Engineered RNA Molecules and Computational Design Methods for Inhibiting Viral Replication and Activating Innate Immunity

Background

The field of antiviral therapeutics and innate immune modulation is of critical importance due to the persistent threat posed by negative-sense RNA viruses, such as influenza, Ebola, and Nipah. These viruses are responsible for significant morbidity and mortality worldwide, with seasonal epidemics and sporadic outbreaks that can rapidly escalate into public health emergencies. Traditional approaches, such as vaccines and small-molecule antivirals, often face challenges including lengthy development timelines, limited efficacy against emerging strains, and the potential for resistance. There is a pressing need for novel strategies that can both directly inhibit viral replication and enhance the host’s innate immune response, providing broad-spectrum and rapid protection, especially during the early stages of outbreaks or in high-risk populations.

Current antiviral methods primarily target viral proteins or processes essential for replication, but these approaches are frequently undermined by the high mutation rates of RNA viruses, leading to drug resistance and reduced long-term effectiveness. Additionally, many existing therapeutics do not sufficiently stimulate the host’s innate immune system, which is crucial for early containment of infection and for shaping adaptive immunity. While some research has explored the use of defective interfering RNAs or natural viral RNA fragments to modulate infection, these strategies often lack specificity, reproducibility, and scalability. Furthermore, the design of RNA-based therapeutics is hampered by the complexity of RNA secondary structures and the difficulty of predicting their interactions with viral and host factors, limiting the ability to rapidly develop effective agents against diverse or newly emerging viruses.

Technology

This technology centers on engineered RNA molecules, 52 to 71 nucleotides in length, designed to inhibit the replication of negative-sense RNA viruses and simultaneously activate the host’s innate immune response. The core feature is a hairpin structure called a “template loop” (t-loop), consisting of a loop of about 20 nucleotides—matching the viral RNA polymerase footprint—supported by a stem of at least 5 base pairs and flanked by viral promoter sequences. When introduced into cells, these RNAs stall the viral RNA polymerase during transcription, reducing viral RNA synthesis and generating aberrant RNA fragments. These fragments are recognized by the host’s RIG-I receptor, leading to robust production of interferon-beta and activation of innate immunity. The technology includes a computational algorithm that uses a sliding window and free energy calculations to design and optimize t-loop sequences for a wide range of negative-sense RNA viruses, such as influenza, Ebola, and Nipah.

What differentiates this technology is its dual-action mechanism and the integration of computational design. Unlike traditional antivirals or vaccine adjuvants, these synthetic RNAs not only directly inhibit viral replication by physically stalling the viral polymerase, but also act as potent immune stimulators by generating RNA species that trigger innate immune sensors. The approach is highly adaptable, leveraging a Python-based algorithm that rapidly identifies and optimizes effective t-loop sequences based on viral genome data, enabling swift responses to emerging viral threats. Experimental validation demonstrates that these engineered RNAs are poorly replicated by viral polymerases yet strongly induce interferon responses, and the computational predictions closely match laboratory outcomes. This combination of targeted molecular engineering and predictive computational modeling sets the technology apart as a versatile platform for both therapeutic and prophylactic antiviral strategies.

Benefits

• Potent inhibition of viral RNA polymerase activity, reducing viral replication.
• Robust activation of the host innate immune response via RIG-I receptor stimulation and interferon-beta production.
• Broad applicability against multiple negative-sense RNA viruses, including influenza, Ebola, and Nipah.
• Computational algorithm enables rapid in silico design and optimization of effective RNA sequences.
• Enhances vaccine efficacy by serving as adjuvants in live-attenuated vaccines.
• Potential for rapid deployment as antiviral therapeutics or protective agents during viral outbreaks.
• Customizable RNA structures allow tuning of inhibitory strength and immune activation.

Applications

• Antiviral therapeutics for RNA viruses
• Adjuvants for live-attenuated vaccines
• Rapid outbreak response agents
• Prophylactic protection for healthcare workers
• Computational RNA therapeutic design services

Additional info

These 52–71 nucleotide engineered RNAs utilize a hairpin “template loop” to stall viral RNA polymerase. Featuring a 20-nucleotide loop and a stem ≥5 base pairs, they inhibit negative-sense RNA virus replication. This stalling produces aberrant RNA that triggers host RIG-I receptors, stimulating interferon-beta production. Optimized through computational algorithms, these molecules function as dual-action antivirals and immune activators against pathogens like influenza, Ebola, and Nipah.