|Budget Amount *help
¥3,100,000 (Direct Cost : ¥3,100,000)
Fiscal Year 2005 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 2004 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 2003 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 2002 : ¥1,600,000 (Direct Cost : ¥1,600,000)
N-linked oligosaccharides in human IgG are known to modulate immunological function. Complex oligosaccharide moieties (biantennary mannose structure, with or without galactose on N-acetylglucosamine outer arms) are attached to asparagine-297 of gamma heavy chains. We previously showed that neonatal cord blood IgG has significantly higher ratio of galactose on its outer arms, compared to that of normal healthy adults [Kimura S, et al. ; Clin Chim Acta. 2000; 299:169-77]. Because the galactose-rich IgGs are supplied from maternal sera, it is possible that the carbohydrate structure could affect the efficacy of IgG transportation via placenta. Based on this idea, we characterized, carbohydrate structures on neonatal serum IgG; to compare with their mothers' sera.
Cord blood samples (n=12; five males and seven females including twins) were collected during deliveries at Dokkyo University Koshigaya Hospital, with the parents' written consent. Their mothers' blood samples (n =11, age 31.3±3.9
) were also collected within a week before delivery The analysis of carbohydrate structure was performed as previously described by us. Briefly, IgG was isolated using a protein A-conjugated Sepharose CL-4B column, followed by neuraminidase digestion. Oligosaccharyl amines were released by rN-glycanase treatment from reduced, carboxymethylated IgG proteins. They were labeled with 9-Fluorenylmethyl chloride, analyzed with HPLC using TSK- GEL Amide 80 column.
Concentration of G2 and G1-IgG were siginificantly higher than that of GO in both neonates and thier mothers (P<0.001, in all cases). Concentration of G2 was significantly higher than that of G1 in both neonates and mothers (p<0.001). Between mothers and neonates, there was no significant difference in total, GO, G1 or G2 concentrations. There was no significant difference of %GO (percent of GO IgG in total IgG), %G1, %G2 between mothers and neonates, either. There were no significant differences of G1/GO and G2/G0 ratio between mothers and neonates (p=0.268, p=0.285, respectively). There was a strong correlation of GO concentration between mothers and neonates (r=0.9355), however, there were weak or no correlation of G2 (r=0.3982) and G1 (r=0.1311) concentration. Concentration of GO, G1, G2 in twins (case 5 and 6) showed almost similar results.
In conclusion, Concentration of galactosyl IgG was significantly increased than that of agalactosyl IgG, in both mothers and neonates. There was no significant difference in total, GO, G1 or G2-IgG concentrations between mothers and neonates. Less