Evolution of HLA-class I compared to HLA-class II polymorphism in Terena, a South-American Indian tribe

Ana M. Lázaro, M. Elisa Moraes, Cintia Y. Marcos, J. Roberto Moraes, Marcelo A. Fernández-Viña, Peter Stastny

Research output: Contribution to journalArticle

48 Scopus citations

Abstract

We have studied the HLA alleles of 60 unrelated healthy Terena and 10 Terena families. They are members of an isolated Brazilian tribe located in Mato Grosso do Sul (South Central Brazil). Six novel alleles were found in this population: HLA-A*0219 (gf = 0.02), A*0222 (gf = 0.15), HLA-B* 3520 (gf = 0.01), B*3521 (gf = 0.03), B*3912 (gf = 0.03) and B*4803 (gf = 0.16). Five of the six novel alleles differ from their putative progenitors by amino acid replacements in residues that contribute to the pockets of the peptide-binding site. Many of the variants defined by molecular methods were not identified correctly by serological typing. We calculated heterozygosity values (H) for HLA-A, -B, -C, DRB1, DQB1 and DPB1. The highest values were observed at the HLA-B locus, followed by HLA-A, -DRB1 and DQB1. Residue positions 9, 24, 45, 62, 67, 95, 114, 116, 156, and 163 of HLA class I showed heterozygosity values greater than 0.50. Nine of them contribute to the peptide-binding specificity pockets and one to the T cell receptor binding site. If HLA antigens are useful for defense against pathogenic agents, heterozygosity would offer an advantage by allowing binding of a larger repertoire of peptides to the class I molecules. Individuals that are heterozygous at these positions would probably have a wider repertoire of peptide presentation to T cells. The observed results including the presence of novel alleles in the class I HLA loci suggest a functionally significant, more rapid evolution of class I compared to class II loci in this South American isolated population.

Original languageEnglish (US)
Pages (from-to)1138-1149
Number of pages12
JournalHuman Immunology
Volume60
Issue number11
DOIs
Publication statusPublished - Nov 1999

    Fingerprint

ASJC Scopus subject areas

  • Immunology
  • Immunology and Allergy

Cite this

Lázaro, A. M., Moraes, M. E., Marcos, C. Y., Moraes, J. R., Fernández-Viña, M. A., & Stastny, P. (1999). Evolution of HLA-class I compared to HLA-class II polymorphism in Terena, a South-American Indian tribe. Human Immunology, 60(11), 1138-1149. https://doi.org/10.1016/S0198-8859(99)00092-0