Immunology

• Two related activities of the immune system:

  Recognition and response
• Two related "systems":


  Innate and adaptive
• Innate responses eg


  - Physical barriers

  - Stomach acid

  - Inflammation
• - 5-10% circulating lymphocytes

  - Attack infected cells and some tumours

  - Release perforin and/or granzymes


  Natural killer cells
• - Some permanently lymphocytes

  - Neutrophils and monocyte derived macrophages

  - Attracted to area of damage/ infection by chemotaxis

  Phagocytes
• Target and Action for complement receptor

  Target: Microbial cell wall

  Action: Complement activation
• Target and Action for Mannose binding receptor

  Target: Mannose containing microbial carbs

  Action: Complement activation
• Target and Action for C-reactive protein receptor

  Target: Microbial membranes

  Action: Complement activation
• Target and Action for LPS receptor

  Target: Bacterial LPS

  Action: Delivery to cell membrane
• Target and Action for TLR

  Target: Microbial components not found in host

  Action: Triggers innate immune responses
• Target and Action for NOD family receptor

  Target: Bacterial cell wall components

  Action: Triggers innate immune responses
• Target and Action for scavenger receptor

  Target: Multiple targets, bacteria, apoptotic host cells

  Action: Induces phagocytosis or endocytosis
• What holds tissues together?

  CAMs
• Immune cells can ? from one part of the body to another

  Transverse
• What use CAMs to interact with tissues?

  Leukocytes
• Superfamily of small polypeptides


  Chemokines
• Chemokines control?


  Adhesion, chemotaxis, leukocyte activation
• Anti viral response

  Innate immunity

  Plays a role in adaptive


  Interferons
• Found in paneth cells of intestine and cytoplasmic granules of neutrophils

  Alpha defensins
• Epithelia and some tissues

  Beta defensin
• Antiviral activity of IFN alpha and IFN beta leads to ?

  Inhibition of protein synthesis
• Promotion of phagocytosis


  Opsonisation
• Removing immune complexes from the circulation


  Immune clearance
• Final product of complement activation

  MAC
• Transmembrane proteins with repeating sequence of AA

  Toll-like receptors
• Leucine rich repeats form?

  Extracellular ligand binding region
• Toll like receptors are important in?

  Recognition of the bacterial 2PS
• Cell surface TLRs recognise?

  Extracellular ligands
• Intracellular TLRs recognise?


  Intracellular ligands
• What leads to repeated, life-threatening bacteraemias?

  Neutropenia or malfunction of neutrophils
• Neutrophils are essential against


  Bacteria and fungi
• Phagocytosis is enhanced by?

  Opsonisation
• Neutrophil granules contain?


  Bactericidal/ permeability increasing protein (BPI)
• "Circulating in blood for 8 hrs; then migrate into tissues and differentiate"

  Monocytes
• In tissues; some are fixed others are mobile

  Macrophage
• Macrophages are activated by?

  TRLs, cytokine receptors
• First line of defence against viruses

  NK cells
• How many types of dendritic cells are there?

  4
• What do dendritic cells do?


  - Antigen capture

  - Antigen presentation

  - T cell activation
• Dendritic cells produce?


  ROS