GPR183

Last updated
GPR183
Identifiers
Aliases GPR183 , EBI2, G protein-coupled receptor 183, hEBI2
External IDs OMIM: 605741 MGI: 2442034 HomoloGene: 28066 GeneCards: GPR183
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_004951

NM_183031

RefSeq (protein)

NP_004942

NP_898852

Location (UCSC) Chr 13: 99.29 – 99.31 Mb Chr 14: 122.19 – 122.2 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

G-protein coupled receptor 183 also known as Epstein-Barr virus-induced G-protein coupled receptor 2 (EBI2) is a protein (GPCR) expressed on the surface of some immune cells, namely B cells and T cells; in humans it is encoded by the GPR183 gene. [5] Expression of EBI2 is one critical mediator of immune cell localization within lymph nodes, responsible in part for the coordination of B cell, T cell, and dendritic cell movement and interaction following antigen exposure. [6] [7] [8] [9] EBI2 is a receptor for oxysterols. [10] [11] The most potent activator is 7α,25-dihydroxycholesterol (7α,25-OHC), with other oxysterols exhibiting varying affinities for the receptor. [8] [7] Oxysterol gradients drive chemotaxis, attracting the EBI2-expressing cells to locations of high ligand concentration. [6] [7] [8] [9] The GPR183 gene was identified due to its upregulation during Epstein-Barr virus infection of the Burkitt's lymphoma cell line BL41, hence its name: EBI2. [12]

Contents

Tissue distribution and function

B cells

EBI2 helps B cell homing to the outer follicular region within a lymph node. Approximately three hours following B cell exposure to plasma-soluble antigen, EBI2 is upregulated via the transcription factor BRRF1. [6] More surface receptors binding the oxysterol ligand results in cellular migration up the gradient, to the outer follicular region. [8] The reason for this early migration is still unknown; however, because soluble antigen enters lymph nodes via afferent lymphatic vasculature, near the outer region of the follicle, it is hypothesized that B cell movement is motivated by increased exposure to the antigen. [8] [6] Six hours after antigen exposure, EBI2 is downregulated to low levels, permitting the B cells to migrate to the border between the B cell and T cell zones of the lymph node. Here, B cells interact with T helper cells previously activated by antigen-presenting dendritic cells. Though CCR7 is the dominant receptor in this stage of B cell migration, EBI2 is still critical, the low expression of which contributes to organized interaction along the T zone border that maximizes interactions with T cells. [8] [6] Following B cell receptor and CD40 co-stimulation, EBI2 is again upregulated. [13] The B cells thus move back toward the outer follicular space, where they begin cell division. [8] At this point, a B cell either downregulates EBI2 expression in order to enter a germinal center or maintains EBI2 expression and remains in outer follicular regions. In germinal centers (GC), B cells downregulate the receptor via the transcriptional repressor B-cell lymphoma-6 (BCL6) and, following somatic hypermutation, differentiate into long-lived antibody-secreting plasma cells or memory B cells. EBI2 must turn off to move B cells to the germinal center from the periphery, and must turn on for B cells to exit the germinal center and re-enter the periphery. [13] Meanwhile, those remaining outside the follicle differentiate into plasmablasts, eventually becoming short-lived plasma cells. [6] [8] Thus, EBI2 expression modulates B cell differentiation by directing cells toward or away from germinal centers.

T cells

EBI2 also regulates intra-lymphatic T cell migration. Mature T helper cells upregulate EBI2 to follow the oxysterol gradient, migrating to the outer edges of the T cell zone to receive signals from antigen-presenting dendritic cells arriving from the tissues. [6] This migration is critical as the resulting T cell-DC interaction induces T helper cell differentiation into T follicular helper cells. [14] In concert with upregulation of CXCR5, the downregulation of EBI2 helps T follicular helper cells move toward the follicle center to help B cells undergoing affinity maturation in germinal centers. [6]

