Expression of the Epstein-Barr virus latent membrane protein (LMP) in insect cells and detection of antibodies in human sera against this protein.

Recombinant baculoviruses containing the complete LMP and truncated LMP genes were generated and high levels of the LMP proteins were expressed in Spadoptera Frugiperda insect cells. A specific rabbit antiserum directed against the N-terminal part of LMP was obtained by immunizing the rabbits with Escherichia coli-expressed trpE-N-terminal part of LMP fusion protein. A total of 127 human sera were studied for their immune response to the recombinant full-length LMP. In immunofluorescence analysis, all sera tested showed no detectable reaction with the recombinant full-length LMP. In immunoprecipitation-immunoblotting analysis, however, sera from patients with nasopharyngeal carcinoma (5/22), patients with Hodgkin's disease (16/27), patients with other diseases exhibiting high EA-IgG titers (3/52), and VCA-IgG-positive healthy individuals (2/26) were shown to contain antibodies against this recombinant LMP. The expressed LMP proteins provided a sufficient and economic source of the proteins for further serological and biological studies.