Development and characterization of a synthetic consensus Mayaro DNA vaccine.

A) Phylogenic analysis based on neighbor joining evaluation of MAYV-envelope sequences deposited in GenBank. The position of the scMAYV-E vaccine sequence in this tree is noted with an asterisk ‘*’ (B) Schematic of the scMAYV-E vaccine construct generated. scMAYV-E encodes all three envelope glycoproteins (E1, E2, and E3) and the 6K/TF polypeptide linked by protease cleavage sites. The IgE-leader sequence was inserted at the 5’ end to increase protein expression. (C) A computer-generated MAYV antigen model. (D) View of E1 showing fusion loop in cyan. The fusion loop is generally conserved among the alphaviruses. E3 (transparent red) is shown to provide orientation. The highly conserved MWGG sequence is visible at the loop’s rightmost position. The M residue is buried and predicted to interact with nearby TYR and PRO residues of E2. The backbone portion of M participates in H-bonds with the nearby G at position i+3 to form a b-turn. (E) Western analyses of lysates from scMAYV-E or pVax1 transfected 293T cells incubated with pooled day 35 sera from scMAYV-E immunized mice. β-actin was used as a loading control for transfected 293T cell lysates.