Biochemical Correction of Very Long-Chain Acyl-CoA Dehydrogenase
Deficiency Following Adeno-associated Virus Gene Therapy.
J. Lawrence Merritt, II, M.D.1*
Tien Nguyen, Ph.D. 2
Jan Daniels2
Dietrich Matern, M.D.2,3
David B. Schowalter, M.D., Ph.D.2
SUPPLEMENTAL INFORMATION
SUPPLEMENTARY MATERIALS AND METHODS
Vector Production, Purification, & Characterization. Recombinant AAV were produced
by triple co-transfection on AAV-293 cells (#240073, Stratagene, LaJolla, CA) at 50%
confluency in forty 20 cm culture dishes. We had previously cloned the human VLCAD
cDNA into the pCMV-MCS plasmid (Stratagene) containing the CMV promoter and a
human growth hormone polyA (hGHpA) sequence.1 The pseudotyped AAV vector,
AAV8-hVLCAD, was then generated using pHelper (Stratagene) and an AAV plasmid
containing a AAV serotype 8 cap sequence, p5E18-VD2/8, using with Trans-IT 293
Transfection reagent (Mirus, Madison, WI). After 72 hour incubation cells were
harvested, freeze-thawed three times, sonicated, incubated with Benzonase (E101525KU, Sigma), precipitated in calcium chloride, triple purified on a cesium chloride
gradient, desalted using an Amicon Ultra – 15 100,000 MWCO centrifugal filter device
(Millipore, Bedford, MA) with sterile phosphate buffered saline (PBS) and 5% sorbitol,
aliquoted, and stored at –80°C. Staining of viral proteins was done by boiling 50 μl of
purified virus stock with 50 μl of 2X Loading dye (Bio-Rad, Hercules, CA) for 10
minutes, loading on a 10% PAGE gel, fixing the gel in 30% ethanol and 10% acetic acid
overnight, three rinses in deionized water for ten minutes with gentle rotation, and final
staining per the manufacturer’s guidelines (Bio-Rad). Electron microscopy was done
using a transmission electron microscopy at the Mayo Clinic Electron Microscopy Core
Facility.
Quantitative Analysis. A modified quantification protocol as described by Potter and
colleagues 2 was completed using a 4 μl aliquot of purified virus stock incubated in 10 U
DNaseI in 200 μl 50 mM Tris-HCl, 10 mM MgCl2 at pH 7.5 for one hour at 37°C
followed by addition of 20 μl of 40 μg Proteinase K in 10 mM Tris-HCl, 10 mM EDTA,
1% SDS at pH 8.0 for one hour at 37°C and then quantification by PCR. Reverse
transcriptase was performed by extracting RNA from flash-frozen liver tissue using
RNeasy Mini Kit combined with the QIA Shredder kit, and RNase-Free DNase Set
(QIAGEN, Valencia, CA) per the manufacturer's recommendations. Genomic DNA was
purified from frozen liver tissue using the Puregene DNA purification per the
manufacturer’s recommendations (QIAGEN). Viral genome quantification was
performed using real-time qPCR with Brilliant® QRT_PCR Master Mix Kit (Stratagene,
Cedar Creek, TX) and a primer and TaqMan® (Applied Biosystems, Foster City, CA)
probe set targeted to amplify the hGHpA region of the pCMV-MCS plasmid (F: 5’-CTG
GGT TCA AGC GAT TCT CC; R: 5’-ATG CAT GAC CAG GCT CAG CT; PB: 5’FAM-TGC CTC AGC CTC CCG AGT TGT TG) on an Applied Biosystems 7900HT
Fast Real-Time PCR System. Standard curves were performed using pCMV-MCS at
seven concentrations. Quantitative PCR conditions were set to 95°C for ten minutes then
repeated for 40 cycles at 95°C for 30 seconds and 58°C for one minute. Reverse
transcriptase-qPCR was performed using Power SYBR Green PCR Master Mix Kit and
GADPH primer set (Applied Biosystems).
SUPPLEMENTARY REFERNCES
1.
Merritt JL, 2nd, Matern D, Vockley J, Daniels J, Nguyen TV, Schowalter DB. In
vitro characterization and in vivo expression of human very-long chain acyl-CoA
dehydrogenase. Mol Genet Metab 2006; 88(4): 351-358.
2.
Potter M, Chesnut K, Muzyczka N, Flotte T, Zolotukhin S. Streamlined largescale production of recombinant adeno-associated virus (rAAV) vectors. Methods
Enzymol 2002; 346: 413-430.