Persistence of Indirect but Not Direct T Cell Xenoresponses in Baboon Recipients of Pig Cell and Organ Transplants

Academic Article


  • © Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons We investigated the contributions of direct and indirect T cell antigen recognition pathways to the immune response to porcine antigens in naïve baboons and baboon recipients of pig xenografts. In naïve baboons, in vitro culture of peripheral blood T cells with intact pig cells (direct xenorecognition pathway) or pig cell sonicates and baboon antigen-presenting cells (indirect xenorecognition pathway) induced the activation and expansion of xenoreactive T cells producing proinflammatory cytokines, interleukin-2 and interferon-γ. Primary indirect xenoresponses were mediated by preexisting memory T cells, whose presence is not typically observed in primary alloresponses. Next, baboons were conditioned with a nonmyeloablative regimen before short-term immunosuppression and transplantation of xenogeneic peripheral blood progenitor cells and a kidney, heart, or pancreatic islets from a miniature swine. All transplants were rejected acutely within 30 days after their placement. Posttransplantation, we observed an inhibition of the direct xenoresponse but a significant expansion of indirectly activated proinflammatory T cells. These results suggest that additional treatment to suppress indirect T cell immunity in primates may be required to achieve tolerance of pig xenografts through hematopoietic chimerism.
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    Author List

  • Buhler L; Illigens BMW; Nadazdin O; Tena A; Lee S; Sachs DH; Cooper DKC; Benichou G
  • Start Page

  • 1917
  • End Page

  • 1922
  • Volume

  • 16
  • Issue

  • 6