CD83 molecule | Elisa - Clia - Antibody - Protein

Background

CD83 is a transmembrane glycoprotein that belongs to the immunoglobulin (Ig) superfamily. It is encoded by the CD83 gene located on chromosome 6p23. CD83 was initially identified on activated lymphocytes and is now recognized as a critical molecule in the regulation of immune responses. The protein is primarily expressed on the surface of mature dendritic cells (DCs), activated T cells, B cells, and other immune cells. CD83 plays a vital role in the immune system by influencing the maturation and function of immune cells, making it a significant molecule in immunology.

Protein Structure

CD83 is a single-pass type I membrane protein. It has several key structural components:

• Extracellular Domain: The extracellular region of CD83 consists of a single immunoglobulin V-set domain. This domain is responsible for interactions with other proteins and ligands in the immune system. The V-set domain is characteristic of the immunoglobulin superfamily and is crucial for the protein's function in immune regulation.
• Transmembrane Domain: The transmembrane segment of CD83 anchors the protein to the cell membrane, ensuring that its extracellular domain is positioned correctly for interactions with other cells and molecules in the immune environment.
• Intracellular Domain: The cytoplasmic tail of CD83 is relatively short and contains signaling motifs that are involved in intracellular signaling pathways. This domain is essential for transmitting signals from the extracellular environment to the cell's interior, influencing cellular responses and functions.

Classification and Subtypes

CD83 is a member of the immunoglobulin superfamily, which includes a wide range of proteins involved in immune functions. Although CD83 does not have subtypes per se, it can exist in different forms:

1. Membrane-bound CD83 (mCD83): This is the full-length form of the protein found on the surface of cells.
2. Soluble CD83 (sCD83): A cleaved or alternatively spliced form of CD83 that is released into the extracellular environment. Soluble CD83 can have immunoregulatory effects distinct from the membrane-bound form.

Function and Biological Significance

Immune Cell Maturation:

• CD83 is highly expressed on mature dendritic cells, which are pivotal for initiating and regulating immune responses. The presence of CD83 on dendritic cells enhances their ability to present antigens and activate T cells, which is crucial for the adaptive immune response.

T Cell Activation:

• CD83 expression on activated T cells suggests a role in T cell activation and function. CD83 enhances the interaction between T cells and antigen-presenting cells (APCs), promoting effective immune responses.

Regulation of Immune Responses:

• Soluble CD83 has been shown to have immunosuppressive properties. It can inhibit the maturation of dendritic cells and reduce the activation of T cells, contributing to immune tolerance and preventing excessive immune responses that can lead to autoimmunity.

Role in Autoimmunity and Transplantation:

• Due to its regulatory functions, CD83 is implicated in autoimmune diseases and transplantation. Therapeutic strategies targeting CD83, such as using soluble CD83 to induce immune tolerance, are being explored to treat autoimmune conditions and improve graft survival in transplant patients.

Cancer Immunotherapy:

• CD83 is also being investigated in the context of cancer. The modulation of CD83 expression on immune cells can influence anti-tumor immunity. Enhancing CD83 expression on dendritic cells can improve their ability to activate T cells against cancer cells, making it a potential target for cancer immunotherapy.

Clinical Issues

Autoimmune Diseases:

• Aberrant expression or function of CD83 is associated with various autoimmune diseases. For instance, decreased CD83 expression on dendritic cells is observed in multiple sclerosis, leading to impaired T cell regulation and autoimmunity. Therapeutic interventions that modulate CD83 expression or function could provide new avenues for treating autoimmune diseases.

Transplantation:

• In organ transplantation, CD83 is a potential target for preventing graft rejection. By using soluble CD83 to induce immune tolerance, researchers aim to reduce the immune response against the transplanted organ, thereby enhancing graft survival and reducing the need for immunosuppressive drugs.

Infectious Diseases:

• CD83 plays a role in the immune response to infections. Modulating CD83 expression can influence the body's ability to fight infections. For example, enhancing CD83 expression on dendritic cells can improve the presentation of viral antigens and the activation of antiviral T cells.

Cancer:

• In cancer, CD83 expression on dendritic cells is crucial for activating anti-tumor T cells. Strategies to enhance CD83 expression on dendritic cells or to block inhibitory signals involving CD83 can boost the immune system's ability to target and destroy cancer cells. Clinical trials are exploring the use of CD83 in cancer immunotherapy, with promising results.

Summary

CD83 is a vital molecule in the immune system, primarily involved in the maturation and function of dendritic cells, T cells, and other immune cells. Its structure includes a single immunoglobulin V-set domain, a transmembrane region, and a short intracellular tail, all contributing to its role in immune regulation. CD83 influences immune responses by enhancing T cell activation, regulating immune cell maturation, and maintaining immune tolerance. Its significance extends to clinical applications, including autoimmune diseases, transplantation, infectious diseases, and cancer immunotherapy. Therapeutic strategies targeting CD83, such as using soluble CD83 or enhancing CD83 expression, hold potential for treating various immune-related conditions and improving patient outcomes. The ongoing research into CD83 continues to uncover its multifaceted roles in immunology, offering new insights and therapeutic opportunities.