Characterisation and Functional Implications of the Two New HLA-G Alleles Found in Amerindian and Caribbean Populations

Hum Immunol. 2016 Sep;77(9):812-6. doi: 10.1016/j.humimm.2016.01.006. Epub 2016 Jan 18.

Abstract

HLA-G polymorphism has been found to be relatively low in all world populations. In the present paper two new HLA-G molecules are described in ancient American natives. A new HLA-G molecule from a Ecuador Amerindian individual (male) showed four codon changes with respect to HLA-G*01:01:01. Silent changes at α1 domain (residue 57, Pro, CCG→CCA) and α2 domain (residue 93, His, CAC→CAT and residue 100, Gly, GGC→GGT) and one productive change in α3 domain (residue 219 changed from Arg to Trp). This α3 change may dramatically alter HLA-G interactions with beta-2 microglobulin, CD8, ILT-2 and ILT-4 ligands present in subsets of T, B, NK, monocytes, macrophages and dentritic cells. Another HLA-G new molecule was found in a woman from Hispaniola Island, Dominican Republic (Sto Domingo): it presented a silent change at α2 domain residue 107, Gly, GGA→GGT and non-silent change at residue 178, Met→Thr (with respect to HLA-G*01:01:01) which is close to class I molecule/clonotypic T cell receptor interaction sites. Functional implications of these findings are discussed.

Keywords: Amerindians; Ecuador; HLA-G; HLA-G and populations; HLA-G function; HLA-G immune interaction; HLA-G ligands; Hispaniola Is; ILT-2; ILT-4.

MeSH terms

  • Alleles
  • Caribbean Region
  • Dominican Republic
  • Ecuador
  • Female
  • Genetics, Population
  • HLA-G Antigens / genetics*
  • Histocompatibility Testing
  • Humans
  • Immunity / genetics
  • Indians, Central American*
  • Indians, South American*
  • Male
  • Mutation / genetics
  • Polymorphism, Genetic

Substances

  • HLA-G Antigens