Immunity Against Infection I Flashcards
Give an example of a bacteria which is ec and depends on epithelial cell binding
Streptococcus
Which epithelial surface bacteria causes gonorrhoea and meningitis
Neisseria
Which fungi causes oral candidiasis
Candida albicans (oral thrush)
Name a few parasites
Trypanosoma
Worms
Protozoa
What does different effector response depend on
Localisation of pathogen (EC or ic)
Stage of infection
Which 2 areas can viruses be seen
EC in fluid like blood - at early stage of infection
Or
Cytoplasmic intracellular
Give 2 examples of intracellular pathogens that live vesicular eg in macrophages
Leishmania and mycobacterium
Can Protozoa be ic and EC
Yes
Which responses are important for extracellular pathogens like candida,streptococcus, viruses in early stages
Antibodies , complement, phagocytosis, epithelial adhesion block by iga, amps
Where are amps made for extracellular protection
Epithelial cells
What responses are for ic cytoplasmic pathogens (viruses or Protozoa)
CD8 cells, NK cells
Which responses needed for vesicular intracellular pathogens like leishmania and mycobacterium
T cell/NK cell macrophage activation
are NK cells part of innate along with barriers , amps and complement
Yes
What type of pathogen needs th1 response and why
Vesicular pathogens - for macrophage activation
Cytoplasmic - for NK and CD8 activation
What type of pathogen is th2 for
Extracellular, stimulates eosinophils granule release, mast cells histamine, antibody igE switching
Why are th17 for extracellular pathogens/fungi like candida
Il17 causes chemotaxis of important cells like neutrophils and other inflammatory cells
Which types of bacteria have thick peptidoglycan wall
Gram positive like streptococcus and staphylococcus
How many types of TLR are there which stimulate innate response
10
Which prr are intracellular
Nod like receptors
Where are tlr located
On vesicles inside cells (for ic killing) or on cell surface (EC killing)
What do Tlr do
Induce inflammation
Mature dendrites via danger signal (upregulate B7 and MHC)
Induce differentiation of T cells by determining cytokine release of apc
B cell ti 1 activation
Can bacteria be ic and EC
Yes.
Mycobacterium are vesicular ic
Strep and neisseria on cell surface
What protects bacteria from phagocytosis
Capsule
What does streptococcus EC bacteria cause
Pneumonia and meningitis
What does vaccine for strep include
23 diff polysaccharides strep has to produce diff antibodies specific for them
Which vaccine for strep helps a TD response by B cells
Conjugate vaccines (for children under 2 don’t recognise the ti2 ag on strep)
Which bacteria are killed by Mac in complement which is activated by antibodies igm and igG
Gram -ve like neisseria
What is importance of antibodies in EC bacteria protection eg strep or neisseria
Opsonisation via fc receptors
Activation of complement and c3b opsonisation
Neutralise toxins eg tetanus
Prevent epithelial adhesion via iga
What are you susceptible to without complement / if you have genetic defect in eg c3b or Mac
Neisseria gonorrhoea (EC cell surface, killed by Mac because gram -ve)
When are bacteria most vulnerable to complement lysis
When dividing
How do mycobacterium tb survive phagocytosis
Survive in macrophages (ic bacteria)
Prevent phagosome fusion with lysosome
Although th1 are mostly important in ic pathogens. How are they important for EC too
Activate macrophages via ifny and cd40L signal
Better at antigen presenting eg to stimulate th2 response and also release cytokines
What does mycobacterium leprae cause (IC)
Tuberculoid leprosy and lepromatous leprosy
Why is tuberculoid leprosy slower in progression and low infect ivory
Th1 response
Allows activation of macrophages, NK and CD8 cells to kill mycobacterium intracellular
why is lepromatous leprosy not effective in response
Th2 response. More ab and not effective for ic pathogens like mycobacterium
Low T cell responses
What forms when th1 macrophages aren’t killing mycobacterium fast enough and they aggregate
Granulomas - necrotic area where infection isn’t cleared fast enough
Do mycobacterium leprae stay alive in macrophages in lepromatous leprocy
Yes. They are not being killed by antibodies because they aren’t effective for ic pathogens
