Which cells develop into plasma and memory cells?
Which PRRs mediate the inflammatory response?
What does TLR-4 recognise?
Lipopolysaccharide of Gram -ve bacteria
What do the RLRs recognise and where are they found?
They recognise viral RNA and are found in the cytoplasm
What do CDSs recognise?
Intracellular DNA and DNA pathogens.
What are the functions of C3b?
- Opsonises the pathogen
- Removal of immune complexes
- Converts C5 into C5a and C5b
How does decay accelerating factor and Factor I inhibit the complement system?
- DAF binds to C4b, displacing C2b - classical
- DAF binds Bb in alternative
- Factor I breaks C4b or C3b
What are the functions of IL-6?
- Activates lymphocytes
- Increases antibody production
- Fever - main cytokine!!!
- Production of acute phase proteins
What do TLR-1, -2 and -6 recognise?
- Zymosan (fungi)
- Peptidoglycan (Gram +ve bacteria)
What do TLR-7/8 recognise?
- Single stranded RNA
- Anti-viral compounds
What do CLRs recognise?
Cell surface receptors important in fungi recognition
How do C4 binding protein and Factor I inhibit complement activation?
They breakdown C3 convertase made up of C4b and C2b.
What happens to a monocytes when it leaves the blood stream?
They differentiate into:
- Tissue macrophages
- Kupffla cells
- Glial cells
How do neutrophils kill ingested pathogens? And how does marcophage pathogen killing differ?
Neutrophils die via a respiratory burst, killing the ingested bacterium.
Macrophages are able to kill without self destruction.
How does membrane co-factor protein and Factor I prevent complement activation?
MCP binds to C3 or C4 when they attach to the cell and the Factor I breaks them down.
What does TLR-3 recognise?
Double stranded RNA
What are the 5 outcomes of acute inflammation?
- Suppuration - abscess
- Organisation - granuloma or scar
- Chronic inflammation
- Progression to severe sepsis
What does TLR-5 recognise?
How is hypochlorite formed?
Combination of H2O2, MPO and a halide within a phagolysosome.
What are the 2 main categories of T-lymphocytes?
- T helper (CD4+/ Th cells)
- Cytotoxic T cells (CD8+/ Tc cells)
What does TLR-9 recognise?
- Unmethylated DNA sequences rich in C and G bases
What are the 3 mechanisms of complement activation?
- Classical with antibodies
- Alternative through spontaneous generation of C3b fragements
- Lectin-binding with mannose-binding lectin
Name different exogenous and endogenous chemokines involved in inflammation.
- Exogenous; bacterial toxins
- Endogenous; C5a, Leukotrienes B4 (LTB4) and IL-8
What is the significance of Virchow's node?
It usually signifies malignancy of the internal organs, stomach cancer for example.
How does C1 inhibitor regulate the complement system?
It de-activates antibody bound C1 of the classical pathway.
Which PRRs mediate phagocytosis?
- Scavenger receptors
- Fc receptors
- Complement receptors
What are the systemic characteristics of acute inflammation?
- Fever, malaise and somnolence
- Tachycardia and hypotension
- Production of acute phase proteins
Name exogenous and endogenous toxins that are related to chronic inflammation.
- Exogenous; coal dust, silica
- Endogenous; toxic lipids in athersclerosis
What receptor is utilised for antigen presentation by macrophages?
The MHC class II receptor.
What does protein S do?
It binds to C7 and prevents the MAC from inserting into the membrane.
What 2 substances do basophils secrete?
What system is the first to change in inflammation?
The vascular system;
- vasodilation through histamine and NO
Increased permeability through:
- Substance P
Which antibiotics have an anti-metabolite effect?
Which TLR is associated with increase susceptibility to Legionnaire's disease?
What are the functions of a macrophage?
They are involved in phagocytosis of foregin particles and antigen presentation to other cells of the immune system.
How long to monocytes typically live within the blood stream?
Where are NLRs found?
In the cytoplasm
What are the 2 main classes of PRRs?
- Those that mediate phagocytosis
- Those that activate pro-inflammatory pathways.
What different morphologies can acute inflammation take?
The enzyme histaminase is secreted by which cell?
Which complement proteins form the membrane attack complex (MAC)?
C5b, C6, C7, C8 and C9 (lots)
What is the main function of dendritic cells?
The are antigen presenting cells, with a greater level of activity compared to macrophages
What is the function of IL-12?
- Activates NK cells
- Induces differentiation of CD4+ into Th1 cells.
Which infections typically cause chronic inflammation?
- Viral and fungal infection
- Parasitic infections
Name the antibiotic groups that disrupt the cell wall of bacteria.
Name the antibiotic groups that inhibit nucleic acid synthesis.
What separates acute inflammation from chronic?
- Chronic inflammation characteristically has active inflammation, tissue destruction and attempts at repair occurring simultaneously.
What are the functions of C3a and C5a?
- Mediators of inflammation
- Phagocyte recruitment
Where are monocytes found?
In the blood stream
What is the function of IL-8?
- Recruits neutrophils, basophils and T cells.
What are the 3 layers of the immune defence?
- External barriers such as skin and the mucous membranes
- Innate immune system including cellular and soluble parts
- Adaptive immune system including cellular and soluble parts.
Which organisms are likely to cause a skin infection?How would you treat each organism?
- Streptococcus - Penicillin V
- Staphylococcus - Flucloxacillin
- Abscess - Anaerobes - Metronidazole
What are the functions of a natural killer cell?
Kill tumours such as melanomas, lymphomas and virally infected cells.
Which 2 cytokines are important in expression of integrins involved in leukocyte extravasation?
Name the antibiotic groups that inhibit protein synthesis.
What type inflammation are DAMPs important?
Sterile inflammation from trauma etc.
What is the function of RAMPs?
To counterbalance inflammatory effects of PAMPs and DAMPs.
What are the functions of IL-1
- Activates vascular endothelium and lymphocytes
- Tissue destruction
- Production of IL-6
What are NLRs important for?
The production and regulation of the inflammasomes.
Where does the thoracic duct drain into? and what is it called when it is enlarged?
It drains into the junction of the left subclavian and left internal jugualr veins
It is referred to as Virchow's node when enlarged.
How does CD59 prevent the formation of the MAC?
It binds to the C5b and prevents the C9 assembly
What is found in the primary granules of a neutrophil?
What is found within the secondary granules?
- Primary granules - peroxidase, lysozyme and other enzymes
- Secondary granules - collagenase, lactoferrin and lysozyme
How do Factor H and Factor I inhibit complement activation?
They work together to break down C3 convertase consisting of C3b and Bb
What process greatly increases phagocytosis?
Opsonisation of the pathogen.
What are the functions of TNF-α