Identification of amino acid positions involved in HLA-E expression.
The cell surface expression of HLA-E molecules by transfection is faint in xenogeneic cells. Therefore, this study was done for the aim of better expression of HLA-E molecules on the surface of pig cells in order to overcome xenograft rejection mediated by human natural killer (NK) cells. The importance of the loading peptide sequence for HLA-E expression has been studied extensively, but much less information is available concerning the HLA-E heavy chain sequence. In our previous study, we developed the S147C substitution of HLA-E as a useful gene tool for xenotransplantation. In this study, a more extensive substitution analysis throughout the entire region led to the identification of nine amino acid positions, positions-9, 11, 25, 40, 66, 67, 74, 99 and 174, that are significantly involved in the cell surface expression of HLA-E molecules. In view of xenotransplantation usage, double and triple point substitutions, HLA-Ev(11,147) and HLA-Ev(11,66,147), were constructed. These constructs led to a high expression on the xenogeneic cell surface and possessed inhibitory functions against human NK cell-mediated cytolysis in an in vitro pig to human xenotransplantation model system.
Matsunami
Katsuyoshi
K
Division of Organ Transplantation, Department of Molecular Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Okura
Eiji
E
Uchida
Hiroko
H
Otsuka
Hideaki
H
Fukuzawa
Masahiro
M
Miyagawa
Shuji
S
D019943:Amino Acid Substitution; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D006680:HLA Antigens / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D021382:Protein Sorting Signals; D013552:Swine / Q000276:immunology; D014183:Transplantation, Heterologous / Q000276:immunology*; D000097625:HLA-E Antigens
D000596:Amino Acids; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D021382:Protein Sorting Signals; D000097625:HLA-E Antigens