Diptericin expression in bacteria infected Drosophila mbn-2 cells - effect of infection dose and phagocytosis.
Drosophila haemocytes play a key role in defence against microbial aggression. Their capacity to sense and dispose of bacteria and also to signal to other immune tissues is probably vital to overcome an infection. In this work we used the haemocyte-like mbn-2 cell line to investigate how expression of the antimicrobial peptide diptericin is affected after a high dose bacterial challenge with diaminopimelic acid (DAP)-peptidoglycan Gram-positive and Gram-negative bacteria. We report that diptericin expression is negatively affected by high infection dose and rapid bacterial growth regardless of the type of infection and bacterial virulence and occurs in the absence of mbn-2 cell death. Furthermore we show that the mbn-2 cell population is heterogeneous, containing both phagocytic and nonphagocytic cells and that contact with large numbers of bacteria decreases diptericin expression in the phagocytic cell population.
Department of Comparative Physiology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
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Johansson
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Söderhäll
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Cerenius
D000818:Animals; D001410:Bacillus megaterium / Q000276:immunology; D001412:Bacillus subtilis / Q000276:immunology; D002460:Cell Line; D003960:Diaminopimelic Acid / Q000378:metabolism; D015536:Down-Regulation; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D004331:Drosophila melanogaster / Q000166:cytology / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D004926:Escherichia coli / Q000276:immunology; D005434:Flow Cytometry; D006434:Hemocytes / Q000502:physiology; D006714:Homoserine / Q000031:analogs & derivatives / Q000378:metabolism; D007783:Lactones / Q000378:metabolism; D008070:Lipopolysaccharides; D010587:Phagocytosis / Q000502:physiology; D016133:Polymerase Chain Reaction; D015003:Yeasts / Q000276:immunology
C054756:DptA protein, Drosophila; D029721:Drosophila Proteins; D007783:Lactones; D008070:Lipopolysaccharides; C091088:N-octanoylhomoserine lactone; D003960:Diaminopimelic Acid; D006714:Homoserine