Immune Tolerance Induction Using Fetal Directed Placental Injection in Rodent Models: A Murine Model

Abstract

ObjectivesInduction 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.MethodsPregnant 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.ResultsBone 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.ConclusionsIn 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.

Generation of reconstituted hemato-lymphoid murine embryos by placental transplantation into embryos lacking HSCs

“…Also, at embryonic day 9, when the placenta and circulation are established, it seems to be the physical limit of intraplacental injection. Furthermore, as the previous paper has shown, transplantation at this time demonstrates immune tolerance to the donor 20 .…”

“…This demonstrates that even xenogeneic cells can be successfully engrafted by placental transplantation into an embryo lacking HSCs without pre-transplantation treatment. Since Takahashi et al reported that immune tolerance was established by placental transplantation into E10.5, our system seems to have established immune tolerance to rats as well 20 . Thus, this model would be useful for xenograft experiments.…”

“…is the most efficient for implantation and is maintained in recipient mice for more than six months 38 . It has been established about intraplacental injection since 1979, and recently a technique for injection into the placental labyrinth of E10 has been reported by using an ultrasound-guided system 19 , 20 . We have performed the transplantation at E11 in the present study, and the main advantage of intraplacental injection can be conducted earlier than i.v.…”

“…Takahashi et al demonstrated immune tolerance induction using intra-chorionic villi injection under ultrasound guidance at E10 in a congenic murine model 20 .…”

Investigating Optimal Autologous Cellular Platforms for Prenatal or Perinatal Factor VIII Delivery to Treat Hemophilia A

“…Approximately, 75% of HA patients have a family history, and fetal DNA within maternal blood enables non-invasive HA diagnosis as early as 7 gestational weeks ( Tsui et al, 2011 ; Hudecova et al, 2017 ; Ragni, 2017 ; Camunas-Soler et al, 2018 ), making prenatal therapy possible ( Porada et al, 2014 ). Adding to the advantages of prenatal correction are studies showing that fetal exposure to foreign antigen induces lifelong tolerance that resists postnatal challenge ( Tran et al, 2001 ; Waddington et al, 2004 ; Colletti et al, 2008 ; Porada and Almeida-Porada, 2012 ; Porada et al, 2013 ; Peranteau et al, 2015 ; Takahashi et al, 2015 ; Davey et al, 2017 ). As such, even if not curative, prenatal treatment would permit postnatal therapies without fear of immune-related complications.…”