Co-expression of functional human Heme Oxygenase 1, Ecto-5′-Nucleotidase and ecto-nucleoside triphosphate diphosphohydrolase-1 by “self-cleaving” 2A peptide system

• We produced an F2A-based tricistronic plasmid encoding the human HO1, E5NT and ENTPD1 genes.
• The three proteins were functionally expressed and possessed relevant enzymatic activities.
• The addition of Furin and spacer sites upstream of F2A sequences decreased proteins expression and activity.
• This new combination of genes could be used in xenotransplantation models to investigate their potential to block rejection.

We developed an F2A-based multicistronic system to evaluate functional effects of co-expression of three proteins important for xenotransplantation: heme oxygenase 1 (HO1), ecto-5′-nucleotidase (E5NT) and ecto-nucleoside triphosphate diphosphohydrolase-1 (ENTPD1). The tricistronic p2A plasmid that we constructed was able to efficiently drive concurrent expression of HO1, E5NT and ENTPD1 in HEK293T cells. All three overexpressed proteins possessed relevant enzymatic activities, while addition of furin site interfered with protein expression and activity. We conclude that our tricistronic p2A construct is effective and optimal to test the combined protective effects of HO1, E5NT and ENTPD1 against xeno-rejection mechanisms.