American Journal of Immunology

The Role of Treg Cells in the Cancer Immunological Response

Zhi-Zhang Yang and Stephen M. Ansell

DOI : 10.3844/ajisp.2009.17.28

American Journal of Immunology

Volume 5, Issue 1

Pages 17-28


Problem statement: T cell-mediated immunosuppression has been observed for decades without clarification as to which factor was responsible for this observation. The identification of CD4+CD25+ regulatory T (Treg) cells represents a milestone in the filed of immunology and provides an explanation for T-cell-mediated immunosuppression. Although Treg cells were originally identified for their ability to prevent organ-specific autoimmune disease in mice, emerging evidence suggests that Treg cells play a pivotal role in tumor immunity and contribute to tumor growth and progression, thereby having an important impact on the outcome of cancer patients. Approach: This article reviewed the medical literature to describe how Treg cells affect anti-tumor immunity. Results: Treg cells suppressed anti-tumor immunity by inhibiting the effector functions of tumor-specific T cells and NK cells. Importantly, tumor cells played an active role in recruiting and generating Treg cells and creating a suppressive tumor microenvironment. Strategies to deplete Treg cells or inhibit their function had yielded promising results by enhancing anti-tumor immunity in experimental studies as well as clinical practice. Conclusion: A better understanding of the pathophysiology of Treg cells not only increased our knowledge in a variety of aspects of immunology but also potentially benefited cancer patients.


© 2009 Zhi-Zhang Yang and Stephen M. Ansell. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.