Post on 16-Feb-2016
description
Humoral and Cellular Immunity
•Cellular immunity – Host defenses that are mediated by antigen-specific T cells and various nonspecific cells of the immune system.
•Humoral immunity – Host defenses that are mediated by antibody present in the plasma, lymph and tissue fluids.
The Complement System
Ricklin and Lambris 2007
Functions of the Complement System
•Viral neutralization
The Complement System
Components of the Complement System:
proteins and glycoproteinssynthesized mainly by liver5% of serumcirculate as zymogens
Designation of complement components:
numerals (C1-C9)letter symbols (factor D)trivial names (homologous restriction factor)
cleavage products – “a” and “b”
Complement Activation Pathways
Immunobiology (Garland Science 2005)
The Complement System
Complement Activation:
The Complement System
The Complement System
Classical Pathway requires antibody interaction:
The Complement System
•The three complement pathways converge at the membrane-attack complex (MAC).
Consequences of Complement Activation
Consequences of Complement Activation
Regulation of the Complement System
Regulation can occur at multiple steps in the complement system:Before assembly of convertase activityAfter assembly of convertaseAssembly of membrane attack complex (MAC)
Turnberg and Botto, 2003
Microbial Evasion•Some microbes can evade complement-mediated damage.
Schneider, et al 2007