2,3,7,8-Tetrachlorodibenzo-p-dioxin modifies expression and nuclear/cytosolic localization of bovine herpesvirus 1 immediate-early protein (bICP0) during infection.
Our previous studies have demonstrated that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases Bovine Herpesvirus 1 (BHV-1) replication through a dose-dependent increase in cytopathy and increased viral titer. Furthermore, TCDD was able to trigger BHV-1-induced apoptosis by up-regulating the activation of initiator caspases 8 and 9, as well as of effector caspase 3. Since TCDD activates caspase 3 after 4 h of infection, we have hypothesized an involvement of BHV-1 infected cell protein 0 (bICP0) in this process. Such protein, the major transcriptional regulatory protein of BHV-1, has been shown to indirectly induce caspase 3 activation and apoptosis. In order to elucidate the role of bICP0 in this apoptotic pathway, here we have analyzed the effects of TCDD on bICP0 expression. Following infection of bovine cells with BHV-1, we detected apoptotic features already at 12 h after infection, only in TCDD exposed groups. Furthermore, in the presence of different doses of TCDD, we observed a time-dependent modulation and increase of bICP0 gene expression levels, as revealed by RT-PCR analysis. Western blot analysis and immunocytochemistry revealed that TCDD induced an increase of bICP0 protein levels in a dose-dependent manner, compared to unexposed groups. Moreover, Western blot analysis of nuclear and cytosolic fractions of infected cells revealed that TCDD anticipated the presence of bICP0 protein in the cytoplasm. In conclusion, both the increase of replication of BHV-1 and anticipation of BHV-1-induced apoptosis could be the result of a relationship between TCDD and bICP0.
Fiorito
Filomena
F
Department of Pathology and Animal Health, University of Naples Federico II, Naples, Italy.
Marfè
Gabriella
G
Granato
Giovanna E
GE
Ciarcia
Roberto
R
De Blasio
Emma
E
Tafani
Marco
M
Florio
Salvatore
S
De Martino
Luisa
L
Muzi
Gianmarco
G
Pagnini
Ugo
U
Giordano
Antonio
A
D021581:Active Transport, Cell Nucleus; D000818:Animals; D017209:Apoptosis; D002417:Cattle; D003600:Cytosol; D015967:Gene Expression Regulation, Viral / Q000187:drug effects*; D006566:Herpesviridae Infections; D007242:Herpesvirus 1, Bovine / Q000737:chemistry / Q000502:physiology; D017874:Immediate-Early Proteins / Q000235:genetics; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics* / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication
D017874:Immediate-Early Proteins; D000072317:Polychlorinated Dibenzodioxins; D015534:Trans-Activators; D014764:Viral Proteins; D044767:Ubiquitin-Protein Ligases; C086729:bICP0 protein, Bovine herpesvirus 1