CD Antigens

Key Biological Properties: CD27 is essential for the generation and long-term maintenance of T cell immunity . It binds to its ligand, CD70, and is involved in the regulation of B-cell activation and immunoglobulin synthesis .

Expression Patterns: CD27 is expressed on both naïve and activated effector T cells, as well as on NK cells and activated B cells . During mouse embryonic development, CD27 is expressed in the aorta-gonad-mesonephros region, defining the first adult definitive hematopoietic stem cells .

Tissue Distribution: CD27 is predominantly found in lymphoid tissues such as the lymph nodes, spleen, and thymus . It is also expressed in the bone marrow, blood, and various other tissues .

Primary Biological Functions: CD27 is crucial for the generation and maintenance of T cell immunity . It plays a significant role in the regulation of B-cell activation and immunoglobulin synthesis .

Role in Immune Responses: CD27 is involved in the differentiation and clonal expansion of T cells upon binding to CD70 . This interaction enhances the survival and memory of cytotoxic T cells and increases the production of certain cytokines .

Pathogen Recognition: CD27, through its role in T and B cell activation, indirectly contributes to the recognition and response to pathogens .

Mechanisms with Other Molecules and Cells: CD27 interacts with its ligand CD70, leading to a signaling cascade that results in T cell differentiation and clonal expansion . This cascade also involves the activation of NF-κB and MAPK8/JNK pathways .

Binding Partners: The primary binding partner of CD27 is CD70 . This interaction is crucial for its role in immune regulation.

Downstream Signaling Cascades: Upon binding to CD70, CD27 transduces signals that activate NF-κB and MAPK8/JNK pathways, leading to various immune responses .

Regulatory Mechanisms: The expression of CD27 is regulated at multiple levels. T cell activation via the TCR/CD3 complex or the CD2 molecule significantly increases CD27 expression . Conversely, direct stimulation of protein kinase C by phorbol esters down-regulates CD27 surface expression .

Transcriptional Regulation: Specific transcription factors involved in the regulation of CD27 expression are not well-documented, but it is known that T cell activation plays a significant role .

Post-Translational Modifications: Post-translational modifications of CD27, such as phosphorylation, may play a role in its function and regulation, although detailed mechanisms are not fully understood .

Biomedical Research: CD27 is used as a marker to distinguish different subsets of T cells, B cells, and NK cells . It is also a target for cancer immunotherapy due to its role in T cell activation .

Diagnostic Tools: CD27 expression levels can be used as a diagnostic marker for certain immune deficiencies and lymphoproliferative disorders .

Therapeutic Strategies: Monoclonal antibodies targeting CD27 are being explored for their potential in cancer immunotherapy . These therapies aim to enhance T cell responses against tumors by modulating CD27 signaling .

Development: CD27 is expressed early in life and plays a role in the formation of memory B cells . It continues to be important throughout life for the maintenance of immune memory .

Aging and Disease: The expression and function of CD27 may decline with age, contributing to weakened immune responses in the elderly . Additionally, CD27 is involved in various immune-related diseases, including autoimmune disorders and cancers .