Recombinant DNA Advisory Committee - 3/3^/94 
employed by the same institution as Dr. Walker, NIH. 
VII. ADDITION TO APPENDIX D OF THE NIH GUIDELINES REGARDING A HUMAN 
GENE TRANSFER PROTOCOL ENTITLED: EXPRESSION OF AN EXOGENOUSLY 
ADMINISTERED HUMAN ALPHA- 1 ANTITRYPSIN GENE IN THE RESPIRATORY 
TRACT OF HUMANS/DiL BRIGHAM 
Review-Dr. Parkman 
Dr. Walters called on Dr. Parkman to present his primary review of the protocol 
submitted by Dr. Kermeth L Brigham of Vanderbilt University, Nashville, Tennessee. 
Dr. Parkman stated that the alpha-l-antitrypsin (AAT) protein is produced by normal 
lung cells to neutralize the damaging proteolytic enzymes. Two clinical settings are 
proposed for this study: (1) patients who have inherited a congenital defect which 
prohibits AAT production, and (2) patients with adult respiratory distress syndrome. 
Patients who inherit a defective AAT gene develop emphysema at an early age. Patients 
with adult respiration distress syndrome release large amounts of digestive enzymes that 
can overwhelm the protective effect of AAT as a result of infection, trauma, etc. The 
basis of this proposal is that lung cells may be protected from the damaging effects of 
excessive levels of digestive enzymes, whether from an inherited deficiency or as a result 
of acute damage, by genetically modifying these cells to produce increased levels of 
AAT. The investigators propose to transfer the AAT gene into the nasal and lower 
airway cells using a plasmid DNA/liposome delivery system. The non-viral plasmid 
DNA construct, pCMV4-AAT, consists of promoters, enhancers, and RNA processing 
sites for the expression of human AAT. Individuals with congenital AAT deficiency will 
be monitored for local AAT expression following administration of pCMV4-AAT to the 
nasal mucosa. Patients scheduled for partial or total lung resection for cancer within 2 
or 3 days will be monitored for the presence and expression of pCMB4-AAT in resected 
lung tissue. 
Dr. Parkman explained that the gene delivery approach is very similar to the methods 
used for the cystic fibrosis protocols that were previously approved by the RAC. 
However, the investigators have submitted insufficient data demonstrating transduction 
efficiency and adequate expression of the AAT gene. Transduction efficiency was 
successfully demonstrated in the cystic fibrosis protocols by visualization of the blue color 
which resulted from the transduction of the reporter gene, p-galactosidase, on the surface 
of the trachea and lung. Although the investigators have provided immunohistochemical 
data on cross sections of lung tissue for the current proposal, it is difficult to estimate the 
percentage of epithelial cells that express the AAT gene. The investigators' written 
response to Dr. Parkman's concerns state that in contrast to the cystic fibrosis 
transmembrane conductance regulator protein, AAT is a secreted protein; therefore, the 
efficacy of gene transfer will depend more on the localization and quantity of protein 
expressed than on the fraction of cells transfected. Dr. Parkman reiterated his 
predilection regarding demonstration of efficient transduction and its importance for this 
in vivo gene transfer experiment. A preferable method would be to stain for the 
expression of the transgene in the mucosal surface of a resected bronchus to estimate the 
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