Molecular cloning and characterization of pig, cow and sheep MAdCAM-1 cDNA and the demonstration of cross-reactive epitopes amongst mammalian homologues.
Full-length cDNA clones for the pig, cow and sheep mucosal addressin cellular adhesion molecule (MAdCAM)-1 homologues were isolated from Peyer's patches by a combination of reverse transcription (RT)-polymerase chain reaction and 5' and 3' RACE strategies. Degenerate primers based on conserved amino acid (aa) sequences within the N-terminal immunoglobulin (Ig)-like domains of the human and rodent MAdCAM-1 molecules were used for initial sequencing of the Ig-like domains. MAdCAM-1 transcripts of 1425 bp, 1525 bp and 1510 bp obtained for the pig, cow and sheep contained an open-reading frame for proteins of 390, 424 and 418 aa, respectively. The pig and ruminant MAdCAM-1 had two N-terminal Ig-like domains, a mucin-like region and a third Ig-like domain found in rodent but not human MAdCAM-1. Antibodies raised against bacterially expressed N-terminal Ig-like domains of pig, human and sheep MAdCAM-1 demonstrated the existence of cross-reactive epitopes, raising the possibility of producing monoclonal antibodies which can be used as multi-species MAdCAM-1-targeting reagent for the development of mucosal vaccines.
Tachedjian
M
M
Cooperative Research Center for Vaccine Technology, CSIRO Livestock Industries, Australian Animal Health Laboratory (AAHL), Private Bag 24, Geelong, Victoria 3220, Australia. mary.tachedjian@csiro.au
Yu
M
M
Lew
A M
AM
Rockman
S
S
Boyle
J S
JS
Andrew
M E
ME
Wang
L
L