Wu Jing, Nie Yifan, Wang Jingya, Feng Guoqing, Hao Le, Ma Yanping, Li Yugu, Liu Zhenxing
Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
J Fish Biol. 2023 Jan;102(1):128-140. doi: 10.1111/jfb.15246. Epub 2022 Nov 4.
The potential for phagocytosis has been proven in teleost B cells, but the research on the regulatory mechanism of phagocytosis remains lacking. In this study, three largemouth bass (Micropterus salmoides) (15 ± 5 g) were injected intraperitoneally with Nocardia seriolae (10 CFU/100 μl/fish) in vivo, and their spleen was collected at 72 h post-infection for mRNA-seq. After the de novo assembly of the paired-end reads, 73,622 unigenes were obtained. Gene expression profiling revealed that 2043 unigenes were differentially expressed after N. seriolae infection, comprising 1285 upregulated and 758 downregulated unigenes (q-value <0.05, log2FC > |2|) of which 181 genes were involved in phagocytosis. The Kyoto Encyclopaedia of Genes and Genomes (KEGG) analysis demonstrated that 12 differentially expressed genes (DEG) associated with phagocytosis were enriched in the Fcγ receptor-mediated phagocytosis signalling pathway. In vitro, the phagocytic ability of mIgM B lymphocytes was validated using indirect immunofluorescence assay (IIFA) and fluorescence activating cell sorter (FACS), and the phagocytosis rates of the mIgM B lymphocytes incubated with a Lyn inhibitor had decreased from 18.533 ± 6.00% to 11.610 ± 4.236% compared with the unblocked group. These results suggested that the Fcγ receptor-mediated phagocytosis signalling pathway had participated in the phagocytosis of B cells and provide further insight into the role of B cells in innate immunology.
硬骨鱼B细胞的吞噬潜力已得到证实，但关于吞噬作用调控机制的研究仍然不足。在本研究中，将3尾大口黑鲈（Micropterus salmoides）（15±5克）腹腔注射嗜水气单胞菌（10 CFU/100μl/鱼）进行体内感染，于感染后72小时采集脾脏进行mRNA测序。对双端读数进行从头组装后，获得了73,622个单基因。基因表达谱分析显示，嗜水气单胞菌感染后有2043个单基因差异表达，其中1285个上调，758个下调（q值<0.05，log2FC>|2|），其中181个基因参与吞噬作用。京都基因与基因组百科全书（KEGG）分析表明，12个与吞噬作用相关的差异表达基因（DEG）富集在Fcγ受体介导的吞噬信号通路中。在体外，使用间接免疫荧光法（IIFA）和荧光激活细胞分选仪（FACS）验证了mIgM B淋巴细胞的吞噬能力，与未阻断组相比，用Lyn抑制剂孵育的mIgM B淋巴细胞的吞噬率从18.533±6.00%降至11.610±4.236%。这些结果表明，Fcγ受体介导的吞噬信号通路参与了B细胞的吞噬作用，并为B细胞在固有免疫中的作用提供了进一步的见解。
