Immunogenicity of Exosomes from Dendritic Cells Stimulated with Toxoplasma gondii Lysates in Ocularly Immunized Mice

Abstract

Immunogenicity of dendritic cell-derived exosomes stimulated with <i>Toxoplasma gondii</i> lysates (TLA exo), mixed with cholera toxin as an adjuvant, was investigated in mice immunized via 2 mucosal routes (ocular vs intranasal). BALB/c mice were injected 3 times with TLA exo vaccine at 2 week interval, and the levels of IgG in serum and IgA in tear, saliva, feces, and vaginal wash were measured. To observe the expression of <i>T. gondii</i>-specific B1 gene, mice infected with ME49 <i>T. gondii</i> cysts were immunized with TLA exo or PBS exo (not stimulated with TLA), and their brain tissues were examined. The mice vaccinated via intranasal route elicited significantly higher humoral and mucosal immune responses compared with mice treated with PBS alone. Also, mice immunized via ocular route (by eyedrop) induced significantly higher <i>T. gondii</i>-specific IgG in serum and IgA in tear and feces in comparison with PBS controls. B1 gene expression was significantly lower in TLA exo vaccinated mice than in PBS or PBS exo vaccinated mice. These results demonstrated that ocular immunization of mice with TLA exo vaccine has the potential to stimulate systemic or local antibody responses. This study also highlighted an advantage of an eyedrop vaccine as an alternative for <i>T. gondii</i> intranasal vaccines.

The End Justifies the Means: Chagas Disease from a Perspective of the Host–Trypanosoma cruzi Interaction

“…Regarding vaccines, Gutierrez et al [143] showed that EVs from the interaction between blood trypomastigotes and bone marrow-derived DCs confer partial protection in animals challenged with lethal T. cruzi infection. These results, together with reports on other pathogens such as Toxoplasma gondii [144,145], Eimeria spp. [146], and Leishmania major [147], place EVs as promising therapeutic agents against infectious diseases.…”

Extracellular vesicles from Trypanosoma cruzi-dendritic cell interaction show modulatory properties and confer resistance to lethal infection as a cell-free based therapy strategy

“…Tumor-derived EVs stimulate antitumor immunogenicity in DCs ( André et al., 2002 ) and more interestingly, Ag-pulsed DC derived exosomes display prophylactic and therapeutic properties in tumour-bearing mice ( Zitvogel et al., 1998 ). Immune protective response triggered by EVs from Ag-loaded DCs has also been described for different pathogens such as Toxoplasma gondii ( Aline et al., 2004 ; Jung et al., 2020 ), Eimeria spp. ( del Cacho et al., 2012 ) and Leishmania major ( Schnitzer et al., 2010 ).…”

Emerging role of extracellular vesicles in veterinary practice: novel opportunities and potential challenges

“…Toxoplasmosis, a globally prevalent zoonosis caused by Toxoplasma gondii, relies primarily on live, attenuated tachyzoites for veterinary immunization ( 110 ). A recent study reported that EVs derived from dendritic cells stimulated with T. gondii lysate elicited protective mucosal and hormonal immune responses against Toxoplasma infection in an animal model ( 111 ). Similarly, a study on Eimeria tenella , the parasite of avian coccidiosis, using exosomes from antigen-loaded dendritic cells showed a protective effect on chickens ( 112 ), suggesting the potential of EVs as a protective vaccine production.…”