Altered Biology of Adeno-associated Virus Type 2 and Human Papillomavirus during Dual Infection of Natural Host Tissue

Abstract

Adeno-associated virus (AAV), a common genital virus, may have a "protective" role against human papillomavirus (HPV)-associated cervical cancer. Epidemiological studies indicate a negative correlation between AAV infection and the incidence of cervical cancer. In contrast, HPV is positively associated with cervical cancer. To investigate interactions between these two viruses we used the organotypic "raft" culture system. The raft culture system is capable of supporting the complete HPV life cycle. Raft tissues that were actively replicating HPV were superinfected with AAV type 2 (AAV-2). We observed a multiplicity of infection (m.o.i.)-dependent enhancement and inhibition of HPV DNA replication, concomitant with AAV-2 replication. The data suggest that at low m.o.i. of AAV-2 infection, HPV DNA replication was slightly increased compared to controls and AAV-2 replicated poorly. At high AAV-2 m.o.i., HPV DNA replication was reduced and AAV-2 replicated to high levels. AAV-2 replication was increased in the presence of HPV compared to primary human keratinocyte, squamous cell carcinoma, and HaCat raft cultures infected with AAV-2 alone. These data suggest that HPV may provide types of "enhancer/helper" functions for AAV-2 replication and progeny formation. Infection with AAV-2 had significant effects on epithelial morphology. During infection with low m.o.i. of AAV-2 the epithelium stratified to a greater extent than in controls. With high m.o.i. of AAV-2 infections, tissue cytopathic effects were observed, indicating an additional factor responsible for the effect of AAV-2 on HPV replication and infection. Our results demonstrate a complex interaction between AAV-2, HPV, and skin during dual infection.

The Cigarette Smoke Carcinogen Benzo[ a ]pyrene Enhances Human Papillomavirus Synthesis

“…To each sample, 100 l of a 5ϫ sample loading buffer was added as described previously (1). Total protein concentrations were measured by using the Lowry method as described previously (34). To determine capsid protein expression, 60 g of the whole-virus extracts were loaded onto 7.5% sodium dodecyl sulfate-polyacrylamide gels.…”

Detection of adeno-associated virus type 2 genome in cervical carcinoma

“…The reverse was seen at high AAV MOI. Thus, suggesting that AAV may have a significant effect upon the kinetics of HPV life cycle regulation in the natural host tissue, where the exact mechanism behind the interaction effect is still largely unknown (Meyers et al, 2001;Agrawal et al, 2002).…”

Adeno-Associated Virus Type 2 Increases Proteosome-Dependent Degradation of p21WAF1in a Human Papillomavirus Type 31b-Positive Cervical Carcinoma Line

“…From each sample, a 500-l aliquot of the supernatant was removed and added to 125 l 5ϫ sample loading buffer (100 mM Tris, pH 8.0, 5 mM EDTA, 10% [wt/vol] sucrose, 2% [wt/vol] SDS, 33 mM DTT, and 0.1 mg/ml pyronin Y). Total protein concentrations were measured using the Peterson protein assay (Lowry method) as previously described (50).…”

“…The tumor-suppressive activities of AAV2 against HPV were first demonstrated by its ability to inhibit bovine papillomavirus (33), as well as HPV-induced transformation in culture (32,34). We have recently demonstrated that AAV2 inhibits HPV type 31b (HPV31b) DNA replication in the differentiation-dependent raft culture system, concomitant with active AAV2 replication as well as infectious AAV2 progeny virion production (50). We also reported that HPV provides enhancer/helper functions for AAV2 replication (50), as our laboratory was also the first to demonstrate that AAV2 is capable of autonomous replication and progeny virion formation in the differentiation-dependent raft culture system, in the absence of any known helper viruses (52).…”

“…We have recently demonstrated that AAV2 inhibits HPV type 31b (HPV31b) DNA replication in the differentiation-dependent raft culture system, concomitant with active AAV2 replication as well as infectious AAV2 progeny virion production (50). We also reported that HPV provides enhancer/helper functions for AAV2 replication (50), as our laboratory was also the first to demonstrate that AAV2 is capable of autonomous replication and progeny virion formation in the differentiation-dependent raft culture system, in the absence of any known helper viruses (52). In parallel, in vivo evidence suggested the possibility of an AAV-HPV interaction based on the finding that DNA of both viruses coexists in the same cervical epithelial lesion (76), as well as in penile condylomatous lesions (3).…”