Inhibition of replication and transcription activator and latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus by morpholino oligomers.
Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with Kaposi's sarcoma and primary effusion lymphoma (PEL). The KSHV replication and transcription activator (RTA) and latency-associated nuclear antigen (LANA) play key roles in activating KSHV lytic replication and maintaining KSHV latency, respectively. Phosphorodiamidate morpholino oligomers (PMO) are similar to short single-stranded DNA oligomers, but possess a modified backbone that confers highly specific binding and resistance to nucleases. In this study, RTA and LANA mRNA in PEL cells were targeted by antisense peptide-conjugated PMO (P-PMO) in an effort to suppress KSHV replication. Highly efficient P-PMO uptake by PEL cells was observed. Treatment of PEL cells with a RTA P-PMO (RP1) reduced RTA expression in a dose-dependent and sequence-specific manner, and also caused a significant decrease in several KSHV early and late gene products, including vIL-6, vIRF-1, and ORF-K8.1A. KSHV viral DNA levels were reduced both in cells and culture supernatants of RP1 P-PMO-treated cells, indicating that KSHV lytic replication was suppressed. Treatment of BCBL-1 cells with P-PMO against LANA resulted in a reduction of LANA expression. Cell viability assays detected no cytotoxicity from P-PMO alone, within the concentration range used for the experiments in this study. These results suggest that RP1 P-PMO can specifically block KSHV replication, and further study is warranted.
Zhang
Yan-Jin
YJ
Center for Pediatric Research, Eastern Virginia Medical School, Norfolk, VA 23510, USA. zhangyj@umd.edu
Wang
Kai-Yu
KY
Stein
David A
DA
Patel
Deendayal
D
Watkins
Rheba
R
Moulton
Hong M
HM
Iversen
Patrick L
PL
Matson
David O
DO
D000956:Antigens, Viral; D001483:Base Sequence; D045744:Cell Line, Tumor; D004261:DNA Replication / Q000187:drug effects; D015967:Gene Expression Regulation, Viral; D019288:Herpesvirus 8, Human / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D006801:Humans; D017874:Immediate-Early Proteins / Q000037:antagonists & inhibitors* / Q000187:drug effects; D008969:Molecular Sequence Data; D009025:Morpholines / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D060172:Morpholinos; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors*; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000187:drug effects; D014764:Viral Proteins / Q000037:antagonists & inhibitors* / Q000187:drug effects; D017735:Virus Latency / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects*
D000956:Antigens, Viral; D017874:Immediate-Early Proteins; D009025:Morpholines; D060172:Morpholinos; D009687:Nuclear Proteins; C417604:Rta protein, Human herpesvirus 8; D015534:Trans-Activators; D014764:Viral Proteins; C109540:latency-associated nuclear antigen