title: Human T-cell receptor BV6 gene polymorphism in relation to expression level and CD4/CD8 skewness.
abstract: Using 50 samples of umbilical cord blood lymphocytes from Japanese donors, we analysed two human T-cell receptor beta variable (TCRBV) genes, BV6S4 and BV6S5, for their polymorphism, usage frequencies and CD4/CD8 skewness. They showed contrasting CD4/CD8 skewness, BV6S4 to CD8+ T cells and BV6S5 to CD4+ T cells. Genotyping of the BV6S4 alleles (A1, A2 and A3) revealed two of the six possible BV6S4 genotypes, A1/A2 and A2/A2. Among the two BV6S4 genotypes, no significant difference was detected in usage frequency or CD4/CD8 skewness. On the other hand, genotyping of the BV6S5 alleles (A1 and A2) revealed all three possible BV6S5 genotypes, A1/A1, A1/A2 and A2/A2, and the gene usage frequency was high, in the order A1/A1 > A1/A2 > A2/A2. These results indicate that the amino acid substitutions in BV6S5 (S36R and G70E) are in some way associated with the expression level of this gene. In the analysis of CD4/CD8 skewness, the three BV6S5 genotypes had similar skewness, indicating that A1 alleles are expressed more frequently than A2 alleles in both CD4+ and CD8+ T-cell populations. Although BV6S5 exhibits marked skewness to CD4+ T cells, our results indicate that the higher expression of A1 alleles is not associated with the increased ratio of CD4+ T cells.
authors.affiliation: Department of Immunology, Kitasato University School of Allied Health Sciences, Sagamihara, Kanagawa, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Obata
authors.forename: R
authors.initials: R
authors.lastname: Shiiba
authors.forename: M
authors.initials: M
authors.lastname: Iizuka
authors.forename: N
authors.initials: N
authors.lastname: Kashiwagi
authors.forename: F
authors.initials: F
authors.lastname: Kurosu
authors.forename: N
authors.initials: N
authors.lastname: Shimada
authors.forename: M
authors.initials: M
authors.lastname: Nishijima
authors.forename: H
authors.initials: H
authors.lastname: Tozawa
mesh_terms: D000483:Alleles; D015704:CD4 Antigens / Q000096:biosynthesis; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D016827:CD8 Antigens / Q000096:biosynthesis; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005312:Fetal Blood; D005786:Gene Expression Regulation / Q000276:immunology*; D019674:Genes, T-Cell Receptor beta / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D011110:Polymorphism, Genetic / Q000235:genetics*; D011247:Pregnancy; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta