Neospora caninum in non-pregnant and pregnant mouse models: cross-talk between infection and immunity.

Neospora caninum is a cyst-forming coccidian which causes abortion in cattle, with a high economic impact globally. Vaccination is considered to be the most cost-effective strategy to control and prevent bovine neosporosis. However, there is no commercial vaccine available to date. To investigate this disease under laboratory conditions, mouse models were developed, and they have been efficiently used as an initial proof-of-concept platform to investigate different immunogenic formulations. We here provide a detailed review on the current knowledge on immunity against neosporosis in non-pregnant as well as pregnant mice, and present a general overview of the most relevant parameters that may be responsible for protective immunity, which in turn could be relevant for vaccine development. Despite the considerable differences in immunity between cattle and mice, it is essential to understand how mice respond immunologically to Neospora caninum infection and how this response influences congenital infection and offspring survival. In this context, pregnant mouse models play a key role, and allow correlation of the outcome of congenital neosporosis with specific immune mechanisms which could also be relevant in cattle.