Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China.
Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China.
Dev Comp Immunol. 2024 Jul;156:105171. doi: 10.1016/j.dci.2024.105171. Epub 2024 Mar 26.
Trace amine-associated receptors (TAARs) are a class of G protein-coupled receptors, playing an immunomodulatory function in the neuroinflammatory responses. In the present study, a TAAR homologue with a 7tm_classA_rhodopsin-like domain (designated as CgTAAR1L) was identified in oyster Crassostrea gigas. The abundant CgTAAR1L transcripts were detected in visceral ganglia and haemocytes compared to other tissues, which were 55.35-fold and 32.95-fold (p < 0.01) of those in adductor muscle, respectively. The mRNA expression level of CgTAAR1L in haemocytes significantly increased and reached the peak level at 3 h after LPS or Poly (I:C) stimulation, which was 4.55-fold and 12.35-fold of that in control group, respectively (p < 0.01). After the expression of CgTAAR1L was inhibited by the injection of its targeted siRNA, the mRNA expression levels of interleukin17s (CgIL17-1, CgIL17-5 and CgIL17-6), and defensin (Cgdefh1) significantly decreased at 3 h after LPS stimulation, which was 0.51-fold (p < 0.001), 0.39-fold (p < 0.01), 0.48-fold (p < 0.05) and 0.41-fold (p < 0.05) of that in the control group, respectively. The nuclear translocation of Cgp65 protein was suppressed in the CgTAAR1L-RNAi oysters. Furthermore, the number of Vibrio splendidus in the haemolymph of CgTAAR1L-RNAi oysters significantly increased (4.11-fold, p < 0.001) compared with that in the control group. In contrast, there was no significant difference in phagocytic rate of haemocytes to V. splendidus in the CgTAAR1L-RNAi oysters. These results indicated that CgTAAR1L played an important role in the immune defense against bacterial infection by inducing the expressions of interleukin and defensin.
痕量胺相关受体（TAARs）是一类 G 蛋白偶联受体，在神经炎症反应中发挥免疫调节功能。本研究在牡蛎（Crassostrea gigas）中鉴定了一个具有 7tm_classA_rhodopsin-like 结构域的 TAAR 同源物（命名为 CgTAAR1L）。与其他组织相比，CgTAAR1L 的大量转录本在内脏神经节和血细胞中被检测到，分别是肌肉组织的 55.35 倍和 32.95 倍（p<0.01）。在 LPS 或 Poly（I:C）刺激后，血细胞中 CgTAAR1L 的 mRNA 表达水平显著增加，并在 3 小时达到峰值，分别是对照组的 4.55 倍和 12.35 倍（p<0.01）。用其靶向 siRNA 注射抑制 CgTAAR1L 的表达后，LPS 刺激 3 小时后白细胞介素 17s（CgIL17-1、CgIL17-5 和 CgIL17-6）和防御素（Cgdefh1）的 mRNA 表达水平显著降低，分别为对照组的 0.51 倍（p<0.001）、0.39 倍（p<0.01）、0.48 倍（p<0.05）和 0.41 倍（p<0.05）。Cgp65 蛋白在 CgTAAR1L-RNAi 牡蛎中的核转位受到抑制。此外，在 CgTAAR1L-RNAi 牡蛎的血淋巴中，灿烂弧菌的数量显著增加（4.11 倍，p<0.001），与对照组相比。然而，在 CgTAAR1L-RNAi 牡蛎中，血细胞对灿烂弧菌的吞噬率没有显著差异。这些结果表明，CgTAAR1L 通过诱导白细胞介素和防御素的表达，在细菌感染的免疫防御中发挥重要作用。
