IHEM, CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina.
Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina.
Front Immunol. 2022 May 26;13:879122. doi: 10.3389/fimmu.2022.879122. eCollection 2022.
We stand as dissenters against the acceptance of scientific knowledge that has not been built on empirical data. With this in mind, this review synthesizes selected aspects of the immunobiology of gastropods and of apple snails (Ampullariidae) in particular, from morphological to molecular and "omics" studies. Our trip went through more than two centuries of history and was guided by an evo-devo hypothesis: that the gastropod immune system originally developed in the mesenchymal connective tissue of the reno-pericardial complex, and that in that tissue some cells differentiated into hematopoietically committed progenitor cells that integrate constitutive hemocyte aggregations in the reno-pericardial territory, whether concentrated in the pericardium or the kidney in a species-specific manner. However, some of them may be freed from those aggregations, circulate in the blood, and form distant contingent aggregations anywhere in the body, but always in response to intruders (i.e., pathogens or any other immune challenge). After that, we reviewed the incipient immunology of the Ampullariidae by critically revising the findings in and , the only ampullariid species that have been studied in this respect, and we attempted to identify the effectors and the processes in which they are involved. Particularly for , which is by far the most studied species, we ask which hemocytes are involved, in which tissues or organs are integrated, and what cellular reactions to intruders this species has in common with other animals. Furthermore, we wondered what humoral factors could also integrate its internal defense system. Among the cellular defenses, we give an outstanding position to the generation of hemocyte nodules, which seems to be an important process for these snails, serving the isolation and elimination of intruders. Finally, we discuss hematopoiesis in apple snails. There have been contrasting views about some of these aspects, but we envision a hematopoietic system centered in the constitutive hemocyte islets in the ampullariid kidney.
我们反对接受没有基于经验数据的科学知识。有鉴于此，本综述综合了腹足动物（尤其是苹果蜗牛）的免疫生物学的几个方面，从形态学到分子和“组学”研究。我们的研究之旅跨越了两个多世纪的历史，受到一个进化发育假说的指导：即腹足动物免疫系统最初是在肾心包复合体的间质结缔组织中发展起来的，在该组织中，一些细胞分化为造血祖细胞，这些祖细胞将组成性血细胞聚集整合到肾心包区域，无论是集中在心包还是肾脏，这都是物种特异性的。然而，其中一些细胞可能会从这些聚集物中释放出来，在血液中循环，并在身体的任何部位形成远处的临时聚集物，但总是对入侵者（即病原体或任何其他免疫挑战）作出反应。之后，我们通过批判性地回顾和中发现的结果，对苹果蜗牛的初级免疫学进行了综述，这是唯一在这方面被研究过的苹果蜗牛物种，并试图确定其效应物及其所涉及的过程。特别是对于，它是迄今为止研究最多的物种，我们询问哪些血细胞参与其中，在哪些组织或器官中整合，以及该物种与其他动物有哪些共同的针对入侵者的细胞反应。此外，我们想知道哪些体液因素也可以整合到其内部防御系统中。在细胞防御中，我们给予血细胞结节的产生以突出地位，这似乎是这些蜗牛的一个重要过程，用于隔离和消除入侵者。最后，我们讨论了苹果蜗牛的造血作用。在这些方面存在一些相反的观点，但我们设想一个以苹果蜗牛肾脏中组成性血细胞岛为中心的造血系统。
