Non-transduced cells secreted low levels of TNF equalling 35, 17, and 
16 pg TNF/10^ cells/24 hours cells for each of the three patients respectively. 
The TNF gene transduced cells from these patients produced 720 (day 35), 231 
(day 17), and 390 (day 16) pg TNF/10^ cells respectively. Thus the transduced 
cells made from 14 to 24 times the amount of TNF produced by the non-transduced 
TIL. Cells from patients 1 and 2 could be readily selected in 300 ug/ml of 
active G418, though as of yet we have been unable to select the cells from 
patient 3 in G418. Sequential measurements of TNF production by non transduced 
and transduced TIL as well as TNF production by transduced cells selected in 
G418 from patient 1 are shown in Table 5. Cells selected in G418 produced 2,8 
times the amount of TNF compared to non-selected cells. Similar results were 
obtained on measurements of selected cells from patient 2. All transduced and 
non-transduced cells retained their growth dependence on IL-2. 
The phenotypic and cytotoxic function of the non-transduced and transduced 
TIL are under study. Preliminary data Indicate that neither the phenotype nor 
the cytotoxicity of the TIL appears to be consistently affected by the transduction 
with the TNF gene. 
These studies indicate that it is feasible to use this retroviral vector 
to stably insert the gene coding for TNF into human TIL and to substantially 
increase the secretion of TNF by these TIL. 
4. Previous gene transfer studies in the Surgery Branch, NCI using tumor 
infiltrating lymphocytes in advanced cancer patients . We have previously 
performed studies of the retroviral transduction of the gene coding for 
neomycin resistance into TIL (24) and the subsequent infusion of these TIL into 
autologous patients with advanced cancer (25). The retroviral vector used in 
the current study is similar to that used in our prior studies except for the 
presence of an additional gene coding for TNF, Reports of these prior studies 
Recombinant DNA Research, Volume 14 
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