甲壳动物血细胞在宿主免疫应答中发挥着重要的作用，其中包括识别、吞噬、包囊黑色素形成、胞毒作用和胞间的信息传递。不同类型的血细胞其防御机制不同，因此血细胞的形态和分类是甲壳动物免疫学的基础。通常情况，十足目甲壳动物的血细胞类型主要依据细胞质中颗粒物质的有无和颗粒物质的相对大小进行分类。研究采用Giemsa染色法、H.E染色法和电子显微技术法对克氏原螯虾血细胞进行分类，观察到3类血细胞：透明细胞、小颗粒细胞、大颗粒细胞，它们所占的比例分别为19.9%，46.1%，34.1%。在电镜下，这3类血细胞的超微结构极为容易辨识。透明细胞通常在3类细胞中最小，核质（N/C）比最高，但无明显的颗粒；相比之下，小颗粒细胞和大颗粒细胞内部的颗粒数量逐渐增多。利用体内和体外培养技术研究克氏原螯虾血细胞对外源体（以Sephadex A-25色谱硅珠作为抗原）的包囊作用，初步探讨克氏原螯虾血细胞在对外源体免疫应答过程中的识别机理。将Sephadex A-25色谱硅珠植入克氏原螯虾体内，抗原物周围被大量血细胞包囊，通过切片技术观察到抗原物周围的血细胞绝大部分为小颗粒细胞，证实在包囊过程中起主要作用的血细胞是小颗粒细胞，即小颗粒细胞在包囊反应中比较活跃。研究结果为以后进一步研究克氏原螯虾的细胞免疫机制和提高其抗病能力提供了科学依据。

Crustacean haemocytes play important roles in the host immune response including recognition, phagocytosis, encapsulation melanization, cytotoxicity and cellcell communication. The various types of haemocytes are responsible for a number of defense mechanisms. Thus, the morphology and classification of haemocytes are the basis of crustacean immunology. Generally, classification of the haemocyte types in decapod crustaceans is based mainly on the presence of cytoplasmic granules and relative size of granules. In this paper, Giemsa's staining, hematoxylin and eosin(H.E) staining and electron microscope techniques were used to classify the haemocytes of Procambarus clarkii. And three types of haemocytes, including hyaline cell(HC), semigranular cell(SGC) and granular cell(GC), were observed, accounting for 19.9%，34.1%，46.1% respectively. In addition, the ultrastructures of haemocytes turned out to be most easily recognized under the electron microscope. The hyaline cells were generally the smallest cells with the highest nuclearcytoplasmatic(N/C) ratio, containing few granules, while the semigranulocytes and the granulocytes had increasing amount of granules inside their cells. Afterwards using in vivo and in vitro incubation methods， the haemocyte immunology responses of P. clarkii were investigated, with Sephadex A25 chromatography beads as the antigens. Meanwhile, the cellular recognition mechanism during the immune responses was also preliminarily discussed. When the Sephadex A25 beads were transplanted into the body of P. clarkii for a certain period of time, a large number of haemocytes, which were almost recognized as semigranular cells with slice technique, encapsulated the antigens. It was proved that semigranular cells played a prominent role during the encapsulation process. Therefore, the semigranular cells were the cells active in encapsulation responses. Besides, the results also laid a scientific foundation for the further study of cellular immunological mechanism and antidisease ability of P. clarkii.

国家自然科学基金（30471349）; 上海市科委科技攻关计划(08dz1206002)