Hidetaka Hara

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BACKGROUND The continued presence of a primate antibody-mediated response to cells and organs from alpha1,3-galactosyltransferase gene-knockout (GTKO) pigs indicates that there may be antigens other than Gal alpha 1,3Gal (alpha Gal) against which primates have xenoreactive antibodies. Human and baboon sera were tested for reactivity against a panel of(More)
Although it is known that activation of natural killer (NK) cells causes liver injury, the mechanisms underlying NK cell-induced killing of self-hepatocytes are not clear. We demonstrated that liver NK cells have cytotoxicity against normal syngeneic hepatocytes in mice. Polyinosinic-polycytidylic acid (poly I:C) treatment enhanced hepatocyte toxicity of(More)
BACKGROUND It has been speculated that host macrophages contribute to rapid clearance of transplanted xenogeneic cells. To address such a possibility, phagocytotic and cytolytic activities of human macrophages toward xenogeneic porcine cells were evaluated in vitro in the absence of antibodies and complement factors. METHODS Human peripheral(More)
The Galalpha1,3Galbeta1,4GlcNAc-R (Gal) epitope is a major factor in the hyperacute rejection of pig organ transplants in primates. Biologic scaffold materials used for tissue reconstruction and composed of xenogeneic extracellular matrix (ECM) may contain the Gal epitope. However, the effect of this epitope upon the host response is controversial. The(More)
PURPOSE Contraction of the scar tissue during corneal wound healing changes the shape of the cornea and corneal refraction. In a previous study, it was found that corneal epithelial cells secrete the factor that stimulates collagen gel contraction by keratocytes in vitro. The purpose of the present study was to purify and identify the(More)
The shortage of organs and cells from deceased individuals continues to restrict allotransplantation. Pigs could provide an alternative source of tissue and cells but the immunological challenges and other barriers associated with xenotransplantation need to be overcome. Transplantation of organs from genetically modified pigs into non-human primates is now(More)
BACKGROUND An understanding of the mechanisms that suppress the human anti-pig cellular response is key for xenotransplantation. We have compared the ability of human regulatory T cells (Tregs) to suppress xenogeneic and allogeneic responses in vitro. METHODS Human peripheral blood mononuclear cells (PBMC), CD4+ T cells, or CD4+ CD25- T cells were(More)
BACKGROUND   Lack of Gal expression on pig cells is associated with a reduced primate humoral immune response as well as a reduction in cytokine production by human cells in vitro. We investigated whether lack of Gal expression is associated with reduced human T-cell response in vitro. METHODS   Peripheral blood mononuclear cells (PBMCs) were obtained(More)
BACKGROUND The role of the innate immune system in the development of thrombotic microangiopathy (TM) after alpha1,3-galactosyltransferase gene-knockout (GTKO) pig organ transplantation in primates is uncertain. METHODS Twelve organs (nine hearts, three kidneys) from GTKO pigs were transplanted into baboons that received no immunosuppressive therapy,(More)