Tolerance and immune suppression in the tumor microenvironment

Cell Immunol. 2016 Jan;299:23-9. doi: 10.1016/j.cellimm.2015.09.011. Epub 2015 Sep 30.


The concept of immunological tolerance has guided and permeated much of modern immunology. Ray Owen's ground-breaking observations in twin cattle provided the first mechanistic explanation for tolerance to self-molecules and established tolerance as a beneficial process that protects the host against autoreactivity. However, his studies also opened the door to understanding that tolerance may be detrimental, such as occurs when cancer cells induce tolerance/immune suppression resulting in inhibition of anti-tumor immunity. This article briefly traces the early history of the field of tumor immunology with respect to tolerance, and then focuses on a relatively recently identified population of cells called myeloid-derived suppressor cells (MDSCs). MDSC are instrumental in causing tolerance/immune suppression in individuals with cancer. They are present in most individuals with cancer and because of their potent immune suppressive activity are a major deterrent to natural anti-tumor immunity and a significant obstacle to immunotherapy.

Keywords: Immune suppression; MDSC; Myeloid-derived suppressor cells; Tolerance; Tumor immunology.

Publication types

  • Historical Article
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cattle
  • History, 20th Century
  • History, 21st Century
  • Humans
  • Immune Tolerance*
  • Immunosuppression
  • Immunotherapy / history
  • Myeloid Cells / immunology*
  • Neoplasms / immunology*
  • Tumor Escape
  • Tumor Microenvironment / immunology*