Mechanisms of immune modulation in the tumor microenvironment and implications for targeted therapy

The efficacy of cancer therapies is limited to a great extent by immunosuppressive mechanisms within the tumor microenvironment (TME). Numerous immune escape mechanisms have been identified. These include not only processes associated with tumor, immune or stromal cells, but also humoral, metabolic, genetic and epigenetic factors within the TME. The identification of immune escape mechanisms has enabled the development of small molecules, nanomedicines, immune checkpoint inhibitors, adoptive cell and epigenetic therapies that can reprogram the TME and shift the host immune response towards promoting an antitumor effect. These approaches have translated into series of breakthroughs in cancer therapies, some of which have already been implemented in clinical practice. In the present article the authors provide an overview of some of the most important mechanisms of immunosuppression within the TME and the implications for targeted therapies against different cancers.

Automated summary

The efficacy of cancer therapies is limited by immunosuppressive mechanisms within the tumor microenvironment. Various immune escape mechanisms have been identified, and they involve tumor, immune, stromal cells, as well as humoral, metabolic, genetic and epigenetic factors within the microenvironment. Strategies such as small molecules, nanomedicines, immune checkpoint inhibitors, adoptive cell and epigenetic therapies have been developed to reprogram the microenvironment and enhance the antitumor immune response, leading to breakthroughs in cancer therapies.