Hepatitis Delta Virus Transfection for the Mouse In Vivo Model

Over the years different strategies have been used to achieve the expression of hepatitis delta virus (HDV) sequences in mice. The first studies used cDNA clones of HDV sequences to make mice transgenic for the expression of the small or the large forms of the delta protein (1 ). Subsequently, three lines of mice transgenic for a cDNA expressing the entire HDV genome were made; these mice demonstrated accumulation of HDV RNA transcripts, but the majority were in the skeletal muscle with only relatively small amounts in the liver (2 ). At about the same time it was demonstrated that direct injections of HDV cDNA into the skeletal muscle of a mouse led to the accumulation of HDV RNA transcripts (3 ).