Immunological response and protection of mice immunized with plasmid encoding Toxoplasma gondii glycolytic enzyme malate dehydrogenase

Abstract

Toxoplasma gondii Malate dehydrogenase (TgMDH) plays an important role as part of the energy production cycle. In this investigation, immunological changes and protection efficiency of this protein delivered as a DNA vaccine have been evaluated. Mice were intramuscularly immunized with pTgMDH, followed by challenge with virulent T. gondii RH strain, 2 weeks after the booster immunization. Compared to the control groups, the results showed that pTgMDH has stimulated specific humoral response as demonstrated by significant high titers of total IgG and subclasses IgG1 and IgG2a , beside IgA and IgM, but not IgE. Analysis of cytokine profiles revealed significant increases of IFN-γ, IL-4 and IL-17, while no significant changes were detected in TGF-β1. In cell-mediated response, both T lymphocytes subpopulations CD4(+) and CD8(+) were positively recruited as significant percentages were recorded in response to immunization with TgMDH. Significant long survival rate, 17 days, has been observed in the TgMDH vaccinated group, in contrast with control groups which died within 8-9 days after challenge. These results demonstrated that TgMDH could induce significant immunological responses leading to a considerable level of protection against acute toxoplasmosis infection.

Protective immunity against acute toxoplasmosis in BALB/c mice induced by a DNA vaccine encoding Toxoplasma gondii elongation factor 1-alpha

“…The induction of IgE has been previously recognized during the T. gondii infection [ 37 , 44 ]. However, our data revealed no significant traces of this immunoglobulin after vaccination with TgEF-1α, an observation consistent with findings from previous studies [ 25 , 45 , 46 ].…”

Evaluation of the immune response in BALB/c mice induced by a novel DNA vaccine expressing GRA14 against Toxoplasma gondii

“…The presence of specific IgG1, IgG2a and IgG2b antibodies against T. gondii TLA was measured by Enzyme-linked immunosorbent assay (ELISA) as previously described. 27,28 Briefly, 96-well plates were coated overnight at 4°C with 20 μg of TLA in 1 mL of PBS and then blocked with PBS containing 1% BSA for 1 hour. Mice sera were diluted 1:100 in PBS prior to testing and applied to well with incubation for 2 hours at 37°C.…”

Retraction notice to “Sequence variability in the structural protein-encoding region of foot-and-mouth disease virus serotype A and O of Ethiopian isolates” [Res. Vet. Sci. Volume 96, Issue 3, June 2014, Pages 558–566]

“…DNA vaccines have shown promise for defense against toxoplasmosis for their ability to induce long-term specific humoral and cellular immune responses Hassan et al, 2014b;Xu et al, 2014). In this study, we demonstrated that DNA vaccine encoding TgGST of T. gondii could elicit significant immune response as well as provide considerable level of resistance leading to partial protection against acute toxoplasmosis infection.…”