International Centre for Genetic Engineering & Biotechnology, New Delhi, India.
There is currently no vaccine to prevent dengue (DEN) virus infection, caused by any one of four closely related serotypes, DEN-1, DEN-2, DEN-3, or DEN-4. A DEN vaccine must be tetravalent, as immunity to a single serotype, does not offer cross protection against the other serotypes. We have developed a novel tetravalent chimeric protein by fusing the receptor-binding envelope domain III (EDIII) of the four DEN virus serotypes. This protein was expressed in the yeast, Pichia pastoris, and purified to near homogeneity in high yields. Antibodies induced in mice by the tetravalent protein, formulated either in alum or Montanide ISA 720, neutralized the infectivity of all four serotypes with titers of >1:80. This, coupled with the high expression capacity of the P. pastoris system and easy one-step purification, makes the EDIII-based recombinant protein a potentially promising candidate for the development of a safe, efficacious, and inexpensive, tetravalent DEN vaccine.
