Peer-Reviewed Journal Details
Mandatory Fields
Bergin, D;Reeves, EP;Renwick, J;Wientjes, FB;Kavanagh, K
2005
July
Infection and Immunity
Superoxide production in Galleria mellonella hemocytes: Identification of proteins homologous to the NADPH oxidase complex of human neutrophils
Published
147 ()
Optional Fields
RESPIRATORY BURST OXIDASE CHRONIC GRANULOMATOUS-DISEASE CYTOCHROME-B KINASE-C PSEUDOMONAS-AERUGINOSA FLAVOCYTOCHROME B(558) ASPERGILLUS-FUMIGATUS PHAGOCYTIC VACUOLES 2-HYBRID SYSTEM MYTILUS-EDULIS
73
4161
4170
The insect immune response has a number of structural and functional similarities to the innate immune response of mammals. The objective of the work presented here was to establish the mechanism by which insect hemocytes produce superoxide and to ascertain whether the proteins involved in superoxide production are similar to those involved in the NADPH oxidase-induced superoxide production in human neutrophils. Hemocytes of the greater wax moth (Galleria mellonella) were shown to be capable of phagocytosing bacterial and fungal cells. The kinetics of phagocytosis and microbial killing were similar in the insect hemocytes and human neutrophils. Superoxide production and microbial killing by both cell types were inhibited in the presence of the NADPH oxidase inhibitor diphenyleneiodonium chloride. Immunoblotting of G. mellonella hemocytes with antibodies raised against human neutrophil phox proteins revealed the presence of proteins homologous to gp91(phox), p67(phox), p47(phox), and the GTP-binding protein rac 2. A protein equivalent to p40(phox) was not detected in insect hemocytes. Immunofluorescence analysis localized insect 47-kDa and 67-kDa proteins throughout the cytosol and in the perinuclear region. Hemocyte 67-kDa and 47-kDa proteins were immunoprecipitated and analyzed by matrix-assisted laser desorption ionization-time of flight analysis. The results revealed that the hemocyte 67-kDa and 47-kDa proteins contained peptides matching those of p67 phox and P47(phox) of human neutrophils. The results presented here indicate that insect hemocytes phagocytose and kill bacterial and fungal cells by a mechanism similar to the mechanism used by human neutrophils via the production of superoxide. We identified proteins homologous to a number of proteins essential for superoxide production in human neutrophils and demonstrated that significant regions of the 67-kDa and 47-kDa insect proteins are identical to regions of the p67(phox) and p47(phox) proteins of neutrophils.
WASHINGTON
0019-9567
10.1128/IAI.73.7.4161-4170.2005
Grant Details