TISSUE TRANSPLANTATION RECTIONS IN SCHISTOSOME TRANSMITTING SNAILS

异位心脏移植物和同种异体移植物存活，即， 持续跳动，6个月后植入体腔内， 光滑双脐螺是血吸虫的主要中间宿主 新世界的曼森尼 然而，来自其他属的异种移植物，除了 那些来自Helisoma trivolvis的，迅速被摧毁，不管 供体-受体分类学（和可能的系统发育）距离。 虽然这些结果增强了我们对人类命运的理解， 在软体动物的组织移植，几个问题仍然存在， 细胞对移植物反应的性质，非我的类型 受体血细胞识别的决定因素， 供体-受体系统发育距离与异种移植物命运的关系。 因此，对同种异体移植物的细胞反应将与 抗同种异体移植物。 接下来，我们将尝试改变 通过改变或掩蔽细胞表面 分子。 辨别生理上的不适应和 免疫排斥作为异种移植物死亡的机制，琼脂糖- 将植入包封的异种移植物。 最后，心脏植入物从 与Helisoma密切相关的两个属将被执行， 进一步阐明了H. trivolvis和 B。光滑的 除了先前的组织学技术之外， 采用，将开发移植物破坏的体外模型，并且 肌动蛋白特异性染色方法将用于评估移植物的命运。

Heterotopic heart allografts and congeneric xenografts survive, i.e., continue to beat, for 6 months when implanted into the body cavity of the snail Biomphalaria glabrata, the main intermediate host of Schistosoma mansoni in the New World. However, xenografts from other genera, except those from Helisoma trivolvis, are rapidly destroyed, regardless of donor-recipient taxonomic (and presumably phylogenetic) distance. Although these results have enhanced our understanding of the fate of tissue transplants in molluscs, several questions remain with respect to the nature of the cellular response against grafts, the types of nonself determinants recognized by the recipient's hemocytes, and the relationship of donor-recipient phylogenetic distance and xenograft fate. Consequently, cellular responses against allografts will be compared to those against isografts. Next, an attempt will be made to alter the fate of allografts and xenografts by altering or masking cell surface molecules. To discern between physiological unsuitability and immunological rejection as the mechanism of xenograft death, agarose- encapsulated xenografts will be implanted. Finally, heart implants from two genera which are closely related to Helisoma will be carried out to further elucidate the phylogenetic relationship between H. trivolvis and B. glabrata. In addition to the histological techniques previously employed, an in vitro model of graft destruction will be developed, and an actin-specific staining method will be used to assess graft fate.