Barbosa M A G, Alexandre-Pires G, Soares-Clemente M, Marques C, Rodrigues O Roos, De Brito T Villa, Da Fonseca I Pereira, Alves L C, Santos-Gomes G M
Universidade Federal Rural de Pernambuco, Departamento de Medicina Veterinária, Recife, Pernambuco, Brazil.
J Comp Pathol. 2011 Nov;145(4):336-44. doi: 10.1016/j.jcpa.2011.03.001. Epub 2011 Apr 20.
Canine leishmaniosis (CanL) caused by the protozoan parasite Leishmania infantum is a chronic systemic disease that is endemic in certain parts of the world. The domestic dog is the most important reservoir of L. infantum and is the main source of infection for other animals and for the human population. The aim of this study was to evaluate and compare the level of expression of genes encoding particular cytokines (interleukin [IL]-12, interferon [IFN]-γ, IL-2 and IL-4) in different tissues and organs of 53 adult dogs with or without clinical signs of leishmaniosis and after treatment for the disease. Asymptomatic dogs showed high expression of genes encoding IL-4 in blood leucocytes and of genes encoding IL-12 and IL-2 in lymph nodes. Blood leucocytes from symptomatic dogs had a mixed Th1 and Th2 cytokine gene expression profile, but lymph nodes from these animals had dominant IL-2 and IFN-γ gene expression, while bone marrow appeared to be unresponsive. The predominance of IL-4 gene expression in the blood of asymptomatic dogs may favour parasite replication, while the balance between Th1 and Th2 cytokine gene expression in the blood of symptomatic dogs may be important in reducing parasite replication and delaying the dissemination of Leishmania to other organs. The drugs used to treat CanL do not completely eliminate the parasite, so the high expression of the gene encoding IL-4 in blood leucocytes and the high expression of IL-12 and IL-4 mRNA in lymph nodes may reflect the persistence of residual Leishmania amastigotes. L. infantum appears able to regulate the host immune response in order to ensure its survival, but also to prevent the host from succumbing to infection. This guarantees its transmission and the completion of its life cycle.
由原生动物寄生虫婴儿利什曼原虫引起的犬利什曼病（CanL）是一种慢性全身性疾病，在世界某些地区流行。家犬是婴儿利什曼原虫最重要的储存宿主，是其他动物和人类的主要感染源。本研究的目的是评估和比较53只患有或未患有利什曼病临床症状以及经过疾病治疗的成年犬不同组织和器官中特定细胞因子（白细胞介素[IL]-12、干扰素[IFN]-γ、IL-2和IL-4）编码基因的表达水平。无症状犬的血液白细胞中IL-4编码基因以及淋巴结中IL-12和IL-2编码基因表达较高。有症状犬的血液白细胞具有混合的Th1和Th2细胞因子基因表达谱，但这些动物的淋巴结具有占主导地位的IL-2和IFN-γ基因表达，而骨髓似乎无反应。无症状犬血液中IL-4基因表达占优势可能有利于寄生虫复制，而有症状犬血液中Th1和Th2细胞因子基因表达之间的平衡可能在减少寄生虫复制和延缓利什曼原虫向其他器官传播方面很重要。用于治疗CanL的药物不能完全消除寄生虫，因此血液白细胞中IL-4编码基因的高表达以及淋巴结中IL-12和IL-4 mRNA的高表达可能反映了残留利什曼无鞭毛体的持续存在。婴儿利什曼原虫似乎能够调节宿主免疫反应，以确保其生存，同时也防止宿主因感染而死亡。这保证了其传播和生命周期的完成。
