Villalta F, Zhang Y, Bibb K E, Kappes J C, Lima M F
Department of Microbiology, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208, USA.
Infect Immun. 1998 Oct;66(10):4690-5. doi: 10.1128/IAI.66.10.4690-4695.1998.
This paper describes a new role for the cysteine-cysteine (CC) chemokines RANTES, MIP-1alpha, and MIP-1beta on human macrophage function, which is the induction of nitric oxide (NO)-mediated trypanocidal activity. In a previous report, we showed that RANTES, MIP-1alpha and MIP-1beta enhance Trypanosoma cruzi uptake and promote parasite killing by human macrophages (M. F. Lima, Y. Zhang, and F. Villalta, Cell. Mol. Biol. 43:1067-1076, 1997). Here we study the mechanism by which RANTES, MIP-1alpha, and MIP-1beta activate human macrophages obtained from healthy individuals to kill T. cruzi. Treatment of human macrophages with different concentrations of RANTES, MIP-1alpha, and MIP-1beta enhances T. cruzi trypomastigote phagocytosis in a dose peak response. The optimal response induced by the three CC chemokines is attained at 500 ng/ml. The macrophage trypanocidal activity induced by CC chemokines can be completely inhibited by L-N-monomethyl arginine (L-NMMA), a specific inhibitor of the L-arginine:NO pathway, but not by its D-enantiomer. Culture supernatants of chemokine-treated human macrophages contain increased NO2- levels, and NO2- production is also specifically inhibited by L-NMMA. The amount of NO2- induced by these chemokines in human macrophages is comparable to the amount of NO2- induced by gamma interferon. The killing of trypomastigotes by NO in cell-free medium is blocked by an NO antagonist or a NO scavenger. This data supports the hypothesis that the CC chemokines RANTES, MIP-1alpha, and MIP-1beta activate human macrophages to kill T. cruzi via NO, which is an effective trypanocidal mechanism.
本文描述了半胱氨酸-半胱氨酸（CC）趋化因子调节活化正常T细胞表达和分泌因子（RANTES）、巨噬细胞炎性蛋白-1α（MIP-1α）和巨噬细胞炎性蛋白-1β（MIP-1β）在人类巨噬细胞功能方面的新作用，即诱导一氧化氮（NO）介导的杀锥虫活性。在之前的一份报告中，我们表明RANTES、MIP-1α和MIP-1β可增强克氏锥虫的摄取，并促进人类巨噬细胞对寄生虫的杀伤作用（M.F.利马、Y.张和F.比利亚尔塔，《细胞与分子生物学》43:1067 - 1076，1997）。在此，我们研究RANTES、MIP-1α和MIP-1β激活从健康个体获取的人类巨噬细胞以杀伤克氏锥虫的机制。用不同浓度的RANTES、MIP-1α和MIP-1β处理人类巨噬细胞，可增强克氏锥虫无鞭毛体的吞噬作用，并呈现剂量峰值反应。三种CC趋化因子诱导的最佳反应在500纳克/毫升时达到。CC趋化因子诱导的巨噬细胞杀锥虫活性可被L - N - 单甲基精氨酸（L - NMMA）完全抑制，L - NMMA是L - 精氨酸：NO途径的特异性抑制剂，但其D - 对映体则无此作用。趋化因子处理的人类巨噬细胞培养上清液中NO2-水平升高，且NO2-的产生也被L - NMMA特异性抑制。这些趋化因子在人类巨噬细胞中诱导产生的NO2-量与γ干扰素诱导产生的NO2-量相当。在无细胞培养基中，NO对无鞭毛体的杀伤作用可被NO拮抗剂或NO清除剂阻断。这些数据支持以下假说：CC趋化因子RANTES、MIP-1α和MIP-1β通过NO激活人类巨噬细胞以杀伤克氏锥虫，这是一种有效的杀锥虫机制。
