Weinstock J V, Kassab J
J Immunol. 1986 Sep 15;137(6):2020-4.
Murine Schistosomiasis mansoni is a parasitic infection associated with a delayed-type hypersensitivity granulomatous reaction to the schistosome eggs. This reaction is characterized by the accumulation of mononuclear cells and other inflammatory cell types around the eggs. Granuloma macrophages produce angiotensin II (AII), which appears to have immunoregulatory function. By using an in vitro chemotaxis assay, this study demonstrated that AII is a chemotactic factor for splenic mononuclear cells derived from infected mice. The response was bimodal, with peak activities occurring at 10(-10) and 10(-6) M. AII was chemotactic for T lymphocytes, B lymphocytes, and a large population of unidentified mononuclear cells at the optimal chemotactic concentrations of the peptide. At high concentrations, AII was also chemotactic for phagocytic mononuclear cells. Sar1, ala8-AII, an analog of AII with antagonist activity, completely blocked AII-induced chemotaxis. A [3H]-AII binding assay revealed high-affinity specific binding on spleen cells. The binding was rapid, was dependent on radioligand concentration, and was reversible. These latter observations suggest that the chemotactic activity of AII for subpopulations of splenic mononuclear cells is mediated via AII receptors.
小鼠曼氏血吸虫病是一种寄生虫感染，与对血吸虫卵的迟发型超敏反应性肉芽肿反应有关。这种反应的特征是单核细胞和其他炎症细胞类型在虫卵周围积聚。肉芽肿巨噬细胞产生血管紧张素II（AII），其似乎具有免疫调节功能。通过体外趋化性测定，本研究表明AII是来自感染小鼠的脾单核细胞的趋化因子。反应呈双峰型，在10^(-10)和10^(-6) M时出现峰值活性。在该肽的最佳趋化浓度下，AII对T淋巴细胞、B淋巴细胞和大量未鉴定的单核细胞具有趋化作用。在高浓度时，AII对吞噬性单核细胞也具有趋化作用。Sar1，ala8-AII，一种具有拮抗活性的AII类似物，完全阻断了AII诱导的趋化作用。一项[3H]-AII结合测定揭示了在脾细胞上的高亲和力特异性结合。这种结合迅速，依赖于放射性配体浓度，并且是可逆的。这些观察结果表明，AII对脾单核细胞亚群的趋化活性是通过AII受体介导的。
