CD Antigens
Product List
CD99 Human
CD99 Human Recombinant
CD99 Human Recombinant produced in Sf9 Baculovirus cells is a single, glycosylated polypeptide chain containing 342 amino acids (23-122a.a.) and having a molecular mass of 37.3kDa (Molecular size on SDS-PAGE will appear at approximately 40-57kDa).
CD99 is expressed with a 239 amino acids hIgG-His tag at C-Terminus and purified by proprietary chromatographic techniques.
Sf9, Baculovirus cells.
Introduction
CD99, also known as MIC2, is a heavily O-glycosylated transmembrane protein encoded by the CD99 gene in humans . It is a member of the Xg blood group system and exists in two isoforms due to alternative splicing . CD99 is involved in various cellular processes and has both oncogenic and tumor suppressor functions depending on the context .
Key Biological Properties: CD99 is a 32 kDa surface glycoprotein that is highly O-glycosylated . It is broadly expressed in humans and primates, with strong expression in specific cell types .
Expression Patterns and Tissue Distribution: CD99 is expressed on all leukocytes, with the highest expression on thymocytes . It is also found in endothelial cells, gingival fibroblasts, and gingival epithelial cells . Additionally, CD99 is overexpressed in various tumors, including Ewing sarcoma and specific subtypes of leukemia .
Primary Biological Functions: CD99 plays a crucial role in cell adhesion, migration, differentiation, and apoptosis . It is involved in the regulation of immune responses and pathogen recognition .
Role in Immune Responses and Pathogen Recognition: CD99 is essential for T-cell adhesion and apoptosis of double-positive T cells . It also participates in the migration and activation of leukocytes, influencing immune responses .
Mechanisms with Other Molecules and Cells: CD99 acts through homophilic interactions, enabling homo- or heterotypic cell aggregation . It mediates diverse cellular processes such as adhesion, transendothelial migration, differentiation, and cell death .
Binding Partners and Downstream Signaling Cascades: CD99 interacts with various molecules, including cyclophilin A . It activates downstream signaling pathways such as RAS-Rac1, which are crucial for its role in cell migration and apoptosis .
Regulatory Mechanisms Controlling Expression and Activity: CD99 expression is regulated at both the transcriptional and post-transcriptional levels . Transcriptional regulation involves various factors that modulate its gene expression, while post-translational modifications, such as glycosylation, influence its activity .
Transcriptional Regulation and Post-Translational Modifications: CD99 is subject to alternative splicing, resulting in two isoforms with distinct functions . Glycosylation is a critical post-translational modification that affects its stability and function .
Biomedical Research: CD99 is a valuable marker in the diagnosis and study of various cancers, including Ewing sarcoma and leukemia . It is also used in research on immune responses and cell adhesion .
Diagnostic Tools: Antibodies against CD99 are employed in immunohistochemistry to distinguish Ewing sarcoma from other tumors with similar histological appearances . CD99 is also used to identify thymic tumors and spindle cell tumors .
Therapeutic Strategies: Targeting CD99 with monoclonal antibodies has shown promise in preclinical studies for treating tumors with high CD99 expression . Anti-CD99 therapy has potential applications in managing CNS inflammation and autoimmunity .
Role Throughout the Life Cycle: CD99 is involved in various stages of the life cycle, from development to aging and disease . It plays a role in the differentiation of primitive neuroectodermal cells and the regulation of leukocyte migration . CD99’s expression and function are crucial in both normal physiological processes and pathological conditions .
