Loret S M, Strand M R
Department of Biochemistry and General Physiology, University of Liège, Belgium.
Eur J Cell Biol. 1998 Jun;76(2):146-55. doi: 10.1016/S0171-9335(98)80028-9.
Hemocyte types involved in encapsulation were characterized using monoclonal antibodies (mAbs). This approach revealed that four hemocyte types in Pseudoplusia includens could be classified into two antigenically distinct cell lines. The first line comprised granulocytes (GR) and spherulocytes (SP) and the second line comprised plasmatocytes (PL) and oenocytoids (OE). One of the mAbs labeled a subpopulation of plasmatocytes that spread on culture plate surfaces. This subclass represented approximately 70% of all plasmatocytes. The cytoplasmic punctate staining of granulocytes clearly decreased upon short term culture, suggesting the associated antigens were released into the culture medium during cell spreading. A follow-up of protein secretion into culture medium by Western blotting confirmed this hypothesis for both granulocytes and plasmatocytes. In a few cases, discharged proteins exhibited a short half-life suggesting they may behave as regulatory molecules. Among them, plasmatocyte proteins of +/-25 kDa might be mobilized at an early stage of encapsulation. The same proteins appeared to accumulate at the periphery of the median plasmatocyte multilayer in late capsules. This location coincides with where an outer monolayer of granulocytes attaches and causes termination of capsule growth. These preliminary results raise the possibility that released proteins regulate hemocyte recruitment during encapsulation.
利用单克隆抗体（mAb）对参与包囊化的血细胞类型进行了表征。该方法表明，斜纹夜蛾中的四种血细胞类型可分为两个抗原性不同的细胞系。第一个细胞系包括粒细胞（GR）和球血细胞（SP），第二个细胞系包括浆血细胞（PL）和绛色细胞（OE）。其中一种单克隆抗体标记了在培养板表面铺展的浆血细胞亚群。该亚类约占所有浆血细胞的70%。粒细胞的细胞质点状染色在短期培养后明显减少，表明相关抗原在细胞铺展过程中释放到培养基中。通过蛋白质印迹法对培养基中蛋白质分泌的后续研究证实了粒细胞和浆血细胞的这一假设。在少数情况下，分泌的蛋白质半衰期较短，表明它们可能作为调节分子发挥作用。其中，约25 kDa的浆血细胞蛋白可能在包囊化早期被调动。相同的蛋白质似乎在晚期包囊中位于中间浆血细胞多层结构的外围积累。该位置与粒细胞外层单层附着并导致包囊生长终止的位置一致。这些初步结果增加了释放的蛋白质在包囊化过程中调节血细胞募集的可能性。
