A simplified strategy to package foreign proteins into baculovirus occlusion bodies without engineering the viral genome

FABRE, MARÍA LAURA; MASSON, TOMÁS; HAASE, SANTIAGO; FERRELLI, MARÍA LETICIA; ROMANOWSKI, VÍCTOR

JOURNAL OF BIOTECHNOLOGY

ELSEVIER SCIENCE BV

Año: 2019

0168-1656

Polyhedron envelope protein (PEP) is the major component of the calyx that surrounds the baculovirus occlusion body (OB).PEP has been associated with the stabilization and resistance of polyhedra in the environment. Due to the abundant levels ofPEP in OBs, we decided to use this protein as a fusion partner to redirect foreign proteins to baculovirus polyhedra. In thisstudy we developed a strategy that involves the generation of a monoclonal transformed insect cell line expressing a protein ofinterest fused to the the Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV) N-terminus of PEP that enables thepackaging of foreign proteins into the OBs without generating a recombinant baculovirus. This proved to be an efficient platform that could be exploited to improve wild type baculovirus for their use as bioinsecticides without facing the concernsof releasing genetically modified DNA to the environment and bypassing the associated regulatory issues.We demonstrated, using immunological, proteomic and microscopy techniques, that the envelope of AgMNPV OBs caneffectively trap chimeric proteins in an infected insect cell line expressing AgMNPV PEP fused to the enhanced greenfluorescent protein (eGFP). Furthermore, packaging of chimeric PEP also took place with heterologous OBs such as those ofAutographa californica multiple nucleopolyhedrovirus (AcMNPV), another group I alphabaculovirus.