Dendritic cells

EBI2 expression on CD4+ dendritic cells is a key initiator of immune response. Antigen-activated dendritic cells are driven to lymph node bridging channels via the oxysterol-EBI2 pathway. [9] In the spleen, bridging channels connect the marginal zone, where dendritic cells pick up plasma-soluble antigen, to the T cell zone, where they present antigen to T helper cells. This results in T cell proliferation and differentiation. [6] Localization to bridging channels is also associated with dendritic cell reception of lymphotoxin beta signaling, which augments their blood pathogen uptake, resulting in an increase in T cell responses. [7]

Ligand

Oxysterols bind to and activate EBI2. [10] [11] The highest affinity oxysterol ligand is 7α,25-dihydroxycholesterol (7α,25-OHC), formed by enzymatic oxidation of cholesterol by the hydroxylases CH25H and CYP7B1. [7] 7α,25-OHC is concentrated in bridging channels and the outer perimeter of B cell follicles. Conversely it is not present in follicle centers, germ centers, nor in the T zone. [6] [8] The enzymes responsible for ligand biosynthesis, CH25H and CYP7B1, are unsurprisingly abundant in lymphoid stromal cells. On the other hand, the enzyme that deactivates the ligand, HSD3B7, is highly concentrated in areas where the ligand concentration should be lowest—the T zone. [7] Though it is not a cytokine, the EBI2 ligand acts much like a chemokine in that its gradient drives cellular migration.

Virus infection

GPR183 plays a crucial role in driving inflammation in the lungs during severe viral respiratory infections such as influenza A virus (IAV) and SARS-CoV-2. Studies using preclinical murine models of infection revealed that the activation of GPR183 by oxidized cholesterols leads to the recruitment of monocytes/macrophages and the production of inflammatory cytokines in the lungs. [15]

Related Research Articles

<span class="mw-page-title-main">Lymph node</span> Organ of the lymphatic system

A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function.

<span class="mw-page-title-main">Memory B cell</span>

In immunology, a memory B cell (MBC) is a type of B lymphocyte that forms part of the adaptive immune system. These cells develop within germinal centers of the secondary lymphoid organs. Memory B cells circulate in the blood stream in a quiescent state, sometimes for decades. Their function is to memorize the characteristics of the antigen that activated their parent B cell during initial infection such that if the memory B cell later encounters the same antigen, it triggers an accelerated and robust secondary immune response. Memory B cells have B cell receptors (BCRs) on their cell membrane, identical to the one on their parent cell, that allow them to recognize antigen and mount a specific antibody response.

<span class="mw-page-title-main">Antigen-presenting cell</span> Cell that displays antigen bound by MHC proteins on its surface

An antigen-presenting cell (APC) or accessory cell is a cell that displays antigen bound by major histocompatibility complex (MHC) proteins on its surface; this process is known as antigen presentation. T cells may recognize these complexes using their T cell receptors (TCRs). APCs process antigens and present them to T-cells.

Gut-associated lymphoid tissue (GALT) is a component of the mucosa-associated lymphoid tissue (MALT) which works in the immune system to protect the body from invasion in the gut.

<span class="mw-page-title-main">Germinal center</span> Lymphatic tissue structure

Germinal centers or germinal centres (GCs) are transiently formed structures within B cell zone (follicles) in secondary lymphoid organs – lymph nodes, ileal Peyer's patches, and the spleen – where mature B cells are activated, proliferate, differentiate, and mutate their antibody genes during a normal immune response; most of the germinal center B cells (BGC) are removed by tingible body macrophages. There are several key differences between naive B cells and GC B cells, including level of proliferative activity, size, metabolic activity and energy production. The B cells develop dynamically after the activation of follicular B cells by T-dependent antigen. The initiation of germinal center formation involves the interaction between B and T cells in the interfollicular area of the lymph node, CD40-CD40L ligation, NF-kB signaling and expression of IRF4 and BCL6.

