HLA-G and its role in solid organ transplants

Solid organ transplantation has been considered the ultimate goal for some end-stage chronic diseases, however, HLA incompatibilities between the donor and the recipient may allow the alloresponse to become deleterious for the transplanted organ, a response that can be both innate and adaptive. HLA-G has been identified as a natural tolerance-inducing molecule (28) mainly in pregnancy and is considered a non-classical HLA class I molecule; however, it shares some structural characteristics with classic HLA. HLA-G genes are characterized by having a limited polymorphism and a cellular and tissue distribution restricted to the fetal trophoblast and thymic epithelial cells, among others. The persistent search for tolerance in organ transplants has allowed a specific study of HLA-G, as a therapeutic possibility to increase grafts and transplant patient's survival; for this reason we carried out a review of this molecule to stimulate research and understanding of its functions.