The field of nuclear agriculture is introduced very briefly. Nuclear agriculture research/development system in Pakistan is described highlighting the achievements of the system partners. Description and discussion ar...The field of nuclear agriculture is introduced very briefly. Nuclear agriculture research/development system in Pakistan is described highlighting the achievements of the system partners. Description and discussion are generalized in concluding remarks at the end of the article. This article is an experimental guide for a developing nuclear agriculture system.展开更多
Cellular immune response is a major barrier to xenotransplantation, and cell adhesion is the first step in intercellular recognition. Flow-cytometric adhesion assay has been used to investigate the differential adhesi...Cellular immune response is a major barrier to xenotransplantation, and cell adhesion is the first step in intercellular recognition. Flow-cytometric adhesion assay has been used to investigate the differential adhesions of monocyte (Mo), natural killer celi (NK) and T lymphocyte (T) present within human peripheral blood mononuclear cells (PBMC) to porcine aortic endothelial cells (PAEC), and to demonstrate the effect of human interferon-γ (hIFN-γ) or/and tumor necrosis factor-α (hTNF-α) pretreatment of PAEC on their adhesiveness f or different PBMC subsets. The preferential sequence for PBMC subset binding to resting PAEC is Mo, NK and T cells, among which T cells show the slightest adherence; hTNF- a can act across the species, and augment Mo, NK and T cell adhesion ratios by 40%, 110% and 3 times, respectively. These results confirm at the cell level that host Mo and NK cells are major participants in the cellular xenograft rejection, thereby, providing a prerequisite for further studying the展开更多
Using human umbilical vein endothelial cells (HUVEC) and porcine aortic endothelial cells (PAEC) as target cells, human peripheral blood NK cells (PBNK) and NK92 cells as effector cells, the differential cytotoxicitie...Using human umbilical vein endothelial cells (HUVEC) and porcine aortic endothelial cells (PAEC) as target cells, human peripheral blood NK cells (PBNK) and NK92 cells as effector cells, the differential cytotoxicities of NK cells to allo- and xeno-endothelial cells were studied. The influence of MHC class I molecules on the cytotoxicity of human NK cells was assayed using acid treatment, and blockades of MHC class I antigens, CD94 and KIR (NKB1). The results indicated that the killing of PAEC by the two kinds of NK cells is higher than that of HUVEC. After acid-treatment, the cytotoxicity of the two kinds of NK cells to PAEC and HUVEC is significantly enhanced, but the magnitude of the enhancement is different. The enhancement of NK killing to acid treated HUVEC is much greater than that to PAEC. Blockade of CD94 mAb did not alter the NK cytotoxicity, while blockade of NKB1 mAb enhanced the cytotoxicity of PBNK to HUVEC and PAEC by 95% and 29% respectively. The results above suggested that the differential recognition of MHC I molecules of xeno-endothelial cells by human NK cells could be the major reason for higher NK cytotoxicity to PAEC. KIR might be the primary molecule that transduced inhibitory signals when endothelial cells were injured by NK cells.展开更多
Cellular immune response is a major barrier to xenotransplantation. Human tumor necrosis factor-α (hTNF-α) possesses cross-species activity and directly amplifies the immune rejection via the upregulation of adhesio...Cellular immune response is a major barrier to xenotransplantation. Human tumor necrosis factor-α (hTNF-α) possesses cross-species activity and directly amplifies the immune rejection via the upregulation of adhesion molecules on porcine endothelium. We investigated the role of protein tyrosine phosphorylation in the induction of expression of E-selectin and vascular cell adhesion molecule-1 (VCAM-1), and the augmentation of adhesion of human peripheral blood monocytes (PBMo) and natural killer cells (PBNK), after rhTNF-α-stimulation of porcine aortic endo-thelial cells (PAEC) in vitro. rhTNF-α-increased adhesiveness of PAEC for both PBMo and PBNK was dose-dependently reduced by pretreatment of PAEC with the selective protein tyrosine kinase (PTK) inhibitor genistein. The inhibitory effect occurred at the early time of PAEC activation triggered by rhTNF-α, and was completely reversible. PTK activity assay indicated that genistein also suppressed rhTNF-α stimulated activation of protein tyrosine展开更多
文摘The field of nuclear agriculture is introduced very briefly. Nuclear agriculture research/development system in Pakistan is described highlighting the achievements of the system partners. Description and discussion are generalized in concluding remarks at the end of the article. This article is an experimental guide for a developing nuclear agriculture system.
文摘Cellular immune response is a major barrier to xenotransplantation, and cell adhesion is the first step in intercellular recognition. Flow-cytometric adhesion assay has been used to investigate the differential adhesions of monocyte (Mo), natural killer celi (NK) and T lymphocyte (T) present within human peripheral blood mononuclear cells (PBMC) to porcine aortic endothelial cells (PAEC), and to demonstrate the effect of human interferon-γ (hIFN-γ) or/and tumor necrosis factor-α (hTNF-α) pretreatment of PAEC on their adhesiveness f or different PBMC subsets. The preferential sequence for PBMC subset binding to resting PAEC is Mo, NK and T cells, among which T cells show the slightest adherence; hTNF- a can act across the species, and augment Mo, NK and T cell adhesion ratios by 40%, 110% and 3 times, respectively. These results confirm at the cell level that host Mo and NK cells are major participants in the cellular xenograft rejection, thereby, providing a prerequisite for further studying the
文摘Using human umbilical vein endothelial cells (HUVEC) and porcine aortic endothelial cells (PAEC) as target cells, human peripheral blood NK cells (PBNK) and NK92 cells as effector cells, the differential cytotoxicities of NK cells to allo- and xeno-endothelial cells were studied. The influence of MHC class I molecules on the cytotoxicity of human NK cells was assayed using acid treatment, and blockades of MHC class I antigens, CD94 and KIR (NKB1). The results indicated that the killing of PAEC by the two kinds of NK cells is higher than that of HUVEC. After acid-treatment, the cytotoxicity of the two kinds of NK cells to PAEC and HUVEC is significantly enhanced, but the magnitude of the enhancement is different. The enhancement of NK killing to acid treated HUVEC is much greater than that to PAEC. Blockade of CD94 mAb did not alter the NK cytotoxicity, while blockade of NKB1 mAb enhanced the cytotoxicity of PBNK to HUVEC and PAEC by 95% and 29% respectively. The results above suggested that the differential recognition of MHC I molecules of xeno-endothelial cells by human NK cells could be the major reason for higher NK cytotoxicity to PAEC. KIR might be the primary molecule that transduced inhibitory signals when endothelial cells were injured by NK cells.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39770700).
文摘Cellular immune response is a major barrier to xenotransplantation. Human tumor necrosis factor-α (hTNF-α) possesses cross-species activity and directly amplifies the immune rejection via the upregulation of adhesion molecules on porcine endothelium. We investigated the role of protein tyrosine phosphorylation in the induction of expression of E-selectin and vascular cell adhesion molecule-1 (VCAM-1), and the augmentation of adhesion of human peripheral blood monocytes (PBMo) and natural killer cells (PBNK), after rhTNF-α-stimulation of porcine aortic endo-thelial cells (PAEC) in vitro. rhTNF-α-increased adhesiveness of PAEC for both PBMo and PBNK was dose-dependently reduced by pretreatment of PAEC with the selective protein tyrosine kinase (PTK) inhibitor genistein. The inhibitory effect occurred at the early time of PAEC activation triggered by rhTNF-α, and was completely reversible. PTK activity assay indicated that genistein also suppressed rhTNF-α stimulated activation of protein tyrosine