<span class="mw-page-title-main">Follicular dendritic cells</span> Immune cells found in lymph nodes

Follicular dendritic cells (FDC) are cells of the immune system found in primary and secondary lymph follicles of the B cell areas of the lymphoid tissue. Unlike dendritic cells (DC), FDCs are not derived from the bone-marrow hematopoietic stem cell, but are of mesenchymal origin. Possible functions of FDC include: organizing lymphoid tissue's cells and microarchitecture, capturing antigen to support B cell, promoting debris removal from germinal centers, and protecting against autoimmunity. Disease processes that FDC may contribute include primary FDC-tumor, chronic inflammatory conditions, HIV-1 infection development, and neuroinvasive scrapie.

<span class="mw-page-title-main">CCL18</span> Mammalian protein found in Homo sapiens

Chemokine ligand 18 (CCL18) is a small cytokine belonging to the CC chemokine family. The functions of CCL18 have been well studied in laboratory settings, however the physiological effects of the molecule in living organisms have been difficult to characterize because there is no similar protein in rodents that can be studied. The receptor for CCL18 has been identified in humans only recently, which will help scientists understand the molecule's role in the body.

<span class="mw-page-title-main">CCL19</span> Mammalian protein found in Homo sapiens

Chemokine ligand 19 (CCL19) is a protein that in humans is encoded by the CCL19 gene.

<span class="mw-page-title-main">CXCL13</span> Mammalian protein found in Homo sapiens

Chemokine ligand 13 (CXCL13), also known as B lymphocyte chemoattractant (BLC) or B cell-attracting chemokine 1 (BCA-1), is a protein ligand that in humans is encoded by the CXCL13 gene.

<span class="mw-page-title-main">CXCR5</span> Mammalian protein found in Homo sapiens

C-X-C chemokine receptor type 5 (CXC-R5) also known as CD185 or Burkitt lymphoma receptor 1 (BLR1) is a G protein-coupled seven transmembrane receptor for chemokine CXCL13 and belongs to the CXC chemokine receptor family. It enables T cells to migrate to lymph node and the B cell zones. In humans, the CXC-R5 protein is encoded by the CXCR5 gene.

<span class="mw-page-title-main">BCL6</span> Transcription factor for converting Naive T cells to TFH

Bcl-6 is a protein that in humans is encoded by the BCL6 gene. BCL6 is a master transcription factor for regulation of T follicular helper cells proliferation. BCL6 has three evolutionary conserved structural domains. The interaction of these domains with corepressors allows for germinal center development and leads to B cell proliferation.

<span class="mw-page-title-main">C-C chemokine receptor type 7</span> Protein-coding gene in the species Homo sapiens

C-C chemokine receptor type 7 is a protein that in humans is encoded by the CCR7 gene. Two ligands have been identified for this receptor: the chemokines ligand 19 (CCL19/ELC) and ligand 21 (CCL21). The ligands have similar affinity for the receptor, though CCL19 has been shown to induce internalisation of CCR7 and desensitisation of the cell to CCL19/CCL21 signals. CCR7 is a transmembrane protein with 7 transmembrane domains, which is coupled with heterotrimeric G proteins, which transduce the signal downstream through various signalling cascades. The main function of the receptor is to guide immune cells to immune organs by detecting specific chemokines, which these tissues secrete.

<span class="mw-page-title-main">Marginal zone B-cell</span>

Marginal zone B cells are noncirculating mature B cells that in humans segregate anatomically into the marginal zone (MZ) of the spleen and certain other types of lymphoid tissue. The MZ B cells within this region typically express low-affinity polyreactive B-cell receptors (BCR), high levels of IgM, Toll-like receptors (TLRs), CD21, CD1, CD9, CD27 with low to negligible levels of secreted-IgD, CD23, CD5, and CD11b that help to distinguish them phenotypically from follicular (FO) B cells and B1 B cells.

