Complement System Mind Map

Nota:

• Complement proteins binds to Fc part of antibody -Activated C1 triggers C4 and C2 = C3 CONVERTASE -Activation of C3 is an important AMPLIFICATION step 

1. Initiated by: Antigen:Antibody complex (antibody required)
2. ALL

Nota:

• Binds to bacterial glycoproteins -Creates C1-like activator  (Activates C4, C2 = C3 Convertase)

1. Initiated by: Mannose-binding Lectin (innate)
2. Converge
   1. C3b = OPSONIZATION (C3b binds to CR1 receptor) coating of virus blocks receptors and makes uptake easier

      Nota:

      • enhances Immune complex clearance: from classical 
      1. "MAC" Membrane Attack Complex C5b triggers the MAC: Forms a pore to cause lysis of target cell

         Nota:

         • C5b678 = interior of MAC complex -C9 = exterior of MAC complex 
   2. C3a & C5a ANAPHYLATOXINS C5a = most potent & dominant INFLAMMATORY toxin -leads to: vascular permeability of blood vessels

      Nota:

      • Blood vessels open up: -Diapedisis -extraversion of complement protein 

Nota:

• -C3 sponateously turns over C3a and C3b (ALWAYS IN SERUM) NATURAL turn over of C3a and C3b-Creates alternative C3 and C5 Convertase leading to MAC formation

1. Initiated by: does not involve antibody binding (innate) -activated by pathogenic peptide (PAMPs) -Alt C3 convertase and Alt C5 convertase (C5b-MAC AND C5a-Inflammation)
2. at C3 CONVERTASE (C3b-Opsonization AND C3a Inflammatory)