EXPANSION OF ACTIVATED LYMPHOCYTES OBTAINED FROM RENAL-CELL CARCINOMAIN AN AUTOMATED HOLLOW-FIBER BIOREACTOR

Immunotherapy using IL-2 alone or combined with activated lymphocytes has been promising for metastatic renal cell carcinoma. Cytotoxic lymp hocytes can be isolated from tumors, expanded in vitro with IL-2, and adoptively transferred back into the tumor-bearing host. These cells c an also be transduced with the genes coding for cytokines for local de livery to tumor sites. A major drawback in adoptive immunotherapy is t he cumbersome and expensive culture technology associated with the gro wth of large numbers of cells required for their therapeutic effect. T o reduce the cost, resources, and manpower, we have developed the meth odology for lymphocyte activation and expansion in the automated hollo w fiber bioreactor IMMUNOSTAR(TM) Cell Expander (ACT BIOMEDICAL, INC) . Tumor Infiltrating Lymphocytes (TIL) isolated from human renal cell carcinoma tumor specimens were inoculated at a number of 10(8) cells i n a small bioreactor of 30 ml extracapillary space volume. We have det ermined the medium flow rates and culture conditions to obtain a signi ficant and repeated expansion of TIL at weekly intervals. The lymphocy tes cultured in the bioreactor demonstrated the same phenotype and cyt otoxic activity as those expanded in parallel in tissue culture plates . Lymphocyte expansion in the hollow fiber bioreactor required lower v olumes of medium, human serum, IL-2 and minimal labor. This technology may facilitate the use of adoptive immunotherapy for the treatment of refractory malignancies.