Immunization of BALB/c Mice with Killed Tachyzoites of  Toxoplasma gondii against Acute Toxoplasmosis

Hai-Ting Guo; Jie Tan; Yu-Lin He; Xia Li; Xue  Liang; Zhong-Yuan Li

doi:10.18502/ijpa.v18i4.14243

Hai-Ting Guo Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Gui-lin, P.R. China
Jie Tan Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Gui-lin, P.R. China
Yu-Lin He Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Gui-lin, P.R. China
Xia Li Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Gui-lin, P.R. China
Xue Liang Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Gui-lin, P.R. China
Zhong-Yuan Li Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Gui-lin, P.R. China

DOI: https://doi.org/10.18502/ijpa.v18i4.14243

Keywords: Toxoplasma gondii; Devitalization; Aluminum adjuvant; Infection

Abstract

Background: Toxoplasma gondii with widespread distribution infects over one third of human populations in the world and can cause serious life-threatening diseases especially for the immunodeficient patients in acute toxoplasmosis. As the clinical pharmaceutical drugs with severe side effects for treatment and non-ideal extant vaccines for prevention, more work starves to be done for keeping advantages in the athletics.

Methods: Aluminum adjuvant and hybrid formaldehyde-killed tachyzoites of T. gondii RH and GT1 isolates were prepared to intramuscularly immunize BALB/c mice for five times at 0, 3, 7, 14 and 21 days post first injection. The triggered humoral and cellular immune responses at two weeks post the last immunization and the survival times of infected mice were examined for the hybrid immunization scheme judgement.

Results: The anti-RH and anti-GT1 specific antibodies were both increased at one week prior to challenge (P < 0.05), and the survival times of immunized mice (7.33 ± 0.71 d for RH, 7.22 ± 0.97 d for GT1) against acute toxoplasmosis were significantly prolonged by the immunizations performed in the study compared to blank control (6.67 ± 0.50 d for RH, 6.33 ± 0.71 d for GT1; P < 0.05), with the higher IFN-γ, IL-2 and IL-12p70 in sera, the elevated CD3e⁺CD4⁺ T and CD3e⁺CD8a⁺ T cells, and the enhanced lymphocyte proliferation in spleen (P < 0.05).

Conclusion: The hybrid killed tachyzoites with aluminum adjuvant induced humoral and cellular immune responses of mice, and offered mildly protective efficacy against acute toxoplasmosis.