College of Pharmacy, Hangzhou Medical College, Hangzhou, 311399, China.
Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, College of Marine Sciences, Beibu Gulf University, Qinzhou, 535011, China.
Immunogenetics. 2022 Feb;74(1):77-98. doi: 10.1007/s00251-021-01236-3. Epub 2021 Dec 2.
The immune cells of the snail Biomphalaria glabrata are classified into hyalinocyte and granulocyte subtypes. Both subtypes are essential for the proper functioning of the snail immune response, which we understand best within the context of how it responds to challenge with the human parasite Schistosoma mansoni. Granulocytes are adherent phagocytic cells that possess conspicuous granules within the cell cytoplasm. Hyalinocytes, on the other hand, are predominantly non-adherent and are known to produce a handful of anti-S. mansoni immune effectors. While our understanding of these cells has progressed, an in-depth comparison of the functional capabilities of each type of immune cell has yet to be undertaken. Here, we present the results of a single-cell RNA-seq study in which single granulocytes and hyalinocytes from S. mansoni-susceptible M-line B. glabrata and S. mansoni-resistant BS-90 B. glabrata are compared without immune stimulation. This transcriptomic analysis supports a role for the hyalinocytes as producers of immune effectors such as biomphalysin and thioester-containing proteins. It suggests that granulocytes are primarily responsible for producing fibrinogen-related proteins and are armed with various pattern-recognition receptors such as toll-like receptors with a confirmed role in the anti-S. mansoni immune response. This analysis also confirms that the granulocytes and hyalinocytes of BS-90 snails are generally more immunologically prepared than their M-line counterparts. As the first single-cell analysis of the transcriptional profiles of B. glabrata immune cells, this study provides crucial context for understanding the B. glabrata immune response. It sets the stage for future investigations into how each immune cell subtype differs in its response to various immunological threats.
钉螺的免疫细胞可分为透明细胞和粒细胞两种亚型。这两种亚型对于钉螺免疫反应的正常运作都至关重要，而我们对钉螺免疫反应的理解主要是基于它对人类寄生虫曼氏血吸虫的挑战的反应。粒细胞是附着的吞噬细胞，其细胞质内有明显的颗粒。另一方面，透明细胞主要是非附着的，已知其产生少量抗曼氏血吸虫的免疫效应物。虽然我们对这些细胞的了解已经取得了进展，但尚未对每种免疫细胞的功能能力进行深入比较。在这里，我们展示了一项单细胞 RNA-seq 研究的结果，该研究比较了易感染曼氏血吸虫的 M 系钉螺和抗曼氏血吸虫的 BS-90 系钉螺的单个粒细胞和透明细胞，而没有进行免疫刺激。这种转录组分析支持透明细胞作为免疫效应物（如生物胞菌素和含硫酯蛋白）的产生者的作用。它表明粒细胞主要负责产生纤维蛋白原相关蛋白，并配备了各种模式识别受体，如 Toll 样受体，它们在抗曼氏血吸虫免疫反应中具有确定的作用。该分析还证实，BS-90 钉螺的粒细胞和透明细胞通常比 M 系钉螺的更具免疫准备性。作为对钉螺免疫细胞转录谱的首次单细胞分析，本研究为理解钉螺免疫反应提供了至关重要的背景。它为未来研究每种免疫细胞亚型对各种免疫威胁的反应差异奠定了基础。
