Centro de Investigación en Sanidad Animal (CISA-INIA), Valdeolmos, Madrid, Spain.
Dev Comp Immunol. 2012 Oct;38(2):302-11. doi: 10.1016/j.dci.2012.07.001. Epub 2012 Jul 31.
In mammals, CCR7 is the chemokine receptor for the CCL19 and CCL21 chemokines, molecules with a major role in the recruitment of lymphocytes to lymph nodes and Peyer's patches in the intestinal mucosa, especially naïve T lymphocytes. In the current work, we have identified a CCR7 orthologue in rainbow trout (Oncorhynchus mykiss) that shares many of the conserved features of mammalian CCR7. The receptor is constitutively transcribed in the gills, hindgut, spleen, thymus and gonad. When leukocyte populations were isolated, IgM(+) cells, T cells and myeloid cells from head kidney transcribed the CCR7 gene. In blood, both IgM(+) and IgT(+) B cells and myeloid cells but not T lymphocytes were transcribing CCR7, whereas in the spleen, CCR7 mRNA expression was strongly detected in T lymphocytes. In response to infection with viral hemorrhagic septicemia virus (VHSV), CCR7 transcription was down-regulated in spleen and head kidney upon intraperitoneal infection, whereas upon bath infection, CCR7 was up-regulated in gills but remained undetected in the fin bases, the main site of virus entry. Concerning its regulation in the intestinal mucosa, the ex vivo stimulation of hindgut segments with Poly I:C or inactivated bacteria significantly increased CCR7 transcription, while in the context of an infection with Ceratomyxa shasta, the levels of transcription of CCR7 in both IgM(+) and IgT(+) cells from the gut were dramatically increased. All these data suggest that CCR7 plays an important role in lymphocyte trafficking during rainbow trout infections, in which CCR7 appears to be implicated in the recruitment of B lymphocytes into the gut.
在哺乳动物中，CCR7 是趋化因子 CCL19 和 CCL21 的趋化因子受体，这些分子在淋巴细胞向淋巴结和肠道黏膜中的派尔氏斑的募集中起主要作用，特别是幼稚 T 淋巴细胞。在目前的工作中，我们在虹鳟鱼（Oncorhynchus mykiss）中鉴定了一个 CCR7 同源物，它与哺乳动物 CCR7 有许多保守特征。该受体在鳃、后肠、脾脏、胸腺和性腺中持续转录。当分离白细胞群体时，头部肾脏中的 IgM(+)细胞、T 细胞和髓样细胞转录了 CCR7 基因。在血液中，IgM(+)和 IgT(+)B 细胞和髓样细胞均转录 CCR7，但 T 淋巴细胞不转录，而在脾脏中，T 淋巴细胞强烈表达 CCR7 mRNA。在感染病毒性出血性败血症病毒（VHSV）时，腹腔内感染后脾脏和头部肾脏中的 CCR7 转录下调，而在水浴感染时，鳃中 CCR7 上调，但在 fins 基部（病毒进入的主要部位）未检测到。关于其在肠道黏膜中的调节，用 Poly I:C 或灭活细菌体外刺激后肠段显著增加了 CCR7 转录，而在感染 Ceratomyxa shasta 的情况下，肠道中 IgM(+)和 IgT(+)细胞的 CCR7 转录水平均显著增加。所有这些数据表明，CCR7 在虹鳟鱼感染期间的淋巴细胞迁移中发挥重要作用，CCR7 似乎参与了 B 淋巴细胞向肠道的募集。
