[Study on the influence of enzymatic digestion upon tumor-infiltrating lymphocytes]

To get a long-term culture of tumor-infiltrating lymphocytes (TILs) is very difficult. The authors have investigated some suitable enzymes, their digestive conditions such as time and temperature, which may influence the viability and cytotoxicity of TILs. The results showed that collagenase II and IV could keep viability of TILs much longer than those treated with trypsin or hyaluronidase. The digestion with collagenase II or IV at 4 degrees C for 24 hours was much less damage to viability of TILs than those treated at 37 degrees C for one hour. The TILs, which digested at 4 degrees C for 24 hours, still had cytotoxicity against autologous tumor cells as long as sixty to seventy-five days.