A. Pretreatment - Baseline studies to test for the presence 
of retrovirus in the blood of the patient (S+L- , 3T3 rescue, 
antibody analysis of serum). 
B. Post- treatment - The following protocol might be modified slightly based 
on experience with the first few patients: 
1. Blood (20 ml, heparinized) 
a) Timing 
(1) 1 minute, 1 hour and days 1,2,3 and 7 
(2) Then monthly or with visits 
b) Analysis 
(1) Cells: See Section IV. D. above 
(2) Plasma: S+L- , 3T3 rescue, antibodies 
2. Tumor and lymph node biopsy 
a) Timing: See Section IV. C. above 
b) Analysis: See Section IV. D. above 
VIII. POTENTIAL RISKS OF RETRQVIRAL-MEDIATED GENE TRANSFER 
The following is a description of the theoretical risks associated 
with the retroviral -mediated gene transfer procedure described in 
this Addition. In simmary, the procedure should produce minimal, 
if any, risk to the patient, no risk to other patients, and no 
risk to health care personnel. 
A. Insertional Mutagenesis . 
Moloney murine leukemia virus (MoMLV) causes T cell lymphomas in 
certain Strains of mice. While malignancy secondary to insertion of retroviral 
vectors is a theoretical concern the actual risk is xinknown but is certainly very 
low. 
MoMLV contains enhancer regions within its LTR, that have a tropism for 
the mouse T cell. The majority of timors studied contain retroviral insertions 
near T cell specific protein kinases (10-13). Abnormal regulation of these proto- 
oncogenes occurs and is presumably important in malignant transformation. The 
specificity of the MoMLV enhancer for the mouse T cell has been shown by 
exchanging enhancer regions between MoMLV and Friend leukemia virus (14-17). The 
altered retroviruses confer malignancy associated with the parent enhancer 
region, specifically MoMLV containing the Friend enhancer causes ery thro leukemia 
rather than T cell lymp,homa and vice versa. Other studies have shown an ablation 
of virulence when this enhancer region is removed or altered, even though the 
capacity to cause retroviremia is not affected (18). These studies suggest that 
the malignant potential of murine leukemia viruses is related to a specific 
interaction between the viral enhancer region and genomic sequences in the mouse 
T cell. It is unknown what, if any, primate cell is susceptible to transformation 
by the MoMLV. 
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Recombinant DNA Research, Volume 14 
