Meningeal immunity as a novel target for treating neurodevelopmental disorders induced by maternal immune activation

孕期母体炎症是子代自闭症的危险因素之一。在目前的实验动物研究中，我们发现骨髓来源的免疫细胞位于覆盖脑实质的脑膜空间。脑膜免疫在感知和反应外周炎症反应中起着关键作用，导致脑实质细胞的激活。在胎儿期，颅内免疫细胞定位于头脑间充质(脑膜前体)，而不定位于脑实质。因此，我们认为母体炎症对胎儿大脑的影响是由孕期头部间充质免疫细胞的反应引起的。

Maternal inflammation during pregnancy is one of the risk factors for autism in offspring. In the present study using experimental animals, we showed that bone marrow-derived immune cells were stationed in the meningeal space that covered the brain parenchyma. The meningeal immunity played a key role to sense and react to peripheral inflammatory responses, resulting in the activation of brain parenchymal cells. Intracranial immune cells were located to the cephalic mesenchyme (meningeal precursors) during the fetal period, but not to the brain parenchyma. Therefore, we suggest that the effects of maternal inflammation on the fetal brains are induced by the reactions exerted by the cephalic mesenchymal immune cells during pregnancy.