Recombinant DNA Advisory Committee - 2/10-11/92 
semi-quantitative PCR analysis will be performed. Since these experiments were successful 
in vitro , TIL and PBL will be isolated from the same patient, transduced with two different 
vectors, expanded, and reinfused into the patient. These patients will then receive either 
IL-2 or IL-2 and IFNaA. Samples of blood, tumor, and adjacent skin and muscle will be 
obtained and both quantitative and semi-quantitative PCR analysis will be performed. 
Data should support TIL localization if the ratio of TILs to PBLs rises and shows that 
there is a greater enrichment in the tumor, as opposed to non-tumor tissue. If there is no 
difference in the TIL to PBL ratio among these tissues (whether the lifespan decreases, 
remains unchanged, or increases), these data would strongly indicate that localization is 
not occurring. All of the patients entered into this gene marking protocol must have 
subcutaneous deposits of tumor. Immunological studies will also be performed. These 
studies include cytotoxicity assays against a variety of tumor targets, phenotype analysis, 
ELISA assays for cytokine production, and RNA PCR assays. 
This protocol could provide a definitive and unambiguous test of the hypothesis that TILs 
localize to tumors. No trials currently underway could provide this information in a 
scientifically rigorous fashion. Additionally, bulk TIL will be compared with CD8( + ) and 
CD4( + ) TIL subpopulations in terms of in vivo trafficking. It will be possible to correlate 
the in vivo behavior of these TIL with in vitro cytotoxicity data, and the phenotype analysis, 
and cytokine production. It is anticipated that there will be a clinical response in a certain 
proportion of patients. 
Discussion 
Dr. Kelley commented that in data from PBL, primarily in ADA deficient patients, the 
half life is extremely long. In other studies, the half life is very short. He asked Dr. 
Economou how these data would be normalized to create ratios that are meaningful. Dr. 
Economou replied that the investigators will be administering both of these cell 
populations, which will be expanded under identical conditions and transduced at 
approximately the same infection rate. These cells will be mixed and administered to the 
patient. An aliquot will be saved which will provide the standard curve for PCR analysis. 
Every time a gel is run, it will be compared with the input ratio. 
Dr. Kelley asked if TILs traffick more rapidly to various tissues than PBL. Will the 
experiment be controlled for this possibility? Dr. Economou said that there may be 
adhesion molecule receptors on TILs that are not present on PBL that account for 
different in vivo trafficking behavior, but that information is not available at the present 
time. There may not be much of a difference, but by independently labeling the cell 
populations, a direct comparison could be made. 
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Recombinant DNA Research, Volume 15 
