title: CD80 and CD86 polymorphisms in populations of various ancestries: 5 new CD80 promoter alleles.
abstract: CD80 and CD86 are closely linked genes on chromosome 3 that code for glycoproteins of the immunoglobulin superfamily, expressed on the surface of antigen-presenting cells. These costimulatory molecules play essential roles for stimulation and inhibition of T cells through binding to CD28 and CTLA-4 receptors. In this study, CD80 promoter and CD86 exon 8 polymorphisms were analyzed to investigate the genetic diversity and microevolution of the 2 genes. We genotyped 1,124 individuals, including Brazilians of predominantly European, mixed African and European, and Japanese ancestry, 5 Amerindian populations, and an African sample. All variants were observed in Africans, which suggests their origin in Africa before the human migrations out of that continent. Five new CD80 promoter alleles were identified and confirmed by cloning and sequencing, and promoter 2 is most likely the ancestral allele. Nucleotide -79 is monomorphic in 4 Amerindian populations, where the presence of the -79 G allele is probably the result of gene flow from non-Amerindians.
authors.affiliation: Human Molecular Genetics Laboratory, Department of Genetics, Federal University of Paraná, 81531-980 Curitiba, Brazil.
authors.forename: Márcia Holsbach
authors.initials: MH
authors.lastname: Beltrame
authors.forename: Márcia Regina
authors.initials: MR
authors.lastname: Pincerati
authors.forename: Ricardo
authors.initials: R
authors.lastname: Dalla-Costa
authors.forename: Roseli
authors.initials: R
authors.lastname: Wassem
authors.forename: Karen Francine
authors.initials: KF
authors.lastname: Köhler
authors.forename: Eleidi Alice
authors.initials: EA
authors.lastname: Chautard-Freire-Maia
authors.forename: Luiza Tamie
authors.initials: LT
authors.lastname: Tsuneto
authors.forename: Maria Luiza
authors.initials: ML
authors.lastname: Petzl-Erler
mesh_terms: D000483:Alleles; D044467:American Indian or Alaska Native / Q000208:ethnology / Q000235:genetics; D044466:Asian People / Q000235:genetics; D018122:B7-1 Antigen / Q000235:genetics*; D051940:B7-2 Antigen / Q000235:genetics*; D044383:Black People / Q000208:ethnology / Q000235:genetics; D001938:Brazil; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007564:Japan / Q000208:ethnology; D015810:Linkage Disequilibrium; D010802:Phylogeny; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics*; D044465:White People / Q000208:ethnology / Q000235:genetics
chemical_list: D018122:B7-1 Antigen; D051940:B7-2 Antigen