CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, PR China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, PR China.
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, PR China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, PR China.
Fish Shellfish Immunol. 2018 Oct;81:423-429. doi: 10.1016/j.fsi.2018.05.062. Epub 2018 Jun 1.
Hemocytes are the first line of defence of the innate immune system of molluscs. For the first time hemocytes of Crassostrea hongkongensis were morphologically and functionally characterized, identifying circulating cell types and studying their involvement in immune responses. In the present study, two main populations, hyalinocytes and granulocytes, were characterized based on the presence or absence of cytoplasmic granules, using light and electron microscopy (TEM), and flow cytometry analyses. Granulocytes are 7-13 μm in diameter and present evident cytoplasmic granules, and hyalinocytes, 6-15 μm in diameter, with a few or no granules. The mean number of circulating hemocytes in the hemolymph was 2.52 × 10 cells/mL. Flow cytometry indicated that both granulocytes and hyalinocytes showed cell phagocytosis and reactive oxygen species (ROS) production. However, phagocytosis and spontaneous production of reactive oxygen species (ROS) in granulocytes are much more active compared with hyalinocytes, which demonstrated that the granulocytes are the main hemocytes involved in the immune response of Hong Kong oyster. Moreover, the cell-free hemolymph showed antibacterial activity against Vibrio alginolyticus. Our results provide the basic information of hemocytes population of Hong Kong oyster for further investigations associated with innate immunity.
血细胞是软体动物先天免疫系统的第一道防线。本研究首次对香港牡蛎的血细胞进行了形态学和功能表征，鉴定了循环细胞类型，并研究了它们在免疫反应中的参与情况。本研究采用光镜和电子显微镜（TEM）以及流式细胞术分析，根据细胞质颗粒的存在与否，将两种主要的细胞群（透明细胞和粒细胞）进行了特征描述。粒细胞直径为 7-13μm，存在明显的细胞质颗粒，而透明细胞直径为 6-15μm，颗粒较少或没有。在血淋巴中循环的血细胞平均数量为 2.52×10^6 个/毫升。流式细胞术表明，粒细胞和透明细胞均表现出细胞吞噬作用和活性氧物质（ROS）的产生。然而，与透明细胞相比，粒细胞的吞噬作用和自发产生活性氧物质（ROS）更为活跃，这表明粒细胞是参与香港牡蛎免疫反应的主要血细胞。此外，无细胞血淋巴对溶藻弧菌具有抗菌活性。我们的研究结果为进一步研究香港牡蛎的先天免疫相关内容提供了血细胞群体的基础信息。
