title: The expression and functional activity of membrane-bound human leukocyte antigen-G1 are influenced by the 3'-untranslated region.
abstract: Human Leukocyte Antigen (HLA)-G is an immunosuppressive molecule acting on both the innate and adaptive immune system. A 14 bp insertion/deletion polymorphism (rs66554220) in the 3'-untranslated region (3'UTR) of the HLA-G gene has been associated with a number of diseases, pregnancy complications, and graft rejection after organ transplantation. We have investigated the effect of HLA-G polymorphism in the 3'UTR on the processing and stability of the membrane-bound HLA-G1 (mHLA-G1) isoform, as well as its functional significance. Different HLA-G1 cDNA sequences were transduced into the human K562 cell line. Flow cytometry, immunohistochemistry, and ELISA were used to examine HLA-G1 protein expression. A quantitative RT-PCR assay was used to quantify transduced HLA-G1 DNA and mRNA transcript levels. Stability of mRNA and functional significance of HLA-G were investigated via Actinomycin D and NK cytotoxicity assays, respectively. Human leukocyte antigen-G mRNA from the 14 bp insertion K562-G1 cells showed a higher degree of stability than the other constructs, and increased mHLA-G1 expression relative to transductants lacking the 14 bp sequence. In line with this, transductants carrying the 14 bp insertion were the most efficient in inhibiting NK cytotoxicity but showed a lower soluble HLA-G1 per mHLA-G1 ratio than the HLA-G1 K562 cells lacking the 14 bp insertion. Our data suggest 3'UTR polymorphism may play an important role in HLA-G regulation with implications on a range of diseases.
authors.affiliation: Department of Clinical Biochemistry, Centre for Immune Regulation and Reproductive Immunology, Copenhagen University Hospital (Roskilde), Roskilde, Denmark.
authors.forename: Signe Goul
authors.initials: SG
authors.lastname: Svendsen
authors.forename: Basil M
authors.initials: BM
authors.lastname: Hantash
authors.forename: Longmei
authors.initials: L
authors.lastname: Zhao
authors.forename: Carsten
authors.initials: C
authors.lastname: Faber
authors.forename: Michael
authors.initials: M
authors.lastname: Bzorek
authors.forename: Mogens Holst
authors.initials: MH
authors.lastname: Nissen
authors.forename: Thomas Vauvert F
authors.initials: TV
authors.lastname: Hviid
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics / Q000502:physiology*; D017951:Antigen Presentation / Q000235:genetics; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease; D059951:HLA-G Antigens / Q000235:genetics*; D006801:Humans; D054643:INDEL Mutation / Q000235:genetics; D007108:Immune Tolerance / Q000235:genetics; D020014:K562 Cells; D011110:Polymorphism, Genetic; D055550:Protein Stability; D019076:Transgenes / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; D059951:HLA-G Antigens