Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche - Università di Palermo, Via Archirafi 18, Palermo, Italy.
Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche - Università di Palermo, Via Archirafi 18, Palermo, Italy.
Fish Shellfish Immunol. 2021 Apr;111:94-101. doi: 10.1016/j.fsi.2021.01.014. Epub 2021 Jan 26.
Pentraxins (PTXs) are a superfamily of conserved proteins which are components of the humoral arm of innate immunity. They are considered to be functional ancestors of antibodies and are classified into short and long types. In this study, we show that a pentraxin-like component (Ptx-like) with a C-terminal PTX domain, highly homologous to the short PTX of H. sapiens CRP, and a long N-terminal domain typical of long PTXs, is involved in the inflammatory response of Ciona robusta under LPS exposure in vivo. Analyses of protein domains as well as 3D modelling and phylogenetic tree supported the close relationship of Ptx-like with mammalian CRP, suggesting that C. robusta Ptx-like shares a common ancestor in the chordate lineages. qRT-PCR analysis showed that Ptx-like was transcriptionally upregulated during the inflammatory process induced by LPS inoculation and that it is involved in the initial phase as well as the secondary phase of the inflammatory response in which matrix remodelling and the achievement of homeostasis occur. In situ hybridisation assays revealed that gene transcription was upregulated in the pharynx post-LPS challenge in vivo, and that Ptx-like was expressed by clusters of haemocytes, mainly granulocytes, inside the pharynx vessels. We also found transcript-expressing granulocytes flowing in the musculature and in the lacunae of the circulatory system. These data supported that Ptx-like is a potential molecule of the acute-phase response in C. robusta immune defence systems against bacterial infection.
五聚素（PTXs）是一个保守蛋白超家族，是先天免疫体液免疫的组成部分。它们被认为是抗体的功能祖先，分为短型和长型。在这项研究中，我们表明，一种带有 C 末端 PTX 结构域的五聚素样成分（Ptx 样），与人类 CRP 的短型 PTX 高度同源，以及一个长 N 末端结构域，这是长型 PTX 的典型特征，参与了 LPS 暴露后秀丽隐杆线虫体内的炎症反应。蛋白结构域分析以及 3D 建模和系统发育树分析支持 Ptx 样与哺乳动物 CRP 的密切关系，表明秀丽隐杆线虫 Ptx 样与脊椎动物共同拥有一个祖先。qRT-PCR 分析表明，Ptx 样在 LPS 接种诱导的炎症过程中转录上调，并且它参与了炎症反应的初始阶段和次级阶段，其中发生了基质重塑和稳态的实现。原位杂交分析显示，体内 LPS 挑战后咽部的基因转录上调，Ptx 样由咽部血管中的一群血细胞，主要是粒细胞表达。我们还发现表达转录的粒细胞在肌肉组织和循环系统的腔隙中流动。这些数据表明，Ptx 样是秀丽隐杆线虫免疫防御系统对细菌感染的急性期反应的一个潜在分子。
