EXPRESSION OF FELINE IMMUNODEFICIENCY VIRUS GAG AND ENV PRECURSOR PROTEINS IN SPODOPTERA-FRUGIPERDA CELLS AND THEIR USE IN IMMUNODIAGNOSIS

The gag and env genes of the feline immunodeficiency virus strain UT11 3 were cloned into a baculovirus transfer vector. The recombinant plas mids were used to create recombinant baculoviruses that expressed eith er the gag or the env precursor protein in insect cells (Sf9 cells). L eader sequence cleavage occurred in Sf9 cells expressing the envelope precursor, but further processing was not observed. Crude lysates of i nsect cells infected with the wild-type baculovirus or with the recomb inant viruses were used to develop an enzyme-linked immunosorbent assa y for the detection of feline immunodeficiency virus-specific antibodi es in cat sera. The assay showed a higher sensitivity and specificity than immunofluorescence and Western blotting (immunoblotting).