Cytotoxic Activity and Memory T Cell Subset Distribution of in vitro-Stimulated CD8+ T Cells Specific for HER2/neu Epitopes

Minimal residual disease remaining after resection of primary tumors can lead to tumor recurrence and metastasis, increasing mortality and morbidity rates among cancer patients. Thus, there is a need for new technologies for recognition and elimination of single cancer cells remaining in a patient’s body after radiation therapy, chemotherapy, or surgical resection. Effector CD8+ T cells, also commonly known as cytotoxic T lymphocytes (CTLs), play a key role in antitumor cellular immunity and, when properly activated, are able to effectively destroy tumor cells. The aims of this study were to obtain CD8+ CTLs specific for the HER2/neu epitopes E75 and E88, and to assess the cytotoxic activity and composition of these cells in terms of the distribution of memory T-cell subsets. We obtained HER2-specific CD8+ T cells and assessed T cell subset distribution among them including naive T cells (TN), central memory T cells (TCM), effector memory T cells (TEM), stem cell-like memory T cells (TSCM) and terminally-differentiated T cells (TEMRA) via eight-color flow cytometry. HER2-specific CTLs were largely (~40–50%) represented by TSCM cells, a population capable of mounting pronounced antitumor immune responses due to a combination of effector function and self-maintenance. In comparison with activated peripheral blood mononuclear cells (PBMCs) and bulk CD8+ T cells, HER2-specific CTLs exhibited greater cytotoxicity against the HER2-expressing human breast adenocarcinoma cell lin...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research