Replication of Human Syncytium‐Forming Virus in Human Cells: Effect of Certain Biological Factors and Selective Chemicals

Abstract

The growth characteristics of the human syncytium-forming virus (HSFV) were examined in several human cell lines of normal and malignant origins and composing of either fibroblastic or epithelial-like cells. Virus production occurred only in the fibroblastic diploid cell lines: HEF (human embryonic cells, Flow #5,000) and HFDL #645 (human fetal diploid lung), but not in the epithelial-like heteroploid cell lines: RA (a continuous line of human amnion), #999 (human bone marrow), and KB (carcinoma of the nasopharynx). While the single-cycle growth pattern of the virus in HEF and HFDL #645 cell lines were essentially similar, the virus yield per cell was greater in the HFDL #645 cells. Furthermore, the physiological state of the cell had a marked effect on virus production. Subconfluent actively growing HFDL #645 cells produced higher yields of virus than density-inhibited confluent HFDL #645 cell cultures. The replication of HSFV was inhibited by actinomycin D at concentrations that did not interfere with poliovirus replication (0.001 to 0.01 microgram/ml). Pretreatment and posttreatments of infected cell cultures with either the polycation polybrene (hexadimethrine bromide) or the synthetic glucocorticosteroid dexamethasone did not enhance HSFV production.

Enhanced Production of a Human Spumavirus (Retroviridae) in Semi-permissive Cell Cultures after Treatment with 5-Azacytidine

“…Infection of HFDL and RA cells by HSFV confirmed previous results that HFDL cells are permissive while RA cells are semi-permissive for HSFV (Loh & Ang, 1981 ;Lob & Matsuura, 1984). While infected HFDL cells showed characteristic syncytia and cytoplasmic vacuolation, infected RA cells showed little or no c.p.e.…”

“…645 cells, and not in epithelial-like aneuploid cells, such as the recovered amnion (RA) cells (Loh & Ang, 1981). The semipermissiveness of the RA cells was found not to be due to the failure of the adsorption of virus to cells (Loh & Matsuura, 1984).…”

“…Virus stocks of HSFV were prepared in HFDL no. 645 cells (Loh & Ang, 1981) and poliovirus type 1 was prepared in RA cells. HSFV was assayed in HFDL cells as previously described (Loh et al, 1977) and poliovirus type 1 was assayed in RA cells using the standard agar overlay plaque technique (Dulbecco & Vogt, 1954).…”

Productive persistent infection of hematopoietic cells by human foamy virus

“…Little is known about the ability of foamy virus to replicate in different cell types other than fibroblasts. It is known that epithelial cells do not support active replication of foamy virus (15); yet, it remains unclear if the resistance of epithelial cells is due to a lack of specific receptors or to the absence of intracellular factors. Several latently infected cultures have been established from epithelial cells (6,11,22) and lymphoblastoid cells (20); failure of HFV replication in these cultures has been suggested to be caused by methylation of proviral DNA (11,22).…”

Molecular cloning of the genome of human spumaretrovirus

“…The molecular clones of HSRV DNA will facilitate further studies on the structure and function of HSRV genome and its gene products. HEL cells were grown as described (Flügel et al, 1987) and HSRV.was kindly provided by Dr. P. Loh (Loh and Ang, 1981 ). Virus was propagated by rnixing infected HEL cells with uninfected growing HEL cells at a ratio of 1: 4 (Neumann- Haefelin et al, 1983).…”