The Biology of Extracellular Vesicles

*Extracellular Vesicles and Their Importance in Human Health*

milk-derived exosomes attenuate cell death in intestinal epithelial cells. Innate Immunity. 2018;**24**:278-284. DOI:

Nevinsky GA. Human milk lactoferrin and antibodies: Catalytic activities, complexes, and other features. In: Milk Proteins—From Structure to Biological Properties and Health Aspects. Rijeka, Croatia: InTech; 2016. pp. 51-80. DOI:

[100] Burkova EE, Dmitrenok PS, Bulgakov DV, Ermakov EA, Buneva VN,

Soboleva SE, et al. Identification of major proteins of a very stable high molecular mass multi-protein complex of human placental tissue possessing nine different catalytic activities. Biochemistry and Analytical Biochemistry. 2018;**07**:1-2. DOI: 10.4172/2161-1009.1000351

10.1177/1753425918785715

10.5772/63200

[99] Sedykh SE, Buneva VN,

**38**

**41**

**Chapter 3**

**Abstract**

**1. Introduction**

Cellular-Defined

Microenvironmental

*Paul A. Vallejos and Nathan R. Wall*

Internalization of Exosomes

*Amber Gonda, Ron Moyron, Janviere Kabagwira,* 

ent types of cells that play a role in exosome internalization.

**Keywords:** exosome, endocytosis, receptors, internalization, uptake

The extracellular environment exhibits a potent effect on cellular growth and development. Exosomes secreted into this milieu carry functional proteins and nucleic acids from the cell of origin to recipient cells, facilitating intercellular communication. This interaction is particularly influential in the tumor microenvironment, transporting oncogenes and oncoproteins within a tumor and to distant sites. The mechanisms by which cells internalize exosomes vary greatly and the factors dictating this process are still unknown. Most cancers show evidence of exosomal transfer of material, but differences in cell type can dictate the effectiveness and extent of the process. Improving therapeutics requires addressing specific cellular functions, illustrating the need to better understand the forces involved in exosome-cell interactions. This review summarizes what is known about the differ-

Intercellular communication is essential to homeostasis and is largely dependent on the cellular secretome [1]. An emerging awareness of the role that the extracellular environment plays is evident in the field of secreted vesicles. The vesicular contribution to the tumor microenvironment (TME) has furthered our understanding of the communication between cells and the surrounding stroma [2]. This relationship has also elucidated many potential therapeutic targets and possible transporters of chemotherapeutics [3, 4]. There are multiple extracellular vesicle types, characterized by biogenesis, size, and common protein markers [5, 6]. Of these, exosomes are the smallest, with sizes ranging from 30 to 150 nm [6]. These vesicles have the most complex synthesis, emerging from the endocytic pathway. They arise from intraluminal invaginations into a multivesicular body (MVB) and are released from the cell when the MVB fuses with the plasma membrane. Exosomes consist of intracellular material surrounded by a lipid membrane that reflects the cellular membrane of the host cell [7]. These specific vesicles have demonstrated promise in several fields of research, including rheumatoid arthritis [8, 9] and neurodegenerative disease [10], but primarily in cancer [11, 12]. Tumor-derived exosomes (TEX) contain oncoproteins and oncogenes from the cell of origin and thus are
