Linked Life Data

16540172

Source:http://linkedlifedata.com/resource/pubmed/id/16540172

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2006-8-29
pubmed:abstractText
Bites by Loxosceles spiders can induce severe clinical symptoms, including dermonecrosis, thrombosis, vascular leakage, haemolysis and persistent inflammation. The causative toxin is a sphingomyelinase D (SMase D) that cleaves sphingomyelin into choline and ceramide-1-phosphate. A similar enzyme, showing comparable bioactivity, is secreted by certain pathogenic corynebacteria and acts as a potent virulence factor. We have previously found that SMase D toxins led to an increased susceptibility of human erythrocytes (E) to activation of complement (C) via the classical pathway (CP) in the absence of antibodies. In the present study we have investigated the CP initiating components involved in the haemolysis induced by SMases from Corynebacterium pseudotuberculosis (PLD) and from Loxosceles intermedia venom (P1). When P1 or PLD treated E were incubated with C8-depleted human serum, an increase in C1q, serum amyloid protein (SAP) and C-reactive protein (CRP) binding was observed. While purified C1q, SAP and CRP were found to bind to P1 or PLD treated E, depletion of SAP or CRP from human serum did not prevent C-mediated lysis, suggesting that pentraxins are not involved in the initiation of C-activation. However depletion of C1 lead to a greatly reduced haemolysis, demonstrating that the activation of the CP is caused by direct binding of C1q to the SMase treated cells. Binding of fluid phase C-regulators C4b-binding protein and factor H was also observed, however these C-regulators in conjunction with the membrane bound C-regulators were unable to prevent haemolysis, demonstrating the potency of SMase D facilitated binding of C1 and activation of C.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0161-5890
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
576-82
pubmed:dateRevised
2007-8-13
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Sphingomyelinases D induce direct association of C1q to the erythrocyte membrane causing complement mediated autologous haemolysis.
pubmed:affiliation
Laboratório de Imunoquímica, Instituto Butantan, São Paulo, Brazil. dvtambourgi@butantan.gov.br
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't