DNA immunization of the grafted liver by particle-mediated gene gun1

BACKGROUND

Direct DNA vaccination of liver allografts before transplantation may provide an effective strategy for inducing protective immunity to infection and malignancy.

METHODS

In this study, the authors examined the feasibility of gene gun-mediated vaccination of liver grafts. Using plasmids expressing luciferase and green fluorescent proteins, their expression was tested in a graft liver.

RESULTS

Protein expression was observed in the graft liver and significantly enhanced in hepatectomized rats. A short course of tacrolimus (FK506) also evoked the expression of these proteins. Effects of primary immunization to the liver on the humoral response were then tested using an expression plasmid encoding hepatitis B virus surface (HBs) antigen and were compared to that of skin immunization alone. The results showed that local immunization to the liver strongly induced antibody formation. Furthermore, the combination of an immunized partial liver graft with tacrolimus significantly enhanced antibody production against HBs antigen.

CONCLUSIONS

A DNA vaccine to the liver may be one strategy for preventing infectious disease associated with liver transplantation under tacrolimus treatment.

Prevention of fungal and hepatitis virus infections in liver transplantation

Invasive fungal infections, especially those caused by Candida albicans, and recurrence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection after transplantation are common complications in orthotopic liver transplant (OLT) recipients. Candida species account for >50% of all invasive fungal infections, which occur in 10%--15% of OLT recipients. The epidemiology and pathogenesis of invasive fungal infections are unique to each type of organism. Fluconazole is effective and safe in the prevention of Candida infection after OLT. Preventive measures against Aspergillus or Cryptococcus remain ill defined. Both HBV and HCV recur almost universally after OLT in infected individuals. The natural course of HBV and HCV, leading to end-stage liver damage, is accelerated. In OLT patients, administration of immunoglobulin with high titers against HBV, alone and/or in combination with lamivudine, immediately after transplantation reduces the recurrence of HBV. The combination of interferon and ribavirin is mildly effective in OLT patients who have evidence of recurrent hepatitis, and additional alternatives are being evaluated.