Inducible factors with antimicrobial activity after immune challenge in the haemolymph of Red Palm Weevil (Insecta).
Innate Immun
; 21(4): 392-405, 2015 May.
Article
de En
| MEDLINE
| ID: mdl-25114180
ABSTRACT
Insects are capable of innate immune responses elicited after microbial infection. In this process, the receptor-mediated recognition of foreign bodies and the subsequent activation of immunocompetent cells lead to the synthesis ex novo of a peptide pool with antimicrobial activity. We investigated the inducible immune response of a coleopteran, Rhynchophorus ferrugineus, challenged with both Gram-negative and Gram-positive bacteria. After immunization, we evaluated the presence of antimicrobial peptides using either biochemical analyses or microbiological techniques. The antimicrobial properties of the newly synthesized protein pool, detectable in haemolymph fractions of low molecular mass, showed strong antibacterial activity against various bacterial strains (Escherichia coli, Pseudomonas sp. OX1, Bacillus subtilis and Micrococcus luteus). In addition to the preliminary study of the mechanism of action of the pool of antimicrobial peptides, we also investigated its effects on bacterial cell walls by means of fluorescence microscopy and scanning electron microscopy. The data suggest that the main effects seem to be directed at destabilizing and damaging the bacterial wall. This study provides data that help us to understand some aspects of the inducible innate immunity in a system model that lacks anticipatory responses. However, the weevil has finely tuned its defensive strategies to counteract effectively microbial infection.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Coléoptères
/
Hémolymphe
/
Paroi cellulaire
/
Infections bactériennes à Gram positif
/
Infections bactériennes à Gram négatif
/
Peptides antimicrobiens cationiques
/
Érythrocytes
Type d'étude:
Prognostic_studies
Limites:
Animals
/
Humans
Langue:
En
Journal:
Innate Immun
Sujet du journal:
ALERGIA E IMUNOLOGIA
/
BACTERIOLOGIA
Année:
2015
Type de document:
Article
Pays d'affiliation:
Italie