Potential Efficacy of Toxoplasma gondii Extracellular Vesicles in Protection against Acute Experimental Toxoplasmosis

Abstract

Abstract Toxoplasmosis is a zoonotic disease thought to infect 1.5 billion people worldwide. It is a significant food- and water-borne illness that can lead to a major opportunistic infection in patients with impaired immune systems. As a result, there is a pressing need to provide better alternatives for effective long-term disease control, such as vaccinations, as there is no treatment that can eradicate bradyzoites within tissue cysts. Exosomes are multivesicular entities that fuses with plasma membranes to form nanograde membrane-bound vesicles that are secreted by the majority of cell types. Exosomes play important functions in intercellular communication and several of them are well described and known to have immunomodulatory capabilities. Exosomes generated from Toxoplasma gondii (T. gondii) were isolated and their protective effectiveness and immunological responses against acute T. gondii infection in mice was investigated. T. gondii exosomes were isolated and identified by transmission electron microscopy. Mice were immunized with T. gondii tachyzoites derived exosomes (100 μg, 3 doses intramuscular with 2 weeks interval) to investigate the vaccine’s efficiency by challenging the mice with T. gondii RH strain tachyzoites administered intraperitoneal. Exosomes from T. gondii were successfully isolated and characterized. T. gondii exosome-immunized mice showed a longer survival rate compared to the unimmunized group. T. gondii derived exosomes could be a promising vaccine candidate for protection against toxoplasmosis.