Amplification, expression, and packaging of a foreign gene by giardiavirus in Giardia lamblia.

摘要: Giardia lamblia is an intestinal protozoan parasite and one of the earliest eukaryotic divergents. The trophozoite multiplies via asexual binary fission lacks all natural means lateral gene transfer. A system developed here for long-term expression a foreign in this organism by exploiting recombinant virions derived from giardiavirus (GLV), double-stranded RNA virus that infects many isolates. An vitro transcript cloned GLV cDNA, comprising firefly luciferase-encoding region flanked 5' 3' fragments positive-strand RNA, was electroporated into GLV-infected trophozoites. Luciferase activity cells peaked on day 2 at levels 6 orders magnitude above background. Expression remained 80% its peak level after 30 days absence selective pressure. chimeric replicated as packaged virus-like particles. were partially purified wild-type helper CsCl equilibrium density-gradient centrifugation used to superinfect At multiplicities infection 100 or higher, these able initiate new rounds luciferase superinfected cells. Thus, engineered virion can be successfully introduce efficiently express heterologous microorganism.