Exosomes and tumor-mediated immune suppression
Theresa L. Whiteside
Theresa L. Whiteside
Published February 29, 2016
Citation Information: J Clin Invest. 2016;126(4):1216-1223. https://doi.org/10.1172/JCI81136.
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Review Series

Exosomes and tumor-mediated immune suppression

Abstract

Tumor-derived exosomes (TEX) are harbingers of tumor-induced immune suppression: they carry immunosuppressive molecules and factors known to interfere with immune cell functions. By delivering suppressive cargos consisting of proteins similar to those in parent tumor cells to immune cells, TEX directly or indirectly influence the development, maturation, and antitumor activities of immune cells. TEX also deliver genomic DNA, mRNA, and microRNAs to immune cells, thereby reprogramming functions of responder cells to promote tumor progression. TEX carrying tumor-associated antigens can interfere with antitumor immunotherapies. TEX also have the potential to serve as noninvasive biomarkers of tumor progression. In the tumor microenvironment, TEX may be involved in operating numerous signaling pathways responsible for the downregulation of antitumor immunity.

Authors

Theresa L. Whiteside

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Figure 3

Effects of TEX on immune cells or immune cell progenitors.

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Effects of TEX on immune cells or immune cell progenitors. In the TME, T...
In the TME, TEX (in blue), produced and released by tumor cells, induce: (a) inhibition of functions necessary for antitumor responses; (b) apoptosis of activated Teffs; (c) expansion and upregulation of suppressive activity in Tregs, MDSCs, and regulatory B cells (Bregs); (d)interference with cellular differentiation; (e) polarization to tumor-promoting phenotypes; and (d) mobilization of cells to tumor. TEX carrying TAAs can interfere with immunotherapies. TEX also mediate autocrine effects and influence the functions of normal cells present in the TME.