Lassmann H, Schmied M, Vass K, Hickey W F
Research Unit for Experimental Neuropathology, Austrian Academy of Sciences, Vienna.
Glia. 1993 Jan;7(1):19-24. doi: 10.1002/glia.440070106.
Infection of the central nervous (CNS) system by the human immunodeficiency virus (HIV) depends on the migration of infected hematogenous cells into the brain. We thus used quantitative light and electron microscopic immunocytochemistry to study the homing and turnover of bone marrow derived cells in the CNS in radiation bone marrow chimeras under normal conditions and in experimental autoimmune encephalomyelitis (EAE) as an experimental model of brain inflammation. Our studies suggest the following conclusions. First, the central nervous system is continuously patrolled by a small number of T-lymphocytes and monocytes. Meningeal and perivascular monocytes are slowly replaced by hematogenous cells under normal conditions, and this turnover is accelerated in the course of inflammation. In contrast, resident microglia represent a very stable cell pool, which in adult animals is only exceptionally replaced by hematogenous cells, even after recovery from severe brain inflammation. Second, although in bone-marrow-chimeric animals resident microglia, astrocytes, and ependymal cells are not able to present antigen to Lewis T-lymphocytes, the inflammatory reaction in EAE is qualitatively and quantitatively similar in these animals compared to fully histocompatible Lewis rats. Finally, resident microglia express the macrophage activation antigen ED1. Thus, microglia cells appear to function as effector cells in EAE lesions.
人类免疫缺陷病毒（HIV）对中枢神经系统（CNS）的感染依赖于受感染的造血细胞迁移至脑内。因此，我们运用定量光镜和电镜免疫细胞化学技术，研究了正常条件下辐射骨髓嵌合体以及作为脑炎症实验模型的实验性自身免疫性脑脊髓炎（EAE）中，骨髓来源细胞在中枢神经系统中的归巢和更替情况。我们的研究得出以下结论。首先，中枢神经系统持续受到少量T淋巴细胞和单核细胞的巡逻。在正常情况下，脑膜和血管周围的单核细胞会被造血细胞缓慢替代，而在炎症过程中这种更替会加速。相比之下，常驻小胶质细胞代表一个非常稳定的细胞池，在成年动物中，即使从严重脑炎症中恢复后，也仅有极少数情况下会被造血细胞替代。其次，尽管在骨髓嵌合动物中，常驻小胶质细胞、星形胶质细胞和室管膜细胞无法将抗原呈递给Lewis T淋巴细胞，但与完全组织相容性的Lewis大鼠相比，这些动物在EAE中的炎症反应在质和量上都相似。最后，常驻小胶质细胞表达巨噬细胞活化抗原ED1。因此，小胶质细胞似乎在EAE损伤中发挥效应细胞的作用。