Within the immune system, Follicular B cells are a type of B cell that reside in primary and secondary lymphoid follicles of secondary and tertiary lymphoid organs, including spleen and lymph nodes. Antibody responses against proteins are believed to involve follicular B cell pathways in secondary lymphoid organs.

<span class="mw-page-title-main">Follicular B helper T cells</span>

Follicular helper T cells (also known as follicular B helper T cells and abbreviated as TFH), are antigen-experienced CD4+ T cells found in the periphery within B cell follicles of secondary lymphoid organs such as lymph nodes, spleen and Peyer's patches, and are identified by their constitutive expression of the B cell follicle homing receptor CXCR5. Upon cellular interaction and cross-signaling with their cognate follicular (Fo B) B cells, TFH cells trigger the formation and maintenance of germinal centers through the expression of CD40 ligand (CD40L) and the secretion of IL-21 and IL-4. TFH cells also migrate from T cell zones into these seeded germinal centers, predominantly composed of rapidly dividing B cells mutating their Ig genes. Within germinal centers, TFH cells play a critical role in mediating the selection and survival of B cells that go on to differentiate either into long-lived plasma cells capable of producing high affinity antibodies against foreign antigen, or germinal center-dependent memory B cells capable of quick immune re-activation in the future if ever the same antigen is re-encountered. TFH cells are also thought to facilitate negative selection of potentially autoimmune-causing mutated B cells in the germinal center. However, the biomechanisms by which TFH cells mediate germinal center tolerance are yet to be fully understood.

FDC-SP or follicular dendritic cell-secreted protein, is a small, secreted protein, located on chromosome 4 in humans. It is thought to play an immune role in the junctional epithelium at the gingival crevice in the human mouth. It is very similar in structure to statherin, a protein contained in saliva.

<span class="mw-page-title-main">Centrocyte</span>

A centrocyte generally refers to a B cell with a cleaved nucleus, as may appear in e.g. follicular lymphoma. Centrocytes are B cells that are found in the light zones of germinal centers. Centrocytes are the non-dividing progeny of Centroblasts, and although they are relatively similar in size, centrocytes lack distinct nucleoli and are more irregularly shaped than centroblasts Centrocytes also express the cell-surface hypermutated B-cell receptor following AID activation. This hypermutated B-cell receptor allows centrocytes to compete for binding of the antigen, internalize it, and then express the processed peptides through their MHC class II receptor. Centrocyte can also refer to a cell with a protoplasm that contains single and double granules of varying size stainable with hematoxylin, as seen in lesions of lichen planus, or a nondividing, activated B cell that expresses membrane immunoglobulin.

Lymph node stromal cells are essential to the structure and function of the lymph node whose functions include: creating an internal tissue scaffold for the support of hematopoietic cells; the release of small molecule chemical messengers that facilitate interactions between hematopoietic cells; the facilitation of the migration of hematopoietic cells; the presentation of antigens to immune cells at the initiation of the adaptive immune system; and the homeostasis of lymphocyte numbers. Stromal cells originate from multipotent mesenchymal stem cells.

<span class="mw-page-title-main">Centroblast</span>

A centroblast generally refers to an activated B cell that is enlarged and is rapidly proliferating in the germinal center of a lymphoid follicle. They are specifically located in the dark zone of the germinal center. Centroblasts form from naive B cells being exposed to follicular dendritic cell cytokines, such as IL-6, IL-15, 8D6, and BAFF. Stimulation from helper T cells is also required for centroblast development. Interaction between CD40 ligand on an activated T helper cell and the B cell CD40 receptor induces centroblasts to express activation-induced cytidine deaminase, leading to somatic hypermutation, allowing the B cell receptor to potentially gain stronger affinity for an antigen. In the absence of FDC and helper T cell stimulation, centroblasts are unable to differentiate and will undergo CD95-mediated apoptosis.

