Modulation of mRNA Translation and Cell Viability by Influenza A Virus Derived Nonstructural Protein 1

Area of Science:

• Molecular Biology
• Immunology
• Virology

Background:

• In vitro transcribed messenger RNA (mRNA) translation is often hindered by cellular innate immune responses.
• Influenza A virus nonstructural protein 1 (NS1) is known for its immune evasion properties.

Purpose of the Study:

• To investigate the impact of co-delivering mRNA encoding NS1 with other mRNA payloads on protein expression and cellular responses.
• To determine if NS1 can enhance mRNA translation and mitigate transfection-associated toxicity.

Main Methods:

• Co-delivery of mRNA encoding NS1 and reporter proteins (GFP, luciferase) in various interferon-competent cell types.
• Assessment of reporter protein expression levels.
• Measurement of interferon production.
• Evaluation of cellular toxicity associated with mRNA transfection.
• Investigation of NS1's role in modulating cleavage and polyadenylation specificity factor 30 kDa (CPSF30) function.

Main Results:

• Co-delivery of NS1 mRNA with GFP mRNA significantly increased GFP expression across four cell types within 6 hours.
• Enhanced mRNA translation correlated with reduced interferon production.
• Substituting a portion of luciferase mRNA with NS1 mRNA increased luciferase production in a cell-type-specific manner.
• NS1 mRNA delivery mitigated toxicity from unmodified mRNA transfection, except when NS1 inhibited CPSF30.
• NS1 with CPSF30 inhibition function exacerbated toxicity.

Conclusions:

• NS1 enhances mRNA translation by actively evading innate immune responses.
• NS1 modulates cellular viability during mRNA transfection, offering a strategy to improve mRNA delivery efficacy and safety.
• The immune evasion function of NS1 is crucial for its beneficial effects on mRNA translation and toxicity reduction.