Laboratory of Experimental Immunology, BioMediTech Institute and Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland.
Laboratory of Immunoregulation, BioMediTech Institute and Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland.
Sci Rep. 2019 Jan 30;9(1):995. doi: 10.1038/s41598-018-37678-1.
Tuberculosis is a multifactorial bacterial disease, which can be modeled in the zebrafish (Danio rerio). Abdominal cavity infection with Mycobacterium marinum, a close relative of Mycobacterium tuberculosis, leads to a granulomatous disease in adult zebrafish, which replicates the different phases of human tuberculosis, including primary infection, latency and spontaneous reactivation. Here, we have carried out a transcriptional analysis of zebrafish challenged with low-dose of M. marinum, and identified intelectin 3 (itln3) among the highly up-regulated genes. In order to clarify the in vivo significance of Itln3 in immunity, we created nonsense itln3 mutant zebrafish by CRISPR/Cas9 mutagenesis and analyzed the outcome of M. marinum infection in both zebrafish embryos and adult fish. The lack of functional itln3 did not affect survival or the mycobacterial burden in the zebrafish. Furthermore, embryonic survival was not affected when another mycobacterial challenge responsive intelectin, itln1, was silenced using morpholinos either in the WT or itln3 mutant fish. In addition, M. marinum infection in dexamethasone-treated adult zebrafish, which have lowered lymphocyte counts, resulted in similar bacterial burden in both WT fish and homozygous itln3 mutants. Collectively, although itln3 expression is induced upon M. marinum infection in zebrafish, it is dispensable for protective mycobacterial immune response.
结核病是一种多因素的细菌性疾病，可以在斑马鱼（Danio rerio）中建模。用亲结核分枝杆菌（Mycobacterium marinum）感染斑马鱼腹腔，会导致成年斑马鱼发生肉芽肿疾病，这种疾病复制了人类结核病的不同阶段，包括原发感染、潜伏和自发性再激活。在这里，我们对低剂量感染亲结核分枝杆菌的斑马鱼进行了转录分析，并在高度上调的基因中鉴定出凝集素 3（itln3）。为了阐明 Itln3 在免疫中的体内意义，我们通过 CRISPR/Cas9 诱变产生了无义 itln3 突变斑马鱼，并分析了亲结核分枝杆菌感染在斑马鱼胚胎和成年鱼中的结果。缺乏功能的 Itln3 不会影响斑马鱼的生存或分枝杆菌负荷。此外，当使用莫洛尼氏法在 WT 或 itln3 突变鱼中沉默另一种对分枝杆菌挑战有反应的凝集素 itln1 时，胚胎的存活率也不受影响。此外，在接受地塞米松治疗的成年斑马鱼中，由于淋巴细胞计数降低，导致亲结核分枝杆菌感染后，WT 鱼和纯合 itln3 突变体中的细菌负荷相似。总之，尽管 itln3 在斑马鱼感染亲结核分枝杆菌后表达上调，但它对于保护性的分枝杆菌免疫反应是可有可无的。
