title: Time course analysis of alpha+ beta+ T cell clones during normal pregnancy.
abstract: During normal pregnancy, the fetus continues to mature inside the uterus without rejection. Inherited paternal antigens could be targeted by the maternal immune system. These reactions are believed to play a role in a number of habitual abortions. However, the precise maternal mechanisms preventing fetal tissue rejection are not well understood. Maternal T cells should recognize fetal antigens, so it is conceivable that antigen-specific T cell response to fetal antigens would occur by proliferation and accumulation of certain T cell clones in the pregnant mother. To elucidate the maternal immune response to the fetus we investigated the clonality of expanded T cells in peripheral blood lymphocytes in ten normal pregnant women. We employed reverse transcriptase-polymerase chain reaction for T cell receptor beta chain gene and subsequently analyzed the PCR product by single-strand conformation polymorphism analysis. A large number of distinctly expanded T cell clones were detected during pregnancy. These accumulations were observed as early as the ninth to tenth week post-conception and reached a maximum during the second trimester, suggesting the existence of dynamic antigen-specific T cell responses in the pregnant mother. However, after the 30th week of gestation, nearly all expanded T cell clones disappeared before parturition and the degree of clonality reached almost normal levels. Our results clearly indicate the existence of dynamic maternal T cell responses during pregnancy.
authors.affiliation: Institute of Medical Science, St. Marianna University, Kawasaki, Japan.
authors.forename: T A
authors.initials: TA
authors.lastname: Höger
authors.forename: M
authors.initials: M
authors.lastname: Tokuyama
authors.forename: K
authors.initials: K
authors.lastname: Yonamine
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: K
authors.initials: K
authors.lastname: Masuko-Hongo
authors.forename: T
authors.initials: T
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Kobata
authors.forename: Y
authors.initials: Y
authors.lastname: Mizushima
authors.forename: K
authors.initials: K
authors.lastname: Nishioka
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000328:Adult; D001483:Base Sequence; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes; D002999:Clone Cells; D005260:Female; D005333:Fetus / Q000276:immunology; D015329:Gene Rearrangement, T-Lymphocyte; D005865:Gestational Age; D006801:Humans; D007108:Immune Tolerance; D007519:Isoantigens / Q000276:immunology; D018655:Lymphocyte Count; D008969:Molecular Sequence Data; D018807:Polymorphism, Single-Stranded Conformational; D011247:Pregnancy / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D016176:T-Lymphocyte Subsets
chemical_list: D007519:Isoantigens; D016693:Receptors, Antigen, T-Cell, alpha-beta