In vitro transcription by T7 RNA polymerase leads to the formation of double stranded RNA (dsRNA), which is highly immunogenic.
Indeed, dsRNA activates TLR3, RIG-I and MDA5. Transduction signals from these receptors trigger the release of type I-interferon, as well as pro-inflammatory cytokines.
Besides, dsRNA activates PKR and OAS leading to translation repression of transfected mRNA.
This contamination of mRNA by dsRNA requires extensive and expensive mRNA purification to get rid of dsRNA.
Nuntius technology is about the synthesis of mRNA devoid of dsRNA contamination. The following step of mRNA purification is simplified, much cheaper and does not require the use of organic solvants, such as actonitrile.
This is achieved by adding a new component to the in vitro transcription mixture, which can be produced in large scale by respecting the cGMP.