RESPIRATORY SYNCYTIAL VIRUS NUCLEOCAPSID PROTEIN (N) EXPRESSED IN INSECT CELLS FORMS NUCLEOCAPSID-LIKE STRUCTURES

The gene coding for the N protein of RSV strain Long has been cloned a nd sequenced. It was introduced behind the polyhedrin promoter of the shuttle vector pVL941 and baculoviruses containing the N gene were con structed by homologous recombination. Infection of Spodoptera frugiper da 9 cells resulted in the production of large amounts of a protein si milar in size and antigenicity to the authentic N protein. The baculov irus expressed N protein was concentrated in the cytoplasm of the inse ct cells and could be extracted at low salt concentration. Nucleocapsi d structures similar to those purified from RSV-infected cells could b e observed by electron microscopy after negative staining of cellular extracts.