News & Events

Eric Josephs, Ph.D.

Posted on October 21, 2022


Date - October 21, 2022
1:00 pm - 2:00 pm


Assistant Professor
Department of Nanoscience
UNC Greensboro
Talk title: Molecular Engineering of CRISPR Gene Editing and Antiviral Biotechnologies


CRISPR biotechnologies, where CRISPR effector proteins recognize and degrade specific nucleic acid targets that are complementary to their guide RNA (gRNA) cofactors, have been primarily used as a tool for precision gene editing but they also possess an emerging potential for novel antiviral diagnostics, prophylactics, and therapeutics. In this seminar, I will discuss the efforts in my laboratory during the COVID-19 pandemic to adapt the approaches we use for molecular engineering of CRISPR gRNAs for “ultra-specific” and high-precision gene editing applications toward applications of CRISPR with maximized antiviral activities. We do this by, instead, engineering gRNAs that are optimized to promote CRISPR activity at multiple viral target sites, simultaneously, given that multiplexed targeting of viral nucleic acids is a critical tactic for inhibiting viral infection, expanding the recognition of clinical strain variants, improving viral detection sensitivity, and limiting mutagenic escape. We find that these “polyvalent” gRNAs, which are able to target multiple viral sequences at the same time, robustly suppress viral propagation significantly better than their “monovalent” counterparts and can reduce in vivo viral RNA levels in the leaves of living plants (Nicotiana benthamiana) after viral infection by >99.5% compared to their untreated counterparts. in vitro, polyvalent gRNAs can be engineered to activate diverse DNA-targeting and RNA-targeting CRISPR effectors at viral sequences diverging by >25 – 40% sequence identity, including in diagnostic applications of SARS-CoV-2. Pairs of nucleotide sequences that are simultaneously CRISPR-targetable are abundant in the genomes of viruses across host range and viral families, and overall, the results presented represent a broadly applicable and powerful new paradigm for gRNA design in antiviral applications that can specifically address some of the differential requirements for CRISPR antivirals vs. precision gene editing.