Generation of cytokine activated antigen non-specific and dendritic cell primed Her2/neu peptide specific cytotoxic T cells from cord blood against human breast cancer

Human umbilical cord blood mononuclear cells (UCBC) are rich source of antitumor cytotoxic effector cells. In this report we describe the generation of antigen non-specific and specific cytotoxic cells from UCBC against human breast cancer cells. Methods: For the non-specific effector cells, mononuclear cells from UCBC were activated with IL-2, IL-15, GM-CSF, G-CSF and M-CSF either alone or in combination in vitro. For the antigen specific cytotoxic T lymphocyte generation, dendritic cells were generated from UCBC using DC specific media and were primed with Her2/neu specific peptide (KIFGSLAFL). Such antigen primed dendritic cells were used to augment the cytotoxicity of CD* positive CTLs from UCBC. Following activation with cytokines or antigen primed dendritic cells, the cytotoxicity of these effector cells were tested against MDA-231, MDA-453 and SKBr3 human breast cancer cells. Results: 1) Antigen Non-Specific Effectors: Cord blood cells activated with IL-15 in combination with GM-CSF showed significantly higher cytotoxicity against breast cancer cells compared to IL-2 alone or other cytokine combinations (P<0.01). The cytokine combination significantly increased CD8+ and CD56+ cells (P<0.01) and correlated with increase in cytotoxicity (r=0.976). RT-PCR analysis of the cytokine activated UCBC showed an increase in Th1 type cytokines gene expression. 2) Antigen-Specific Effectors: Dendritic cell primed Her2/neu specific CTLs showed a significant cytotoxicity against Her2/neu high-expressing human MDA-453 and SKBr3 but not against Her2/neu low-expressing MDA-231 breast cancer cells. Conclusion: These results indicate that both antigen non-specific and antigen specific cytotoxic effector cells can be generated from cord blood against breast cancer. These studies lay a foundation for development of concurrent cord blood derived cellular therapy for breast cancer to eliminate both antigen negative and antigen positive breast cancer cells in patients.