Co-Isolation of Cytokines and Exosomes: Implications for Immunomodulation Studies.

Exosomes play a vital role in intercellular communication and their immunomodulatory potential have become an important focus in cancer research. Various methods have been developed for the isolation although each method differs in the number and purity of exosomes they yield. In melanoma, tumor-derived exosomes drive immunosuppression within the tumor microenvironment.

A Rapid Exosome Isolation Using Ultrafiltration and Size Exclusion Chromatography (REIUS) Method for Exosome Isolation from Melanoma Cell Lines.

Cells release extracellular vesicles (EVs) that can be detected both in vivo and in cell culture medium. Among EVs, exosomes are 50-150 nm vesicles that are systematically packaged into multivesicular bodies for release into the external environment. In cancer, these intentionally packaged exosomes carry a payload of proteins such as RNAs and surface receptors that facilitate the reprogramming of proximal cells to assemble a protumor microenvironment.

An Immunosuppressive Effect of Melanoma-derived Exosomes on NY-ESO-1 Antigen-specific Human CD8 T Cells is Dependent on IL-10 and Independent of BRAF Mutation in Melanoma Cell Lines.

Exosomes, including human melanoma-derived exosomes (HMEX), are known to suppress the function of immune effector cells, which for HMEX has been associated with the surface presence of the immune checkpoint ligand PD-L1. This study investigated the relationship between the BRAF mutational status of melanoma cells and the inhibition of secreted HMEX exosomes on antigen-specific human T cells. Exosomes were isolated from two melanoma cell lines, 2183-Her4 and 888-mel, which are genetically wild-type BRAF and BRAF, respectively.

Purity and yield of melanoma exosomes are dependent on isolation method.

Both exosomes and soluble factors have been implicated in the generation of an immunosuppressive tumour microenvironment. Determining the contribution of each requires stringent control of purity of the isolated analytes. The present study compares several conventional exosome isolation methods for the presence of co-enriched soluble factors while isolating exosomes from human melanoma-derived cell lines.

Publisher Correction: Metabolic reprogramming of stromal fibroblasts by melanoma exosome microRNA favours a pre-metastatic microenvironment.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Metabolic reprogramming of stromal fibroblasts by melanoma exosome microRNA favours a pre-metastatic microenvironment.

Local acidification of stroma is proposed to favour pre-metastatic niche formation but the mechanism of initiation is unclear. We investigated whether Human Melanoma-derived exosomes (HMEX) could reprogram human adult dermal fibroblasts (HADF) and cause extracellular acidification. HMEX were isolated from supernatants of six melanoma cell lines (3 BRAF V600E mutant cell lines and 3 BRAF wild-type cell lines) using ultracentrifugation or Size Exclusion Chromatography (SEC).