Characterization of Measles Virus-Specific Proteins Synthesized In Vivo and In Vitro from Acutely and Persistently Infected Cells

Abstract

Measles virus protein synthesis was analyzed in acutely [African green monkey kidney CV-1] and persistently [human cervical carcinoma Hela K11-HG and K11A-HG-1] infected cells. To assess the role of measles in subacute sclerosing panencephalitis (SSPE), measles viral proteins synthesized in vivo or in vitro were tested for reactivity with serum from a guinea pig(s) immunized with measles virus and sera from patients with SSPE. Guinea pig anti-measles virus serum immunoprecipitates the viral polypeptides of 78,000 MW (glycosylated [G]), 70,000 MW (phosphorylated [P]), 60,000 MW (nucleocapsid [N]) and 35,000 MW (matrix [M]) from cells acutely infected with measles virus and from chronically infected cells, but in the latter case, immunoprecipitated M protein has a reduced electrophoretic migration. Sera of SSPE patients immunoprecipitated all but the G protein in acutely infected cells and only the P and N proteins from chronically infected cells. In immunoprecipitates of viral polypeptides synthesized in a reticulocyte [rabbit] cell-free translation system, in response to mRNA from acutely or persistently infected cells, the 78,000 MW form of the G protein was not detected among the cell-free products of either mRNA. Guinea pig anti-measles virus serum immunoprecipitated P, N and M polypeptides from the products of either form of mRNA, whereas SSPE serum immunoprecipitated the P and N polypeptides but not the M polypeptide. The differences in immunoreactivity of the anti-measles virus antiserum and the SSPE serum are discussed in terms of possible modifications of measles virus proteins in SSPE.