Gene structure, expression and polymorphism of the HLA-G locus

Abstract

The HLA-G gene is classified as one of the non-classical HLA class I genes because of its low level of polymorphism, and its expression restricted to particular cell types. Although classified as non-classical, the HLA-G protein appears to play a role as an immune checkpoint molecule in pregnancy immunity, suppressing immune responses during organ transplantation, immune escape of tumors and viruses, and developing autoimmune diseases. The gene is known to be not highly polymorphic, but it has been recently reported that 14 bp insertion/deletion polymorphism (rs66554220) and one SNP (rs1063320) located in the 3’UTR of the HLA-G gene are associated with the risk of acute graft versus host disease and overall survival. We report here the determination of 22 full-length HLA-G allele sequences in the Japanese population, including the regions such as 3’UTR that are absent from the allele sequences released from the IPD-IMGT/HLA database.