CD Antigens

Key Biological Properties: CD5L is a secreted glycoprotein that plays a crucial role in lipid metabolism and immune responses . It has serine-type endopeptidase activity and is involved in zymogen activation .

Expression Patterns: CD5L is predominantly expressed by macrophages in lymphoid and inflamed tissues . It is also found in the spleen, lymph nodes, thymus, bone marrow, and fetal liver .

Tissue Distribution: CD5L is widely distributed in various tissues, including lymphoid organs and inflamed tissues . It is also present in non-lymphoid tissues such as the liver and adipose tissue .

Primary Biological Functions: CD5L acts as a key regulator of lipid synthesis and inflammatory responses . It inhibits lipid droplet size in adipocytes and regulates fatty acid synthase activity, leading to lipolysis .

Role in Immune Responses: CD5L plays a significant role in immune responses by modulating macrophage polarization and enhancing phagocytosis . It also regulates the expression of pro-inflammatory genes in T-helper Th17 cells .

Pathogen Recognition: CD5L is involved in pathogen recognition by binding to pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) .

Mechanisms with Other Molecules and Cells: CD5L interacts with various molecules and cells, including CD36, fatty acid synthase (FASN), and nuclear receptors such as ROR-gamma (RORC) . It modulates lipid content and limits the synthesis of cholesterol ligands .

Binding Partners: CD5L binds to CD36, which mediates its endocytosis into adipocytes . It also interacts with cytosolic FASN, inhibiting its activity .

Downstream Signaling Cascades: CD5L-induced lipolysis involves downstream signaling cascades that regulate lipid metabolism and inflammatory responses .

Transcriptional Regulation: The expression of CD5L is transcriptionally regulated by liver X receptors (LXRs), which are members of the nuclear receptor family .

Post-Translational Modifications: CD5L undergoes various post-translational modifications, including glycosylation, which is essential for its stability and function .

Biomedical Research: CD5L is a valuable tool in biomedical research for studying lipid metabolism, immune responses, and inflammatory diseases .

Diagnostic Tools: CD5L can be used as a diagnostic marker for various diseases, including sepsis, atherosclerosis, and autoimmune disorders .

Therapeutic Strategies: CD5L has potential therapeutic applications in treating inflammatory diseases, metabolic disorders, and infections .

Development: CD5L plays a role in the development of the immune system by regulating macrophage function and lipid metabolism .

Aging: CD5L expression and activity may change with aging, affecting immune responses and lipid metabolism .

Disease: CD5L is involved in the pathogenesis of various diseases, including infections, atherosclerosis, and autoimmune disorders .