TRANSFER AND EXPRESSION OF THE HUMAN INTERLEUKIN-4 GENE IN CARCINOMA AND STROMAL CELL-LINES DERIVED FROM LUNG-CANCER PATIENTS

Introduction of the interleukin-4 (IL-4) gene into cells derived from human tumor tissue provides a means for generating a specific tumor va ccine. Such a vaccine could be produced by either transducing tumor-de rived stromal cells with the IL-4 vector and coinjecting tumor cells, or by transducing the tumor cells themselves. We have developed a prot ocol for culturing cells from non-small cell lung tumors and routinely produce tumor cultures from 25% of tumors, and stromal cultures from >80% of specimens. Several of these cultures were transduced with the incompetent retroviral vector G1NaSvi4.25, which encodes the human IL- 4 cDNA and the G418-resistance gene. Infection of cells by viral titer s of 2-5 x 10(4) plaque-forming units/ml, and a multiplicity of infect ion of 0.1:1 to 1:1 yielded transfer efficiencies of 3.3-32.0 transfec tants per 10(4) cells in six of eight attempts. Following selection wi th the neomycin analog G418, IL-4-producing cells were isolated. IL-4 titers ranged from 142 to 593 U/ml/10(6) in a 24-h collection. Success ful transfer of the IL-4 gene was demonstrated by polymerase chain rea ction amplification of cDNA derived from reverse-transcribed total RNA , by immunohistochemistry, and by enzyme-linked immunosorbent assay. T he IL-4-producing cells were shown to stimulate the proliferation of a utologous peripheral blood lymphocytes in one individual by 7.5-fold o ver control and by 4.1-fold over non-IL-4 producing tumor celts. Gene transfer was performed between 18 and 60 days after acquisition for st romal cells,and within 150 days for tumor cells. Cells from lung cance r patients may have potential for generating tumor vaccines. In additi on, use of lung tumor-derived stromal cells for transfection may have some advantages over dermal fibroblasts for use in gene therapy.