Micro- and Macro-Anatomical Frameworks of Lymph Nodes Indispensable for the Lymphatic System Filtering Function

• DOI: 10.3389/fcell.2022.902601
• Publication Date: 2022-06-20T04:44:41Z
• Authors: Madoka Ozawa; Shihori Nakajima; Daichi Kobayashi; Koichi Tomii; Nan-Jun Li; Tomoya Watarai; Ryo Suzuki; Satoshi Watanabe; Yasuhiro Kanda; Arata Takeuchi; Tomoya Katakai
• Keywords: Lymphatic Endothelium; Reticular cell; Lymphatic vessel

In the lymphatic vascular system, lymph nodes (LNs) play a pivotal role in filtering and removing lymph-borne substances. The function of LNs involves resident macrophages tightly associated with unique sinus structures. Moreover, an intermittently arranged LN pathway is considered to cooperatively prevent substances from entering blood circulation. However, functional significance tissue microarchitecture, cellular composition, individual "LN chain" system not fully understood. To explore mechanistic histo-anatomical as fluid filters, we subcutaneously injected fluorescent tracers into mice examined details transport qualitatively quantitatively. Lymph-borne were selectively accumulated MARCO+ subcapsular-medullary border (SMB) region LN, which reticular endothelial cells CD169+F4/80+ medullary construct dense meshwork physical barrier, forming main body capture tracers. We also demonstrated stepwise filtration via chain basin, prevented tracer leakage blood. Furthermore, inflammatory responses that induce remodeling well reinforce overall capacity basin. Taken together, specialized infrastructure their systematic orchestration constitute integrated for recirculation.