マウス自然発生癌の腫瘍内浸潤リンパ球を用いた養子免疫療法に関する研究

抄録

Adoptive immunotherapy was carried out using tumor infiltrating lymphocytes (TIL)cultured with rlL-2 after isolation from transplantable spontaneous squamous cell carcino-ma from inbred WHT/Ht lnice. Effector cells involved in antitumor reaction were investigated. TIL were collected at l×10⁵ cells/1gof tumor tissue. The viabnity amounted to more than 85% and the ratio of mixed tumor cells was less than 8%. By being cultured with rlL-2, TIL could be proliferated and maintained without tumor cells. A lymphocyte subsets were analyzed by FACScan. It was found that, fresh TIL were dominated by L3T4⁺ cells but a significant increase in Lyt-2⁺ cells was observed when TIL were cultured with rlL-2. The cytolytic activities of both cell lines were determined by means of ⁵¹ Cr release assay. Fresh TIL had no activity against syngeneic tumor cells, but cultured TIL had higher activity. These findings showed that the cytolytic activity was induced by rIL-2. Adoptive immunotherapy performed with cultured TIL produced no therapeutic effect in the group of TILalone, but had an inhibitory effect against tumor growth and a significant life-prolongation effect in the groups of TIL十rlL2 and CY十TIL十rlL-2. In conclusion, Lyt-2⁺ cells were presumed to play a main role in the cytolytic activity in TIL proliferated with rIL-2. TIL was suggested to be useful as a source of adoptive immunotherapy.