Polarized immune responses differentially regulate cancer development


Lisa M. Coussens
Department of Pathology
University of California, San Francisco
2340 Sutter Street, N-221
San Francisco, CA 94143, USA
Tel.: +1 415 502 6378
Fax: +1 415 514 0878
e-mail: coussens@cc.ucsf.edu


Summary: Tumor-associated immune responses assert varied responses toward developing neoplasms that can either act to eradicate malignant cells via engagement of potent cytotoxic programs or alternatively enhance tumor growth through release of multifunctional pro-tumor mediators. Seemingly paradoxical, these disparate activities reflect a continuum of polarization (or activation) states possible for distinct leukocyte subsets that demonstrate tissue, organ, and tumor selectivity. Herein, we review clinical and experimental studies investigating cellular and molecular mechanisms utilized by neoplastic tissues to alternatively polarize immune responses that favor either pro- or anti-tumor immunity.