NK Cell–derived Exosomes From NK Cells Previously Exposed to Neuroblastoma Cells Augment the Antitumor Activity of Cytokine-activated NK Cells

Abstract

Immune cell-derived exosomes can increase immunity against tumors. In contrast, tumor-derived exosomes can reduce the immunity and can change the tumor microenvironment to further develop and provide metastasis. These effects take place by an alteration in the innate and adaptive immune cell functions. In this experiment, we studied the natural killer (NK) cells' effectiveness on tumor cells after expansion and thereafter incubated it with exosomes. The exosomes were derived from 2 populations of NK cells: (1) naive NK cells and, (2) NK cells previously exposed to neuroblastoma (NB) cells. Moreover, we have studied the NB-derived exosomes on NK cell function. The molecular load of the characterized exosomes (by means of nanoparticle-tracking analysis, flow cytometry, scanning electron microscopy, and western blot) from NK cells exposed to the NB cell revealed their expression of natural killer cell receptors in addition to CD56, NKG2D, and KIR2DL2 receptors. These exosomes were used to treat NK cells and thereafter administered to NB tumor cells both in vitro and in vivo. Our results showed some kind of NK cells' education by the exosomes. This education from NK cells previously exposed to NB cell-derived exosomes caused efficient and greater cytotoxicity against NB tumors, but NB-derived exosomes act as tumor promoters by providing a tumor supporting niche. Hence, this method of preparing the exosomes has a dramatic effect on activation of anti-NK cells against NB cells.

Novel alternatives to extracellular vesicle-based immunotherapy – exosome mimetics derived from natural killer cells

“…They have been the focus of more than 150 cellular-based immunotherapy clinical trials as of March 2017 (clinicaltrials.gov). The antitumour behaviour of NK cells has been harnessed to treat hematologic malignancies that include acute myeloid leukaemia, acute lymphoblastic leukaemia multiple myelomas [4], solid tumours such as melanoma [5,6], breast cancer [7,8], thyroid cancer [2] and glioblastoma [1,9]. Because of the low number of NK cells in peripheral or cord blood, immune cell therapy with NK cells requires an ex vivo expansion process to achieve relevant numbers that express activation markers, natural cytotoxicity receptors (natural-killer group 2, member D [NKG2D], NKp44, Fas ligand [FasL], etc.)…”

“…Because of the low number of NK cells in peripheral or cord blood, immune cell therapy with NK cells requires an ex vivo expansion process to achieve relevant numbers that express activation markers, natural cytotoxicity receptors (natural-killer group 2, member D [NKG2D], NKp44, Fas ligand [FasL], etc.) and cytokines (tumour necrosis factor-alpha [TNF-a], granzyme A and B, perforin) [2,4,10].…”

“…Tumour exosome crosstalk with immune cells leads to attenuation of the cells by downregulation of their anti-tumour activity [21,22]. Immune cells such as NK cells can release exosomes (NK exosomes, NK-Exo) that express cytotoxic proteins including FasL and perforin [11,13,23] and cytokines including granzyme A, granzyme B and TNF-a [4,11]. NK-Exo display anti-tumour activity.…”

Dynamic plasma extracellular vesicle long RNA profiling changes during the peri-operative period

“…Innate immune cells, such as NK cells, neutrophils, mast cells (MCs), macrophages, and eosinophils, and adaptive immune cells, including DCs, T cells, and B cells, derived from exosomes can directly interact with cancer cells and uptake by tumor cells can induce different types of immune responses [26,27]. Accumulating evidence has shown that EVs derived from immune cells can promote pro-tumor and antitumor immunity, which suggests a complex relationship between the immune cell-derived EVs and the immune system [28][29][30][31]. NK cells that were previously exposed to neuroblastoma (NB) can secrete exosomes containing NK cell receptors, such as CD56, KIR2DL2, and NKG2D receptors, which can subsequently stimulate normal NK cells, generating greater and more e cient cytotoxicity against NB tumor cells [30].…”

“…Accumulating evidence has shown that EVs derived from immune cells can promote pro-tumor and antitumor immunity, which suggests a complex relationship between the immune cell-derived EVs and the immune system [28][29][30][31]. NK cells that were previously exposed to neuroblastoma (NB) can secrete exosomes containing NK cell receptors, such as CD56, KIR2DL2, and NKG2D receptors, which can subsequently stimulate normal NK cells, generating greater and more e cient cytotoxicity against NB tumor cells [30]. CD8+ T cell-derived exosomes with membrane expression of Fas ligand (FasL) can promote invasion and metastasis of Fas+ tumor cells through matrix metalloproteinase-9 (MMP-9)mediated degradation of extracellular matrix proteins [28].…”