Cloning And Expression Of Human SCD40L And Analysis Of Its Biological Functions

Nowadays, Atherosclerosis(AS) is currently considered a chronic inflammatory disease combined with a disorder of lipid metabolism and deposition.Many researches confirm that hypercholesterinemia ,especial high low density lipoprotein cholesterol, is the main course for AS,and pathogenesis of AS have relation with the fatty substance's depositing in the wall of artery,but more and more evidences indicate that many factors ,such as abnormality of fatty metabolism,blood aggregation factor ,cytokine, haemodynamics,inheritance,behaviors,infect,lead to the AS. Several studies clearly demonstrate that the CD40-CD40L system plays an important role not only in cellular immunity and inflammation, but also in the pathophysiology of atherosclerosis. There are lots of activated CD4 + T lymph cell and megalophage in the imflammation plague. In the immune reaction the CD40 ligand plays important role and involves the antigen presentation and autoimmune reaction, it also has relation with the activation of T lymph cell and macrophages. CD40 ligand belongs to TNF superfamily,it can activate B lymph cell and make it excrete antibody by binding with its receptor CD40.Recently many studies indicate that CD40L can adjust imflammation reaction in the plague (including vascular endothelial cell, vascular smooth muscle cell and megalophage) in addition to participating imflammation cell signal transduction.Lots of evidences manifest that CD40L has closely relation with the occurrence and progression of AS,it is the center piece of AS.The mRNA of human CD40L have 1803 bp , it exists in two types (solubility type and transmembrane type) and both of them have biological activity. Therefore, we cloned the cDNAs encoding human sCD40L and constructed the prokaryotic expression vectors. Then the target proteins were induced by IPTG. Next, the target proteins were purified through Ni²⁺-NTA chromatography and polymyxin B column. Finally, their biological activitives were assayed. This study aims at providing a foundation for further study on the mechanism of CD40L.Objectives:...