Potentiation of tumor eradication by adoptive immunotherapy with T-cell receptor gene-transduced T-helper type 1 cells.

Adoptive immunotherapy using antigen-specific T-helper type 1 (Th1) cells has been considered as a potential strategy for tumor immunotherapy. However, its application to tumor immunotherapy has been hampered by difficulties in expanding tumor-specific Th1 cells from tumor-bearing hosts. Here, we have developed an efficient protocol for preparing mouse antigen-specific Th1 cells from nonspecifically activated Th cells after retroviral transfer of T-cell receptor (TCR)-alpha and TCR-beta genes. We demonstrate that Th1 cells transduced with the TCR-alpha and -beta genes from the I-A(d)-restricted ovalbumin (OVA)(323-339)-specific T-cell clone DO11.10 produce IFN-gamma but not interleukin-4 in response to stimulation with OVA(323-339) peptides or A20 B lymphoma (A20-OVA) cells expressing OVA as a model tumor antigen. TCR-transduced Th1 cells also exhibited cytotoxicity against tumor cells in an antigen-specific manner. Moreover, adoptive transfer of TCR-transduced Th1 cells, but not mock-transduced Th1 cells, exhibited potent antitumor activity in vivo and, when combined with cyclophosphamide treatment, completely eradicated established tumor masses. Thus, TCR-transduced Th1 cells are a promising alternative for the development of effective adoptive immunotherapies.

An efficient method to prepare T cell receptor gene-transduced cytotoxic T lymphocytes type 1 applicable to tumor gene cell-therapy.

Genes encoding 2C T cell receptor (TCR) alpha, beta chains from H-2(b)-restricted L(d)-specific CD8(+) cells were successfully transduced into polyclonally activated CD8(+) cells by retroviral modification to generate antigen-specific cytotoxic T lymphocytes (CTL). Antigen-nonspecific CD8(+) T cells polyclonally expanded in the presence of interleukin (IL)-2, Th1 cytokines (interferon (IFN)-gamma and IL-12) and anti-IL-4 monoclonal antibody showed neither cytokine production nor cytotoxicity in response to L(d)-expressing P815 tumor cells. However, 2C-TCR gene-modified CD8(+) T cells exhibited both IFN-gamma production and cytotoxicity in response to P815 tumor cells. The antitumor activity of TCR gene-modified Tc1 cells was also demonstrated in vivo by Winn's assay. Thus, we have developed an efficient method to induce TCR gene-modified antigen-specific Tc1 cells that exhibit antitumor activity both in vitro and in vivo.