Lipopolysaccharide interaction with hemolin, an insect member of the Ig-superfamily.
This study is an attempt to reach some understanding of how insects recognize intruding microorganisms and foreign entities while executing an immune response. We used lipopolysaccharide (LPS) from Escherichia coli, bound to a radiolabeled iodinated crosslinker, to identify hemolymph proteins from the Hyalophora cecropia moth that have the capacity to bind LPS. High amounts of radioactivity were conferred to hemolin, an immunoglobulin and NCAM-related protein, the concentration of which increases in insect hemolymph upon bacterial infection. We could demonstrate a concentration-dependent binding of hemolin to LPS. In addition we could show that Lipid A can compete for this binding, whereas KDO has no effect, indicating that hemolin interacts specifically with the Lipid A moiety of LPS.
Daffre
S
S
Departamento de Parasitologia, Instituto Ciencias Biomedicas, Universidade Sao Paulo, Brazil.
Faye
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I
D000345:Affinity Labels; D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D015153:Blotting, Western; D003432:Cross-Linking Reagents / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000737:chemistry; D006458:Hemolymph / Q000737:chemistry; D007136:Immunoglobulins / Q000276:immunology / Q000378:metabolism; D019476:Insect Proteins / Q000276:immunology / Q000378:metabolism; D008050:Lipid A / Q000031:analogs & derivatives / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology / Q000378:metabolism*; D009036:Moths / Q000276:immunology*; D011506:Proteins / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism
D000345:Affinity Labels; D003432:Cross-Linking Reagents; D007136:Immunoglobulins; D019476:Insect Proteins; D008050:Lipid A; D008070:Lipopolysaccharides; D011506:Proteins; D011994:Recombinant Proteins; C066846:hemolin