Cantón Germán J, Katzer Frank, Benavides-Silván Julio, Maley Stephen W, Palarea-Albaladejo Javier, Pang Yvonne, Smith Sionagh, Bartley Paul M, Rocchi Mara, Innes Elisabeth A, Chianini Francesca
Vet Res. 2013 Jul 22;44(1):60. doi: 10.1186/1297-9716-44-60.
Despite Neospora caninum being a major cause of bovine abortion worldwide, its pathogenesis is not completely understood. Neospora infection stimulates host cell-mediated immune responses, which may be responsible for the placental damage leading to abortion. The aim of the current study was to characterize the placental immune response following an experimental inoculation of pregnant cattle with N. caninum tachyzoites at day 210 of gestation. Cows were culled at 14, 28, 42 and 56 days post inoculation (dpi). Placentomes were examined by immunohistochemistry using antibodies against macrophages, T-cell subsets (CD4, CD8 and γδ), NK cells and B cells. Macrophages were detected mainly at 14 days post inoculation. Inflammation was generally mild and mainly characterized by CD3+, CD4+ and γδ T-cells; whereas CD8+ and NK cells were less numerous. The immune cell repertoire observed in this study was similar to those seen in pregnant cattle challenged with N. caninum at early gestation. However, cellular infiltrates were less severe than those seen during first trimester Neospora infections. This may explain the milder clinical outcome observed when animals are infected late in gestation.
尽管犬新孢子虫是全球范围内牛流产的主要原因，但其发病机制尚未完全明确。新孢子虫感染会刺激宿主细胞介导的免疫反应，这可能是导致胎盘损伤进而引起流产的原因。本研究的目的是在妊娠210天时给怀孕母牛实验性接种犬新孢子虫速殖子，以描述胎盘的免疫反应。在接种后14、28、42和56天对母牛实施安乐死。使用抗巨噬细胞、T细胞亚群（CD4、CD8和γδ）、NK细胞和B细胞的抗体，通过免疫组织化学检查胎盘小叶。巨噬细胞主要在接种后14天被检测到。炎症通常较轻，主要特征为CD3 +、CD4 +和γδ T细胞；而CD8 +和NK细胞数量较少。本研究中观察到的免疫细胞组成与妊娠早期感染犬新孢子虫的怀孕母牛相似。然而，细胞浸润比妊娠早期新孢子虫感染时轻。这可能解释了动物在妊娠后期感染时观察到的临床症状较轻的原因。
