Neospora caninum tachyzoite immunome study reveals differences among three biologically different isolates

Area of Science:

• Veterinary Parasitology
• Immunology
• Molecular Biology

Background:

• Bovine neosporosis pathogenesis is influenced by host and parasite factors, including Neospora caninum isolate virulence.
• Previous work showed virulent isolates (Nc-Liv, Nc-Spain7) have higher tachyzoite protein abundance than low-virulent Nc-Spain1H.

Purpose of the Study:

• To investigate and compare the immunomes of three Neospora caninum isolates with varying virulence.
• To identify differences in antigen recognition based on isolate virulence and host immune response.

Main Methods:

• Comparative analysis of protein extracts from Nc-Liv, Nc-Spain1H, and Nc-Spain7 isolates using 2-DE immunoblot.
• Sera from mice experimentally infected with each of the three isolates were used for probing.

Main Results:

• All isolates showed similar antigenic patterns when probed with the same serum.
• Differences in immunome profiles were dependent on the sera used, not the protein extract.
• Sera from virulent isolate-infected mice (Nc-Liv, Nc-Spain7) recognized more antigens than sera from the low-virulent isolate (Nc-Spain1H).
• Specific proteins (e.g., GAP45, NcGRA1) and spots were not recognized by sera from low-virulent isolate-infected mice.

Conclusions:

• Immunome variations in Neospora caninum are linked to the host's immune response induced by each isolate.
• Differentially recognized antigens may serve as potential virulence markers for bovine neosporosis.