patient. Rosenberg concluded that this procedure was both feasible and safe 
( 20 ). 
Prior safety studies have shown that exposure of primates to large infusion of 
infectious murine amphotrophic virus produces no acute pathologic effects (37). 
Twenty-one primates transplanted with retroviral gene modified bone marrow 
showed no evidence of toxicity related to the gene transfer as long as five years 
after infusion (38). The first adenosine deaminase-deficient patient with Severe 
Combined Immunodeficiency (SCID) underwent successful retroviral-mediated 
adenosine deaminase gene transfer approximately one year ago at the NCI. So 
far, investigators observed partial reconstitution of cellular immune function 
without any ill effect on the patient. 
To investigate whether the findings from the murine system could be extended, 
human tumor cell lines were infected with cytokine-containing retroviral vectors. 
To date, the human IL-2 gene, human IFN-gamma gene and the human 
epidermal growth factor receptor gene have been successfully transduced into a 
variety of human cell lines. In collaboration with Dr. Raymon Taetle (University 
of Arizona), the epidermal growth factor gene has been introduced into the 
Burkitts lymphoma cell line, Namalwa; the receptor was shown to be expressed 
on the cell surface and fully functional. Stimulation of these transduced cells with 
the epidermal growth factor leads to the appropriate binding of the ligand and 
signal transduction (39). In addition, the IL-2 or the IFN-gamma gene have been 
introduced and expressed in primary and established renal cell carcinoma lines. 
These genetically modified cells secreted constitutively up to 20 U/ml 
recombinant IL-2 into the supernatant. Constitutive IFN-gamma expression led to 
the upregulation of HLA class I and class II on the cell surface of renal cell 
carcinoma cells (Gansbacher unpublished data). Injection of the IL-2 secreting 
tumor cells into nude mice led to tumor rejection in contrast to unmodified cells. 
Irradiation of the genetically altered renal cell carcinomas does not abrogate IL-2 
secretion (see appendix F). After lethal irradiation, IL-2 was continuously 
secreted for 2-3 weeks in amounts comparable to nonirradiated transduced cells. 
2.7 Rationale 
We propose to study whether immunization with allogenic renal carcinoma cells 
expressing a recombinant human IL-2 gene can be well tolerated without evident 
toxicity. There is substantial experience at MSKCC and other institutions that has 
established the general safety of immunization using irradiated allogeneic tumor 
cells (42,43). The choice of allogeneic HLA-A2 positive tumor cells is based on 
two considerations. First, the use of a single established immunizing cell line 
bypasses the necessity to infect autologous tumor cells for each patient. Growing 
autologous tumor cells in tissue culture is a difficult and time intensive 
Recombinant DNA Research, Volume 15 
