Surface Glycoproteins of Exosomes Shed by Myeloid-Derived Suppressor Cells Contribute to Function

Author/Creator ORCID

Date

2016-10-20

Department

Program

Citation of Original Publication

Sitara Chauhan, Steven Danielson, Virginia Clements, Nathan Edwards, Suzanne Ostrand-Rosenberg, and Catherine Fenselau, Surface Glycoproteins of Exosomes Shed by Myeloid-Derived Suppressor Cells Contribute to Function, J. Proteome Res., 2017, 16 (1), pp 238–246 DOI: 10.1021/acs.jproteome.6b00811

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This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Proteome Research, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.jproteome.6b00811

Abstract

In this report, we use a proteomic strategy to identify glycoproteins on the surface of exosomes derived from myeloid-derived suppressor cells (MDSCs), and then test if selected glycoproteins contribute to exosome-mediated chemotaxis and migration of MDSCs. We report successful modification of a surface chemistry method for use with exosomes and identify 21 surface N-glycoproteins on exosomes released by mouse mammary carcinoma-induced MDSCs. These glycoprotein identities and functionalities are compared with 93 N-linked glycoproteins identified on the surface of the parental cells. As with the lysate proteomes examined previously, the exosome surface N-glycoproteins are primarily a subset of the glycoproteins on the surface of the suppressor cells that released them, with related functions and related potential as therapeutic targets. The “don’t eat me” molecule CD47 and its binding partners thrombospondin-1 (TSP1) and signal regulatory protein α (SIRPα) were among the surface N-glycoproteins detected. Functional bioassays using antibodies to these three molecules demonstrated that CD47, TSP1, and to a lesser extent SIRPα facilitate exosome-mediated MDSC chemotaxis and migration.