Persistent infection of some standard cell lines by lymphocytic choriomeningitis virus: transmission of infection by an intracellular agent

Abstract

Cell-free cytoplasmic extracts of the Syrian hamster cell lines C13/SV28 and BHK-21F were immunogenic in Syrian hamsters. The resulting antisera crossreacted completely with antisera against lymphocytic choriomeningitis virus (LCMV) in an immunoradiometric assay employing BHK-21F antigen. Several other Syrian hamster cell lines not previously known to be infected with LCMV were also strongly positive when assayed for viral antigens. Also, several mouse sera and antisera raised in Syrian hamsters against cells transformed by papovaviruses had high titers of anti-LCMV activity. No cytopathic effect was evident in any of the persistently infected cell lines. Culture media from these cells were not infectious and showed no evidence of defective interfering particles. However, cell-free extracts of all the persistently infected cells contained material capable of transmitting the persistent infection to uninfected cells of Syrian hamsters, rats. mice, green monkeys, and humans. The onset of infection is much slower than when LCMV virions are used. When 2 x 106 uninfected BHK cells were treated

Defective Viral Genomes Arising In Vivo Provide Critical Danger Signals for the Triggering of Lung Antiviral Immunity

“…Notably, DVGs of different forms and compositions have been described in the sera of patients chronically infected with a number of different viruses [13,14,15,16,17] and DVGs of various viruses have been shown to promote persistent infections in tissue cultures [45,46,47,48,49,50,51,52,53] supporting a role for DVGs in the maintenance of chronic viruses. The role of naturally arising DVGs in promoting virus persistence in vivo remains to be investigated.…”

Oncolytic viruses in cancer therapy

“…In addition to facilitating virus spread, syncytiosome formation may be directly toxic to the cells and syncytia are also more readily recognized by the immune system, increasing the tumor-killing capacity of oncolytic viruses even further or confer-ring killing capacity to otherwise apathogenic constructs [64]. Viral genomes may also piggyback on exocytosed vesicles or jump from cell to cell through tight junctions, as has been documented for a variety of different viruses and viral vectors [65][66][67]. Moreover, some vectors may not be based on any specific virus yet still be packaged into VLPs.…”

In Vitro Assembly of the Murine Coronavirus Membrane Protein E1

“…MHV strain A59 was grown in Sac(-) cells, labelled with~S methionine, and purified as described previously (12,13). Iodination of the virus was carried out using Iodogen (14) and the final specific activity was 1.9 uCI/ug. Poly(A)+-RNA from infected cells was prepared as described previously (13) except that poly(U)-Sepharose (15) was used to select the RNA.…”