Kidney Week

Abstract: SA-PO647

Proximal Tubule-Targeted Adeno-Associated Virus (AAV) Gene Therapy for Cystinuria

Session Information

• Genetic Kidney Diseases: Models, Mechanisms, and Therapies
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Genetic Diseases of the Kidneys

• 1202 Genetic Diseases of the Kidneys: Non-Cystic

Authors

• Peek, Jennifer L., Vanderbilt University Medical Scientist Training Program (MSTP), Nashville, Tennessee, United States

Jennifer L. Peek

• Rosales, Alan, Duke University Department of Biomedical Engineering, Durham, North Carolina, United States

Alan Rosales, MS

• Qi, Julie, Vanderbilt University Division of Nephrology and Hypertension, Nashville, Tennessee, United States

Julie Qi

• Menshikh, Anna, Vanderbilt University Division of Nephrology and Hypertension, Nashville, Tennessee, United States

Anna Menshikh

• Welch, Richard C., Vanderbilt University Division of Nephrology and Hypertension, Nashville, Tennessee, United States

Richard C. Welch

• Bock, Fabian, Vanderbilt University Division of Nephrology and Hypertension, Nashville, Tennessee, United States

Fabian Bock, MD, PhD

• Woodard, Lauren Elizabeth, Vanderbilt University Division of Nephrology and Hypertension, Nashville, Tennessee, United States

Lauren Elizabeth Woodard, PhD

• Asokan, Aravind, Duke University Department of Biomedical Engineering, Durham, North Carolina, United States

Aravind Asokan, PhD

• Wilson, Matthew H., Vanderbilt University Division of Nephrology and Hypertension, Nashville, Tennessee, United States

Matthew H. Wilson, MD, PhD

Background

Gene therapy for kidney disease remains a challenge primarily due to lack of gene delivery. Cystinuria, the most common inherited kidney stone disorder, results from deficiency of cystine transport and reabsorption in the proximal tubule. Cystinuria patients suffer from cystine stones, obstruction, and CKD development; effective treatments are lacking for this lifelong disease. We have previously shown significant reductions in urinary cystine levels in murine models of type A (Slc3a1^-/-) cystinuria through plasmid delivery of Slc3a1, which encodes rBAT. However, gene transfer was estimated to be <5% of proximal tubular epithelial cells (PTECs) and therefore did not affect stone formation.

Methods

Recent innovations in viral vectors have improved kidney transduction. With novel adeno-associated viruses (AAV) including AAV.cc47, we have shown efficient kidney delivery in vivo, in vitro, and in human kidney organoids. We have used AAV.cc47 to deliver fluorescent reporters and therapeutic transgenes in both healthy and cystinuric mice. Immunofluorescence analysis and statistics were performed in QuPath and GraphPad Prism, respectively.

Results

We observed that AAV.cc47 consistently targeted the kidney, with >80% of PTECs transduced in all mice injected with at least 1x10¹¹ viral genomes (p=0.0011). Further quantification revealed a dose-dependent increase in the % transduced PTECs and strength of transduction. We next identified AAV.cc47 specifically targets S1 and S2 PTECs in the kidney, as >90% of all transduced cells were SGLT2+ (p=0.0009). Finally, we have shown rBAT expression post-delivery of AAV.cc47-Slc3a1 to cystinuric mice and investigation of phenotypic changes is ongoing.

Conclusion

We have shown Slc3a1 gene delivery for type A cystinuria gene therapy in vivo utilizing a proximal tubule-targeted vector, AAV.cc47. Phenotypic correction of a kidney disease remains a challenge, but our current efforts to optimize the delivery and stable expression of desired transgenes provide hope for overcoming the barriers to kidney gene therapy.

Funding

• NIDDK Support