Cima Francesca, Sabbadin Armando, Zaniolo Giovanna, Ballarin Loriano
University of Padova, Department of Biology, Via U. Bassi 58/B, 35100 Padova, Italy.
Comp Biochem Physiol A Mol Integr Physiol. 2006 Nov;145(3):376-82. doi: 10.1016/j.cbpa.2006.07.017. Epub 2006 Aug 4.
We re-investigated the behavior of hemocytes during the non-fusion (rejection) reaction between genetically incompatible colonies of the ascidian Botryllus schlosseri. In the course of the reaction, hemocytes - mainly morula cells - crowd inside the blind ends of marginal vascular vessels (known as ampullae) of the colonial leading edge (LE) facing the foreign colony which suggests the occurrence of chemotactic attraction of circulating hemocytes towards the ampullar lumen. Then, cells migrate, through the ampullar tips, into the partially fused tunics and contribute to the formation of the necrotic spots along the contact borders which characterize the reaction. Studies on histological sections clearly indicate that, although morula cell concentration is always higher in ampullae of the LE than in those of the lateral (L) part of the colony, their frequency significantly increases in LE ampullae of rejecting colonies with respect to LE ampullae of both fusing and isolated colonies. In addition, in vitro chemotaxis experiments demonstrated that blood plasma from incompatible colonies can stimulate morula cell migration through polycarbonate filters and this passage is inhibited by antibodies raised against mammalian pro-inflammatory cytokines. The possible nature and role of molecules recognized by anti-cytokine antibodies in hemocyte migration are discussed.
我们重新研究了海鞘Botryllus schlosseri基因不相容群体之间非融合（排斥）反应过程中血细胞的行为。在反应过程中，血细胞——主要是桑椹细胞——聚集在殖民地前沿（LE）边缘血管盲端（称为壶腹）内，这些盲端朝向外来殖民地，这表明循环血细胞向壶腹管腔发生趋化吸引。然后，细胞通过壶腹尖端迁移到部分融合的被囊中，并在接触边界处形成坏死斑点，这是该反应的特征。组织学切片研究清楚地表明，尽管LE壶腹中的桑椹细胞浓度总是高于殖民地侧面（L）部分的壶腹，但与融合和孤立殖民地的LE壶腹相比，排斥殖民地的LE壶腹中它们的频率显著增加。此外，体外趋化实验表明，不相容群体的血浆可以刺激桑椹细胞通过聚碳酸酯滤膜迁移，并且这种迁移受到针对哺乳动物促炎细胞因子产生的抗体的抑制。我们讨论了抗细胞因子抗体识别的分子在血细胞迁移中的可能性质和作用。
