268 and 631 pg TNF/IO^ cells respectively). These levels of TNF secretion are 
similar to those of TNF-gene modified TIL. In our previous immunotherapy trials 
we have administered up to 1.5 x 10^^ LAK cells along with IL— 2 to 180 cancer 
patients (286 treatment courses). These patients thus received over 17 times the 
amount of TNF that will be produced by the starting dose of TNF modified TIL. 
The TNF gene Inserted into the TIL is the native type TNF cDNA. 
Although we have not been able to successfully introduce the TNF-NeoR 
genes into murine TIL we have used this retroviral vector to introduce these 
genes into a non-cytolytic long term murine T-cell line. This transduced murine 
T cell line produced 300-500 pg TNF/10^ cells/24 hrs. and 5 x 10^ cells/kg were 
injected i.v. or 2 x 10^ cells/kg were injected i.p. into 18 syngeneic C57BL/6 
mice and all tolerated the TNF producing T cells without toxicity. Similarly, 
the same vector was used to transduce the MCA-205 tumor line, syngeneic to 
C57BL/6 mice. This tumor line produced from 10,000 to 12,000 pg TNF/10^ cells/24 
hours. This TNF producing tumor cell line was injected into 131 mice and no 
toxic side effects were noted in the mice due to the TNF production by this 
tumor. The tumors grew and produced TNF for approximately one week and then 
regressed . 
The estimates presented above suggest that it is very unlikely that TNF 
production by gene-modified TIL will cause systemic toxicity at the starting 
doses of TIL in this protocol. If serious toxicity does occur, however, 
several therapeutic options can be undertaken. All treatment with IL-2 
will cease. Patients may receive steroids (4mg dexamethasome i.v. every 6 
hours for 2 days). Prior studies have shown that steroid administration 
can abrogate lymphocyte mediated toxicity (36, 37). Efforts are being made to 
obtain anti-TNF antibodies suitable for human administration that may also 
be useful. 
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Recombinant DNA Research, Volume 14 
