Pfaff A W, Candolfi E
Institut de Parasitologie et de Pathologie Tropicale, EA 3950, Université Louis Pasteur, 3 rue Koeberlé, 67000 Strasbourg, France.
Parassitologia. 2008 Jun;50(1-2):55-8.
Toxoplasma gondii is one of the few pathogens that can cross the placenta. Frequency and severity of transmission vary with gestational age. While acquired toxoplasmosis is already well explored, the control of maternal-foetal transmission of the parasite remains almost unknown. This is partly due to inherent inadequacies of animal models. This review summarises the studies which have been undertaken and shows that the mouse is a valuable model despite obvious differences to the human case. The paramount role of the cellular immune response during primary infection has been consistently shown. Surprisingly, IFN-g has a dual role in this process. While its beneficial effects in the control of toxoplasmosis are well known, it also seems to have transmission-enhancing effects within the placenta and can also directly harm the developing foetus. This shows the importance of designing vaccines which protects both mother and foetus. Therefore, it is useful to study the mechanisms of natural resistance against transmission during a secondary infection. In this setting, the process is more complicated, involving cellular, but also humoral components of the immune system. In summary, even if the whole process is far from being elucidated, important insights have been gained so far which will help us to undertake rational vaccine research.
弓形虫是少数能够穿过胎盘的病原体之一。传播的频率和严重程度随孕周而变化。虽然获得性弓形虫病已得到充分研究，但寄生虫母婴传播的控制几乎仍不为人知。部分原因是动物模型存在固有的不足。本综述总结了已开展的研究，并表明尽管与人类情况存在明显差异，但小鼠仍是一种有价值的模型。初次感染期间细胞免疫反应的首要作用已得到一致证实。令人惊讶的是，干扰素-γ在这一过程中具有双重作用。虽然其在控制弓形虫病方面的有益作用众所周知，但它似乎也在胎盘内具有增强传播的作用，并且还可能直接损害发育中的胎儿。这表明设计既能保护母亲又能保护胎儿的疫苗非常重要。因此，研究二次感染期间自然抵抗传播的机制是有用的。在这种情况下，过程更为复杂，涉及免疫系统的细胞成分和体液成分。总之，即使整个过程远未阐明，但到目前为止已获得了重要见解，这将有助于我们进行合理的疫苗研究。
