title: OX40 ligation enhances primary and memory cytotoxic T lymphocyte responses in an immunotherapy for hepatic colon metastases.
abstract: Previously, we showed that the eradication of murine hepatic metastatic colon carcinomas was achieved by using a combination therapy with adenovirus-mediated gene delivery of interleukin 12 (IL-12) and anti-4-1BB agonistic antibody. However, the therapeutic efficacy was compromised severely when mice with tumors larger than 8 x 8 mm(2) were treated. In this report, we studied the effect of OX40 costimulation through agonistic anti-OX40 in combination with the IL-12 + anti-4-1BB immunotherapy on primary and memory anti-tumor cytotoxic T lymphocyte responses in a large-tumor setting (8 x 8 to 12 x 12 mm(2)). Tumor-infiltrating leukocytes (TILs) isolated from mice treated with the combination therapy of IL-12, anti-4-1BB, and anti-OX40 showed a significantly higher ex vivo direct cytotoxic T lymphocyte (CTL) activity against parental tumors, as compared with those from mice treated with IL-12 and anti-4-1BB. In vivo depletion of CD4(+)T cells during combination therapy significantly decreased the number of tumor-infiltrating CD8(+)T cells and their cytotoxic activity in mice treated with IL-12 + anti-4-1BB + anti-OX40 combination therapy but not in the group treated with IL-12 + anti-4-1BB, which indicated that in vivo OX40 engagement on CD4(+) T cells led to the higher CTL responses observed in animals treated with IL-12 + anti-4-BB + anti-OX40 combination therapy. Furthermore, the combination therapy of IL-12, anti-4-1BB, and anti-OX40 resulted in a significantly higher survival rate in treated mice, as compared with treatment with IL-12 and anti-4-1BB. More importantly, long-term surviving mice from the combination therapy with IL-12, anti-4-1BB, and anti-OX40 exhibited higher memory CTL responses against parental tumor cells. The results demonstrated that OX40 ligation of CD4(+) T cells facilitated the development of primary and memory CTL responses against tumorcells and that coordinated immune activation by IL-12, anti-4-1BB, and anti-OX40 resulted in a significantly higher survival rate in mice with large tumor burdens. Thus, the combination therapy with the adenovirus encoding IL-12 (Adv.mIL-12) + anti-4-1BB + anti-OX40 antibodies may provide a better treatment modality for patients with advanced cancers, often associated with a state of immune suppression or tolerance.
authors.affiliation: Carl C. Icahn Institute for Gene Therapy and Molecular Medicine, Mount Sinai School of Medicine, New York, New York 10029, USA.
authors.forename: Ping-Ying
authors.initials: PY
authors.lastname: Pan
authors.forename: Yunjuan
authors.initials: Y
authors.lastname: Zang
authors.forename: Kaare
authors.initials: K
authors.lastname: Weber
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Meseck
authors.forename: Shu-Hsia
authors.initials: SH
authors.lastname: Chen
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D000943:Antigens, Differentiation / Q000276:immunology*; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000276:immunology*; D007156:Immunologic Memory; D007167:Immunotherapy; D018664:Interleukin-12 / Q000494:pharmacology; D008113:Liver Neoplasms / Q000188:drug therapy / Q000276:immunology*; D051379:Mice; D009362:Neoplasm Metastasis / Q000188:drug therapy / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*
chemical_list: D000906:Antibodies; D000943:Antigens, Differentiation; C406562:OX40Ig; D018664:Interleukin-12