o' Pi ro hh (D 
HEPATOCELLULAR TRANSPLANTATION AND TARGETING GENETIC MARKERS TO HEPATIC CELLS 
II. SPECIFIC AIMS 
1 . Clinical feasibility and efficacy of hepatocellular transplantation. 
a. Can hepatocytes be safely transplanted into a patient with acute hepatic 
failure? 
b. Is end stage failure ameliorated by hepatocellular transplantation? 
c. Can hepatocellular transplantation be used as a bridge to subsequent 
orthotopic liver transplantation? 
d. Will hepatocellular transplantation lead to long-term restoration of hepatic 
function with donor cells or provide time for regeneration of host hepatic 
functions? 
How severe is immune rejection of hepatocytes compared to whole organs? 
What are the short-term and long-term clinical consequences or complications 
of hepatocellular transplantation? 
Fate and function of transplanted hepatocytes in vivo. 
Does engraftraent of hepatocytes occur after implantation? 
Identify transplanted cells in the host using naturally occurring polymorphism 
in genetic structure or recombinant marker gene, 
c. Describe location, longevity, differentiation, and function of transplanted 
hepatocytes . 
3 . Introduction of genetic markers into hepatocytes using recombinant retroviral 
vectors . 
a. Can primary human hepatocytes be efficiently transduced with recombinant 
retroviral vectors under conditions suitable for subsequent transplantation? 
b. What is the efficiency of this retroviral transduction? Is the transduction 
efficiency and target cell viability observed in vitro paralleled by that 
observed after transplantation of cells into human hosts? 
c. What is the level of expression of the marker gene in vivo following 
transplantation of hepatocytes? 
d. Is there an immune response against transplanted hepatocytes or the 
recombinant marker gene? 
4. The safety of recombinant retroviral vectors in human clinical research. 
a. Is there any evidence for defective or wild type viruses in patients after 
transplantation of transduced cells? 
b. Is there evidence for recombination with endogenous viruses? 
c. Are there untoward consequences of hepatocyte transduction? 
Recombinant DNA Research, Volume 14 
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