2003 AAI Abstract

Adoptively Transferred Tim-3⁺ T-bet⁺ Tumor Specific TH1 Cell Clones Co-localize With and Inhibit Development and Growth of B Cell Lymphomas

W. J. Simmons¹, M. Koneru², M. Mohindru³, R. Thomas², S. Cutro¹, P. Singh¹, R.H. DeKruyff⁴, G. Inghirami², A. Coyle⁵, B. S. Kim³, N. M. Ponzio¹

¹UMDNJ - NJ Med Sch & Grad Sch Biomed Sci, ²NYU Sch of Med, ³Northwestern U Sch of Med, ⁴Stanford U Sch of Med, ⁵Millennium Pharmaceuticals

Effective tumor immunity is dependent on recognition of tumor antigens by TH cells and precursor CTL, followed by clonal expansion and differentiation into tumor-specific effector cells that can destroy tumor targets. Human B cell neoplasms are often infiltrated with activated CD4+ TH cells, yet their function is unclear. The very existence of neoplasms in these patients indicates that these TH cells failed to support a tumor-specific cytotoxic immune response. Activated T cells can produce TH2 cytokines (e.g., IL-4 & IL-5) that, in some instances, promote neoplasia. One example of this phenomenon is in the SJL B cell lymphoma model. It is well known, however, that in the presence of IL-12 p35p40 heterodimers the TH2 cytokine pattern is downregulated and IFN-g production is induced. To exploit this property, Phase 2 clinical trials using IL-12 therapy were conducted in cancer patients. Positive responses were observed, but toxicities and mortalities halted these trials. In the SJL model, daily injections of up to 2 mg IL-12 had no effect on tumor growth. However, addition of IL-12 in vitro to naïve T cells stimulated by irradiated (g-) tumor cells caused the appearance of CTL that killed tumor target cells. Therefore, we repeatedly stimulated naïve T cells with g-tumor cells in the presence of IL-12 to produce tumor-responsive TH1 cell clones. These TH1 cell clones expressed surface Tim-3, CD4, and CD30. In addition, mRNA for T-bet, but not GATA-3, was transcribed by the TH1 cell clones. Intracellular and secreted cytokine analysis revealed increased IFN-g, but minimal IL-4 production. The TCRb chain of the TH1 cell clones was consistently skewed towards a single Vb (due to stimulation by the superantigen expressing tumor cells). Functionally, the TH1 clones proliferated in response to tumor cells (but not allogeneic cells), replaced the need for IL-12 in the in vitro development of tumor-specific CTL against lymphoma target cells, but did not lyse these targets directly. To determine if the TH1 cell clones functioned in vivo, 5 million CFSE labeled TH1 cell clones were injected iv into young mice. Spleen sections from these mice showed localization of CFSE+ cells in the T cell zones of the white pulp. The CFSE+ cells did not co-localize with CD19+ B cells (in the same sections) but localized around and outside of the B cell areas. In contrast to vehicle injected mice, young SJL mice that received Tim-3+ TH1 cell clones prior to viable tumor cell challenge, had reduced tumor burden and a decreased absolute number of tumor cells in their lymphoid organs. In addition, young mice that received a single dose of 5 million cloned Tim-3+ TH1 cells rarely developed primary lymphomas (7% incidence) by 12 months of age, a time at which 90% of SJL mice typically exhibit these tumors. Overall, these data indicate that SJL mice can develop tumor-specific cytotoxicity following adoptive transfer of Tim-3+ tumor specific TH1 cell clones, which provides a novel strategy for development of immunotherapy for cancer patients.