Long-term or permanent remission of tumors after conventional cancer treatments is an ongoing clinical challenge. Therefore, the development of therapies that can kill a single cancer cell would be valuable in addressing this gap in effective cancer therapy. Immunotherapies are promising options that may fill this gap. Cytotoxic T cells are the main players in antitumor immune responses, and dendritic cells are very efficient in presenting tumor antigens to T cells, triggering tumor-specific cytotoxicity.
Antigen-specific cytotoxic T cells responding to tumor antigens can be isolated from peripheral blood mononuclear cells (PBMCs). Given this knowledge, recent research efforts have focused on developing a method to generate cytotoxic T cells specific for human epidermal growth factor receptor (HER2/neu), an antigen overexpressed in a number of cancer types including an aggressive form of breast cancer. The effect of these cytotoxic T cells on tumor cells that express HER2/neu was also evaluated.
The approach involved a method to isolate functional and viable antitumor antigen−specific cytotoxic T cells more effectively than methods using T cell receptor interactions and fluorescent markers. Peripheral blood was obtained from healthy donors, and PBMC monocytes were differentiated into immature dendritic cells by culturing with granulocyte-macrophage colony-stimulating factor and IL-4. The maturation of immature dendritic cells to mature cells was accomplished by adding TNF-alpha to the immature dendritic cell culture. Mature dendritic cells were activated with HER2 antigen by transfection with a DNA construct encoding HER2/neu epitopes.
Monocyte-depleted PBMC cells were co-cultured with dendritic cells to generate active HER2-specific cytotoxic T cells. These activated T cells were tagged with magnetic nanoparticles and isolated by magnetic-activated cell sorting. Human breast adenocarcinoma cells (MCF-7) were co-cultured with of the HER2-specific T cells to assess toxicity against the tumor cells using flow cytometry. The HER2-specific cytotoxic T cells were found to be strongly cytotoxic to the MCF-7 tumor cells, and the described methods improved the isolation of viable and functional HER2/neu-specific cytotoxic T cells. These results suggest a method that can overcome tumor recurrence subsequent to traditional cancer therapies.
Kuznetsova, M., Lopatnikova, J., Khantakova, J., Maksyutov, R., Maksyutov, A., & Sennikov, S. (2017). Generation of populations of antigen-specific cytotoxic T cells using DCs transfected with DNA construct encoding HER2/neu tumor antigen epitopes. BMC Immunology, 18(1). doi:10.1186/s12865-017-0219-7