Generation of cytotoxic effector lymphocytes by MLTC using tumor cells genetically modified to secrete interleukin-2.
The in vitro generation of effector lymphocytes cytotoxic to cancer cells, was investigated with a mixed lymphocyte-tumor culture (MLTC) system using genetically modified human cancer cells, followed by stimulation with the interleukin (IL)-2 plus immobilized anti-CD3 antibody (IL-2/CD3) system. A gastric cancer cell line, GC022588 (HLA-A2, 24, B35, 55, C1,3), was retrovirally transduced with the human interleukin (IL)-2 gene (GC/IL-2) or the neomycin-resistance gene (GC/Neo). The secretion of biologically active IL-2 was detectable in GC/IL-2 cells but not in GC/Neo or parental GC022588 cells. The cytotoxic activity against the parental GC022588 cells of peripheral blood mononuclear cells (PBMC) was greater among PBMC activated with MLTC using GC/IL-2 than among those activated with MLTC using GC/Neo or without MLTC. The IL-2/CD3 stimulation could efficiently expand the effector lymphocytes without any reduction of the cytotoxic activity generated. The cytotoxic activity generated by this system was reproducible in several HLA-A2- or A24-positive donors. The effector lymphocytes could kill the other adenocarcinoma cells expressing HLA-A2 or A24. The phenotypes of the effector lymphocytes generated with the system were 40% CD4+ and 70% CD8+. Both phenotypes may have been responsible for the cytotoxicity. The removal of adherent cells from PBMC before the MLTC did not affect the generation of cytotoxicity, whereas neutralization of tumor-derived IL-2 with a specific antibody during the MLTC significantly inhibited the generation of cytotoxicity. These results suggest that IL-2 gene-transduction augments the immunogenicity of the tumor cells that efficiently stimulate lymphocytes to be cytotoxic, and that the IL-2/CD3 system may be practical for the expansion of effector lymphocytes for use in adoptive immunotherapy for cancer. The mechanism by which IL-2 gene-modified tumor cells stimulate immune reactivity was discussed.
Yamaguchi
Y
Y
Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan. shogo@hiroshima-u.ac.jp
Ohta
K
K
Shimizu
K
K
Minami
K
K
Noma
K
K
Hihara
J
J
Toge
T
T
D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D002448:Cell Adhesion; D002478:Cells, Cultured; D015234:HLA-A Antigens / Q000276:immunology; D015789:HLA-A2 Antigen / Q000276:immunology; D059871:HLA-A24 Antigen; D006801:Humans; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000187:drug effects*; D007959:Lymphocyte Culture Test, Mixed; D016853:Muromonab-CD3 / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013274:Stomach Neoplasms / Q000276:immunology / Q000473:pathology*; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000276:immunology / Q000378:metabolism*
D015234:HLA-A Antigens; D015789:HLA-A2 Antigen; D059871:HLA-A24 Antigen; D007376:Interleukin-2; D016853:Muromonab-CD3; D011993:Recombinant Fusion Proteins