HLA-G truncated isoforms can substitute for HLA-G1 in fetal survival

Hum Immunol. 2000 Nov;61(11):1118-25. doi: 10.1016/s0198-8859(00)00194-4.

Abstract

Pregnancy is considered as an immunologic paradox because the fetus can be viewed as a semiallograft by the mother's immune system. Among the different factors implicated in the maternal-fetal tolerance, a central role has been attributed to HLA-G. The primary HLA-G mRNA is alternatively spliced, encoding four membrane-bound isoforms (HLA-G1, -G2, -G3, and -G4), and three soluble forms (HLA-G5, -G6, and -G7). Whereas HLA-G1 is expressed on trophoblast cells, HLA-G2, -G3, and -G4 isoforms have been only identified as transcripts in trophoblast and term placentas. In this work, we first showed that these HLA-G transcripts are translated into proteins in first trimester cytotrophoblast cells. Then, using a target cell line transfected with HLA-G genomic DNA, we analyzed the functional implication of HLA-G isoforms expression on NK function. Our results show that not only HLA-G1, but also the other HLA-G truncated isoforms, can inhibit NK cytolysis and therefore contribute to immune privilege for the fetus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytotoxicity Tests, Immunologic
  • Cytotoxicity, Immunologic
  • Female
  • Fetus / immunology*
  • HLA Antigens / genetics
  • HLA Antigens / immunology*
  • HLA-G Antigens
  • Histocompatibility Antigens Class I / genetics
  • Histocompatibility Antigens Class I / immunology*
  • Humans
  • Immune Tolerance*
  • Killer Cells, Natural / immunology
  • Pregnancy
  • Pregnancy Trimester, First
  • Protein Isoforms / immunology
  • Transfection
  • Trophoblasts / immunology
  • Tumor Cells, Cultured

Substances

  • HLA Antigens
  • HLA-G Antigens
  • Histocompatibility Antigens Class I
  • Protein Isoforms