This article describes the role of complement receptor 2 (CR2) in regulating normal humoral immune responses and the development of autoimmunity. The protein is expressed primarily on mature B cells and follicular dendritic cells and has three known protein isoforms in humans.
What Cells Express Cr2?
The 145 kDa transmembrane glycoprotein CR2 is mainly expressed by B lymphocytes and follicular dendritic cells (10, 11).
What Does Cr2 Bind?
CR2 binds to opsonized antigens by attaching C3d (or iC3b or C3dg) to the B-cell receptors when they bind the B-cell receptors. B cells are greatly stimulated to respond to the antigen as a result.
What Is The Function Of Cd21?
In addition to C3d, C3dg, and iC3b, CD21 also functions as a complement component for EBV and IFNalpha. B cells are activated by binding to CD21 and forming a large signal-transduction complex that also includes CD19, CD81, and Leu13.
Where Is Cd21 Found?
Human blood plasma contains a soluble form of CD21 (sCD21) that is shed from the cell surface. shedding is thought to be caused by an unknown protease. A certain clinical condition may result in altered levels of sCD21.
Is Cr2 Same As Cd21?
Human CR2 gene is responsible for encoded complement receptor type 2 (CR2), also known as complement C3d receptor, Epstein-Barr virus receptor, and CD21 (cluster of differentiation 21).
What Is Cd21 A Marker For?
In the CD21–/low B cells, markers indicate previous activation. Flow cytometry was used to analyze peripheral blood mononuclear cells (PBMCs) from healthy donors.
What Is Cr2 In Immunology?
Human CR2 gene is responsible for encoded complement receptor type 2 (CR2), also known as complement C3d receptor, Epstein-Barr virus receptor, and CD21 (cluster of differentiation 21). A complement system is managed by CR2. binds to iC3b (inactive derivative of C3b), C3dg, or C3d.
Which Cells Express Complement Receptors?
A white blood cell’s surface is a place where complement receptors are expressed, such as monocytes and macrophages. The four complement receptors can bind to fragments of complement component 3 or complement component 4, but they trigger different downstream reactions depending on the receptors.
What Cells Have Cd21?
A key component of complement 3 receptors, CD21 is expressed primarily on mature B cells and follicular dendritic cells  and plays an important role in the uptake and retention of immune complexes.
How Is Cr2 Normally Important For Activation Of Naive B Cells?
The role of CR2 is to promote B cell memory development in two ways. Second, CR2 expression on B cells is essential for firm contact with the antigens retained on FDCs, an event that provides a crucial survival signal that allows stimulated B cells to enter follicles and initiate a germinal center reaction.
What Does Cr2 Bind To?
In addition to CR2, CR21 is also a EBV receptor (EBV/C3d, CD21). Two distinct binding sites are present in CR2 to bind to its two extracellular ligands, C3d and EBV capsid glycoprotein gp350/220. In order to induce proliferation, CR2 is used.
Which Virus Binds To B Cells Via Type Ii Complement Receptors?
A complement receptor, CD21, is activated by the Epstein-Barr virus (EBV), which causes normal B cells to become infected.
Do T Cells Have Cd21?
B cells, follicular dendritic cells, and T cells are all known to express CD21.
What Cells Express Cd20?
A protein called CD20 (cluster of differentiate 20) is expressed on the surface of B cells, starting at the pre-B cell stage and extending to mature B cells in the bone marrow and peripheral blood.
Which Cells Express Cd21?
T helper 21 is expressed on thymocytes, a subset of peripheral T cells, follicular dendritic cells, astrocytes, and some epithelial cells (14–18).