title: Persistent infection with a nontransforming RNA virus leads to impaired growth factor receptors and response.
abstract: The potential role of viral persistence with nontransforming viruses on cellular growth and cellular function has received little attention. We found that when infected with type 3 reovirus (five plaque-forming units (PFU/cell), balb/C 3T3 cells (a mouse embryo fibroblast cell line) undergo a limited lytic phase. The surviving cells, about 90% of the original cells, appear morphologically normal by light microscopy and exhibit normal growth patterns in serum-supplemented medium but are persistently infected by electron microscopy. These persistently infected cells shed infectious virus in the culture medium (1.6-60 X 10(6) PFU per 10(6) cells per 24 h). In comparison to control uninfected 3T3 cells, the persistently infected cells exhibit a 70-90% decrease in receptor number for epidermal growth factor (EGF). This occurs without production of any EGF-like material and is associated with a parallel decrease in EGF-stimulated DNA synthesis. By contrast, insulin receptors are increased in number three-fold and insulin and serum stimulated DNA synthesis are comparable to control uninfected cells. These results suggest that persistent infection with a nontransforming virus may lead to major alteration in control of cell growth by specific growth factors.
mesh_terms: D000818:Animals; D004261:DNA Replication; D004622:Embryo, Mammalian; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors; D005347:Fibroblasts / Q000378:metabolism* / Q000382:microbiology / Q000648:ultrastructure; D012089:Mammalian orthoreovirus 3 / Q000302:isolation & purification / Q000502:physiology*; D051379:Mice; D011972:Receptor, Insulin / Q000032:analysis; D011956:Receptors, Cell Surface / Q000172:deficiency / Q000378:metabolism*; D012087:Reoviridae / Q000502:physiology*
chemical_list: D011956:Receptors, Cell Surface; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011972:Receptor, Insulin