Structure and function of the spleen

Mebius, Reina E.; Kraal, Georg

doi:10.1038/nri1669

Cited by 1,842 publications

(1,853 citation statements)

References 122 publications

Supporting

Mentioning

1,763

Contrasting

Unclassified

Order By: Relevance

“…2). 13, 33, 34 However, other possibilities also include lack of proliferation or increased apoptosis, which seem unlikely based on current observations,9, 10 and abnormal expression of homing chemokines 16…”

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 77%

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 99%

“…The structure of the spleen is crucial for its function 16. For example, the incoming blood goes through the marginal zone, where many macrophages and B‐cells act to filter the blood for foreign antigens 16. In this manner, they trigger an innate immune response directly but also an adaptive immune response given their close proximity to the white pulp region, where T‐cells and B‐cells are located 16.…”

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 99%

“…For example, the incoming blood goes through the marginal zone, where many macrophages and B‐cells act to filter the blood for foreign antigens 16. In this manner, they trigger an innate immune response directly but also an adaptive immune response given their close proximity to the white pulp region, where T‐cells and B‐cells are located 16. Moreover, the spleen contains unique subsets of specialized macrophages that have better recognition for certain pathogens 17, 18, 19, 20.…”

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 99%

“…Moreover, the spleen contains unique subsets of specialized macrophages that have better recognition for certain pathogens 17, 18, 19, 20. Indeed, this places the spleen as a major player in the clearance of encapsulated bacteria like Mycobacterium tuberculosis and Streptococcus pneumoniae , but also of Staphylococcus aureus , and potentially of viruses 16, 17, 18, 19, 20. Moreover, asplenic patients are immunodeficient, are recommended to be on a more stringent immunization schedule, and more aggressive clinical management is initiated at an earlier stage when facing fever or infection 21, 22…”

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 99%

See 4 more Smart Citations

New insights into SMA pathogenesis: immune dysfunction and neuroinflammation

Deguise

Kothary

2017

Ann Clin Transl Neurol

View full text Add to dashboard Cite

Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by motor neuron degeneration, although defects in multiple cell types and tissues have also been implicated. Three independent laboratories recently identified immune organ defects in SMA. We therefore propose a novel pathogenic mechanism contributory to SMA, resulting in higher susceptibility to infection and exacerbated disease progression caused by neuroinflammation. Overall, compromised immune function could significantly affect survival and quality of life of SMA patients. We highlight the recent findings in immune organ defects, their potential consequences on patients, our understanding of neuroinflammation in SMA, and new research hypotheses in SMA pathogenesis.

show abstract

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 77%

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 99%

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 99%

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 99%

Section: Potential Functional Consequences Of Lymphoid Organ Defects mentioning

confidence: 99%

See 3 more Smart Citations

New insights into SMA pathogenesis: immune dysfunction and neuroinflammation

Deguise

Kothary

2017

Ann Clin Transl Neurol

View full text Add to dashboard Cite

show abstract

Spleen

Steiniger¹

2011

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

The spleen is a secondary lymphoid organ present in all vertebrates, which monitors the blood. It consists of sessile stroma cells (fibroblasts), migratory cells of the immune system and blood‐filled spaces and vessels. Splenic functions and microanatomy differ according to the species investigated. Certain functions such as immunological monitoring of bloodborne antigens, destruction of intravasal microorganisms and aged or abnormal blood cells, are more or less invariant. In rodents and humans the spleen is composed of two large compartments, the white pulp and the red pulp. The white pulp harbours dense accumulations of more or less migratory lymphocytes and antigen‐presenting cells, which crawl on a meshwork of specialised fibroblasts. The red pulp is composed of connective tissue cords containing arterioles and capillaries and of sinuses, which represent a spleen‐specific initial part of the venous circulation. The connective tissue of the red pulp cords is filled with blood and represents the only place where an open circulation occurs in the body. In addition, the cords harbour a dense population of specialised macrophages and some plasma cells. The article describes the microanatomical compartments of rat and human spleens, the course of B lymphocyte immune reactions in rodent spleens and the consequences of splenectomy in humans. Key Concepts: The spleen monitors the antigen composition of the blood. The monitoring is predominantly carried out by lymphocytes recirculating through the spleen in the white pulp and by sessile macrophages in the red pulp cords. Specialised fibroblasts recruit lymphocytes and macrophages to their compartments with the help of several mechanisms, such as secretion of chemokines or expression of certain adhesion molecules. The splenic red pulp cords are the only location in the body with an open circulation. This means that blood flows in spaces not lined by any barrier‐forming cells such as endothelia. The open circulation thus permits a direct contact between the blood and resident macrophages. In rodents and humans the spleen contains a special type of B lymphocytes, the marginal zone cells. These cells recognise polysaccharide antigens and are easily activated to become antibody‐secreting plasma cells. In humans, splenectomy leads to the loss of marginal zone‐type B cells in the blood and to a reduced resistance against bacteria with polysaccharide capsules. This is especially relevant in children. The susceptibility to overwhelming post‐splenectomy infections in humans may be due to loss of the marginal zone and its special stromal cells in combination with loss of the large phagocyte compartment in the splenic red pulp.

show abstract

Lymphocytes: Recirculation

Jalkanen¹,

Salmi²

2013

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

Successful immunosurveillance requires endless patrolling of lymphoid tissues by lymphocytes in search of foreign antigens. Lymphocytes enter the lymphoid tissues either through the blood vessel walls or via the afferent lymphatic vessels. To leave the circulation, bloodborne lymphocytes first tether to the endothelial lining of the vessels and start to roll. After an activation step they firmly adhere and transmigrate through the vessel wall. They then navigate through the tissue stroma following chemotactic and other guidance molecules, possibly encounter their cognate antigens and eventually return via the lymphatic vessels back into the blood to be dispersed to the other tissues of the body. In this tightly controlled process called lymphocyte recirculation, different adhesion molecules and activation signals on the two opposing cell types play a critical role. Dysregulated lymphocyte recirculation is involved in the pathogenesis of many inflammatory diseases and immunodeficiencies, and nowadays several drugs target this process. Key Concepts: Lymphocytes continuously recirculate between blood and lymphoid organs. Majority of the lymphocytes enter the lymph nodes via specialised vessels called high endothelial venules (HEV). The remaining lymphocytes (15–20%), together with dendritic cells and antigens, enter the lymph nodes via afferent lymphatics. Lymphocytes leave the lymph nodes via efferent lymphatics. Lymphocyte recirculation allows the lymphocytes to meet their cognate antigens and other leucocyte subsets to evoke an efficient immune response. Lymphocytes interact with the vessel wall in a multistep fashion, using several leucocyte surface molecules, which recognise their counter receptors on endothelial cells. The rolling and tethering of lymphocytes on the vessel wall is mediated by selectins. Chemokines and their receptors are needed to activate leucocyte integrins. Activated integrins mediate firm adhesion between lymphocytes and endothelium. The transmigration of leucocytes into the tissues requires adhesion molecules, proteinases and repair mechanisms.

show abstract

Structure and function of the spleen

Cited by 1,842 publications

References 122 publications

New insights into SMA pathogenesis: immune dysfunction and neuroinflammation

New insights into SMA pathogenesis: immune dysfunction and neuroinflammation

Spleen

Lymphocytes: Recirculation

Contact Info

Product

Resources

About