Silveira Amanda S, Matos Gabriel M, Falchetti Marcelo, Ribeiro Fabio S, Bressan Albert, Bachère Evelyne, Perazzolo Luciane M, Rosa Rafael D
Laboratory of Immunology Applied to Aquaculture, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, 88040-900 Florianópolis, SC, Brazil.
Ifremer, UMR 5244, IHPE Interactions-Hosts-Pathogens-Environment, UPVD, CNRS, Université de Montpellier, CC 080, F-34095 Montpellier, France.
Dev Comp Immunol. 2018 Feb;79:44-50. doi: 10.1016/j.dci.2017.10.005. Epub 2017 Oct 14.
Much of our current knowledge on shrimp immune system is restricted to the defense reactions mediated by the hemocytes and little is known about gut immunity. Here, we have investigated the transcriptional profile of immune-related genes in different organs of the digestive system of the shrimp Litopenaeus vannamei. First, the tissue distribution of 52 well-known immune-related genes has been assessed by semiquantitative analysis in the gastrointestinal tract (foregut, midgut and hindgut) and in the hepatopancreas and circulating hemocytes of shrimp stimulated or not with heat-killed bacteria. Then, the expression levels of 18 genes from key immune functional categories were quantified by fluorescence-based quantitative PCR in the midgut of animals experimentally infected with the Gram-negative Vibrio harveyi or the White spot syndrome virus (WSSV). Whereas the expression of some genes was induced at 48 h after the bacterial infection, any of the analyzed genes showed to be modulated in response to the virus. Whole-mount immunofluorescence assays confirmed the presence of infiltrating hemocytes in the intestines, indicating that the expression of some immune-related genes in gut is probably due to the migratory behavior of these circulating cells. This evidence suggests the participation of hemocytes in the delivery of antimicrobial molecules into different portions of the digestive system. Taken all together, our results revealed that gut is an important immune organ in L. vannamei with intimate association with hemocytes.
我们目前对虾免疫系统的了解大多局限于血细胞介导的防御反应，而对肠道免疫知之甚少。在此，我们研究了凡纳滨对虾消化系统不同器官中免疫相关基因的转录谱。首先，通过半定量分析评估了52个知名免疫相关基因在经热灭活细菌刺激或未刺激的虾的胃肠道（前肠、中肠和后肠）、肝胰腺和循环血细胞中的组织分布。然后，通过基于荧光的定量PCR对实验感染革兰氏阴性哈维氏弧菌或白斑综合征病毒（WSSV）的动物中肠中18个关键免疫功能类别的基因表达水平进行了定量。虽然某些基因的表达在细菌感染后48小时被诱导，但所分析的基因中没有一个显示出对病毒有反应性调节。全组织免疫荧光分析证实肠道中有浸润的血细胞，这表明肠道中一些免疫相关基因的表达可能归因于这些循环细胞的迁移行为。这一证据表明血细胞参与了抗菌分子向消化系统不同部位的传递。综上所述，我们的结果表明肠道是凡纳滨对虾的一个重要免疫器官，与血细胞密切相关。
