Rhinovirus type 14 persistence in hela cells studied by use of guanidine

Guanidine at 2 mM completely prevents replication of rhinovirus type 14 (RV14) in HeLa cells and spares these cells from RV14‐induced cytopathic effects. Three serial subcultivations of these cells in the continued presence of guanidine reduced infectious virus titers in cell lysates to undetectable levels. However, the capacity of RV14‐infected guanidine‐cultured cells to form infectious centers when cultured in the absence of guanidine was not completely abolished until the fifth serial subcultivation (14 days post‐inoculation). Production of defective‐interfering particles of RV 14 in HeLa cells was not observed. Thermal stability and transmission of uncoated RV 14 to daughter cells in the presence of guanidine can account for the persistence. Cells inoculated with RV14 and cultured in the presence of guanidine synthesized genomic RNA associated with a structure of 1.394 gm/ml density in CsCI, and these structures exhibited low infectivity by standard plaque assay. Nascent RV14 RNA did not appear in virions in cells treated with guanidine. HeLa cell lines (HeLa V+G ), established following six serial subcultures of cells initially infected with RV 14 and continuously cultured in the presence of guanidine, were negative for RV 14 antigens by specific immunofluorescence tests. HeLa V+G cells were as efficient as normal HeLa cells in production of interferon; replication of RV 14 and mengovirus; and plaque assay of RV 14, rhinovirus type 2, and coxsackievirus B3.