Investigation Of The Effect Of Th Cell And Its Cytokines To Predict Immune State In Rat Liver Allotransplantation

IntroductionSignificant enhancement in long-term livability of clinic organ transplantation makes it an optimal therapy protocol for treatment of end stage disease. However, allogeneic rejection is still a major problem in organ transplantation. Inducing immunotolerance may be the essential method to overcome rejection reaction in organ transplantation.At present, there is no systemic predictability and estimation method for transplantation tolerance from the point of immunology and immunogenetics. Although clinically used biopsy provide accuracy results, but it display a significant hysteresis for immune state changes of organism. Meanwhile, there is a limitation in obtaining specimen. Conventional adopted large dosage immunosuppression therapy procedure post organ transplantation lead to serious side effects, such as direct damage to organ systems of kidney toxicity, liver toxicity and marrow suppression et al., various infection and morbidity increase of malignancy et al. resulted from decreased immunity of patients. Consequently, developing expectation method for accepter immune tolerance of organ transplantation to provide basis for clinically personal administration of transplantation patients, reducing or stopping administration for tolerance patients, improving patient prognosis and live quality, decreasing financial burden, early diagnosis to immunorejection and guiding prognosisjudgment of patient, this have significant influences on liver transplantations that have higher probability for spontaneous tolerance occurrence.In 1986, Mosmann et al. reported that CD4+ T cell can produce Th1 type (IL-2, IFN-γ) and Th2 type (IL-4, IL-10) cytokines. Recent studies suggest that changes expressed by Thl and Th2 type cytokines are closely related with the appearance and maintaining of immunotolerance and occurrence of rejection reaction.Inducing allogeneic rejection transplantation liver of rat, to obtain long-term accepted and tolerance transplantation model, was achieved by administration of minimal dose CsA in our laboratory. The aim is to study whether there is similarity between expression of Th cell in peripheral blood and transplantation liver, whether it can be used as an estimation parameter for acute rejection and tolerance post liver transplantation.Materials and MethodsOrthotopic rat liver transplantation was performed. (Brown-Norway) BN rats were used as syngeneic donors and Lewis (LEW) were used as allogeneic donors. All recipients were BN rats who were randomly divided as follows: Group I: Syngeneic control (BN-to- BN); Group II: Acute rejection treated with CsA 2mg/kg/d by subcutaneous injection from day 0-7. Group III: Acute rejection (LEW -to- BN).A11 groups were subdivided into day 1, 3, 5, 7,14(n=4 each) posttransplantation respectively for sample harvesting; and additional subgroups (n=6) for observation of general situation and survival time. Liver graft specimens were harvested at indicated time to determine morphological changes by pathological examination and gene expression by reverse transcription-polymerase chain reaction (RT-PCR), as well as the hybridization in situ. Recipient splenocytes were isolated and phenotypes of spleen T cell subsets were analyzed by confocal microscopy. Recipient T cell subsets in peripheral blood were analyzed by flow cytometry and blood serum cytokines were analyzed by Enzyme-linked immunoadsordent assay (ELISA) .Results1. The general situation and survival time posttransplantationThe general situation of syngeneic group was very well and survival time was over 100 days after transplantation. As for CsA treated group, the general situation was bad during CsA medication but with only mild rejection and the four of six recipients survived over 100 days .in the acute rejection group, all recipients died from 28 to38 days after transplantation and the mean survival time was 33.3 days. The general situation of syngeneic group and CsA treated group was remarkably better than that of acute rejection group.2. Histopathologic examination and rejection gradeNo signs...