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The effect of the haemolymph protein apolipophorin-III on the antimicrobial responses of the insect Galleria mellonella to the bacterium, Bacillus subtilis /

Apolipophorin-III (apoLp-III) is known to influence the haemocyte-mediated induction of antimicrobial peptides in Galleria mellonella and yeast phagocytosis, bind to Gram-negative and Gram positive bacteria and limit the activation of the haemocytes and the prophenoloxidase system by bacterial surface antigens. The effects of apoLp-III on haemocyte adhesion to glass slides and to bacteria were herein examined. ApoLp-III bound to haemocytes limiting the adhesion of both granular cells and plasmatocytes to glass and the contact of the plasmatocytes with Bacillus subtilis. The percentage of granular cells with bacteria was increased by the protein. However, the total number of bacteria adhering to haemocytes in vitro declined in the presence of apoLp-III. Bacterial removal from the haemolymph in vivo by the haemocytes was slowed by the protein. / The adhesion of both the granular cells and plasmatocytes to slides was decreased by inhibiting protein tyrosine kinase and increased by inhibiting protein kinase A (PKA) and protein kinase C (PKC) activity. The latter was confirmed with haemocytes inhibited by the general PKC inhibitor H-7 using phorbol-3-myfstate (PMA) which, by activating PKC, diminished the adhesion of both haemocyte types. Limiting the formation of PKC activation by diacylglycerides which is produced by phosholipase C (PLC), using PLC inhibitor also increased haemocyte attachment. Although binding of B. subtilis to haemocytes decreased PKC activity, the effect of apoLp-III on PKC was inconclusive.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.33862
Date January 2002
CreatorsZakarian, Robert J.
ContributorsDunphy, Gary B. (advisor)
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Science (Department of Natural Resource Sciences.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 001872489, proquestno: MQ78979, Theses scanned by UMI/ProQuest.

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