Objective: To determine the immunologic characteristics of tumor infiltrating lymphocytes (TILs) in comparison with the corresponding peripheral blood lymphocytes (PBLs) of patients with ovarian cancer in order to detect specific antitumor-reactive-immunocompetent cells.
Methods: Tumor infiltrating lymphocytes and PBLs were phenotyped by their surface markers, cytokine pattern, proliferation rate, and cytotoxic ability.
Results: The phenotypes of both lymphocyte populations were very heterogeneous. Peripheral blood lymphocytes had a higher proliferative activity and cytotoxicity against natural killer-sensitive tumor cells than the corresponding TILs. Furthermore TILs showed increased interleukin-4 expression whereas in PBLs, interferon-gamma production predominated.
Conclusion: Peripheral blood lymphocytes showed more potentially valuable behavioral characteristics than TILs. In the future we need to combine several methods in order to define immune cells with antitumor activity. These cells should be expanded ex vivo and stimulated specifically for use in the immunotherapy of ovarian cancer.