Yongxin Zhang, Ying Wang, Zhenxiang Wang, Monica Zhang and Zhenying Wang
Objective: The use of therapeutic immune cell subsets is becoming an increasingly cost-effective and attractive strategy for the treatment of cancer. Nonetheless, the field of cell therapy is hampered by the inability to consistently generate and expand sufficient numbers of high quality cells from a majority of patients. To address this critical issue, the investigators developed a sophisticated bioreactor technology that maximizes metabolic support and minimizes the damaging shear-stress forces, automatically monitors functional correlates to allow cell harvest at peak functional capacity, and permits cell sorting in situ to minimize cell loss and microbial contamination. In current study, the established cancer-specific CTL expansion system will be tested for its potency of cancer cell killing both in vitro and in vivo.
Methods: To test the cell expansion efficiency of ZYX Bioreactor, the CD8+ T cells expanded in different culture systems were enumerated by flow cytometry and the Cancer-specific cytotoxic T lymphocyte (CTL) activity was measured for their cytokine production and against autologous tumor targets by CTL cytotoxicity assay in vitro and in vivo as well as Annexin V staining to detect low-level cytolytic activity. In the in vivo CTL assay, mouse cancer cell line was used as stimulators and targets for the expanded mouse CTL evaluation in BALB/c mice and human lung cancer cells and expanded human CTL were injected into immunodeficient mice for human CTL evaluation.
Results: In comparison of other cell culture systems, ZYX Bioreactor has significantly higher efficiency in the cancer specific CD8+ T cell expansion, and these CD8+ T cells expanded in ZYX Bioreactor exhibited higher specific CTL cytotoxicity in both in vivo and in vitro studies.
Conclusion: ZYX Bioreactor can provide the adequate metabolic support to the growing cancer-specific CD8+ CTLs and the proper condition for the stimulation of cancer cell-carried antigens to the CTLs.