da Cunha A, Jefferson J J, Tyor W R, Glass J D, Jannotta F S, Cottrell J R, Resau J H
Laboratory of Cell Biology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
J Interferon Cytokine Res. 1997 Nov;17(11):655-64. doi: 10.1089/jir.1997.17.655.
Ameboid microglia express human immunodeficiency virus 1 (HIV-1) more frequently than do ramified microglia. These two microglial subtypes might also differ in the frequency with which they express transforming growth factor-beta1 (TGF-beta1), a cytokine that regulates HIV-1 expression in monocytes. Results described here show that ameboid and ramified microglia express TGF-beta1. In brain tissues from HIV-1-infected individuals as compared with seronegative controls, ameboid rather than ramified microglia more frequently expressed TGF-beta1. Ameboid microglia, isolated and cultured from postmortem adult human brain more frequently expressed TGF-beta1 in presence of interleukin-1(IL-1), a cytokine that is elevated in brains of HIV-1-infected individuals when compared with seronegative controls. The stimulation of TGF-beta1 by IL-1 was dose and time dependent, occurring with ameboid microglia isolated from either frontal cortex or globus pallidus but not midbrain pons. Ameboid microglia are similar to the RCA-1-positive cells that form clusters, called microglial nodules, in the brain of HIV-1-infected individuals. Pathologic conditions, such as disseminated microglial nodules, are associated with HIV-1 encephalitis, direct infection of the brain, and moderate to severe neurologic impairment. TGF-beta1 expression in ameboid microglia may play a role in HIV-1 neuropathogenesis.
阿米巴样小胶质细胞比分支状小胶质细胞更频繁地表达人类免疫缺陷病毒1（HIV-1）。这两种小胶质细胞亚型在表达转化生长因子-β1（TGF-β1）的频率上也可能存在差异，TGF-β1是一种调节单核细胞中HIV-1表达的细胞因子。本文所述结果表明，阿米巴样和分支状小胶质细胞均表达TGF-β1。与血清阴性对照相比，在HIV-1感染个体的脑组织中，阿米巴样小胶质细胞而非分支状小胶质细胞更频繁地表达TGF-β1。从成人尸检大脑中分离并培养的阿米巴样小胶质细胞，在白细胞介素-1（IL-1）存在的情况下更频繁地表达TGF-β1，与血清阴性对照相比，IL-1在HIV-1感染个体的大脑中水平升高。IL-1对TGF-β1的刺激呈剂量和时间依赖性，从额叶皮质或苍白球分离的阿米巴样小胶质细胞会出现这种情况，但中脑脑桥则不会。阿米巴样小胶质细胞类似于在HIV-1感染个体大脑中形成簇状的RCA-1阳性细胞，即小胶质结节。诸如弥漫性小胶质结节等病理状况与HIV-1脑炎、大脑直接感染以及中度至重度神经功能损害有关。阿米巴样小胶质细胞中TGF-β1的表达可能在HIV-1神经发病机制中起作用。
