Hussein Manal T, Zaccone Giacomo, Albano Marco, Alesci Alessio, Marino Sebastian, Alonaizan Rasha, Mokhtar Doaa M
Department of Cell and Tissues, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt.
Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy.
Life (Basel). 2025 May 7;15(5):751. doi: 10.3390/life15050751.
Goldfish () gills function as both respiratory and immune-regulatory organs, integrating neuroendocrine and immune responses to environmental stimuli. This study explores the spatial organization and interaction of neuroendocrine cells (NECs) and immune cells within goldfish gills using confocal immunohistochemistry and transmission electron microscopy. NECs, identified near blood capillaries and nerve fibers, highlight their role in environmental sensing and physiological regulation. These cells express serotonin (5-HT), a neurotransmitter critical for neuroimmune communication. Two distinct macrophage subsets were observed: iNOS-positive macrophages, concentrated in the basal epithelium, suggest a pro-inflammatory role, whereas 5-HT-positive macrophages, dispersed in the subepithelium, likely contribute to immune modulation. The co-localization of MHC-II and CD68 in macrophages further supports an active antigen-processing system in the gills. Ultrastructural analysis revealed diverse immune cells, including rodlet cells, telocytes, and lymphocytes, within the gill epithelium. Telocytes formed intricate networks with immune cells, highlighting their role in immune coordination and tissue homeostasis. These findings provide new insights into the neuroimmune interactions in fish gills, contributing to a broader understanding of aquatic immune systems and environmental adaptability.
金鱼的鳃兼具呼吸和免疫调节器官的功能，整合神经内分泌和免疫反应以应对环境刺激。本研究使用共聚焦免疫组织化学和透射电子显微镜，探索金鱼鳃内神经内分泌细胞（NECs）和免疫细胞的空间组织及相互作用。在毛细血管和神经纤维附近发现的NECs，凸显了它们在环境感知和生理调节中的作用。这些细胞表达血清素（5-HT），这是一种对神经免疫通讯至关重要的神经递质。观察到两种不同的巨噬细胞亚群：诱导型一氧化氮合酶（iNOS）阳性巨噬细胞集中在基底上皮，表明其具有促炎作用，而5-HT阳性巨噬细胞分散在上皮下，可能有助于免疫调节。巨噬细胞中主要组织相容性复合体II类分子（MHC-II）和CD68的共定位进一步支持鳃中存在活跃的抗原处理系统。超微结构分析揭示了鳃上皮内存在多种免疫细胞，包括小棒状细胞、间充质干细胞和淋巴细胞。间充质干细胞与免疫细胞形成复杂的网络，凸显了它们在免疫协调和组织稳态中的作用。这些发现为鱼类鳃中的神经免疫相互作用提供了新见解，有助于更广泛地理解水生免疫系统和环境适应性。
