Engineering of SauriCas9 with enhanced specificity

Area of Science:

• Molecular Biology
• Gene Editing Technologies
• Biotechnology

Background:

• SauriCas9 is a compact Cas9 nuclease with potential for in vivo therapeutics.
• Off-target effects are a major concern for Cas9 specificity in therapeutic applications.
• Enhancing specificity is crucial for the safe and effective use of gene editing tools.

Purpose of the Study:

• To improve the specificity of the SauriCas9 nuclease.
• To develop a SauriCas9 variant with reduced off-target effects.
• To validate the efficacy of the enhanced SauriCas9 variant in gene disruption for CAR-T cell therapy.

Main Methods:

• Introduced mutations to SauriCas9 to eliminate polar contacts with target DNA, creating the SauriCas9-R253A variant.
• Utilized SauriCas9-R253A to disrupt key genes (B2M, TRAC, PDCD1) essential for allogeneic CAR-T cell therapy.
• Assessed gene disruption efficiency and evaluated off-target effects using sensitive detection methods.

Main Results:

• The SauriCas9-R253A variant demonstrated enhanced specificity compared to the wild-type.
• Efficient disruption of B2M, TRAC, and PDCD1 genes was achieved using SauriCas9-R253A.
• No detectable off-target effects were observed for the most efficient single-guide RNAs with SauriCas9-R253A.

Conclusions:

• SauriCas9-R253A represents a significant advancement in Cas9 specificity for gene editing.
• The enhanced specificity of SauriCas9-R253A supports its potential for safe in vivo therapeutic applications.
• This improved nuclease is a promising tool for developing next-generation CAR-T cell therapies.