background: inappropriate activation or blockage of the inhibition of complement system could cause tissue damages in autoimmune diseases particularly rheumatoid arthritis (ra). defect in complement component regulation may cause damages to tissues, on the other hand, or the damaged tissue might affect the unnecessary activation of complement components.   objective: to investigate the expressi...

Complement system is a major effecter system of the innate immunity that bridges with adaptive immunity. The system consists of about 40 humoral and cell surface proteins that include zymogens, receptors and regulators. The zymogens get activated in a cascade fashion by antigen-antibody complex, antigen alone or by polymannans, respectively, by the classical, alternative and mannose binding lec...

Human-pathogenic microbes possess various means to avoid destruction by our immune system. These include interactions with the host complement system that may facilitate pathogen entry into cells and tissues, expression of molecules that defuse the effector complement components and complexes, and acquisition of host complement inhibitors to downregulate complement activity on the surface of th...

The modern trend in complement research concerns the functionally relevant interactions of complement components and the biologic activities of the complement system. The pri mary interest of students of complement today centers on complement as a humoral effector system which constitutes an integral part of the immunologically competent organism. There exists only a secondary interest at prese...

The complement system is a crucial defensive network that protects the host against invading pathogens. It is part of the innate immune system and can be initiated via three pathways: the lectin, classical and alternative activation pathway. Overall the network compiles a group of recognition molecules that bind specific patterns on microbial surfaces, a group of associated proteases that initi...

A number of proteins anchored on the cell surface function to protect host tissues from bystander injury when complement is activated. In humans, they include decay-accelerating factor (DAF, CD55), membrane cofactor protein (MCP, CD46), complement receptor 1 (CR1, CD35) and CD59. Although disease conditions directly attributable to abnormal function of these proteins are relatively rare, it has...

The complement system is a complex cascade involving proteolytic cleavage of serum glycoproteins often activated by cell receptors. This cascade ultimately results in induction of the inflammatory response, phagocyte chemotaxis and opsonization, and cell lysis. Complement factors C3a, C5a, and C4 can induce vasodilatation, increased capillary permeability, and expression of leukocyte adhesion m...