Study on the immune responses to porcine embryonic stem cells after transplantation

Jenn-Rong Yang

　　The purpose of this study was to realize the differences of immune responses between brain and spinal cord xenotransplantation by transplanting porcine embryonic stem (pES) cells into Sprague-Dawley (SD) rat’s brain and spinal cord. The pES cells of different differentiated stages were used in this study, including: undifferentiated porcine embryonic stem cells (D0 pES), neuron progenitors at day 12 differentiation (D12 NP), and neuron progenitors at day 18 differentiation (D18 NP). We investigated the expression of immune response associated factors IL 1A, IL 1B, IL 6, and TNFa by real-time PCR after transplantation. The results demonstrated: (1) Brain transplantation: the immune responses of IL 1A, IL 1B, IL 6, and TNFa reached the peak on day 3 after transplantation for the rats transplanted with D0 pES and D12 NP exhibiting an instant immune response; for the rats transplanted with D18 NP, the immune response reached the peak on day 7 of transplantation. (2) Spinal cord transplantation: for the rats transplanted with D0 pES and D18 NP, the immune response reached the peak on day 7 post transplantation, while those with D12 NP having their immune responses reached the peak on day 3 after transplantation. (3) The expression of immune response associated factors returned to the basal level on day 14 post transplantation in all treatment rats. The results obtained could provide a tool to realize the differences of immune responses between brain and spinal cord xenotransplantation with pES cells and render the application of pES cells on stem cell therapy and regenerative medicine in the future.