CD4⁺ T-cell help controls CD8⁺ T-cell memory via TRAIL-mediated activation-induced cell death

Nature 434, 88–93, 2005

Speaker : 賴柏吟                      Time : 14:10~15:00, 20 Apr 2005

Commentator : 徐麗君 博士            Place : Room 601

Abstract

A long-standing paradox in cellular immunology concerns the conditional requirement for CD4⁺ T-helper (T_H) cells in the priming of cytotoxic CD8⁺ T lymphocyte (CTL) response in vivo. The authors had demonstrated in their previous study that although both T_H-dependent and T_H-independent CTL can follow primary expansion, however, T_H-dependent CTL obtain a license for memory response during their first priming, which is the capacity for secondary expansion on re-encounter with antigen¹. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a membrane protein belonging to the TNF family, which preferentially induces cell apoptosis in a wide variety of tumor cells but not in normal cells, leading to an interest in the clinical use of recombinant TRAIL for cancer immunotherapy². In this report, the authors explored T_H cells control CTL memory via regulating TRAIL expression in CTL during first priming. T_H-dependent CTL expressed anti-apoptotic proteins and underwent secondary expansion after restimulation whether T_H-independent CTL expressed TRAIL and went on apoptosis fate³. In conclusion, TRAIL may be relevant to the establishment and maintenance of peripheral tolerance, which may play a novel role in immune homeostasis.

References

1.          Janssen, E. M. et al. CD4⁺ T cells are required for secondary expansion and memory in CD8⁺ T lymphocytes. Nature 421, 852–856, 2003.

2.          French, L. E. and Tschopp, J. The TRAIL to selective tumor death. Nature Med. 5, 146-147, 1999.

3.          Janssen, E. M. et al. CD4⁺ T-cell help controls CD8⁺ T-cell memory via TRAIL-mediated activation-induced cell death. Nature 434, 88-93, 2005.