Anticipating the Next Chess Move: Blocking SARS-CoV-2 Replication and Simultaneously Disarming Viral Escape Mechanisms

Abstract

The COVID-19 pandemic initiated a race to determine the best measures to control the disease and to save as many people as possible. Efforts to implement social distancing, the use of masks, and massive vaccination programs turned out to be essential in reducing the devastating effects of the pandemic. Nevertheless, the high mutation rates of SARS-CoV-2 challenge the vaccination strategy and maintain the threat of new outbreaks due to the risk of infection surges and even lethal variations able to resist the effects of vaccines and upset the balance. Most of the new therapies tested against SARS-CoV-2 came from already available formulations developed to treat other diseases, so they were not specifically developed for SARS-CoV-2. In parallel, the knowledge produced regarding the molecular mechanisms involved in this disease was vast due to massive efforts worldwide. Taking advantage of such a vast molecular understanding of virus genomes and disease mechanisms, a targeted molecular therapy based on siRNA specifically developed to reach exclusive SARS-CoV-2 genomic sequences was tested in a non-transformed human cell model. Since coronavirus can escape from siRNA by producing siRNA inhibitors, a complex strategy to simultaneously strike both the viral infectious mechanism and the capability of evading siRNA therapy was developed. The combined administration of the chosen produced siRNA proved to be highly effective in successfully reducing viral load and keeping virus replication under control, even after many days of treatment, unlike the combinations of siRNAs lacking this anti-anti-siRNA capability. Additionally, the developed therapy did not harm the normal cells, which was demonstrated because, instead of testing the siRNA in nonhuman cells or in transformed human cells, a non-transformed human thyroid cell was specifically chosen for the experiment. The proposed siRNA combination could reduce the viral load and allow the cellular recovery, presenting a potential innovation for consideration as an additional strategy to counter or cope COVID-19.

Endogenous piRNAs Can Interact with Omicron Variant of the SARS-CoV-2 Genome

“…Such a large value of ΔG is also associated with the length of piRNAs from 28 nt to 31 nt. These spiRNAs, fully complementary to gRNAs, are identical in function to widely used siRNAs that cause inhibition of viral RNA protein synthesis [49][50][51][52][53]. These examples demonstrate the possibility of creating drugs that suppress the reproduction of coronavirus in human cells.…”

“…Each of these spiRNAs will reliably block both synthesis of the protein encoded by the spiRNAs target and gRNA replication. The effectiveness of spiRNAs is expected to be the same as in many experiments using synthetic interfering siRNA molecules [49][50][51][52][53].…”

Endogenous piRNAs Can Interact with the Omicron Variant of the SARS-CoV-2 Genome

“…Each of these spiRNAs will reliably block both the synthesis of the protein encoded by the spiRNAs target and gRNA replication. The effectiveness of spiRNAs is expected to be the same as in many experiments using synthetic interfering siRNA molecules [ 51 , 52 , 53 , 54 , 55 ].…”

RNA Interference Approach Is a Good Strategy against SARS-CoV-2

“…Therefore, we suggest using the shRNA cocktail to provide better protection or therapeutic effects for COVID-19 [ 31 ]. Four siRNAs have been demonstrated to bind complementary sequences in the SARS-CoV-2 genome and presented in every clinically relevant published SARS-CoV-2 genome, including variants α, β, γ, and Omicron, effectively reducing viral load [ 32 ]. Moreover, a siRNA formulation with an available delivery/adjuvant—such as intranasal administration in clinical settings—may serve as a powerful prophylactic or therapeutic application.…”