Dysregulation of TGFβ1 Activity in Cancer and Its Influence on the Quality of Anti-Tumor Immunity

TGF beta 1 is a pleiotropic cytokine that exhibits a variety of physiologic and immune regulatory functions. Although its influence on multiple cell types is critical for the regulation of numerous biologic processes in the host, dysregulation of both TGF beta 1 expression and activity is frequently observed in cancer and contributes to various aspects of cancer progression. This review focuses on TGF beta 1's contribution to tumor immune suppression and escape, with emphasis on the influence of this regulatory cytokine on the differentiation and function of dendritic cells and T cells. Clinical trials targeting TGF beta 1 in cancer patients are also reviewed, and strategies for future therapeutic interventions that build on our current understanding of immune regulation by TGF beta 1 are discussed.