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Proceedings of the National Academy of... Oct 2023The immune system is a complex network of cells with critical functions in health and disease. However, a comprehensive census of the cells comprising the immune system...
The immune system is a complex network of cells with critical functions in health and disease. However, a comprehensive census of the cells comprising the immune system is lacking. Here, we estimated the abundance of the primary immune cell types throughout all tissues in the human body. We conducted a literature survey and integrated data from multiplexed imaging and methylome-based deconvolution. We also considered cellular mass to determine the distribution of immune cells in terms of both number and total mass. Our results indicate that the immune system of a reference 73 kg man consists of 1.8 × 10 cells (95% CI 1.5-2.3 × 10), weighing 1.2 kg (95% CI 0.8-1.9). Lymphocytes constitute 40% of the total number of immune cells and 15% of the mass and are mainly located in the lymph nodes and spleen. Neutrophils account for similar proportions of both the number and total mass of immune cells, with most neutrophils residing in the bone marrow. Macrophages, present in most tissues, account for 10% of immune cells but contribute nearly 50% of the total cellular mass due to their large size. The quantification of immune cells within the human body presented here can serve to understand the immune function better and facilitate quantitative modeling of this vital system.
Topics: Male; Humans; Human Body; Lymphocytes; Lymph Nodes; Spleen; Macrophages
PubMed: 37871201
DOI: 10.1073/pnas.2308511120 -
Fish & Shellfish Immunology Jan 2024In the present study, we review the structure and function of fish spleen with special emphasis on its condition in Elasmobranchs, Teleosts and Lungfish. Apart from the... (Review)
Review
In the present study, we review the structure and function of fish spleen with special emphasis on its condition in Elasmobranchs, Teleosts and Lungfish. Apart from the amount of splenic lymphoid tissue, the histological organization of the organ ensures the existence of areas involved in antigen trapping, the ellipsoids, and exhibit numerous melano-macrophages which appear isolated or forming the so-called melano-macrophage centres. An extensive discussion on the functional significance of these centres conclude that they are mere accumulations of macrophages consequence of tissue homeostasis rather than primitive germinal centres, as proposed by some authors.
Topics: Animals; Spleen; Lymphoid Tissue; Macrophages; Fishes
PubMed: 38086514
DOI: 10.1016/j.fsi.2023.109280