Innate Defences Flashcards
What are the 3 defences in innate
Barriers
Cell defences eg neutrophils
Molecular defence
What are the 5 physical barriers to pathogens
Skin
Mucus/cilia
Tears with lysozymes
Low ph in vagina
Acidic stomach
Which areas are commensal microbiota good for defences
Skin and mucus
How do lysozymes kill pathogens as anti microbial enzymes
Attack the peptidoglycan cell walls
Apart from lysozymes what other antimicrobial enzymes are there
Phospholipase A2
What are anti microbial peptides
Cationic proteins eg on peyers patch or mucosal surfaces which destroy pathogens via pores
Where do lectins have antimicrobial effects
Liver
What are the receptors called on macrophages, neutrophils etc in innate immunity
Pattern recognition receptor (PRR)
What are the 3 major PAttern recognition receptors
Toll like receptors TLR
Nod like receptors NLR
Rig 1 like helicases
Which PRR is cell surface
Toll like receptors
What kind of receptors do nod like and rig 1 like receptors have
Intracellular
What are the things called which the 10 types of toll like receptors recognise and bind
Pamps
Give 4 examples of pamps toll like receptors recognise on pathogens
Mannose oligosaccharides
Peptidoglycan (cell wall)
Lipopolysaccharides (on gram -ve)
CPG dna
What do leucocytes include
Lymphocytes Ie b,t, NK
Mast cells
Granulocytes/myeloblast ie neutro,baso,eosino
Monocytes ie macrophages in tissue
Dendritic cells
Which leucocytes are both innate and adaptive
Dendritic cells
What are the 2 types of leucocytes which are APC
Macrophages and dendritic cells
Which leucocytes kill antibody coated pathogens
Eosinophils
Are neutrophils involved in phagocytosis as well as macrophages
Yes
Which leucocytes have granules such as histamine
Mast cells
What are the 3 cell defences in innate response
Phagocytosis
Inflammation
Extra cellular killing
Which leucocytes involved in pahagocytosis are multi lobed nuclei and short lived
Neutrophils
What is the difference between monocytes and macrophages
Monocytes when in blood
Macrophages when in tissue
Explain the steps of phagocytosis
Macrophage/ neutrophils detect via toll receptors usually eg LPS or mannose
Bind to bacteria and release cytokines
Macrophages engulf the bacteria (endocytosis)
Forms a vacuole called phagosome
Fuses with lysosomes and lysozymes digest the bacteria in the phagolysosome
Why are lysozymes acidification important
Bacteria static or bacteriocidal effects
What are the other things which are bacteriocidal other than the hydrolase lysozymes
Antimicrobial peptides
Toxic NO
Toxic Oxygen products
Lactoferrins
What are lactoferrins and how do they stop bacteria
Fe competitors which bacteria need
How are toxic oxygen intermediates produced which are bacteriocidal/ static
Via NADPH oxidase
Other than the NADPH oxidase producing toxic oxygen , what other oxygen pathway kills bacteria
Halogenation
Which fungal prone disease lacks the NADPH oxidase pathway so can’t kill bacteria
CGD
How are macrophages activated
Bacteria products or cytokines
What is extracellular killing for
When organisms are too large for phagocytosis
Which 2 leucocytes are involved in EC killing
Eosinophils and NK cells
Give an example of an antibody coated pathogen eosinophils kill in EC killing
Worms
Which chemicals do eosinophils involve give examples
Chemokines
Cytokines
Which types of things do NK cells attack in EC killing
Viruses eg influenza
Tumour cells
What do NK cells release which is helpful to control viruses before the adaptive response kicks in
Interferon IFN y(gamma)
Which proteins do NK cells have for EC killing
Perforin
Granzymes
What are eosinophils and NK cells activated by for EC killing
Cytokines eg interferons , IL, TNF a
What are the 5 categories of cytokines which stimulate EC killing and also phagocytosis
Interferons Interleukins Chemokines Lymphokines TNFa
What are lymphokines
Cytokines produced by lymphocytes
Do cytokines also stimulate inflammation?
Yes
How do cytokines have effect
Binding to receptors
How can cytokine response be reduced
Control of expression of cytokine receptors
Can cytokines trigger their own production
Yes
Which 3 functions do cytokines have
Innate mediators eg EC killing, phagocytosis, inflammatory
Adaptive mediators eg lymphokines
Stimulate haematopoiesis
What is the name of the chemokine which attracts T cells and neutrophils and is produced by macrophages
IL 8
Which 3 cytokines produced by macrophages cause a fever due to stimulation of hypothalamus
TNFa
IL 1B
IL 6
Why do cytokines act on endothelium
Make them leaky eg nose to allow wbc escape to site of infection
Which things is inflammation triggered by
Macrophage or lymphocyte cytokines
Complement system (IE T cells and B cells)
Mast cells (histamine granules)
What 3 things happens in inflammation to allow cells to get from blood into tissues through endothelium
Increase in vasodilation for blood flow
Endothelial permeability eg via histamines or cytokines
Increase in adhesion molecules for cells
What causes pain (dolor) in inflammation
Cells such as neutrophils which flood to the tissues forming swelling (tumour/Edema)
What happens for cytokines to be released to allow inflammation eg release of TNF a
Macrophage phagocytosis
Which types of things are attracted into tissues after dilation and endothelial permeability
Platelets (for wound healing)
More phagocytes eg neutrophils
Lymphocytes to start the adaptive response
Which bacteria need to be phagocytosed to cause an endotoxic shock (inflammation)
Gram -ce, the release of their lipopolysaccharide endo toxins
What does cytokine storm cause (inflammation which is systemic)
Circulatory shock (lack of blood flow eg due to dilation)
Clot formation (too many platelets)
Edema (swelling due to increased fluid/ cells in the tissues)
What is it called when too many clots form in inflammation
DIC
What is systemic inflammation/ cytokine storm called
Sepsis / toxic shock
