Wambreuse Noé, Caulier Guillaume, Eeckhaut Igor, Borrello Laura, Bureau Fabrice, Fievez Laurence, Delroisse Jérôme
Biology of Marine Organisms and Biomimetics Unit, Research Institute for Biosciences, University of Mons (UMONS), 7000, Mons, Belgium; Belaza Marine Station (IH.SM-UMONS-ULB-ULIEGE), Toliara, 601, Madagascar.
Biology of Marine Organisms and Biomimetics Unit, Research Institute for Biosciences, University of Mons (UMONS), 7000, Mons, Belgium; Belaza Marine Station (IH.SM-UMONS-ULB-ULIEGE), Toliara, 601, Madagascar.
Fish Shellfish Immunol. 2025 Mar;158:110144. doi: 10.1016/j.fsi.2025.110144. Epub 2025 Jan 20.
Holothuria scabra is one of the most valuable species of sea cucumber owing to its exploitation as a seafood product. This study aims to describe the main molecular and cellular actors in the immunology of this species. First, a detailed description of the immune cells - the cœlomocytes - is provided, highlighting five main cell types including phagocytes, small round cells (SRCs), spherulocytes, fusiform cells, and crystal cells, with a further five subtypes identified using transmission electron microscopy. Cœlomocyte aggregates were also described morphologically, yielding two main types, one comprising three successive maturation stages. A comparison of the concentration and proportion of cell populations was carried out between the two main body fluids, namely the hydrovascular fluid of the Polian vesicle (HF) and the perivisceral fluid of the general cavity (PF), and no clear relation could be highlighted. Next, the cœlomocyte immune response was studied 24 h after lipopolysaccharide (LPS) injection in the two body fluids. Firstly, the fluctuation in cell populations was assessed, and despite a high inter-individual variability, it shows a decrease in the phagocyte proportion and an increase in the SRC proportion. Secondly, the differential gene expression of PF cœlomocytes was studied by de novo RNA-sequencing between LPS-injected and control-injected individuals: 945 genes were differentially expressed, including 673 up-regulated and 272 down-regulated in the LPS-injected individuals. Among these genes, 80 had a presumed function in immunity based on their annotation, covering a wide range of immune mechanisms. Overall, this study reveals a complex immune system at both molecular and cellular levels and constitutes a baseline reference on H. scabra immunity, which may be useful for the development of sustainable aquaculture and provides valuable data for comparative immunology.
糙海参是最具价值的海参品种之一，因其可作为海产品进行开发利用。本研究旨在描述该物种免疫学中的主要分子和细胞成分。首先，对免疫细胞——体腔细胞进行了详细描述，重点介绍了五种主要细胞类型，包括吞噬细胞、小圆细胞（SRCs）、球形细胞、梭形细胞和晶体细胞，并通过透射电子显微镜鉴定出另外五种亚型。还对体腔细胞聚集体进行了形态学描述，得出两种主要类型，其中一种包括三个连续的成熟阶段。对两种主要体液，即波氏囊的水管系统液（HF）和总腔的围脏液（PF）中的细胞群体浓度和比例进行了比较，未发现明显关联。接下来，在两种体液中注射脂多糖（LPS）24小时后研究体腔细胞免疫反应。首先，评估细胞群体的波动情况，尽管个体间差异很大，但显示吞噬细胞比例下降，SRC比例增加。其次，通过对注射LPS和注射对照的个体进行从头RNA测序，研究PF体腔细胞的差异基因表达：945个基因差异表达，其中注射LPS的个体中有673个上调，272个下调。在这些基因中，根据注释有80个在免疫方面可能具有功能，涵盖广泛的免疫机制。总体而言，本研究揭示了糙海参在分子和细胞水平上的复杂免疫系统，构成了糙海参免疫的基线参考，这可能有助于可持续水产养殖的发展，并为比较免疫学提供有价值的数据。
