Recovery of infectious proviral DNA from mammalian cells infected with respiratory syncytial virus.

Abstract

The DNA fraction from a line of bovine embryonic kidney cells originally exposed as primary cultures several months earlier to a temperature-sensitive (ts) mutant of respiratory syncytial (RS) virus could be used to transfect human HEp-2 cells with the production of infectious RS virus. The DNA donor cells, designated BEK/RS ts, retained their healthy fibroblastic appearance during continuous cultivation at a temperature (390) restrictive for growth of the original infecting mutant and showed no evidence for RS virus replication or viral antigen synthesis when directly examined for these activities by conventional methods.

Establishment of Respiratory Syncytial Virus Persistence in Cell Lines: Association with Defective Interfering Particles

“…RSV persistence has been documented in murine [8,9], monkey [10], bovine [11], and human cell lines [12][13][14]. RSV chronicity cultures have been established with RSV long [8,9,11,13] and A2 strains [10,12] and with temperature-sensitive mutants from these strains [10,11]. Although viral stocks used were obtained from plaque-purified virus, it is probable that some defective interfering particles (DIP) were present, if only in minor amounts.…”

“…Although characteristic RSV syncytia with concomitant cell death and infectious virus production are usually observed in human epithelial cell lines infected with RSV [1], the virus can persist under certain circumstances. RSV persistence has been documented in murine [8,9], monkey [10], bovine [11], and human cell lines [12][13][14]. RSV chronicity cultures have been established with RSV long [8,9,11,13] and A2 strains [10,12] and with temperature-sensitive mutants from these strains [10,11].…”

“…RSV stock fractions [10][11][12][13] whose buoyant density of 1.18 g/ cm 3 did not interfere with viral infectivity ( fig. 2) were regarded as virus with low or non-DIP content and were designed as stock B.…”

The Mechanisms of Appearance of Viral Glycoproteins at the Cell Surface Membrane

“…The work of M a r c u s [96] points to a continuous increase in the amount of viral antigen per cell. Integration of the viral genome into the cellular genome as DNA in chroni cally infected cells [142][143][144], but not in lytically infected cells, may account for the difference observed. Expression of viral antigens could perhaps follow more closely cellular events when the viral genome is integrated into the cell genome than when the genome is not in an integrated form.…”

On the Mechanism of the Persistence of Lymphocytic Chorio-meningitis Virus in the Continuous Cell Line Detroit-6

“…Thymidine analogues (BrDU and 1DU) stimulated the synthesis of antigen. DNA of the persistently infected cell line was transfected to the mouse lymphoid cell line, Liaio, which became persistently infected with the virus.It has been established that a subline of the continuous cell line, Detroit-6, is persistently infected with lymphocytic choriomeningitis (LCM) virus [I], This subline, designated as D6-LCM, presents a convenient model for the study of virus persistence, which is characteristic of LCM virus [2,3], Recently, the formation of DNA proviruses of RNA viruses in chronically infected cells was described [4,5]. This phenomenon demonstrates the complexity of 'gentleman' relationships between the virus and the cell [6] that may be ob served in the course of virus persistence.…”