Enhancement of protein expression by alphavirus replicons by designing self-replicating subgenomic RNAs

Significance One of the goals of modern molecular medicine is delivery and expression of heterologous genes in living organisms. RNA-based delivery vectors are a safer choice than DNA vectors, but they are prone to degradation and are highly dependent on efficient delivery methods. One of the ways to improve RNA vector performance is to increase the level of expression of the encoded proteins. We followed this approach and modified standard alphavirus replicon-based expression systems to make the transcribed subgenomic RNA additionally amplifiable by viral replication enzymes. Higher levels of subgenomic RNA synthesis increased the replicons’ expression efficiency at least 10-fold. Such replicons can be widely applied for development of efficient DNA and RNA vaccines and protein production in vitro.