title: Immune tolerance induction using fetal directed placental injection in rodent models: a murine model.
abstract: OBJECTIVE
  Induction of the immune response is a major problem in replacement therapies for inherited protein deficiencies. Tolerance created in utero can facilitate postnatal treatment. In this study, we aimed to induce immune tolerance towards a foreign protein with early gestational cell transplantation into the chorionic villi under ultrasound guidance in the murine model.
  
  
  METHODS
  Pregnant C57BL/6 (B6) mice on day 10 of gestation were anesthetized and imaged by high resolution ultrasound. Murine embryos and their placenta were positioned to get a clear view in B-mode with power mode of the labyrinth, which is the equivalent of chorionic villi in the human. Bone marrow cells (BMCs) from B6-Green Fluorescence Protein (B6GFP) transgenic mice were injected into the fetal side of the placenta which includes the labyrinth with glass microcapillary pipettes. Each fetal mouse received 2 x 105 viable GFP-BMCs. After birth, we evaluated the humoral and cell-mediated immune response against GFP.
  
  
  RESULTS
  Bone marrow transfer into fetal side of placenta efficiently distributed donor cells to the fetal mice. The survival rate of this procedure was 13.5%(5 out of 37). Successful engraftment of the B6-GFP donor skin grafts was observed in all recipient (5 out of 5) mice 6 weeks after birth. Induction of anti-GFP antibodies was completely inhibited. Cytotoxic immune reactivity of thymic cells against cells harboring GFP was suppressed by ELISPOT assay.
  
  
  CONCLUSIONS
  In this study, we utilized early gestational placental injection targeting the murine fetus, to transfer donor cells carrying a foreign protein into the fetal circulation. This approach is sufficient to induce both humoral and cell-mediated immune tolerance against the foreign protein.
authors: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors: Kei
authors: K
authors: Takahashi
authors: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors: Masayuki
authors: M
authors: Endo
authors: Department of Perinatology and Gynecology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors: Takekazu
authors: T
authors: Miyoshi
authors: Department of Perinatology and Gynecology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors: Mitsuhiro
authors: M
authors: Tsuritani
authors: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors: Yukiko
authors: Y
authors: Shimazu
authors: Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka, Japan.
authors: Hiroshi
authors: H
authors: Hosoda
authors: Department of Gene Therapy Science, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors: Kotaro
authors: K
authors: Saga
authors: Department of Stem Cell Therapy Science, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors: Katsuto
authors: K
authors: Tamai
authors: Center for Fetal Diagnosis and Treatment, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America.
authors: Alan W
authors: AW
authors: Flake
authors: Department of Perinatology and Gynecology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors: Jun
authors: J
authors: Yoshimatsu
authors: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors: Tadashi
authors: T
authors: Kimura
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation; D017690:Cell Transplantation; D002824:Chorionic Villi; D005260:Female; D005333:Fetus / Q000276:immunology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010920:Placenta / Q000637:transplantation*; D011247:Pregnancy; D016038:Skin Transplantation; D014019:Tissue Donors
chemical_list: D049452:Green Fluorescent Proteins