A viral transmembrane recombinant protein-based enzyme-linked immunosorbent assay for the detection of bovine immunodeficiency virus infection

The expression of bovine immunodeficiency virus (BIV) truncated transmembra ne envelope protein (designated hereafter tTM) in insect cells has been des cribed previously (Abed, Y., St-Laurent, G., Zhang, H., Jacobs, R.M., Archa mbault, D., 1999. Development of a Western blot assay for detection of bovi ne immunodeficiency-like virus using capsid and transmembrane proteins expr essed from recombinant baculovirus. Clin. Diagn. Lab. Immunol. 6, 168-172). In this study, a tTM-based enzyme-linked immunosorbent assay (ELISA) was d eveloped for the serodetection of BIV infection. A total of 109 bovine sera including 86 BIV-negative and 23 BIV-positive serum samples were tested. T he ELISA results were compared with those of three Western blot assays usin g, as test antigens, cell culture-derived whole virus proteins (WB1), and t he tTM (WB2) and p26 (WB3) fusion proteins expressed from recombinant bacul ovirus in insect cells, respectively. The concordances of the ELISA results with those of the WB1, WB2, and WB3 were 97.2, 100 and 97.2%, respectively . The tTM protein-based ELISA and Western blot permitted the detection of B IV infection in cattle whose sera failed to react with the p26 fusion prote in and the whole virus protein preparation. The tTM recombinant protein was also used to study the kinetics of appearance of antibodies against BIV tr ansmembrane envelope protein in rabbits infected experimentally with BIV. A ntibodies to tTM were detected at 28 days post-infection and persisted thro ugh the entire 36-39.5 months experimental time period. The results of this study showed that the tTM-ELISA might: be useful for the serodetection of BIV-infected animals, and for basic studies on BIV replication life cycle. (C) 2000 Elsevier Science B.V. All rights reserved.