Possibility of exosome‑based coronavirus disease 2019 vaccine (Review)

Abstract

Coronavirus disease 2019 (COVID‑19) is a global pandemic that can have a long‑lasting impact on public health if not properly managed. Ongoing vaccine development trials involve classical molecular strategies based on inactivated or attenuated viruses, single peptides or viral vectors. However, there are multiple issues, such as the risk of reversion to virulence, inability to provide long‑lasting protection and limited protective immunity. To overcome the aforementioned drawbacks of currently available COVID‑19 vaccines, an alternative strategy is required to produce safe and efficacious vaccines that impart long‑term immunity. Exosomes (key intercellular communicators characterized by low immunogenicity, high biocompatibility and innate cargo‑loading capacity) offer a novel approach for effective COVID‑19 vaccine development. An engineered exosome‑based vaccine displaying the four primary structural proteins of SARS‑CoV‑2 (spike, membrane, nucleocapside and envelope proteins) induces humoral and cell mediated immunity and triggers long‑lasting immunity. The present review investigated the prospective use of exosomes in the development of COVID‑19 vaccines; moreover, exosome‑based vaccines may be key to control the COVID‑19 pandemic by providing enhanced protection compared with existing vaccines.

Keywords: coronavirus disease 2019; exosome; pandemic; severe acute respiratory syndrome coronavirus 2; vaccine.

Figure 1.

Schematic diagram of severe acute respiratory syndrome coronavirus 2. The four structural proteins (spike, envelope, membrane and nucleocapside) are shown; the spike glycoprotein mediates host cell binding.

Figure 2.

Structure and hallmarks of exosomes. Exosomes are surrounded by a phospholipid bilayer and consist of proteins including CD63, an exosomal marker, and tetraspanins for cell targeting. HSP, heat shock protein; TSG101, tumor susceptibility 101.

Figure 3.

Approaches to exosome-based vaccine in the management of coronavirus disease 2019. EVs, extracellular vesicles; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Figure 4.

Diagrammatic representation of ultracentrifugation-based exosome isolation (Korean patent application no. 10-2020-0062365) for the mass production of 293T cell-derived apoptotic exosomes. SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; EV, extracellular vesicle.