♛VVIP Hyderabad Call Girls Chintalkunta🖕7001035870🖕Riya Kappor Top Call Girl ...
Complement system proteins and enzymes s
1. COMPLEMENT SYSTEM
Prof Dr. Naael H Ali, Ph.D
Clinical Immunology
Dep. of Microbiology
College of Medicine
University of Basrah
2. Introduction
The term complement refers to a set of 50-plus serum proteins
that cooperates with both the innate and the adaptive immune
systems to eliminate pathogens, dying cells, and immune
complexes from the body .
It is named “complement system” because it was first identified
as a heat-labile component of serum that “complemented”
antibodies in the killing of bacteria.
Normally, these proteins are in an inactive form
(proenzyme), but specific signal can activate the first
protein
3. Component of Complement system
Over 50 serum and cell surface proteins:
Complement components
(in serum inactive, activated sequentially as a cascade)
Complement receptors
(cell surface, recognize activated components)
Regulatory proteins of complement
(both in serum and cell surface, inhibit activated
components)
4. Properties of Complements
Source of complement proteins produced by hepatocytes,
macrophages and intestinal epithelial cells.
Fibroblasts and intestinal epithelial cells make C1, while the liver
makes C3, C6, and C9.
Heating at 56 c for 30 minutes can inactivate complements.
Complete deterioration within a day or two and even in the
refrigerator, considerable loss of activity occurs in 3-4 days.
Complement may be destroyed by acids and alkalis,
So, all glassware must be chemically clean, although not
necessarily sterile.
Complements may be preserved by freezing and lyophilization.
Serum complement levels, especially C3, often drop during
infection (complement is activated faster than it is produced).
10. Major biologic activity of Complement
Complement is the term applied to a plasma effector
system:
direct mediation of acute inflammatory reactions
destruction of many kinds of cells, bacteria and
viruses.
Complement factors has some hormone-like properties:
recruit other humoral and cellular effectors;
induces directed neutrophil migration;
triggers histamine release from mast cells;
stimulates release of lysosomal enzymes from PMN's.
19. Diagnostic significant
Increased complement activity
may be seen in:
Cancer
Certain infections
Ulcerative colitis
Decreased complement activity
may be seen in:
Cirrhosis
Glomerulonephritis
Hereditary angioedema
Hepatitis
Kidney transplant rejection
Lupus nephritis
Malnutrition
Systemic lupus erythematosis
20. Regulation of complement system:
1- CI Inhibitor (C1-INH) Classical pathway .
2- C3a inactivator (C3a-INA; Carboxypeptidase B) It inactivates C3a.
3- Factor H & I: Alternative pathway
4- Decay accelerating factor [DAF] Both.
5- C4 binding protein (C4-BP) and Factor I Alternative .
6- Protein S (vitronectin): MAC pathway.
