title: Role of human non-invariant NKT lymphocytes in the maintenance of type 2 T helper environment during pregnancy.
abstract: The molecular and cellular mechanisms that generate the T(h)2 cytokine environment necessary for the maintenance of pregnancy are still not fully understood. We herein show that the human decidua is highly enriched for TCR alpha beta(+)CD161(+) NKT cells. They express non-invariant antigen receptors encoded by diverse TCRV alpha- and V beta-chain gene segments, thereby referred to as non-invariant NKT (non-iNKT) cells. In spite of their diverse TCR expression, they do not recognize fetal allo-antigens but specifically responded to CD1d-transfected cell lines. In contrast to the peripheral blood non-iNKT cells, the decidua-residing non-iNKT cells had a marked T(h)2 bias. In addition, they suppress the mixed leukocyte reaction directed against the paternal antigens. The T(h)2 cytokines have been known to stimulate trophoblast outgrowth and invasion. Thereby, the non-iNKT cells residing in the decidual tissue may have a functionally important interaction with the villous and extravillous trophoblast cells expressing CD1d and may therefore play a pivotal role in successful pregnancy by inhibiting fetal rejection and enhancing placental growth. These findings may reflect one mechanism that is an essential component for the T(h)2 environment necessary for the maintenance of pregnancy.
authors.affiliation: Department of Allergy and Immunology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama 350-0495, Japan. uemura@saitama-med.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Uemura
authors.forename: Motoharu
authors.initials: M
authors.lastname: Suzuki
authors.forename: Tian-Yi
authors.initials: TY
authors.lastname: Liu
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Narita
authors.forename: Shinya
authors.initials: S
authors.lastname: Hirata
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohyama
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishihara
authors.forename: Sho
authors.initials: S
authors.lastname: Matsushita
mesh_terms: D019002:CD56 Antigen / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D003656:Decidua / Q000166:cytology / Q000276:immunology*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D055651:NK Cell Lectin-Like Receptor Subfamily B / Q000276:immunology; D055611:Natural Killer T-Cells / Q000276:immunology*; D011247:Pregnancy / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D019002:CD56 Antigen; D055651:NK Cell Lectin-Like Receptor Subfamily B; D016693:Receptors, Antigen, T-Cell, alpha-beta