Extracellular Vesicles Tropism: A Comparative Study between Passive Innate Tropism and the Active Engineered Targeting Capability of Lymphocyte-Derived EVs

Abstract

Cellular communications take place thanks to a well-connected network of chemical–physical signals, biomolecules, growth factors, and vesicular messengers that travel inside or between cells. A deep knowledge of the extracellular vesicle (EV) system allows for a better understanding of the whole series of phenomena responsible for cell proliferation and death. To this purpose, here, a thorough immuno-phenotypic characterization of B-cell EV membranes is presented. Furthermore, the cellular membrane of B lymphocytes, Burkitt lymphoma, and human myeloid leukemic cells were characterized through cytofluorimetry assays and fluorescent microscopy analysis. Through cytotoxicity and internalization tests, the tropism of B lymphocyte-derived EVs was investigated toward the parental cell line and two different cancer cell lines. In this study, an innate capability of passive targeting of the native EVs was distinguished from the active targeting capability of monoclonal antibody-engineered EVs, able to selectively drive the vesicles, enhancing their internalization into the target cancer cells. In particular, the specific targeting ability of anti-CD20 engineered EVs towards Daudi cells, highly expressing CD20 marker on their cell membrane, was proved, while almost no internalization events were observed in HL60 cells, since they did not express an appreciable amount of the CD20 marker on their plasma membranes.

Nanotechnological engineering of extracellular vesicles for the development of actively targeted hybrid nanodevices

“…Moreover, it is worth to note that treating cells with the pristine TNH did not affect cells viability. This result highlights the high biocompatibility of the proposed TNH, similar to what measured using the native lymphocyte-derived EVs at the same concentration and time points on the three cell lines, as previously reported by some of us [ 25 ].

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“…To obtain TNH CD20 samples, vesicle membranes were functionalized with anti-CD20 antibody as previously reported in [ 25 ] and schematically represented in Additional file 1 : Fig. S2c.…”

“…Additionally, the engineering of EVs for drug delivery purposes is not limited to cargo customization but concerns also the biological and/or biochemical functionalization of their external surface, mainly devoted to improve their homing and target specificity. Although EVs harbor native homing and targeting properties [ 25 ], this intrinsic tropism is often insufficient to achieve an effective delivery within specific organ, tissues or cells. Concerning EVs application in oncology, single domain and monoclonal antibodies, small peptides and glycans [ 26 ] are currently investigated as ligands for biomolecular markers specific of the target cells and tumor microenvironment [ 10 ].…”

Lipid-Based Nanovesicular Drug Delivery Systems

“…Both apoptotic bodies and microvesicles, with dimensions ranging between 500 nm and 2 µm and from 50 nm to 1 µm, respectively, arise from plasma cell membrane outward blebbing and fragmentation. On the other side, exosomes, deriving from the endocytic pathway, have diameters between 30 to 120 nm [246]. Many authors reported about the EVs use in drug delivery since their surface is characterized by antigens, related to the parental cells, able to direct specific homing or targeting phenomena [247].…”

Isolation of Extracellular Vesicles From Microalgae: A Renewable and Scalable Bioprocess

“…Extracellular vesicles (EVs) are a diverse group of membranous nanoparticles originated from cells and involved in several biological processes ( Yáñez-Mó et al, 2015 ; Margolis and Sadovsky, 2019 ). EVs perform specific and selective cargo release to cells or target tissues via different mechanisms, including endocytosis, fusion, or receptor interaction, and in general they take part in intercellular signal transduction ( Van Niel et al, 2018 ; Raposo and Stahl, 2019 ; Limongi et al, 2021a ). Beyond their physiological functions, EVs have a role in several diseases, including cancer ( Vagner et al, 2018 ; Raimondi et al, 2020 ), and in numerous pathological conditions, for instance, in stimulating an immune response ( Zhou et al, 2020 ) or intervening in multidrug resistance in cancer treatments ( Samuel et al, 2017 ; Pasini and Ulivi, 2020 ) and in virus infections and transmission ( Urbanelli et al, 2019 ; Pocsfalvi et al, 2020 ).…”