Girard M, Ayed Z, Preux P M, Bouteille B, Preud'Homme J L, Dumas M, Jauberteau M O
Laboratories of Immunology and CNRS ESA 6031 (University Hospital) Limoges, France.
Parasite Immunol. 2000 Jan;22(1):7-12. doi: 10.1046/j.1365-3024.2000.00264.x.
In stage II human african trypanosomiasis (HAT), which is characterized by central nervous system (CNS) involvement, neurones and oligodendrocytes might be targets of dysimmune processes. Nitric oxide (NO) production by peripheral macrophages is documented in HAT. We studied the production of NO by murine astrocytes and microglia cocultured with Trypanosoma brucei (T. b.) brucei AnTat 1.9. Purified astrocytes or microglia from mouse brains were cocultured with T. b. brucei, and in some instances with interferon (IFN)-gamma, which is known to be released during the disease and also to be a growth factor for trypanosomes. Inducible NO synthase (iNOS) expression was studied by indirect immunofluorescence and reverse transcriptase-polymerase chain reaction. NO production was determined by measuring nitrite generation in culture. Detection of iNOS in astrocytes and microglia in the presence of T. b. brucei, was closely associated with nitrite production and was strongly enhanced by the addition of IFN-gamma to the culture medium. The stimulation of iNOS activity required parasite-cell contact and likely occurred at the transcriptional level. This study demonstrates the induction of iNOS in CNS-related macrophage cells in the presence of trypanosomes and its potentiation by IFN-gamma.
在以中枢神经系统（CNS）受累为特征的二期人类非洲锥虫病（HAT）中，神经元和少突胶质细胞可能是免疫失调过程的靶标。在HAT中已证实外周巨噬细胞可产生一氧化氮（NO）。我们研究了与布氏锥虫（T. b.）brucei AnTat 1.9共培养的小鼠星形胶质细胞和小胶质细胞产生NO的情况。从小鼠脑中分离出的纯化星形胶质细胞或小胶质细胞与布氏锥虫共培养，在某些情况下还与干扰素（IFN）-γ共培养，已知IFN-γ在疾病期间会释放，并且还是锥虫的生长因子。通过间接免疫荧光和逆转录聚合酶链反应研究诱导型一氧化氮合酶（iNOS）的表达。通过测量培养物中亚硝酸盐的生成来确定NO的产生。在布氏锥虫存在的情况下，星形胶质细胞和小胶质细胞中iNOS的检测与亚硝酸盐的产生密切相关，并且向培养基中添加IFN-γ可强烈增强这种相关性。iNOS活性的刺激需要寄生虫与细胞接触，并且可能发生在转录水平。这项研究证明了在锥虫存在的情况下，CNS相关巨噬细胞中iNOS的诱导及其被IFN-γ增强的作用。
