A Study On Protection Of In Vitro Liposome-mediated Cotransfection Of Human Interleukin-10 And TGF-β1 Gene To Donor Lungs After Lung Transplantation In Rats

Lung transplantation has evolved into an effective therapeutic option in the management of patients with end-staged pulmonary diseases. However, compared with transplantation of some parenchymatous organs, such as heart and kidney, lung transplantation is still a young clinical area. Lung allograft ischemia-reperfusion injuries as well as acute and chronic rejection continue to be challenges to the success of lung transplantation. Obviously, the key to prolong patient's life is to inhibit these two reactions.Gene transfer is a process of temporary introduction of exogenous functional genes to the patient resulting in transient gene expression and production of a functional gene produce to modify the tissue responses, provide a potential to enhance the donor's capability aiming in withstanding the process of transplantation better and eliminate theinjury of ischemia-reperfusion and rejection, though effective and successful application in this setting has yet to be realized.Interleukin-10 (IL-10) excreted by macrophages and Th-2 cells can inhibit antigen presenting cells which are activated by Th-1 cells to synthesize cytokines. Therefore, the inhibition of activation of mononuclear phagecytes and functions of antigen presenting cells can minimize the immunoreaction induced by inflammation and T cell. It is suggested that IL-10 might be useful in the treatment of ischemia-reperfusion and transplant rejection.Transforming growth factor-β₁ (TGF-β₁) is one of a group of closely related, multifunctional molecules that play central roles in embryonic development, tumorigenesis, wound healing, fibrosis, and immunoregulation. The immunomodulator function is expressed by suppressing the proliferation of B and T cells; antagonizing the inflammatory cytokines such as IL-1, tumor necrosic factor-alpha (TNF-α), or interferon-gamma (IFN-γ); and inhibiting natural killer cells. Virus-mediated immunosuppressive cytokine gene therapy prolongs the cardiac allograft survival in rat's heart transplant model, when TGF-β₁ expressed much more after recombined virus was injected into cardiac muscle. Most of donor hearts' lives were prolonged.It is still uncertain whether there be a coordinated protective mechanism from cotransfection of human IL-10 and TGF-β₁ transfered into the doner lung to minimize the injury of ischemia-reperfusion as well as the reaction of rejection after lung transplantation. Our study was designed to investigated the protective mechanism ofcotransfection of human IL-10 and TGF-Pi gene to donor lungs after lung transplantation in rats in vitro.1. Effects of in vitro liposome-mediated transfer of human interIeukin-10 gene to donor lungs to ischemia-reperfusion injury and acute rejection after lung transplantation in rats. We cloned human IL-10 gene from peripheral blood lymphocytes, and constructed its vector. After duplication of rat lung grafts model, IL-10 gene was transferred into donor lungs by liposome mediation. Wet/dry ratio of lung and lung permeability index were detected. Myeloperoxidase (MPO) of lung tissue was measured by colorimetry. Serum level of IL-2 and TNF-a were detected by enzyme-linked immunosorbent assay (ELISA). Results showed that lipid-mediated in vitro IL-10 gene transfer into rat lung allografts reduced the lung water content, increased lung permeability index, improved graft gas exchange, reduced histologic rejection scores, downregulated graft IL-2, TNF-a expression, but showed no significant change to MPO content.2. Effects of in vitro liposome-mediated transfer of human TGF-Pi gene to donor lungs to ischemia-reperfusion injury and acute rejection after lung transplantation in rats. We cloned human TGF-β₁ gene from peripheral blood platelets, and constructed its vector. After duplication of rat lung grafts model, TGF-β₁ gene was transferred into donor lungs by liposome mediation. Indexes were detected followed the methods of experimental 1. Results showed that lipid-mediated in vitro TGF-β₁ gene transfer into rat lung allografts reduced the lung water content, increased lung permeability index and oxygenation of artery blood, improved graft gas exchange, reduced the histologic rejection scores, downregulated graft IL-2, TNF-a...