Fig. 2:

Binding of infant human (n=42) serum antibodies to WT and GTKO pig PBMCs. (MFI index = mean fluorescence intensity of the serum sample divided by the MFI of the isotype control sample).

(a) Distribution of IgM reactivity against WT and GTKO PBMCs during the first year of life. Correlation of MFI index with age of each group is indicated by a line (versus WT, p=0.073, r=0.316; versus GTKO, p=0.129, r=0.238). There is a slow increase in IgM directed to Gal antigens on cells from wild-type (WT) pigs, but little increase in IgM to nonGal antigens.

(b) Distribution of IgG reactivity against WT and GTKO PBMC. Correlation of MFI index with age of each group is indicated by a line (versus WT, p=0.381, r= −0.158; versus GTKO, p=0.021, r=0.356). The high level of IgG against Gal antigens on wild-type (WT) pig cells at birth is almost certainly related to the presence of maternal IgG (that crosses the placenta) in the neonate. This falls rapidly after birth. IgG directed to nonGal antigens slowly increases throughout the first year of life. (Reprinted with permission from Rood et al. 2007.)