Separation and expansion of tumor infiltrating lymphocytes of digestive systemin Vitro and their cytotoxicity

Abstract

Primary tumor tissues in the digestive system were harvested form 15 patients. By mincing, enzymatic digestion and gradient density separation, sufficient TILs (>5 × 10⁶) were obtained from 13 of 15 (88. 7 %) patientsin vitro in the presence of 500 μ/ml of recombinant interleukin-2 and 5 % fetal calf serum after one month culture. 92. 3 % (12/13) of TILs proliferated wellin vitro (92. 3%). TILs expanded from 10²-folds to 10³-folds after being cultured for one month. CD₂₅⁺ cell of the most fresh TILs was more than that of peripheral blood lymphocytes. CD₂₅⁺ cells of TILs during 4th week of the culture was significantly greater (P <0. 01) than that of fresh TILs. CD₄⁺/CD₈⁺ ratio was decreased during four culture weeks because of increase of CD₈ cells. By using modified colonmetric MTT assay for measuring activity of TILs against various tumor cells the results showed that cytotoxicity of gastro-intestinal TILs amtologous tumor cells is greater than on the other tumor cells.

Keywords

tumor-infiltrating lymphocytes / cytotoxicity of MTT assay / phenotype / interleukin-2

References

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