Lise Vanderkelen

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Lysozymes are ancient and important components of the innate immune system of animals that hydrolyze peptidoglycan, the major bacterial cell wall polymer. Bacteria engaging in commensal or pathogenic interactions with an animal host have evolved various strategies to evade this bactericidal enzyme, one recently proposed strategy being the production of(More)
Lysozymes are key effectors of the animal innate immunity system that kill bacteria by hydrolyzing peptidoglycan, their major cell wall constituent. Recently, specific inhibitors of the three major lysozyme families occuring in the animal kingdom (c-, g- and i-type) have been discovered in Gram-negative bacteria, and it has been proposed that these may help(More)
Peptidoglycan is the major structural component of the bacterial cell wall. It provides resistance against turgor and its cleavage by hydrolases such as lysozymes results in bacteriolysis. Most, if not all, animals produce lysozymes as key effectors of their innate immune system. Recently, highly specific bacterial proteinaceous lysozyme inhibitors against(More)
Lysozymes represent important innate immune components against bacteria. In this study, Atlantic salmon (Salmo salar) goose (g-) and chicken (c-) types of lysozyme were subjected to protein characterisations and tissue expression analyses. Specific bacterial protein inhibitors of g- and c-type lysozymes were employed to discriminate between respective(More)
Invertebrate (I-) type lysozymes, like all other known lysozymes, are dedicated to the hydrolysis of peptidoglycan, the major bacterial cell wall polymer, thereby contributing to the innate immune system and/or digestive system of invertebrate organisms. Bacteria on the other hand have developed several protective strategies against lysozymes, including the(More)
The production of lysozyme inhibitors, competitively binding to the lysozyme active site, is a bacterial strategy to prevent the lytic activity of host lysozymes. Therefore, suppression of the lysozyme-inhibitor interaction is an interesting new approach for drug development since restoration of the bacterial lysozyme sensitivity will support bacterial(More)
A reverse zymogram method for the detection of bacterial lysozyme inhibitors was developed. This method was validated by using a periplasmic protein extract of Escherichia coli containing a known inhibitor and subsequently led to the detection of a new proteinaceous hen egg white lysozyme inhibitor in Proteus mirabilis.
The goose-type lysozyme inhibitor PliG enhances the survival of Escherichia coli in goose but not in chicken egg white, which contains goose- and chicken-type lysozymes, respectively. These results indicate that both the type of host lysozyme and the type of bacterial lysozyme inhibitor may affect bacterium-host interactions.
Lysozymes are antibacterial effectors of the innate immune system in animals that hydrolyze peptidoglycan. Bacteria have evolved protective mechanisms that contribute to lysozyme tolerance such as the production of lysozyme inhibitors, but only inhibitors of chicken (c-) and invertebrate (i-) type lysozyme have been identified. We here report the discovery(More)
Gram-negative bacteria can produce specific proteinaceous inhibitors to defend themselves against the lytic action of host lysozymes. So far, four different lysozyme inhibitor families have been identified. Here, we report the crystal structure of the Escherichia coli periplasmic lysozyme inhibitor of g-type lysozyme (PliG-Ec) in complex with Atlantic(More)