Molecular characterization of a new IgZ3 subclass in common carp (Cyprinus carpio) and comparative expression analysis of IgH transcripts during larvae development.
Molecular characterization of a new IgZ3 subclass in common carp (Cyprinus carpio) and comparative expression analysis of IgH transcripts during larvae development.
复制标题
DOI：
10.1186/s12917-021-02844-7
复制
发表时间：
2021-04-14
影响因子：
2.6
通讯作者：
Yang G
中科院分区：
文献类型：
--
作者：
Zhang F;Li M;Lv C;Wei G;Wang C;Wang Y;An L;Yang G
分布在全身免疫组织和粘膜免疫组织中的免疫球蛋白（Igs）在保护硬骨鱼免受富含病原体的水生环境中的感染方面发挥着重要作用。具有不同组织表达模式的硬骨鱼IgZ/IgT亚类可能具有不同的免疫功能。在本研究中，在鲤鱼（Cyprinus carpio）中克隆并鉴定了一种新型分泌型 IgZ 重链基因。该基因表现出与报道的基因 IgZ1 和 IgZ2 不同的组织特异性表达谱。获得的 IgZ 样亚类基因命名为 CcIgZ3，具有完整的开放阅读框，包含 1650 bp，编码 549 个氨基酸残基的蛋白质。系统发育分析表明，CcIgZ3 与鲤鱼 IgZ2 属于同一分支，并且与其他硬骨鱼的 IgZ/IgT 基因处于同一分支。对健康成年鲤鱼免疫球蛋白重链（IgH）的基础表达检测表明，CcIgZ3转录本在全身免疫组织和粘膜相关淋巴组织中广泛表达。 CcIgZ3在头肾、鳃和性腺中表达水平最高，其次是脾脏、后肠、口腔上皮、肝脏、脑、肌肉、前肠和血液；它在皮肤中的表达水平非常低。外周血细胞中分离的白细胞中CcIgZ3的转录表达量显着高于脾脏中分离的白细胞。通过腹腔注射或浸泡的方式感染不同群体的鲤鱼。 RT-qPCR 分析表明，在所有检查组织（包括头肾、脾脏、肝脏和后肠）中，浸泡组和注射组之间的 CcIgZ3 mRNA 水平存在显着差异。特别是，浸泡组后肠中的 CcIgZ3 mRNA 水平高于注射组。鲤鱼中不同途径的嗜水气单胞菌暴露对 IgM 反应的影响比对 CcIgZ3 反应的影响要轻。进一步研究鲤鱼发育过程中IgH基因的相对表达情况表明，CcIgZ3的组织特异性表达谱与其他基因有很大不同。 RT-qPCR分析表明，鲤鱼受精后1天至31天幼虫发育早期，CcIgZ3 mRNA水平逐渐升高，动态趋势与IgZ1和IgZ2类似，其中IgM为优势Ig，丰度明显升高。对鲤鱼 65 dpf 后 IgH 组织特异性表达的分析表明，CcIgZ3 在粘膜部位表达，包括后肠和鳃；相反，IgZ1优先在后肠中表达，IgZ2优先在鳃中表达。除了RT-qPCR分析之外，还进行原位杂交来检测CcIgZ3表达细胞和IgM表达细胞。结果表明，65 dpf 后，在鲤鱼的脾脏、鳃和后肠中可检测到 CcIgZ3 和 IgM 转录本。这些结果表明，CcIgZ3基因转录物在鲤鱼的发育阶段不仅在全身组织而且在粘膜组织中表达。嗜水气单胞菌通过浸泡和腹腔注射攻击可以在免疫组织中诱导CcIgZ3表达，且表达谱差异显着，这表明CcIgZ3参与抗菌免疫反应，并可能在肠道粘膜免疫中发挥重要作用。
Immunoglobulins (Igs) distributed among systemic immune tissues and mucosal immune tissues play important roles in protecting teleosts from infections in the pathogen-rich aquatic environment. Teleost IgZ/IgT subclasses with different tissue expression patterns may have different immune functions. In the present study, a novel secreted IgZ heavy chain gene was cloned and characterized in common carp (Cyprinus carpio). This gene exhibited a different tissue-specific expression profile than the reported genes IgZ1 and IgZ2. The obtained IgZ-like subclass gene designated CcIgZ3, had a complete open reading frame contained 1650 bp encoding a protein of 549 amino acid residues. Phylogenetic analysis revealed that CcIgZ3 was grouped with carp IgZ2 and was in the same branch as IgZ/IgT genes of other teleosts. Basal expression detection of the immunoglobulin heavy chain (IgH) in healthy adult common carp showed that CcIgZ3 transcripts were widely expressed in systemic immune tissues and mucosal-associated lymphoid tissues. CcIgZ3 was expressed at the highest levels in the head kidneys, gills, and gonads, followed by the spleen, hindgut, oral epithelium, liver, brain, muscle, foregut, and blood; it was expressed at a very low level in the skin. The transcript expression of CcIgZ3 in leukocytes isolated from peripheral blood cells was significantly higher than that in leukocytes isolated from the spleen. Different groups of common carp were infected with Aeromonas hydrophila via intraperitoneal injection or immersion. RT-qPCR analysis demonstrated that significant differences in CcIgZ3 mRNA levels existed between the immersion and injection groups in all the examined tissues, including the head kidney, spleen, liver, and hindgut; in particular, the CcIgZ3 mRNA level in the hindgut was higher in the immersion group than in the injection group. The different routes of A. hydrophila exposure in common carp had milder effects on the IgM response than on the CcIgZ3 response. Further study of the relative expression of the IgH gene during the development of common carp showed that the tissue-specific expression profile of CcIgZ3 was very different from those of other genes. RT-qPCR analysis demonstrated that the CcIgZ3 mRNA level increased gradually in common carp during the early larval development stage from 1 day post fertilization (dpf) to 31 dpf with a dynamic tendency similar to those of IgZ1 and IgZ2, and IgM was the dominant Ig with obviously elevated abundance. Analyses of the tissue-specific expression of IgHs in common carp at 65 dpf showed that CcIgZ3 was expressed at mucosal sites, including both the hindgut and gill; in contrast, IgZ1 was preferentially expressed in the hindgut, and IgZ2 was preferentially expressed in the gill. In addition to RT-qPCR analysis, in situ hybridization was performed to detect CcIgZ3-expressing cells and IgM-expressing cells. The results showed that CcIgZ3 and IgM transcripts were detectable in the spleens, gills, and hindguts of common carp at 65 dpf. These results reveal that CcIgZ3 gene transcripts are expressed in common carp during developmental stage not only in systemic tissues but also in mucosal tissues. CcIgZ3 expression can be induced in immune tissues by A. hydrophila challenge via immersion and intraperitoneal injection with significantly different expression profiles, which indicates that CcIgZ3 is involved in the antimicrobial immune response and might play an important role in gut mucosal immunity.
登录
查看更多内容
影响因子：
5.5
作者：
Hordvik I
通讯作者：
Hordvik I
影响因子：
2.9
作者：
Chettri, Jiwan K.;Raida, Martin K.;Buchmann, Kurt
通讯作者：
Buchmann, Kurt
影响因子：
2.9
作者：
KOUMANSVANDIEPEN, JCE;EGBERTS, E;ROMBOUT, JHWM
通讯作者：
ROMBOUT, JHWM
影响因子：
3.2
作者：
Savan, R;Aman, A;Sakai, M
通讯作者：
Sakai, M
影响因子：
2.9
作者：
Velazquez, Janet;Acosta, Jannel;Pablo Estrada, Mario
通讯作者：
Pablo Estrada, Mario