Aptamers for Anti-Viral Therapeutics and Diagnostics

Abstract

Viral infections cause a host of fatal diseases and seriously affect every form of life from bacteria to humans. Although most viral infections can receive appropriate treatment thereby limiting damage to life and livelihood with modern medicine and early diagnosis, new types of viral infections are continuously emerging that need to be properly and timely treated. As time is the most important factor in the progress of many deadly viral diseases, early detection becomes of paramount importance for effective treatment. Aptamers are small oligonucleotide molecules made by the systematic evolution of ligands by exponential enrichment (SELEX). Aptamers are characterized by being able to specifically bind to a target, much like antibodies. However, unlike antibodies, aptamers are easily synthesized, modified, and are able to target a wider range of substances, including proteins and carbohydrates. With these advantages in mind, many studies on aptamer-based viral diagnosis and treatments are currently in progress. The use of aptamers for viral diagnosis requires a system that recognizes the binding of viral molecules to aptamers in samples of blood, serum, plasma, or in virus-infected cells. From a therapeutic perspective, aptamers target viral particles or host cell receptors to prevent the interaction between the virus and host cells or target intracellular viral proteins to interrupt the life cycle of the virus within infected cells. In this paper, we review recent attempts to use aptamers for the diagnosis and treatment of various viral infections.

The Possibility of Nucleic Acids to Act as Anti-Viral Therapeutic Agents—A Review

“…Aptamers might be used not only to treat the infection, but also to prevent it-viral infection can be inhibited in almost any step of the disease. Many studies confirmed that the most effective therapeutic strategy is to block the penetration of viruses into the cells and/or inhibition of enzymes involved in their replication (Figure 18) [94]. They are suitable subjects of structural modifications as in vivo biostability improvement and conjugation with other therapeutic molecules, such as s mall interfering RNA (siRNA) and ribozymes [95] [96].…”

Aptamer Applications in Emerging Viral Diseases

“…As possible strategies for therapy, aptamers may block the entry of viral particles into host cells by either competing with binding to host cell receptors or virus entry proteins [ 130 ]. On the other site, intracellular virus targeting by aptamers is also a promising strategy [ 131 ]. Aptamers were developed for blocking nucleocapsid assembly or targeting proteins involved in viral replication, such as SARS CoV NTPase/helicase [ 117 ], HIV reverse transcriptase [ 132 ], and hepatitis C virus (HCV) RNA polymerase [ 133 ], among other examples.…”

Aptamers for Viral Detection and Inhibition

“…In Table 1 , we briefly summarize the pros and cons of using aptamers for virus detection and inhibition when compared with antibody-based methods. 22 − 24 …”

“…Also, aptamers are quickly excreted by renal filtration from the bloodstream and thus need to be attached to other higher-molecular-weight molecules such as cholesterol or polyethylene glycol for prolonged bioavailability when used as diagnosis/imaging reagents or as part of drug complexes. In Table , we briefly summarize the pros and cons of using aptamers for virus detection and inhibition when compared with antibody-based methods. − …”