CD40L protein lacking first naturally occurring Methionine codon induces highest levels of IL-12 secretion in DCs. Panel A: SDS-Page Analysis of CD40L polypeptides translated in vitro obtained from RNAs with consecutively knocked out 1–4 methionine codons. No RNA: in vitro translation products of reaction containing no RNA template. C: translation of a positive control unrelated RNA Panel D: intracellular staining of DCs with anti-CD40L antibody of DCs harvested at indicated time point post-electroporation with either CD40L WT or CD40L ΔXE Met 1 RNAs as indicated on the bottom of the graph. Panel F: levels of IL-12 cytokine measured by ELISA accumulated in supernatants collected at indicated time point post-electroporation in DC cultures electroporated with either CD40L WT or CD40L ΔXE Met 1 RNAs. Each electroporation was performed in triplicate. All CD40L RNAs were ARCA-capped with a long poly(A) tail. GFP is a negative control RNA.