In vitro inhibition of the hepatitis delta virus replication mediated by interferon and trans-ribozyme or antisense probes.
OBJECTIVE
In this study, the inhibition of hepatitis delta virus replication mediated by trans-ribozyme and antisense probes, alone or in combination with recombinant interferon alpha-2a, has been assayed.


METHODS
A 60-nucleotide-long designed trans-ribozyme, which contains the catalytic core of the hammerhead ribozyme, and a 163-nucleotide-long antisense probe were directed against the same region of the viral genome in in vitro and cell culture systems.


RESULTS
The ribozyme activity, assayed in a chemically isolated system, resulted in the trans-cleavage of 10-20% of the 40-nucleotide-long RNA substrate. A 5-nucleotide deletion in one of the flanking arms, obtained by random mutagenesis, resulted in enhancement of the trans-cleavage activity in as many as 40-60% of the substrate molecules. The efficiency of the optimized trans-ribozyme and antisense probes against the complete viral genome was assayed in a cell culture system. The inhibitory efficacy (25%) of the trans-ribozyme is lower than that of the antisense probe (35%) or interferon at 1000 U/ml (47%). An enhancement of the interferon efficacy was achieved when it was administered in cells having a previous basal expression of ribozyme (70%) or antisense probes (83%).


CONCLUSIONS
These results suggest that the combination of ribozyme or antisense probes with interferon could be a promising approach to the treatment of RNA virus infections.
Madejón
A
A
Hepatology Unit, Fundación Jiménez Díaz, Madrid, Spain.
Bartolomé
J
J
Carreño
V
V
D015088:2',5'-Oligoadenylate Synthetase / Q000187:drug effects; D016375:Antisense Elements (Genetics) / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use*; D001483:Base Sequence; D004359:Drug Therapy, Combination; D016679:Genome, Viral; D003698:Hepatitis Delta Virus / Q000187:drug effects*; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016337:RNA, Catalytic / Q000627:therapeutic use; D012367:RNA, Viral / Q000096:biosynthesis; D011994:Recombinant Proteins; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured; D014779:Virus Replication / Q000187:drug effects*
D016375:Antisense Elements (Genetics); D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D016337:RNA, Catalytic; D012367:RNA, Viral; D011994:Recombinant Proteins; D015088:2',5'-Oligoadenylate Synthetase