A monoclonal IgM antibody to a methylcholanthrene-induced tumour. I. Specificity for alpha-N-acetylgalactosamine but with no cross-reactivity to the human blood group A determinant
Gigliotti, D.; Teneberg, S.; Andersson, R.; Angström, J.; Karlsson, K.A.; Wigzell, H.; Hansson, M.
Scandinavian Journal of Immunology 33(4): 345-355
1991
ISSN/ISBN: 0300-9475 PMID: 1708163 Document Number: 386631
A monoclonal IgM antibody, H17, has been obtained from rats immunized with mouse fibrosarcoma cells from an in vitro established methylcholanthrene (MCA)-induced tumuor. H17 shows specific and very selective binding to .alpha.-N-acetylgalactosamine (GalNAc.alpha.) when tested for reactivity to a panel of glycolipids. It cross-reacts with GalNAc.alpha. on the Forssman and antigen extracted from dog small intestine, but not from the human blood group A determinant, a finding not commonly observed among antibodies with this specificity. Despite its specificity, H17 does not react with TA3-Ha, a mouse mammary adenocarcinoma, known to express the Tn antigen (GalNAc.alpha.-O-Ser/Thr). The uniqueness of H17 probably relates to the fact that it has been generated against an MCA-induced tumour rather than against the pure saccharide itself. Minimum energy conformation structures of different GalNAc.alpha. containing saccharide molecules were computer modelled to allow a plausible interpretation of the accessible site of GalNAc.alpha. for successful interaction with the H17 paratope as compared to other GalNAc.alpha. binding antibodies.