Cluster of Differentiation (CD) Protein Overview

CD protein (Cluster of Differentiation proteins) is a kind of membrane protein expressed on the surface of immune cells, which is mainly used to mark and identify specific types and functional states of immune cells. CD proteins are identified by antibody labeling and immunophenotyping techniques, and hundreds of CD proteins have been identified so far. CD protein plays an important role in immune cell recognition, activation, proliferation and regulation. They mediate cell-cell interactions, signaling and localization of immune cells. Specific CD proteins are expressed on the surface of different types of immune cells, such as T cells, B cells, macrophages and natural killer cells.

By studying the expression and function of CD protein, we can better understand the types, differentiation status and functional characteristics of immune cells. This is of great significance for studying the normal function of the immune system, the pathogenesis of immune-related diseases, and developing new immunotherapy strategies.

As a kind of membrane protein expressed on the surface of immune cells, CD protein plays a key role in the recognition and regulation of immune cells.

Research field of CD Protein

The research field of CD protein is very extensive and involves many fields. The following are some of the main areas of research for CD proteins:

1. Immune cell typing and identification: CD protein is widely used to label and identify different types of immune cells, such as T cells, B cells, macrophages, natural killer cells, etc. Researchers use the expression patterns and combinations of CD proteins to type and identify immune cells to gain insight into the types, differentiation status, and functional properties of immune cells.
2. Immunomodulation and immunotherapy: CD protein plays an important role in immunomodulation and immunotherapy. Researchers study the regulatory mechanism of CD protein in the process of immune cell activation, proliferation, apoptosis, etc., as well as the interaction between CD protein and its ligands, and develop antibody drugs and immunotherapy against CD protein for the treatment of tumors, Diseases such as autoimmune diseases and transplant rejection.
3. Immune-related diseases: CD protein is also of great significance in the research of immune-related diseases. Researchers study the relationship between the abnormal expression and dysfunction of CD protein and the occurrence and development of autoimmune diseases, infectious diseases and inflammatory responses. Find new targets and strategies for the treatment of immune-related diseases by in-depth study of the mechanism of action of CD protein.
4. Neuroimmunology: In recent years, CD protein has received more and more attention in neuroimmunology research. Researchers study the expression and regulation of CD proteins in the nervous system, and their roles in neuroinflammation, neurodegenerative diseases, and neuroimmune regulation. This has important implications for understanding neuroimmune interactions and developing treatments for related diseases.

The research field of CD protein involves many aspects such as immune cell typing and identification, immune regulation and immunotherapy, immune-related diseases and neuroimmunology. Through the study of CD protein, we can better understand the characteristics and functions of immune cells, and promote the development of immunotherapy and disease treatment.

Popular CD Protein

CD3

CD3 is a complex composed of four subunits, CD3δ, CD3ε, CD3γ and CD3ζ, and is mainly expressed on the surface of T cells. Together with the T cell receptor (TCR), they form the TCR-CD3 complex, which is involved in the recognition and signal transduction of T cells.

The CD3 complex plays a key role in T cell activation and immune response. When the TCR binds to an antigen, the CD3 complex transmits a signal that leads to T cell activation and proliferation, which in turn initiates an immune response against the antigen. Different subunits in the CD3 complex have specific functions, among which the CD3ζ subunit is a key component of signaling.

CD3 is also widely used in immunology research and clinical application. In terms of research, scientists can use CD3 antibody to label and identify T cells, and study the typing, activation and function of T cells. In terms of clinical application, CD3 antibody can be used to treat malignant tumors and autoimmune diseases.

CD4

CD4 is a membrane protein widely expressed on the surface of helper T cells (CD4+ T cells). It is a key molecule in the immune system, involved in regulating and coordinating immune responses.

The main function of CD4 is to play a role in the process of antigen recognition by T cell receptor (TCR). When TCR binds to an antigen, the CD4 molecule helps T cells recognize the antigen and activate an immune response by binding to major histocompatibility complex class II (MHC-II) molecules. CD4 is also involved in regulating the differentiation and function of T cells, such as promoting the differentiation of helper T cells to specific subsets, enhancing cytokine production and regulating the activation of other immune cells.

CD4 is also widely used in research and clinical applications. In terms of research, scientists use CD4 antibodies to identify and isolate CD4+ T cells to study their function, activation and regulatory mechanisms. In terms of clinical application, the expression level of CD4 can be used as one of the indicators for evaluating immune function and monitoring disease progression.

CD8

CD8 is a membrane protein mainly expressed on the surface of cytotoxic T cells (CD8+ T cells). It plays a key role in the immune response and cellular immunity. The CD8 protein has two isoforms: CD8α and CD8β. These two subtypes form the CD8 molecular complex, which is involved in the process of cellular immunity by binding to the T cell receptor (TCR). CD8 protein plays an important role in cellular immunity. By combining with MHC-I molecules, it helps T cells recognize and kill infected cells, tumor cells and abnormal cells themselves.

CD8+ T cells are called cytotoxic T cells or CTLs (Cytotoxic T Lymphocytes), which have the ability to directly kill infected cells. CD8 triggers the death of target cells by releasing cytotoxins and apoptotic signaling molecules. This cytotoxic activity is critical for clearing pathogenic infections and controlling tumor growth.

CD8 can also be used as a marker for immune monitoring and diagnosis. By detecting the expression level of CD8, it is possible to evaluate the cellular immune function, monitor the disease state and evaluate the therapeutic effect. In research and clinical practice, the expression level of CD8 is often used as an important indicator to evaluate immune activity and disease progression.

References:

[1] Várady G, Cserepes J, Németh A, Szabó E, Sarkadi B. Cell surface membrane proteins as personalized biomarkers: where we stand and where we are headed. Biomark Med. 2013;7(5):803-819. doi:10.2217/bmm.13.90 https://pubmed.ncbi.nlm.nih.gov/24044572/

[2] Franco R, Martínez-Pinilla E, Lanciego JL, Navarro G. Basic Pharmacological and Structural Evidence for Class A G-Protein-Coupled Receptor Heteromerization. Front Pharmacol. 2016;7:76. Published 2016 Mar 31. doi:10.3389/fphar.2016.00076 https://pubmed.ncbi.nlm.nih.gov/27065866/

[3] Perdomo-Celis F, Taborda NA, Rugeles MT. CD8+ T-Cell Response to HIV Infection in the Era of Antiretroviral Therapy. Front Immunol. 2019;10:1896. Published 2019 Aug 9. doi:10.3389/fimmu.2019.01896 https://pubmed.ncbi.nlm.nih.gov/31447862/