Enhancement of Adenovirus Growth in African Green Monkey Kidney Cell Cultures by SV40

Abstract

Mixed infection with simian virus 40 (SV40) and adenovirus 1 2 can occur in African green monkey kidney (AGMK) cells in vitro, and electron micrographs demonstrating both viruses within the nucleus of a single cell have been presented ( 1 ) . Variable degrees of partial exclusion were produced by altering the time interval between inoculation of SV40 and adenovirus 12, and approximately 40% of the cells contained both viruses when the adenovirus was inoculated 24 hours after SV40(1). Further studies of AGMK cultures infected with both viruses compared with cultures infected with adenovirus 12 only have shown that SV40 enhances the growth of the adenovirus. A similar enhancement of growth of adenovirus 5 has been found when AGMK cultures were infected with SV40 and adenovirus 5.Materials and methods. Cell Cultures: Primary AGMK cell cultures were obtained from Microbiological Associates, Inc., Bethesda, Md., and primary human embryo kidney cell cultures (HEK) from the Virology Research Resources Branch, National Cancer Institute, through the kindness of Drs. Robert E. Stevenson and Theodore Malinin. Roller tube cultures maintained in a medium composed of 2 % fetal bovine serum and 98% mixture 199 and incubated at 36.5"C were used in all experiments.Viruses: SV40 and adenovirus 12 strains were the same as those previously described (1). Adenovirus 5 was obtained from the American Type Culture Collection. SV40 was grown and titrated in AGMK cell cultures, and adenoviruses 12 and 5 were grown and titrated in HEK cultures. Viruses were titrated by serial 10-fold dilutions with 3 to 5 tubes per dilution. Titrations were observed for 2 1 days and titers were calculated by the Reed-Muench method.The amount of adenovirus in the AGMK cultures after infection with both SV40 and adenovirus 12 or adenovirus 5 was determined by titration in HEK cell cultures in which a typical adenovirus-type CPE was produced. Although Shein and Enders have shown that SV40 can produce an incomplete CPE in HEK cell cultures after more than 17 days (2), the cellular degeneration described by them did not resemble the CPE produced by adenovirus 12 and 5, and the inocula they used contained considerably more SV40 than could have been present in the terminal dilutions in our titrations.Experiments and results. In the first experiment, AGMK cell cultures infected with adenovirus 12 only were compared with similar cultures infected simultaneously with both SV40 and adenovirus 12 (Table I). After 48 hours' incubation, clusters of rounded refractile cells were observed in both the singly and doubly infected cultures although the changes were more extensive in the doubly infected cultures. Uninfected control cultures showed no changes. At 72 and 122 hours, the CPE had progressed in all infected tubes; however, it continued to be more severe and extensive in the doubly infected cultures.Electron microscopic studies at 72 and 122 hours showed a significant difference between the singly and doubly infected cultures. In the singly infected cultures, althou...

Tissue culture adaptation of natural isolates of simian virus 40: changes occur in viral regulatory region but not in carboxy-terminal domain of large T-antigen.

“…A carboxy-terminal fragment of T-ag can relieve a block to Ad replication in monkey cells (Rabson et al, 1964 ;Kelley & Lewis, 1973 ;Cole et al, 1979) by an unknown mechanism. The hr\hf domain was identified because T-ag carboxy-terminal deletion mutants exhibited different growth properties in monkey cell lines ; these mutants grew well in BSC and Vero cells, but not in CV-1 cells (Lewis et al, 1983 ;Pipas, 1985 ;Tornow et al, 1985 ;Cole & Stacy, 1987).…”

Altered mRNA splicing in monkey cells abortively infected with human adenovirus may be responsible for inefficient synthesis of the virion fiber polypeptide.

“…The block to replication of Ad2 in monkey cells can be overcome by coinfection with simian virus 40 (SV40; ref. 1) or by infection with Ad2-SV40 hybrid viruses (e.g., Ad2+ND1) that contain a segment of the SV40 genome encoding only the carboxyl terminus of the SV40 large tumor antigen (2)(3)(4)(5). In addition, mutants of human adenovirus have been isolated (Ad2hr400-403, Ad5hr404, Ad2+ND3hr600-603) that grow efficiently in monkey cells as well as human cells (6)(7)(8).…”

“…The 5' ends of fiber messages from productively and abortively infected human and monkey cells were analyzed by a primer extension procedure. Single-stranded radiolabeled synthetic oligodeoxynucleotide primer complementary to the 5' end of the 1 main body of the fiber message was hybridized to RNA from productively or abortively infected cells and elongated with AMV reverse transcriptase to make complete cDNA copies of the 5' ends of fiber messages (Fig. 1).…”

Superinfection of HVJ Carrier HeLa Cells with Ultraviolet‐Irradiated Newcastle Disease Virus

“…Rabson et al [25] found that the growth of adenovirus in African green monkey kidney cells was enhanced by mixed infection with SV40 which is quite distinct from adenovirus. Although the mechanism of this enhancement is unknown, it seems interesting to examine whether UV-irradiated adenovirus can be reactivated in the cell simultaneously infected with SV40.…”