Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil.
Fundação Ezequiel Dias, Belo Horizonte, Brazil.
BMC Microbiol. 2019 Jan 7;19(1):4. doi: 10.1186/s12866-018-1371-9.
Leptospirosis is a widespread zoonosis caused by pathogenic prokaryotic microbes of the genus Leptospira. Although there are several reports in the literature, host-pathogen interaction is still poorly understood. The role of chemokine expression is important on the chemotaxis, activation and regulation of immune cells. Recent studies have shown that their expression profiles play an important role on the severity of leptospirosis outcome. We evaluated the phagocytosis of Leptospira by spleens cells from C3H/HeJ, C3H/HePas and BALB/c mouse strains, respectively susceptible, intermediate and resistant to leptospirosis, and by RAW 264.7 macrophages. Besides, we evaluated the effects of CCL2 treatment on the phagocytosis. The cells were incubated with or without CCL2 chemokine, and infected with virulent L. interrogans sv Copenhageni. Cells and culture supernatants were collected for subsequent analysis.
The number of leptospires was higher in BALB/c cells, CCL2 pre-treated or only infected groups, when compared to C3H/HeJ and C3H/HePas cells. Indeed, CCL2 activation did not interfere in the phagocytosis of Leptospira. Expression of chemokines CXCL5 and CCL8 levels were significantly inhibited in infected BALB/c cells when compared to the non-infected control.
Higher ability to phagocytosis and early modulation of some chemokines correlated with the resistance to leptospirosis disease. Exposure to CCL2 did not interfere on phagocytosis of Leptospira in our experimental conditions, but acted in the modulation of chemokines expression during Leptospira infection.
钩端螺旋体病是一种由钩端螺旋体属的致病性原核微生物引起的广泛人畜共患病。尽管文献中有几篇报道，但宿主-病原体相互作用仍知之甚少。趋化因子表达的作用对于免疫细胞的趋化、激活和调节非常重要。最近的研究表明，它们的表达谱在钩端螺旋体病的严重程度中起着重要作用。我们评估了 C3H/HeJ、C3H/HePas 和 BALB/c 三种对钩端螺旋体易感性不同的小鼠品系的脾细胞以及 RAW 264.7 巨噬细胞对钩端螺旋体的吞噬作用，并评估了 CCL2 处理对吞噬作用的影响。细胞在有或没有 CCL2 趋化因子的情况下孵育，并感染强毒力的 L. interrogans sv Copenhageni。收集细胞和培养上清液进行后续分析。
与 C3H/HeJ 和 C3H/HePas 细胞相比，BALB/c 细胞、CCL2 预处理或仅感染组的钩端螺旋体数量更高。事实上，CCL2 的激活并没有干扰对钩端螺旋体的吞噬作用。与未感染对照组相比，感染 BALB/c 细胞的趋化因子 CXCL5 和 CCL8 水平的表达明显受到抑制。
更高的吞噬能力和某些趋化因子的早期调节与对钩端螺旋体病的抗性相关。在我们的实验条件下，暴露于 CCL2 不会干扰对钩端螺旋体的吞噬作用，但会在钩端螺旋体感染期间调节趋化因子的表达。
