Engineered circular RNA compatible with complete nucleoside modification and rolling circle translation through a...

Area of Science:

• Biotechnology
• Molecular Biology
• Immunology

Background:

• Circular RNA (circRNA) offers stability and protein expression advantages.
• Nucleoside modification and rolling circle translation (RCT) can improve circRNA efficiency and reduce immunogenicity.
• Producing modified, protein-encoding circRNA remains a challenge.

Purpose of the Study:

• To develop a novel system for producing scarless, nucleoside-modified circRNA.
• To leverage a black beetle virus (BBV) cap-independent translation enhancer (CITE) for efficient translation.
• To evaluate the therapeutic potential of modified circRNA in cancer, metabolic disorders, and autoimmune diseases.

Main Methods:

• Identification and application of the BBV CITE element.
• Development of an in vitro transcription (IVT) system for scarless circRNA production.
• Preclinical evaluation of modified circRNA vaccines and therapeutics in murine models.

Main Results:

• The BBV CITE facilitated translation of modified RNA and RCT of engineered circRNA.
• Nucleoside-modified circRNA vaccines inhibited tumor growth more effectively than m1ψ-mRNA vaccines.
• Modified circRNA therapies demonstrated efficacy in reducing blood glucose, ameliorating liver damage, and alleviating experimental autoimmune encephalomyelitis (EAE).

Conclusions:

• A versatile, nucleoside-modified circRNA platform was established, enabling efficient translation with minimal immunogenicity.
• This platform expands circRNA applications beyond vaccines into therapeutics for metabolic and autoimmune diseases.
• The developed circRNA technology presents a promising alternative to existing mRNA-based therapies.