Background: T lymphocytes are important mediators of ischemia reperfusion injury (IRI) during organ transplantation. Using genetically engineered mice, we demonstrated that augmentation of Nrf2 dependent antioxidant response in T lymphocytes significantly protects during IRI in kidney and heart. To develop clinically translatable T cell specific antioxidant therapy, we used CRISPR technology to delete Keap1, the inhibitor of Nrf2, in human T cells, Jurkat cells.

Methods: We targeted exon 2 of Keap1 gene at three different loci using loci specific guide RNA. Briefly, 2X10⁵ Jurkat T cell were electroporated 1.5[micro]g of Cas9 nuclease protein and 350ng of target site specific guide RNA using a Neon transfection system at 1700V/20ms/1 pulse. Control cells were electroporated in the absence of cas9 protein/guide RNA complex. Cell were harvested 48h and 72h after electroporation and assessed for cell number and viability, quantification of Keap1 gene editing using genomic cleavage detection (GCD) assay and quantitative real-time PCR based Nrf2 target gene expression analysis.

Results: Electroporation of Cas9 protein/guide RNA complex in to Jurkat T cell using Neon transfection system had no effects on cell expansion either at 48h or 72h and ≥ 95% cells were viable. Furthermore, GCD analysis showed editing of Keap1 gene in 19%, 12% and 26% cells using guide RNA against target site 1, 2 and 3 respectively, 48h after electroporation. GCD analysis, 72h post electroporation showed 10%, 20% and 42% Keap1 editing at target site 1, 2 and 3 respectively. Further quantitative real-time PCR based studies showed significant increases in Nrf2 targets Nqo1 (upto 8 fold) and Gclm (upto 7 fold) mRNA at 48h (p≤0.05, p≤0.001 and p≤0.01) and 72h (p≤0.001, p≤0.01 and p≤0.01) following Keap1 deletion at target site 1, 2 and 3 respectively, compared to untreated control cells.

Conclusions: These data demonstrate that targeting Keap1 exon 2 using CRISPR technology increases Nrf2 regulated antioxidant response in human T cells. Primary T cells specific augmentation of antioxidant response could improve immune cell based therapy for IRI during transplantation and may also help reduce allograft rejection.

CITATION INFORMATION: Noel S, Lee S, Sadasivam M, Hamad A, Rabb H. Gene Editing of Keap1/Nrf2 in Human T Cells Using CRISPR-Cas9 to Improve Outcome from Ischemia Reperfusion Injury and Other T Cell Mediated Diseases. Am J Transplant. 2017;17 (suppl 3).

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