Scientific Abstract 
16.0 Scientific Abstract 
The goal of immunotherapy is to stimulate the immune system 
by modification of tumor cells or expansion of lymphocytes which 
respond specifically to tumor antigens. In this study, we will 
apply techniques of direct gene transfer to enhance immune 
response against tumors in vivo. Patients with advanced cancer 
who have failed all effective therapy will be treated by 
injection of a DNA/ liposome complex directly within the tumor. 
DNA will be used which encodes a heterodimeric cell surface 
protein recognized in the transplantation response. These genes 
include the HLA-B7 histocompatibility antigen and £-2 
microglobulin gene in a non-viral plasmid eukaryotic expression 
vector. For this vector, a safe and effective dose to introduce 
this recombinant gene in HLA-B7” patients will be established. 
HLA-B7 expression will be confirmed in vivo, and the immune 
response stimulated by the expression of this antigen will be 
characterized. We will also determine whether this treatment 
facilitates tumor regression alone or in combination with other 
treatment modalities. This study will employ a similar strategy 
to our previous gene therapy protocol, but employs four 
improvements in technology, including more efficacious liposomes, 
optimize vector expression, catheter delivery and application to 
other several types of cancer. These studies will facilitate the 
development of other approaches, using different recombinant 
genes or in combination with cytokines or adoptive T cell 
therapy, to augment tumor immunity, and allow for greater 
potential efficacy. This method will also establish the safety 
Recombinant DNA Research, Volume 17 
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