Modulacja humoralnej odpowiedzi odpornościowej gąsienic Galleria mellonella przez enzymy proteolityczne bakterii Pseudomonas aeruginosa

Modulation of the humoral immune response in Galleria mellonella larvae by proteolytic enzymes produced by Pseudomonas aeruginosa
M. Andrejko

1. Wstęp. 2. Barciak większy (Galleria mellonella) jako organizm modelowy. 3. Wrażliwość gąsienic G. mellonella na zakażenie P. aeruginosa. 4. Wpływ proteaz P. aeruginosa na reakcje immunologiczne gąsienic G. mellonella. 4.1. Układ oksydazy fenolowej. 4.2. Lizozym (muramidaza, glikohydrolaza mukopeptydowa, EC 4.3. Peptydy o właściwościach przeciwdrobnoustrojowych (peptydy odpornościowe). 4.4. Apolipoforyna III (apoLp-III). 5. Podsumowanie

Abstract: The greater wax moth G. mellonella is a useful model organism for investigations of pathogenicity and identification of P. aeruginosa virulence factors. Strains differing in the protease profiles elicit different responses of the G. mellonella immune system to infection. The immune response depends on the bacterial strain used and the composition of the bacterial culture medium. Proteases in the initial phase of infection activate the immune system (involving increased lysozyme synthesis, induction of synthesis of immune peptides and metalloproteinase inhibitors, and altered apolipophorin III levels), thereby increasing the antibacterial activity of insect hemolymph. As bacteraemia progresses, they overcome the humoral immune response of the host by inhibiting the phenoloxidase activity, degradation of immune peptides and apolipophorin III. Different proteases exhibit different involvement in the degradation of key elements of insect immune response and/or proteins, while immune peptides display varied sensitivity to proteolytic activity. Elastase B has a double role during infection: it is an inducer of immune response (involving induction of antimicrobial peptide synthesis and metalloproteinase inhibitors, and increasing expression and activity of lysozyme and the level of apolipophorin III) and a virulence factor involved in the degradation of antimicrobial peptides. Increased quantities and activity of lysozyme in the hemolymph of larvae infected with the P. aeruginosa indicates that lysozyme is not very sensitive to the activity of bacterial proteases. Induction of synthesis of humoral immune response factors in G. mellonella larvae in the presence of metalloproteinases (elastase B) implies the “danger” resistance model in this organism.

1. Introduction. 2. Greater wax moth Galleria mellonella as a model system. 3. Sensitivity of G. mellonella larvae to infection with P. aeruginosa. 4. Effect of P. aeruginosa proteases on G. mellonella immune response. 4.1. Phenoloxidase system. 4.2. Lysozyme (muramidase, mucopeptide glycohydrolase, EC2.2.1.17). 4.3. Antimicrobial peptides (immune peptides). 4.4. Apolipophorin-III. 5. Summary