[Characteristics of mumps virus intracellular ribonucleoprotein during chronic infection of cell cultures].

Viral nucleocapsids isolated from cell cultures of human origin (HEp-2 and L-41) persistently infected with mumps virus for 4 years were analysed. In persistent infection, nucleocapsids accumulated in the cells in greater amounts than in primary infection. The synthesis of NP protein of nucleocapsids in persistent infection was approximately 10 times lower than that in primary infection. Morphologically, nucleocapsids in primary infection are rigid linear helical structures whereas in persistent infection they are of convoluted shape, fragmented, and partially or completely despiralized and destructuralized.