RNA vaccine by Moderna contains Luciferin dissolved with 66.6ml of distilled phosphate

The researchers, who had previous experience developing novel ionizable lipids that would be useful for LNP formulations to achieve siRNA delivery, examined the potential use of several ionizable lipids in vivo. They identified appropriate lipids that would allow the mRNA to escape from the endosomal compartment and enter the cytosol for translation.

They selected two of the most popular LNPs for testing their vaccine formulation. They employed a luciferase indicator to demonstrate the uptake of the mRNA and thus assess the LNP formulation’s efficacy.

The two selected formulations were found to produce intense and long-lived expression of luciferase, with a burst of luminescence after the addition of luciferin. The investigators found a limited antibody response after one immunization, but a higher level of cellular response directed against the luciferase antigen. Both LNPs elicited comparable cellular immunity, but the luminescence with one was more transient than the other.

The pattern of protein expression does not, therefore, predict the immunogenicity of the molecule. Rather, this is determined by the antigen’s uptake efficiency by the antigen-presenting cells (APC), which deliver it to the lymphocytes in the lymph node.  This will result in the activation of T cells and the production of immune mediators.

In the current experiment, the immune response appeared to be robust because of the expressed protein’s tissue and cell distribution. Further research is required to examine how the luciferase protein is expressed in various tissues and organs. Source