Immunomodulation of the Tumor Microenvironment: Turn Foe Into Friend

Front Immunol. 2018 Dec 11:9:2909. doi: 10.3389/fimmu.2018.02909. eCollection 2018.


Immunotherapy, where the patient's own immune system is exploited to eliminate tumor cells, has become one of the most prominent new cancer treatment options in the last decade. The main hurdle for classical cancer vaccines is the need to identify tumor- and patient specific antigens to include in the vaccine. Therefore, in situ vaccination represents an alternative and promising approach. This type of immunotherapy involves the direct intratumoral administration of different immunomodulatory agents and uses the tumor itself as the source of antigen. The ultimate aim is to convert an immunodormant tumor microenvironment into an immunostimulatory one, enabling the immune system to eradicate all tumor lesions in the body. In this review we will give an overview of different strategies, which can be exploited for the immunomodulation of the tumor microenvironment and their emerging role in the treatment of cancer patients.

Keywords: cancer; immunotherapy; in situ vaccination; oncolytic virotherapy; radiotherapy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Cancer Vaccines / immunology
  • Cancer Vaccines / therapeutic use
  • Humans
  • Immunologic Factors / immunology
  • Immunologic Factors / therapeutic use
  • Immunomodulation / immunology*
  • Immunotherapy / methods*
  • Neoplasms / immunology
  • Neoplasms / therapy*
  • Photochemotherapy / methods
  • Reproducibility of Results
  • Tumor Microenvironment / drug effects
  • Tumor Microenvironment / immunology*
  • Vaccination / methods


  • Cancer Vaccines
  • Immunologic Factors