Non-α1,3Gal Carbohydrate Antigenic Epitopes

Non-Gal (Non-α1,3-Gal) antigenic epitope is also targeted by the cellular immune system. Preformed natural non-Gal Abs do not cause HR in pig-to-human xenografts. However, non-α1,3Gal Abs can induce graft-injured damages to cells in both vascularized organs and tissues. Transplanted xenografts induce production of non-α1,3Gal-specific Abs in the hosts. Likely to the human allograft rejection, the anti-non-α1,3Gal Abs control survivals of xenografts in the host. The pig MHC molecules-specific Abs of humans preferably bind to the glycan structures, but not proteins. Elucidation on the relationship between non-α1,3Gal antigenic epitope structures of pigs and the reactive non-α1,3Gal Abs of humans is interesting in understanding of the Abs-mediated graft damages in near future. Relevant understanding of downstream reaction of non-α1,3Gal antigens in pig xenografts to human Abs should be systematically explained and edited in future. When α1,3-Gal antigen-based HR is overcome, AHR is elicited by low levels of natural Abs to α1,3Gal epitopes, which occur within 3 days to 3 weeks. However, AHR is poorly understood. As a similar expression, AVR or DXR is known. Non-α1,3Gal antigenic epitopes and non-α1,3Gal Abs are suggested to involve in such AHR, AVR, or DXR. To date, a representative and predominant non-α1,3Gal antigen is Neu5Gc as the major non-α1,3Gal xenoantigen.