Involvement of apolipophorin III in antibacterial defense of Galleria mellonella larvae.
Apolipophorin III (apoLp-III) is an abundant hemolymph protein involved in lipid transport and immune response in insects. We investigated involvement of apoLp-III in the antibacterial response in Galleria mellonella larvae. Immune challenge with Gram-negative (Escherichia coli, Klebsiella pneumoniae) and Gram-positive (Micrococcus luteus) bacteria led to an increase in the level of apoLp-III in G. mellonella hemolymph, 0.5-2h and 8h after treatment, respectively. ApoLp-III purified from larval hemolymph as well as that present in hemolymph extracts adsorbed on the surface of different bacteria. The adsorption capacity of apoLp-III on bacterial cells prompted us to investigate the effect of this phenomenon on bacterial growth. Our results demonstrate antibacterial activity of apoLp-III against selected Gram-positive and Gram-negative bacteria in vitro. Among bacteria tested, Salmonella typhimurium and K. pneumoniae were the most sensitive to apoLp-III. LIVE/DEAD staining of bacteria incubated with purified apoLp-III revealed their growth inhibition; however, neither morphological changes in the cell shape nor formation of cell aggregates was noticed. The results suggest that apoLp-III is a multifunctional protein in G. mellonella hemolymph.
Department of Invertebrate Immunology, Institute of Biology, Maria Curie-Skłodowska University, 19 Akademicka St., 20-033 Lublin, Poland.
Agnieszka
A
Zdybicka-Barabas
Małgorzata
M
Cytryńska
D000327:Adsorption; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology; D001053:Apolipoproteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000276:immunology*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000254:growth & development / Q000276:immunology*; D007814:Larva / Q000276:immunology / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D016982:Micrococcus luteus / Q000187:drug effects / Q000254:growth & development / Q000276:immunology*; D009036:Moths; D013045:Species Specificity; D013499:Surface Properties
D000900:Anti-Bacterial Agents; D001053:Apolipoproteins; C042470:apolipophorin III