Gut-specific homing is the mechanism by which activated T cells and antibody-secreting cells (ASCs) are targeted to both inflamed and non-inflamed regions of the gut in order to provide an effective immune response. This process relies on the key interaction between the integrin α4β7 and the addressin MadCAM-1 on the surfaces of the appropriate cells. Additionally, this interaction is strengthened by the presence of CCR9, a chemokine receptor, which interacts with TECK. Vitamin A-derived retinoic acid regulates the expression of these cell surface proteins.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000169508 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000051212 - Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. "Entrez Gene: EBI2 Epstein-Barr virus induced gene 2 (lymphocyte-specific G protein-coupled receptor)".
  6. 1 2 3 4 5 6 7 8 9 10 Barington L, Wanke F, Niss Arfelt K, Holst PJ, Kurschus FC, Rosenkilde MM (August 2018). "EBI2 in splenic and local immune responses and in autoimmunity". Journal of Leukocyte Biology. 104 (2): 313–322. doi:10.1002/JLB.2VMR1217-510R. PMID   29741800. S2CID   13699151.
  7. 1 2 3 4 5 6 Kurschus FC, Wanke F (October 2018). "EBI2 - Sensor for dihydroxycholesterol gradients in neuroinflammation". Biochimie. "Current trends in oxysterols and related sterols". 153: 52–55. doi:10.1016/j.biochi.2018.04.014. PMID   29689289. S2CID   13855522.
  8. 1 2 3 4 5 6 7 8 9 Gatto D, Brink R (July 2013). "B cell localization: regulation by EBI2 and its oxysterol ligand". Trends in Immunology. 34 (7): 336–341. doi:10.1016/j.it.2013.01.007. PMID   23481574.
  9. 1 2 3 Daugvilaite V, Arfelt KN, Benned-Jensen T, Sailer AW, Rosenkilde MM (July 2014). "Oxysterol-EBI2 signaling in immune regulation and viral infection". European Journal of Immunology. 44 (7): 1904–1912. doi:10.1002/eji.201444493. PMC   4209795 . PMID   24810762.
  10. 1 2 Liu C, Yang XV, Wu J, Kuei C, Mani NS, Zhang L, et al. (July 2011). "Oxysterols direct B-cell migration through EBI2". Nature. 475 (7357): 519–523. doi:10.1038/nature10226. PMID   21796211. S2CID   4414566.
  11. 1 2 Hannedouche S, Zhang J, Yi T, Shen W, Nguyen D, Pereira JP, et al. (July 2011). "Oxysterols direct immune cell migration via EBI2". Nature. 475 (7357): 524–527. doi:10.1038/nature10280. PMC   4297623 . PMID   21796212.
  12. Birkenbach M, Josefsen K, Yalamanchili R, Lenoir G, Kieff E (April 1993). "Epstein-Barr virus-induced genes: first lymphocyte-specific G protein-coupled peptide receptors". Journal of Virology. 67 (4): 2209–2220. doi:10.1128/JVI.67.4.2209-2220.1993. PMC   240341 . PMID   8383238.
  13. 1 2 Pereira JP, Kelly LM, Xu Y, Cyster JG (August 2009). "EBI2 mediates B cell segregation between the outer and centre follicle". Nature. 460 (7259): 1122–1126. Bibcode:2009Natur.460.1122P. doi:10.1038/nature08226. PMC   2809436 . PMID   19597478.
  14. Willinger T (April 2019). "Oxysterols in intestinal immunity and inflammation". Journal of Internal Medicine. 285 (4): 367–380. doi:10.1111/joim.12855. PMC   7379495 . PMID   30478861.
  15. Foo CX, Bartlett S, Chew KY, Ngo MD, Bielefeldt-Ohmann H, Arachchige BJ, et al. (March 2023). "GPR183 antagonism reduces macrophage infiltration in influenza and SARS-CoV-2 infection". The European Respiratory Journal. 61 (3). doi:10.1183/13993003.01306-2022. PMC   9686317 . PMID   36396144.

Further reading

This article incorporates text from the United States National Library of Medicine, which is in the public domain.