Development of a New Reverse Genetics System for Ebola Virus

Ebola virus from the family Filoviridae is very pathogenic and has caused several deaths especially in west Africa. It has a non segmented single stranded RNA genome encoding for seven genes. Reverse genetics are systems that are used to study these pathogenic viruses by production of mutant viruses that are safer and suitable models. For Ebola virus several reverse genetics system have been generated in the past. These systems require studying under biosafety level 4 conditions or subvirals under biosafety level 2 conditions. These earlier systems require multiple plasmids expressing viral proteins and viral genomes that are important for Ebola virus replication to be transfected. This study came up with a novel reverse genetic system for Ebola virus that required only a single viral genome transfection into a helper cell line. This cell line expresses nucleoprotein (NP), viral protein 35 and VP30 and the large protein (L) which have been fine tuned for Ebola replication. Compared to other systems this novel reverse genetic system has advantages. One is that it only requires single viral RNA genome to be transfected, the second advantage is that the helper cell lines can also be used to rescue infectious virions as well as subviral particles. Disadvantage is that the rescue of the virions is restricted to only the helper cells.

(BEC)