RECENT FINDINGS: Studies related to iGb3 and neoantigens after knocking out GalT (GGTA1) were reviewed. Available data do not support the conclusion that GalT-KO remains iGb3 and/or that neoantigens are produced in the pigs. Concerning non-Gal
antigen, in addition to the Hanganutziu-Deicher (H-D)
antigen (NeuGc), Forrsman
antigen, Galα1-3Lew(x), α-linked or β-linked GalNAc, β3 linked Gal, NeuAc, such as Neu5Acα2-3Galβ1-3GlcNAc, and
Sid blood group (Sd(a))-like
antigens are candidates. However, to date some of these remain controversial and others need further study to completely identify them. Regarding the H-D
antigen, different from the α-Gal, it has a complicated expression system, but has cytotoxic effects toward pig cells. To modify other
carbohydrate antigen apart from α-Gal, only the overexpression of GnT-III appears to have an effect on the suppression of the N-linked
sugar of non-Gal
antigen. Concerning innate cell receptors related to
carbohydrates (
ligands), the focus turned from natural killer (NK) receptor to others, such as monocytes. Finally, PERV contains a
ligand with an N-linked
sugar. Modification of the glycosylation pattern appears to be associated with regulating PERV infectivity.
SUMMARY: A considerable amount of data related to
carbohydrate antigens is now available. At the same time, however, discrepancies between studies complicate this issue. Further studies will be needed to completely understand this complicated area of interest.