CD Antigens

Key Biological Properties: CD80 is a transmembrane glycoprotein with an extracellular immunoglobulin constant-like domain and a variable-like domain required for receptor binding .

Expression Patterns: CD80 is primarily expressed on antigen-presenting cells (APCs) such as dendritic cells, activated B-cells, and macrophages . It can also be found on T-cells under certain conditions .

Tissue Distribution: CD80 is widely distributed in lymphoid tissues, including the spleen, lymph nodes, and thymus. It is also present in non-lymphoid tissues such as the lung and pancreas .

Primary Biological Functions: CD80 plays a pivotal role in the activation and regulation of T-cells. It provides the necessary costimulatory signals for T-cell activation and proliferation by binding to CD28 and CTLA-4 receptors on T-cells .

Role in Immune Responses: CD80 is essential for initiating and sustaining immune responses. It enhances T-cell activation, leading to the production of cytokines and the proliferation of T-cells .

Pathogen Recognition: CD80 is involved in the recognition and response to pathogens by facilitating the activation of T-cells, which are crucial for adaptive immunity .

Mechanisms with Other Molecules and Cells: CD80 interacts with CD28 and CTLA-4 on T-cells. Binding to CD28 provides a costimulatory signal that enhances T-cell activation, while binding to CTLA-4 delivers an inhibitory signal that downregulates T-cell responses .

Binding Partners: CD80 primarily binds to CD28 and CTLA-4 on T-cells .

Downstream Signaling Cascades: The interaction of CD80 with CD28 activates downstream signaling pathways such as PI3K/Akt, Ras/MAPK, and NF-κB, leading to T-cell activation and cytokine production .

Regulatory Mechanisms: The expression and activity of CD80 are tightly regulated at multiple levels. Transcriptional regulation involves various transcription factors that bind to the promoter region of the CD80 gene .

Post-Translational Modifications: CD80 undergoes post-translational modifications such as glycosylation, which are essential for its stability and function .

Biomedical Research: CD80 is widely studied in immunology and cancer research due to its role in T-cell activation and immune regulation .

Diagnostic Tools: CD80 expression levels can serve as biomarkers for certain diseases, including autoimmune disorders and cancers .

Therapeutic Strategies: Targeting CD80 with specific antibodies or fusion proteins is being explored as a therapeutic strategy for enhancing immune responses in cancer and for modulating immune responses in autoimmune diseases .

Development: CD80 is involved in the development and maturation of the immune system, particularly in the activation and differentiation of T-cells .

Aging: The expression and function of CD80 may change with age, potentially affecting immune responses in the elderly .

Disease: Dysregulation of CD80 expression or function can contribute to various diseases, including autoimmune disorders, infections, and cancers .