Interferon induction by adenovirus type 12: stimulatory function of early region 1A

Abstract

Adenoviruses are generally weak interferon inducers, triggering chicken embryo fibroblast cells by a UV-resistant viral component, probably the capsid or capsid elements, to produce 50 to 100 IU of interferon per ml. Adenovirus types 12, 18, and 31, however, can induce by a UV-sensitive mechanism 10 to 20 times more interferon than other types do. By using mutant and recombinant adenoviruses, we demonstrated that early region 1A was responsible for the enhanced interferon production of chicken cells infected with adenovirus type 12.

Activation of the human beta interferon gene by the adenovirus type 12 E1B gene

“…In this report, we examine the expression of the endogenous human IFN-,B gene by adenoviruses in human embryo kidney (HEK) cells and the expression of the exogenously transfected hybrid plasmid (pIFN-CAT) by adenoviruses in CEF and HEK cells. The expression of the endogenous IFN-1 gene was induced by Adl2 but not by Ad5, in agreement with the production of IFN in CEF cells (22). However, the Adl2 gene involved in the induction was the E1B gene and not the ElA gene, in contrast to previous results in CEF cells (22).…”

“…The expression of the endogenous IFN-1 gene was induced by Adl2 but not by Ad5, in agreement with the production of IFN in CEF cells (22). However, the Adl2 gene involved in the induction was the E1B gene and not the ElA gene, in contrast to previous results in CEF cells (22). The expression of the exogenously transfected IFN-1 gene was activated by both Adl2 and Ad5 in CEF and HEK cells.…”

“…Since both Adl2 and AdS activated the exogenous pIFN-DISCUSSION The adenoviruses are considered IFN inducers (8). Most of the adenovirus types induce low titers (50 to 100 IU/ml) of IFN in CEF cells, but some types (Adl2, Adl8, Ad3l) induce high titers (a few thousand international units per milliliter) of IFN in CEF cells (22,23). The ElA region is responsible for the enhanced IFN-inducing ability of Adl2 (22,24).…”

“…endogenous IFN-13 mRNA was activated by Adl2 infection but not by Ad5 infection. This finding is correlated with the induction of IFN in CEF cells (22). However, the endogenous chicken IFN is produced in rc-l (AdS dl312 containing the Adl2 ElA region)-infected but not in d1203 (Adl2 ElA deletion)-infected CEF cells (22).…”

“…Previous studies show that adenovirus type 12 (Adl2) induces IFN with high titers in chicken embryo fibroblast (CEF) cells, but Ad5 induces IFN with low titers (22,23). It was also shown that the product of Adl2 early region 1A (ElA) increased low, virus capsid-mediated IFN production, but the AdS ElA product did not show this function (22,24). The increased production of IFN with Adl2 is also induced in chicken leukocytes (Toth et al, submitted for publication).…”