ENZYME-LINKED-IMMUNOSORBENT-ASSAY USING RECOMBINANT ANTIGENS FOR SERODIAGNOSIS OF JAPANESE ENCEPHALITIS

Recombinant Japanese encephalitis (JE) virus proteins were evaluated a s antigens for serodiagnosis of JE using an enzyme-linked immunosorben t assay (ELISA). The premembrane/membrane (prM/M) and envelope (E) pro teins of JE virus were expressed in HeLa cells infected with a recombi nant vaccinia virus that encodes the JE virus prM and E genes and were released from cells in a particulate form. The particulate antigens w ere partially purified from culture fluid from the infected cells by p recipitation of particles with polyethylene glycol and then dissociate d from the particles with 0.1% Triton X-100. This antigen preparation was used to evaluate one preimmune and two postvaccination sera from 2 0 volunteers given three inoculations of the commercial JE vaccine (Bi ken vaccine) by a conventional ELISA. The results from this assay corr elated with neutralization data. The results of an IgM capture ELISA c arried out with the recombinant antigen also correlated with the resul ts of an existing IgM capture ELISA performed with JE virus-infected m ouse brain, when tested with 29 serum and 13 cerebrospinal fluid sampl es from JE patients. These results indicated that recombinant JE virus antigens are useful for ELISA as an antigenically equivalent, highly productive, and safe alternative to authentic JE virus antigens. (C) 1 996 Wiley-Liss, Inc.