Chimeric RNA-DNA Molecules-Based Anti-monkeypox Drug Discovery Solutions

What is Monkeypox Virus?

The monkeypox virus (MPXV), a double stranded DNA virus that belongs to the Orthopoxvirus genus of the Poxviridae family, was first detected in 1958 in an outbreak of a vesicular diseases in captive monkeys brought to Copenhagen, Denmark from Africa for research purposes. It has been found in rodents and squirrels and the specific host reservoir has not yet been identified. The extent of the host animal reservoir, the natural history, and pathogenesis of monkeypox in both animals and humans remains unknown and requires definition through case-control studies. In August 1970 the first human case of monkeypox was identified in a 9-year-old child with smallpox-like vesicular skin lesions in the village of Bukenda in the Equatorial region of Zaire.

Fig.1 Schematic diagram of monkeypox virus.

Mechanisms of RNA/DNA Chimeric Molecule Mediated Targeted Gene Correction

Targeted correction of disease-related mutations or site-directed inactivation of viral genes by homologous recombination is an effective strategy for gene therapy. In 1996, Yoon's group (Yoon, 1996) published an article that ushered in the era of RNA/DNA chimeric molecule-mediated gene correction. They proposed a gene targeting strategy, which uses the natural recombinogenicity of RNA-DNA hybrids to design vectors featured with double-hairpin capped ends to avoid destabilization or destruction by cellular helicases or exonucleases.

A chimeric oligonucleotide was designed so that it aligns in perfect register with a specified genomic target or in imperfect register such that a single base pair is different between the oligonucleotide and a specified targeted nucleotide. In the latter case, the structural distortion created by the mismatched base pair should be recognized by the endogenous repair systems, and a change in sequence on either chimeric oligonucleotide or the target sequence would ensue. An additional feature in the design of chimeric oligonucleotides was the modification of the RNA residues by 2'-O-methylation of the ribose sugar to render the oligonucleotide resistant to the RNaseH activity present in mammalian cells. Viral genes are potential targets for chimeric oligonucleotides as strategically placed mutations can be introduced into the episomal genome to inactivate key viral proteins.

Development of Anti-Monkeypox Drugs Based on RNA/DNA Chimeric Molecules

Currently, there are no specific clinically proven treatments for monkeypox infection. The emergence of RNA/DNA chimeric molecules has brought great possibilities for the realization of inhibition of monkeypox virus replication, implementation of that may require the following steps.

• Design of Chimeric DNA-RNA hammerhead ribozyme targeting MPXV.
• Synthesis of ribozymes and synthetic target viral RNA with T7 RNA polymeras.
• In vitro cleavage reactions with ribozyme.
• Evaluation of the effect of chimeric ribozyme on multiplication of MPXV.
• RNA Extraction and reverse transcription-polymerase chain reaction (RT-PCR) assay for MPXV, and statistical analysis.

At Creative Biolabs, we provide services related to the development of anti-monkeypox drugs to our clients all over the world for your research, if you are interested in our service, please feel free to contact us for more information.

Reference

1. Yoon, K.; et al. Targeted gene correction of episomal DNA in mammalian cells mediated by a chimeric RNA.DNA oligonucleotide. Proceedings of the National Academy of Sciences of the United States of America. 1996, 93(5): 2071-6.