栉孔扇贝血液细胞的免疫功能

Immunological functions of blood cells in the scallop Chlamys farreri

利用光镜、扫描电镜和透射电镜技术对栉孔扇贝(Chlamysferreri)血细胞与细胞免疫功能相关的几个因素进行了初步研究。对血细胞的数量和不同功能细胞的比例研究结果表明,健康血淋巴中血细胞的平均密度为3.03±0.11×107cell/ml,其中颗粒细胞占42.6%,透明细胞占57.4%;病贝血淋巴中血细胞的平均密度为2.78±0.34×107cell/ml,其中颗粒细胞占40.2%,透明细胞占59.8%。扫描电镜观察表明,血细胞的表面结构主要有表面光滑型,表面松果型和表面褶皱阿米巴型3类。透射电镜观察表明,颗粒细胞吞噬外源性颗粒(Ⅰ型颗粒)通过溶酶体(Ⅱ型颗粒)进行降解。并观察到同心片层结构出现在吞噬泡的降解过程中。利用APIZYM试剂盒对栉孔扇贝血细胞及血清中的19种酶进行检测,结果在血清中检测到了13种酶,在血细胞中检测到10种酶,健康血淋巴中酶的含量高于病贝。对血细胞吞噬活性的研究结果表明,血细胞对大肠杆菌和对类立克次体(RLO)的吞噬率分别为25.4%和21.7%。颗粒细胞的吞噬活性(30%-40%)远远大于透明细胞(4.8%-14%)。环境胁迫对血细胞吞噬活性的影响的研究结果表明,病原菌感染和温度、盐度等环境胁迫因素对血细胞的吞噬活性均有不同程度的影响,其中高温因素影响较大。

The internal defence system of bivalves is mostly represented by circulating haemocytes of the haemolymph. Light, electron and scanning electron microscopic studies were conducted to characterize the haemocytes and several parameters associated with cellular immunity in the scallop Chlarnys farreri. The hemocyte densities in healthy and diseased scallop haemolymph were assessed 3.03±0.11×10^7 cell/ml and 2.78±0.34×10^7 cell/ml, respectively. The healthy haemolymph was comprised of about 42.6% granulocytes and 57.4 hyalinocytes, and the diseased haemolymph showed 40.2% and 59.8%, respectively. Assays of APIZYM on enzymatic activities of 19 enzymes in haemolymph were performed and, of these, 13 and 10 enzymes were detected in serum and cells, respectively. The level of these enzymes were higher in healthy haemolymph than in diseased ones. The results of phagocytosis revealed that phagocytic abilities for E.coli and Rickettsia-like organisms （RLOs） were 25.4% and 21.7% , respectively. Both granulocytes and hyalinocytes showed phagocytic response to the two strains of bacteria, E.coli and RLOs when incubated in suspension. The phagocytic ability of granulocyte which was 30%-40% was significantly higher than that of hyalinocyte which was 4.8%-14%. The study of influence of environmental stress factors on phagocytosis activity revealed that the stress of pathogen infection and higher temperature could reduce the phagocytosis activity, and no significant influence of senility or age showed in this study [Acta Zoologica Sinica 51（4）： 669-677, 2005].