Immunization of mice with dengue structural proteins and nonstructural protein NS1 expressed by baculovirus recombinant induces resistance to dengue virus encephalitis.

We have constructed a recombinant baculovirus containing a 4.0-kilobase dengue virus cDNA sequence that codes for the three virus structural proteins, capsid (C) protein, premembrane (PreM) protein, and envelope glycoprotein (E), and nonstructural proteins NS1 and NS2a. Infection of cultured Spodoptera frugiperda cells with this recombinant virus resulted in the production of E and NS1 proteins that were similar in size to the corresponding viral proteins expressed in dengue virus-infected simian cells. Other dengue virus-encoded proteins such as PreM and C were also synthesized. Rabbits immunized with the dengue virus protein products of the recombinant virus developed antibodies to PreM, E, and NS1, although the titers were low, especially to PreM and E. Nevertheless, the dengue virus antigens produced by the recombinant virus induced resistance in mice to fatal dengue encephalitis.