysis showed that cell migration towards this peptide was chemotactic rather than chemokinetic. Moreover, Scatchard analysis using 125I-labelled LL-37-derived peptide revealed that LL-37 has at least two classes of receptors, namely high- and low-affinity receptors, on mast cells. Furthermore, the competitive binding assay suggested that LL-37 is unlikely to utilize formyl peptide receptor-like 1 (FPRL1), a functional LL-37 receptor for neutrophil and monocyte migration, on mast cells. In addition, the treatment of cells with pertussis toxin and phospholipase C inhibitor, U-73122, inhibited LL-37-mediated migration, indicating that LL-37 induces mast cell chemotaxis through a Gi protein-phospholipase C signalling pathway. These results show that besides its antibacterial activities, LL-37 may have the potential to recruit mast cells to inflammation foci.
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PMID:A cathelicidin family of human antibacterial peptide LL-37 induces mast cell chemotaxis. 1197 28

Antibacterial peptides function as effectors for defense in innate immunity. In mammals, they are implicated in the barrier protection of epithelia where their expression can be induced during infection and inflammation. Over a dozen of antibacterial peptides have been identified in humans. Among these, defensins and cathelicidins have been well characterized. Two types of defensins (alpha- and beta-defensins) are recognized based on the presence of their conserved six cysteine residues, whereas cathelicidins are characterized by a homologous cathelin sequence in the pro-region and a variable antibacterial C-terminal sequence. Human beta-defensins and cathelicidin hCAP18/LL-37 are mainly expressed in epithelial tissues where mast cells are present. Here we review the structure of human beta-defensins and cathelicidin, and describe their multiple activities on mast cells to induce chemotaxis, degranulation and prostaglandin D(2) production, acting through receptors coupled to G-protein-phospholipase C pathway. Thus, in addition to their bactericidal activities, epithelial cell-derived antibacterial peptides may modulate the inflammatory responses by recruiting mast cells to inflammation foci and inducing the degranulation as well as prostaglandin production from this cell population.
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PMID:Epithelial cell-derived antibacterial peptides human beta-defensins and cathelicidin: multifunctional activities on mast cells. 1456 Nov 57

CAMP factor (protein B) is a pore-forming protein secreted by Streptococcus agalactiae. It causes lysis of sheep red blood cells when these have been sensitized with staphylococcal sphingomyelinase. We here show that CAMP factor binds to GPI-anchored proteins, and that this interaction involves the carbohydrate core of the GPI-anchor. Enzymatic cleavage of GPI-anchors with phosphatidylinositol-specific phospholipase C strongly reduces the sensitivity of erythrocytes to CAMP factor. Incorporation of alkaline phosphatase, a model GPI-anchored protein, into liposome membranes renders the latter susceptible to permeabilization by CAMP factor. GPI-anchored proteins therefore function as cellular receptors for CAMP factor.
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PMID:Streptococcus agalactiae CAMP factor binds to GPI-anchored proteins. 1677 78

Besides their microbicidal functions, human beta-defensins (hBD) and LL-37 activate different immune and inflammatory cells, and their expression is enhanced in inflamed skin and cutaneous wound sites. To protect against pathogens, the skin produces antimicrobial peptides including hBDs and LL-37. Therefore, the aim of our study was to investigate whether hBDs participate in cutaneous inflammation and wound healing by inducing keratinocyte migration, proliferation, and production of proinflammatory cytokines/chemokines. We found that hBD-2, -3, and -4 but not hBD-1 stimulated human keratinocytes to increase their gene expression and protein production of IL-6, IL-10, IP-10, monocyte chemoattractant protein-1, macrophage inflammatory protein-3alpha, and RANTES. This stimulatory effect was markedly suppressed by pertussis toxin and U-73122, inhibitors for G protein and phospholipase C, respectively. We also demonstrated that hBDs elicited intracellular Ca2+ mobilization, and increased keratinocyte migration, and proliferation. In addition, these peptides induced phosphorylation of EGFR, signal transducer and activator of transcription (STAT)1, and STAT3, which are intracellular signaling molecules involved in keratinocyte migration and proliferation. In our study, inhibition of these molecules significantly reduced hBD-mediated keratinocyte migration and proliferation. In conclusion, this study provides evidence that human antimicrobial peptides may be involved in skin immunity through stimulating cytokine/chemokine production, and participate in wound healing by promoting keratinocyte migration and proliferation.
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PMID:Antimicrobial peptides human beta-defensins stimulate epidermal keratinocyte migration, proliferation and production of proinflammatory cytokines and chemokines. 1729 32


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