Avaliação da história evolutiva do gene HLA-G por meio de polimorfismos de base única e da inserção AluyHG

• Ano de defesa: 2013
• Autor(a) principal: Santos, Kaisson Ernane dos
• Orientador(a): Castelli, Erick da Cruz
• Banca de defesa: Castelli, Erick da Cruz, Soares, Thannya Nascimento, Silva, Daniela Melo e
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Biologia (ICB)
• Departamento: Instituto de Ciências Biológicas - ICB (RG)
• País: Brasil
• Palavras-chave em Português: Complexo principal de histocompatibilidade; Antígenos leucocitários humanos; HLA-G; Desequilíbrio de ligação; Haplótipos; AluyHG
• Palavras-chave em Inglês: Major histocompatibility complex; Human leukocyte antigens; HLA-G; AluyHG; Linkage disequilibrium; Haplotypes
• Área do conhecimento CNPq: GENETICA::GENETICA HUMANA E MEDICA
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/6686

The Major Histocompatibility Complex is mainly composed by genes of the adaptive immune response. In humans, part of this complex is known as the Human Leukocyte Antigens (HLA), whose genes are responsible for specific antigen presentation to effector immune cells. The classical class I HLA genes (HLA-A, -B and -C) are responsible for antigen presentation to T CD8+ cells and they constitute the most polymorphic genes in the human genome. This variability is maintained by selection mediated by microorganisms. In contrast to their classical counterparts, the non classical class I genes (HLA-G, -E and -F) present low variability and are associated with immune tolerance due to the interaction with NK and T cells inhibitor receptors. HLA-G is the most studied non classical gene, which is associated with immune response modulation, mainly during pregnancy. Considering that natural selection is acting on the HLA-G regulatory regions maintaining high heterozigosity in this region, we evaluated a nearby Alu insertion (AluyHG) correlating this Alu element with coding and 3’UTR HLA-G polymorphisms. The AluyHG insertion was particularly associated with the HLA-G haplotype known as G*01:01:01:01/UTR-1, considered a high-expressing HLA-G haplotype. The G*01:01:01:01/UTR-1/AluyHG haplotype would be the most recent HLA-G haplotypes, in spite of its high frequency in worldwide populations.