DEMONSTRATION OF IGM ANTIBODIES OF HIGH-AFFINITY WITHIN THE ANTI-GAL-ALPHA-1-3GAL ANTIBODY REPERTOIRE

Citation
J. Lee et al., DEMONSTRATION OF IGM ANTIBODIES OF HIGH-AFFINITY WITHIN THE ANTI-GAL-ALPHA-1-3GAL ANTIBODY REPERTOIRE, Transplantation, 66(8), 1998, pp. 1117-1119
Citations number
11
Categorie Soggetti
Transplantation,Surgery,Immunology
Journal title
ISSN journal
00411337
Volume
66
Issue
8
Year of publication
1998
Pages
1117 - 1119
Database
ISI
SICI code
0041-1337(1998)66:8<1117:DOIAOH>2.0.ZU;2-W
Abstract
Background. Human anti-Gal alpha 1-3Gal IgG and IgM xenoantibodies can distinguish between very similar epitopes with a high degree of selec tivity. Methods. Anti-Gal alpha 1-3Gal antibodies were affinity isolat ed using two separate Gal alpha 1-3Gal-based immunoadsorbents, Gal alp ha 1-3Gal itself and Gal alpha 1-3Gal beta 1-4Glc. IgG and IgM were se parated using a protein G column. Antibody purity was achieved by seri al adsorption/elutions from the columns. By this means, different anti body fractions were prepared that contained either IgG or IgM, reactiv e with either Gal alpha 1-3Gal, Gal alpha 1-3Gal beta 1-4Glc, or both. The dissociation equilibrium constants (K-d) of these antibodies were then measured using an IAsys biosensor. Results and Conclusions. Sera from two individuals were used and K-d values for one IgG (fraction 1 A) and two IgM (fractions 1B and 2A) fractions were obtained. The K-d for the IgG was 4.85 x 10(-7) M (fraction 1A). Far IgM, the K-d values were higher at 7.8x10(-10) M (fraction 1B) and 1.07x10(-10) M (fracti on 2A). Natural anti-pig antibodies include high affinity IgM that con tinue to be produced without class switch. The B cell mechanism behind this is not known. It may be possible to exploit this mechanism in fu ture xenotransplantation strategies.