Cloning and characterization of a beta-galactoside-binding protein (galectin) from the gut of the gastrointestinal nematode parasite Haemonchus contortus.
A cDNA encoding a beta-galactoside-binding lectin (galectin) was identified by immunoscreening a Haemonchus contortus cDNA library with antisera from lambs vaccinated with a membrane protein complex (H-gal-GP) derived from the parasites' gut. The cDNA sequence, exhibiting a tandem repeat structure and designated Hco-gal-2, showed significant levels of similarity with galectins from several species of nematode as well as mammalian galectin type 4. Native galectin was preferentially extracted from the H-gal-GP complex and also from an insoluble membrane fraction prepared from adult worms using lactose-agarose affinity chromatography. The affinity-purified material had apparent molecular mass of around 35 kDa with 3 distinct bands visible on SDS-PAGE. All 3 bands were identified as galectins by reaction with antiserum raised to recombinant Hco-GAL-2 on Western blot. To determine whether H. contortus galectins have any protective capacity against infection lambs were vaccinated with affinity-purified galectin and subsequently given a single challenge infection. Vaccination did not confer any protection against infection with H. contortus as judged by faecal egg output or worm counts.
Newlands
G F
GF
Moredun Research Institute, International Research Centre, Penicuik, UK. newlg@mri.sari.ac.uk
Skuce
P J
PJ
Knox
D P
DP
Smith
S K
SK
Smith
W D
WD
D000595:Amino Acid Sequence; D000818:Animals; D000909:Antibodies, Helminth / Q000096:biosynthesis; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D018509:DNA, Helminth / Q000737:chemistry / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005260:Female; D005697:Galactosides / Q000737:chemistry; D037161:Galectins; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D006188:Haemonchiasis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D006189:Haemonchus / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D006388:Hemagglutinins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008297:Male; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology / Q000469:parasitology* / Q000517:prevention & control; D014611:Vaccination / Q000662:veterinary
D000909:Antibodies, Helminth; D017931:DNA Primers; D018509:DNA, Helminth; D005697:Galactosides; D037161:Galectins; D006388:Hemagglutinins; D011994:Recombinant Proteins