CD4+ T cells have been found to play critical roles in the control of both acute and chronic
Toxoplasma infection. Previous studies identified a protective role for the Toxoplasma CD4+ T celleliciting
peptide AS15 (AVEIHRPVPGTAPPS) in C57BL/6J mice. Herein, we found that immunizing
mice with AS15 combined with GLA-SE, a TLR-4 agonist in emulsion adjuvant, can be either helpful
in protecting male and female mice at early stages against Type I and Type II Toxoplasma parasites
or harmful (lethal with intestinal, hepatic, and spleen pathology associated with a storm of IL6).
Introducing the universal CD4+ T cell epitope PADRE abrogates the harmful phenotype of AS15. Our
findings demonstrate quantitative and qualitative features of an effective Toxoplasma-specific CD4+ T
cell response that should be considered in testing next-generation vaccines against toxoplasmosis.
Our results also are cautionary that individual vaccine constituents can cause severe harm depending
on the company they keep.
Description:
SUPPLEMENTARY MATERIALS : FIGURE S1: Cartoon model showing the conceptual advance provided by this work.
DATA AVAILABILITY STATEMENT : Data sharing is not applicable to this article.
