Fuller Laboratories, Fullerton, California, USA.
Infect Immun. 2024 Jul 11;92(7):e0048123. doi: 10.1128/iai.00481-23. Epub 2024 Jun 5.
The currently accepted initiation of Babesia infection describes a sporozoite stage infused into the host, along with other saliva components, by the tick vector. This sporozoite can enter and initiate erythrocyte infection directly. In the particular case of , however, that sporozoite loses the ability to further propagate once deprived of its natural host. True do not require the host collaboration described in this study. Hence it has become a current topic of research involving (), a rather unique species that requires host collaboration to maintain an erythrocyte propagation cycle. The main attachment protein is synthesized by this parasite in excess and exported to the host from the erythrocyte infrastructure to immunize the host at all stages of infection. The synthesis of host immune IgM antibody is necessary for the propagation of , being central to entry into uninfected host erythrocytes. Sequential use of the host immune system then involves complement factor C3b to complete the three-part assembly necessary to initiate the rhoptry sequence for invasion of uninfected erythrocytes and further propagation. These several components must be furnished within the culture medium and the sequence of these reactions is discussed. The corollary view of the parasite survival versus the host immune defenses is also discussed as it involves the same host factors promoting continuing parasite growth. This is the first description of continuous propagation of .
目前公认的疟原虫感染起始过程描述了疟原虫子孢子阶段随同其他唾液成分一起，由蜱虫媒介注入宿主。这种子孢子可以直接进入并引发红细胞感染。然而，在 的特殊情况下，一旦失去其自然宿主，该子孢子就会丧失进一步繁殖的能力。真正的 并不需要本研究中描述的宿主协作。因此，它已成为一个涉及 （）的当前研究课题，这是一种非常独特的物种，需要宿主协作来维持红细胞繁殖周期。主要的附着蛋白是由寄生虫过量合成并从红细胞基础设施中输出到宿主，以在感染的所有阶段对宿主进行免疫。宿主免疫 IgM 抗体的合成对于 的繁殖是必要的，对于进入未感染的宿主红细胞至关重要。随后，宿主免疫系统的连续使用涉及补体因子 C3b，以完成入侵未感染红细胞和进一步繁殖所需的三部分组装。这些几个组件必须在 培养基中提供，并且讨论了这些反应的顺序。还讨论了寄生虫存活与宿主免疫防御之间的相关性，因为涉及到相同的宿主因素促进持续的寄生虫生长。这是对 的连续繁殖的首次描述。
