Synthetic Oligonucleotide Compositions for Activating RNase L Pathway to Induce Targeted Cell Death and Immunity

Background

The field of innate immunity has long been a focus of research for developing therapies against cancer and viral infections. Central to this area is the activation of cellular pathways that can recognize and eliminate abnormal or infected cells. One of the most potent mechanisms involves the 2′-5′-oligoadenylate synthetase (OAS)/RNase L pathway, which, when triggered, leads to the degradation of cellular RNA, inhibition of protein synthesis, and induction of apoptosis. Traditionally, this pathway is activated through interferon (IFN) signaling, a cornerstone of the body’s antiviral and anti-tumor defenses. However, the broad and sometimes unpredictable effects of IFN-based therapies, including their ability to modulate immune responses, have highlighted the need for more targeted approaches that can harness the power of innate immunity without the drawbacks of systemic immune activation.

Current approaches that rely on interferon signaling to activate the OAS/RNase L pathway face significant limitations. IFN therapies, while effective at inducing antiviral and anti-tumor responses, often result in the upregulation of immunosuppressive genes, which can dampen the overall immune response and reduce therapeutic efficacy. Additionally, IFN treatment is associated with a range of adverse effects, including flu-like symptoms, fatigue, and, in some cases, severe autoimmune reactions. These side effects limit the dosage and duration of IFN therapy, reducing its utility for chronic or aggressive diseases. Furthermore, the reliance on Dicer and other components of the RNA interference machinery introduces variability and potential resistance in target cells. As a result, there is a critical need for strategies that can selectively activate the RNase L pathway without engaging the broader, and often counterproductive, effects of interferon signaling.

Technology

This technology centers on synthetic DNA oligonucleotides, designed with phosphorothioate linkages and 2’-O-methyl RNA modifications at their termini, to precisely activate the RNase L pathway for therapeutic purposes. These oligonucleotides, ranging from 10 to 100 bases and available as single- or double-stranded molecules, are engineered to induce a cellular stress response that generates immunogenic double-stranded RNA. This RNA is sensed by OAS3, which then activates RNase L, leading to the cleavage of ribosomal and transfer RNA, inhibition of protein synthesis, and induction of apoptosis in target cells such as tumors or virus-infected cells. The chemical modifications—phosphorothioate linkages and 2’-O-methyl RNA bases—are essential for this activity, and the oligonucleotides are designed to avoid homology with mammalian genomes, minimizing off-target effects. These molecules can be formulated for various delivery routes, including oral, injectable, or nanoparticle-based systems, and can be used alone or in combination with other therapies.

What differentiates this technology is its ability to activate the RNase L pathway independently of interferon signaling and Dicer activity, thereby circumventing the immunosuppressive effects commonly associated with interferon-based therapies. Unlike traditional approaches that rely on interferon to stimulate innate immune responses, these modified oligonucleotides directly induce the production of endogenous immunogenic dsRNA, triggering OAS3 and RNase L without upregulating interferon-stimulated genes. This results in potent anti-tumor and antiviral effects without the risk of secondary immune suppression. The sequence-independent mechanism allows for broad applicability and flexibility in design, while robust experimental validation confirms its specificity and efficacy. This unique combination of targeted immune activation, minimized side effects, and versatile delivery options positions the technology as a significant advancement in the treatment of cancer and viral infections.

Benefits

• Activates RNase L pathway independently of interferon signaling, avoiding immunosuppressive effects.
• Induces targeted apoptosis and inhibits protein synthesis in tumor and virus-infected cells.
• Utilizes chemically modified synthetic oligonucleotides for enhanced stability and efficacy.
• Stimulates innate immune responses without upregulating interferon-stimulated genes.
• Applicable for treating various cancers and viral infections, either as monotherapy or in combination with other treatments.
• Supports multiple administration routes and delivery systems for flexible therapeutic use.
• Demonstrated specificity and effectiveness confirmed by molecular and cellular experimental validation.

Applications

• Cancer therapeutics
• Antiviral therapies
• Combination immunotherapy regimens
• Targeted apoptosis induction

Additional info

These synthetic DNA oligonucleotides (10–100 bases) utilize phosphorothioate linkages and terminal 2’-O-methyl RNA modifications to activate the OAS3/RNase L pathway. By inducing cellular stress and endogenous immunogenic RNA, they bypass interferon signaling to trigger RNase L-mediated cleavage of ribosomal and transfer RNA. This inhibits protein synthesis and induces apoptosis in malignant or infected cells, suppressing proliferation without the upregulation of immunosuppressive genes.