TY - JOUR
T1 - Constitutive and retinoic acid-inducible expression of cytomegalovirus immediate-early genes in human teratocarcinoma cells
AU - LaFemina, R.
AU - Hayward, G. S.
PY - 1986
Y1 - 1986
N2 - Human teratocarcinoma stem cells are nonpermissive for human cytomegalovirus (HCMV) but become permissive after being induced to differentiate by treatment with retinoic acid. We show that in uninduced teratocarcinoma stem cells, and also in transformed human 293 cells expressing adenovirus E1a gene products, the HCMV immediate-early (IE) 68,000-molecular-weight polypeptide (68K polypeptide) was not expressed, and consequently input viral genomes were not replicated. However, after differentiation of the teratocarcinoma cells, synthesis of the HCMV IE 68K polypeptide was induced, and viral DNA replication occurred. In contrast to our observations for HCMV, simian cytomegalovirus (SCMV) displayed constitutive expression of its analogous IE 94K polypeptide, and the input SCMV genomes were replicated in both uninduced stem cells and 293 cells. Since little, if any, HCMV IE RNA was detectable in human teratocarcinoma or 293 cells after infection under IE conditions, we suggest that a direct transcriptional block to permissivity occurs in these cells. The presence of tandemly repeated sequences which bind nuclear factor I protein in the promoter for the SCMV IE 95K polypeptide gene but not in the promoter for the HCMV IE 68K polypeptide gene may allow the expression of the simian but not the human IE gene product in transformed cells.
AB - Human teratocarcinoma stem cells are nonpermissive for human cytomegalovirus (HCMV) but become permissive after being induced to differentiate by treatment with retinoic acid. We show that in uninduced teratocarcinoma stem cells, and also in transformed human 293 cells expressing adenovirus E1a gene products, the HCMV immediate-early (IE) 68,000-molecular-weight polypeptide (68K polypeptide) was not expressed, and consequently input viral genomes were not replicated. However, after differentiation of the teratocarcinoma cells, synthesis of the HCMV IE 68K polypeptide was induced, and viral DNA replication occurred. In contrast to our observations for HCMV, simian cytomegalovirus (SCMV) displayed constitutive expression of its analogous IE 94K polypeptide, and the input SCMV genomes were replicated in both uninduced stem cells and 293 cells. Since little, if any, HCMV IE RNA was detectable in human teratocarcinoma or 293 cells after infection under IE conditions, we suggest that a direct transcriptional block to permissivity occurs in these cells. The presence of tandemly repeated sequences which bind nuclear factor I protein in the promoter for the SCMV IE 95K polypeptide gene but not in the promoter for the HCMV IE 68K polypeptide gene may allow the expression of the simian but not the human IE gene product in transformed cells.
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U2 - 10.1128/jvi.58.2.434-440.1986
DO - 10.1128/jvi.58.2.434-440.1986
M3 - Article
C2 - 3009858
AN - SCOPUS:0022481562
VL - 58
SP - 434
EP - 440
JO - Journal of Virology
JF - Journal of Virology
SN - 0022-538X
IS - 2
ER -