Molecules involved in Inflammation

Molecules involved in Inflammation

1. DAMPS

   • Signals released by necrosis
     • Trigger inflammation
   • E.g. DNA, histones

2. PAMPS

   • Are on the surface of pathogens
   • E.g. foreign cell wall components: LPS

3. PRRs

   • Detect PAMPs and DAMPs
   • Found in/on immune cells
   • Cause release of inflammatory mediators

4. Cytokines

   • Chemokines
     • Recruit circulating immune cells
     • Chemoattractants
   • They are messenger hormones
   • Examples
     • Interleukins
     • TNFs
     • IFNs
       • Type 1 = alpha and beta
         • Anti-viral
       • Type 2 = gamma
         • From T-cells
   • Activate resident, endothelial or circulating immune cells
     • To maintain vasodilation and cause lysis of infected cells
       • Allows pathogen to be exposed to the immune system

5. Myeloid derived cells

   • Monocyte
     • Macrophage
       • Perform phagocytosis
       • Produce cytokines

6. Opsonins

   • Mark cells for phagocytosis
     • Phagocytosis can be oxygen dependent or independent

7. NETs

   • Neutrophil extracellular traps
     • Streps are resistant because they have fibrin degrading enzymes
     • S. aureus are resistant because they hide within fibrin layers
   • If pathogen cannot be phagocytosed, then an enzyme moves into the neutrophil nucleus, releasing its contents
     • This acts as a net which prevents spread