Chemokines are low-molecular-weight proteins that play an important role in the inflammatory response. During the development of aquaculture for the large yellow croaker (Larimichthys crocea, L. crocea), infectious diseases caused by viruses, bacteria, and parasites have become increasingly frequent and severe. In particular, bacterial infections caused by Vibrio anguillarum result in significant economic losses. The widespread usage of antibiotics as a traditional treatment has led to an imbalance in microenvironmental conditions, which causes environmental pollution and has an ultimately negative effect on human health. In this research, we studied the gene expression of the C-C motif chemokine ligand 2 (CCL2) and C-C motif chemokine ligand 3 (CCL3) chemokines in different organs of L. crocea after infection with V. anguillarum. The novel nucleotide sequences encoding L. crocea CCL2 and CCL3 were determined as a result of the performed analysis. We identified the transcriptional levels of these chemokine genes (CCL2 and CCL3) in the organs of L. crocea individuals infected with V. anguillarum and studied the effective domain of the response mechanism of CCL2 and CCL3. Real-time PCR results showed a quantitative increase in the expression of the two types of genes in certain organs. These results could be useful for the study of the mechanisms of innate immune activation in fish species and the role of chemokines in enhancing the immune response. This information could help in developing methods of disease resistance in the aquaculture industry and, thus, decrease the amounts of antibiotic and chemical drugs used to treat fish.

中文翻译：

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大黄鱼 (Larimichthys Crocea) 中 CCL2 和 CCL3 趋化因子的抗感染免疫机制

趋化因子是低分子量蛋白质，在炎症反应中起重要作用。在大黄鱼（Larimichthys crocea、L. crocea）养殖发展过程中，病毒、细菌、寄生虫等引起的传染病日趋频繁和严重。尤其是鳗弧菌引起的细菌感染造成重大经济损失。抗生素作为传统治疗方法的广泛使用导致微环境条件失衡，从而造成环境污染并最终对人类健康产生负面影响。在本研究中，我们研究了大黄鱼在感染鳗鲡后不同器官中 CC 基序趋化因子配体 2 (CCL2) 和 CC 基序趋化因子配体 3 (CCL3) 趋化因子的基因表达。作为所进行分析的结果，确定了编码大黄鱼CCL2和CCL3的新核苷酸序列。我们确定了这些趋化因子基因（CCL2 和 CCL3）在大黄鱼个体器官中的转录水平。V. anguillarum并研究了 CCL2 和 CCL3 响应机制的有效域。实时荧光定量 PCR 结果显示这两种基因在某些器官中的表达量有所增加。这些结果可用于研究鱼类先天免疫激活的机制和趋化因子在增强免疫反应中的作用。这些信息可以帮助开发水产养殖业的抗病方法，从而减少用于治疗鱼类的抗生素和化学药物的数量。