Proteomics study of human cord blood reticulocyte-derived exosomes

Abstract

Reticulocyte-derived exosomes (Rex), extracellular vesicles of endocytic origin, were initially discovered as a cargo-disposal mechanism of obsolete proteins in the maturation of reticulocytes into erythrocytes. In this work, we present the first mass spectrometry-based proteomics of human Rex (HuRex). HuRex were isolated from cultures of human reticulocyte-enriched cord blood using different culture conditions and exosome isolation methods. The newly described proteome consists of 367 proteins, most of them related to exosomes as revealed by gene ontology over-representation analysis and include multiple transporters as well as proteins involved in exosome biogenesis and erythrocytic disorders. Immunoelectron microscopy validated the presence of the transferrin receptor. Moreover, functional assays demonstrated active capture of HuRex by mature dendritic cells. As only seven proteins have been previously associated with HuRex, this resource will facilitate studies on the role of human reticulocyte-derived exosomes in normal and pathological conditions affecting erythropoiesis.

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Conditional expression of PfAP2-G for controlled massive sexual conversion in Plasmodium falciparum

“…Human cord blood samples were obtained from the Barcelona Blood and Tissue Bank (www.bancsang.net/), following approval for the protocol and informed consent by the Clinical Research Ethics Committee of Vall d'Hebron University Hospital [PR(CS)236/2017]. Human reticulocyte preparations were performed as previously described (55), with some modifications. Briefly, samples were centrifuged at 1000g for 15 min (acceleration = 6, deceleration = 2), and plasma was removed.…”