Vaccination with Neospora GRA6 Interrupts the Vertical Transmission and Partially Protects Dams and Offspring against Neospora caninum Infection in Mice.

Ragab M Fereig,Hanan H Abdelbaky,Yoshifumi Nishikawa

doi:10.3390/vaccines9020155

Abstract

Vaccination is the mainstay of preventative measures for numerous infectious diseases. Neospora caninum infection induces storms of abortion in pregnant cows and ewes, resulting in drastic economic losses because of fetal losses and culling of the dams. Herein, we evaluated the potential of recombinant protein of N. caninum dense granule protein 6 fused with glutathione-S-transferase (NcGRA6+GST) as a vaccine candidate against neosporosis in a pregnant mouse model. The protective efficacy was investigated by subcutaneous inoculation of BALB/c mice with recombinant NcGRA6+GST (25 pmol), and GST alone (25 pmol) or phosphate-buffered saline (PBS) as the controls. This study revealed the partial ability of NcGRA6+GST to protect the dams and offspring from N. caninum infection during the critical period of pregnancy. This ability was revealed by higher survival rate and lower parasite burden in brains of offspring of the NcGRA6+GST-immunized group in comparison with the control groups. In addition, mouse dams from NcGRA6+GST-immunized groups exhibited lower clinical score and minimum alteration in body weight in comparison with PBS or GST groups after challenge with N. caninum tachyzoites. Taken together, our results suggest the efficacy of recombinant NcGRA6 for interrupting the vertical transmission of N. caninum in mice by reducing the severity of infections in dams and offspring.

Highlights

IntroductionNeospora caninum is a protozoan parasite that infects a wide range of animal species
Published: 15 February 2021Neospora caninum is a protozoan parasite that infects a wide range of animal species
In our previous study employing a non-pregnant mouse model, we indicated that recombinant NcGRA6 possessed an immune-stimulatory effect

Summary

Introduction

Neospora caninum is a protozoan parasite that infects a wide range of animal species. It induces storms of abortion in pregnant cows and ewes, resulting in drastic economic losses. There is no evidence for neosporosis in humans, the disease recently gained significant interest because of the substantial economic losses associated with the abortion of cattle [2]. As a result, infected pregnant cows may abort at any stage of gestation, with most abortions occurring at five to six months. Fetuses may die in uteri, be born clinically infected, or be clinically normal but congenitally infected. Infected calves remain persistently infected and can pass the infection onto their offspring [1,2]

Results

Discussion

Conclusion