Circulating exosomes carrying an immunosuppressive cargo interfere with cellular immunotherapy in acute myeloid leukemia.

ABSTRACT: Exosomes, small (30-150 nm) extracellular vesicles (EVs) isolated from plasma of patients with acute myeloid leukemia (AML) carry leukemia-associated antigens and multiple inhibitory molecules. Circulating exosomes can deliver suppressive cargos to immune recipient cells, inhibiting anti-tumor activities. Pre-therapy plasma of refractory/relapsed AML patients contains elevated levels of immunosuppressive exosomes which interfere with anti-leukemia functions of activated immune cells. We show that exosomes isolated from pre-therapy plasma of the AML patients receiving adoptive NK-92 cell therapy block anti-leukemia cytotoxicity of NK-92 cells and other NK-92 cell functions. NK-92 cells do not internalize AML exosomes. Instead, signaling via surface receptors expressed on NK-92 cells, AML ex

SUBMITTER: Hong CS 

PROVIDER: S-EPMC5666018 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature