An insect multiligand recognition protein functions as an opsonin for the phagocytosis of microorganisms.
We characterize a novel pathogen recognition protein obtained from the lepidopteran Galleria mellonella. This protein recognizes Escherichia coli, Micrococcus luteus, and Candida albicans via specific binding to lipopolysaccharides, lipoteichoic acid, and beta-1,3-glucan, respectively. As a multiligand receptor capable of coping with a broad variety of invading pathogens, it is constitutively produced in the fat body, midgut, and integument but not in the hemocytes and is secreted into the hemolymph. The protein was confirmed to be relevant to cellular immune response and to further function as an opsonin that promotes the uptake of invading microorganisms into hemocytes. Our data reveal that the mechanism by which a multiligand receptor recognizes microorganisms contributes substantially to their phagocytosis by hemocytes. A better understanding of an opsonin with the required repertoire for detecting diverse invaders might provide us with critical insights into the mechanisms underlying insect phagocytosis.
From the Department of Biotechnology, Hoseo University, Asan City, Chungnam 336-795, South Korea.
Chong Han
CH
Kim
Yong Pyo
YP
Shin
Mi Young
MY
Noh
Yong Hun
YH
Jo
Yeon Soo
YS
Han
Yeon Sun
YS
Seong
In Hee
IH
Lee
D000818:Animals; D002176:Candida albicans / Q000378:metabolism / Q000502:physiology; D004926:Escherichia coli / Q000378:metabolism / Q000502:physiology; D005434:Flow Cytometry; D006434:Hemocytes / Q000378:metabolism / Q000382:microbiology; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000378:metabolism / Q000382:microbiology; D007915:Lepidoptera / Q000378:metabolism* / Q000382:microbiology*; D008070:Lipopolysaccharides / Q000378:metabolism; D009895:Opsonin Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010587:Phagocytosis / Q000235:genetics / Q000502:physiology*; D011485:Protein Binding; D051192:Receptors, Pattern Recognition / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013682:Teichoic Acids / Q000378:metabolism; D046509:Tissue Culture Techniques; D047071:beta-Glucans / Q000378:metabolism
D019476:Insect Proteins; D008070:Lipopolysaccharides; D009895:Opsonin Proteins; D051192:Receptors, Pattern Recognition; D013682:Teichoic Acids; D047071:beta-Glucans; C009900:lipoteichoic acid; C033363:beta-1,3-glucan