[Tumor infiltrating T lymphocyte components in malignant pleural effusion of lung adenocarcinoma and their killing activities to autologous tumor cells].

Objective: To analyze the components of tumor infiltrating T lymphocyte (TIL) cells in malignant pleural effusion of lung adenocarcinoma, and evaluate their killing activities to autologous tumor cells. 
 Methods: Malignant pleural effusions were collected from 17 patients with lung adenocarcinoma. Mononuclear cells were isolated by Ficoll density gradient centrifugation and flow cytometer was used to analyze TIL cell components. TIL and tumor cells were separated through adherent culture. The tumor cells were identified via intramuscular injection of adherent cells into nude mice and the killing effect of cultured lymphocytes on autologous tumor cells was studied.
 Results: Of the TIL in malignant pleural effusions, T cells accounted for 60.6%-79.3%, while T helper cells were significantly higher than T killer cells (36.63%±1.90% vs 24.64%±2.32%, P<0.001). There were also natural killer (NK) cells and NK T cells in the effusions. Tumor cells were successfully isolated and cultured. The killing activity of cultured TIL to autologous tumor cells was 39.14%±12.04%, and the killing activity of TIL with high proliferation rate to autologous tumor cells was higher than that of low proliferation group (50.51%±3.80% vs 29.04%±5.77%, P<0.001).
 Conclusion: T lymphocytes are the major components of TIL in malignant pleural effusions derived from lung adenocarcinoma, and T helper cells are more than T killer cells. The killing activity of TIL with strong proliferation ability to autologous tumor cells is higher than that of TIL with weak proliferation ability. Therefore, cells from malignant pleural effusions could be used for cellular immunotherapy against tumor.