Effects of Exosomal Viral Components on the Tumor Microenvironment

Abstract

Exosomes are extracellular membrane vesicles with a diameter of 30-100 nm, produced by different eukaryotic cells that contain multitudinous lipids, nucleic acids, and proteins. They transfer membrane components and nucleic acids between cells, thereby performing an information exchange between cells. Many studies have shown that a variety of tumor-associated viruses can exert their biological functions through exosomes. The tumor microenvironment (TME) is very important in the occurrence, development, and chemoresistance of tumors. It is composed of tumor cells, fibroblasts, endothelial cells, immune cells, stromal cells, and acellular components, such as exosomes and cytokines. This review focuses on the effects of virus-related components secreted by tumor cells over the TME in several virus-associated cancers.

Keywords: cancers; exosome; oncovirus; tumor microenvironment.

Figure 1

The occurrence of exosomes. The occurrence of exosomes is formed by the invagination of the cell membrane to form multivesicular bodies (MVBs). After the outer membrane of MVB fuses with the cell membrane, its contents are released into the extracellular matrix, and the secreted vesicles are called exosomes.

Figure 2

The role of exosomes in the EBV-associated tumor microenvironment. The figure shows the EBV-related components and their receptor cells that function in the exosomes, and the EBV-related components are shown in italics, and ↑ indicates that they play a role in promotion.

Figure 3

The role of exosomes in the HPV-associated tumor microenvironment. The figure shows the HPV-related components and their receptor cells that function in the exosomes, and the HPV-related components are shown in italics, ↑ means promotion, ↓ means inhibition.

Figure 4

The role of exosomes in hepatitis virus-associated tumor microenvironment. The figure shows the liver cancer-related virus components and their receptors that play a role in exosomes, and the liver cancer-related virus components are shown in italics, ↑ indicating promotion and ↓ indicating inhibition.

Figure 5

The role of exosomes in HIV-associated tumor microenvironment. The figure shows HIV-related components and their receptor cells at work in exosomes; HIV-related components are shown in italics, and ↑ indicates promotion.