Schematic representation of the novel Pr4LS5E and PrS5E synthetic hybrid promoters.

<p>The Pr4LS5E promoter consists of four late elements (dark grey boxes) which include from 5’ to 3’: the ATI late promoter (ATI), the short synthetic late promoter (PrSSL) and the MVA123L and MVA124L late promoters (PrMVA123L and PrMVA124L). The Pr4LS5E contains downstream of these four late elements one PrS promoter sequence (white box) followed by five modified early promoter elements derived from the p7.5k promoter (7.5e; light-grey boxes). The PrS5E promoter consists only of the PrS promoter sequence followed by the five 7.5e elements. The promoters were used to drive the expression of the ovalbumin (OVA) gene. The position of the promoter sequences relative to the start (ATG) of the OVA open reading frame (ORF) is shown. Arrows indicate the direction of transcription. The OVA expression cassettes were introduced into the MVA genome at the intergenic region (IGR) between the MVA genes MVA044L and MVA045L (IGR 44/45) shown as black arrows in the direction of gene transcription.