Flashcards
Why is immunology important?
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- 1What are three reasons Why is immunology important?it underpins vaccination
immunological techniques underpin many diagnostic technologies
many of the diseases of the modern world are caused by the immune system going wrong - 2What is the basic function of the immune system?to distinguish between self and non-self
- 3How much bacteria do we have in the gut?10,000 species
10^14 cells - 4What species of bacteria can you find on the skin and in the throat?skin - staphlycocci
throat - Klebsiella/Neisseria/Pneumococci - 5If we have all this bacteria on our skin and in our throat why are we still alive?most bacteria fine when on superficial surfaces but if get into important tissues or brain, without an immune system we can die
even with an immune system they can still kill us - 6What is the biggest reason people with HIV die?HIV kills T-cells
so patients die of opportunistic infections
e.g.
Pneumocystis carinii
Cryptosporidium
atypical Mycobacteria - 7What is SCID? Why is this dangerous? What treatment is available?severe combined immune deficiency
lack of lymphocytes
a baby with SCID may have recurrent bacterial, viral or fungal infections that are more serious and less responsive to treatment than would normally be expected
bone marrow transplant needed to replace immune system - 8Where do the different cells of the immune system come from?the cells of the immune system come from a pluripotent stem cell circulating in the marrow
- 9How can a bone marrow transplant be carried out?take out marrow - painful
new technology:
give patient drugs causing stem cells to come out of marrow and into blood
harvest stem cells from blood
can put into other people or back into same person - 10What are the different types of cells you find in the blood and immune system?Eosinophil
Basophil
Neutrophil
Monocyte
Thrombocyte
Erythrocyte
B cell
T cell - 11What is hematopoiesis?the production of all types of blood cells
in adults this occurs in the bone barrow and lymphatic tissues - 12How do pluripotent stem cells become antibodies and T cells?pluripotent stem cell
lymphoid stem cell
B cell and T cell
B --> antibody
T --> CD4 helper and CD8 cytotoxic - 13CD4 and CD8 cells are both major classifications of T lymphocytes. What is the difference between them?CD4 helper
-carry CD4 antigens
CD8 cytotoxic
-carry CD8 antigens
-includes cytotoxic T lymphocytes and suppressor cells - 14Where are T cells and B cells identified?T cells - thymus
B cells - first identified in Bursa (in gut of chicken), made in bone marrow in most mammals - 15What are the three types of Primary lymphoid tissue? Why are they classed as 'primary'?thymus, bursa, bone marrow
they work and produce cells in the absence of antigens - original source of immune cells - 16Give some examples of secondary lymphoid tissuestonsils
lymph nodes
lymphatic vessels
liver
spleen
Peyer's patch on small intestine
appendix - 17What are secondary lymphoid tissues?regions/organs where mature and immune competent lymphocytes colonize and function in response to antigenic stimuli
- 18How does the immune system recognise pathogens?by responding to non-self
- 19What is an antigen?anything which elicits an adaptive immune response
self antigen - when the immune system goes awry and starts responding to self
foreign antigen - when the antigen comes from outside you e.g. vaccine - 20What does the adaptive immune system show? In what way is the immune system and the brain similar?the adaptive immune system shows exquisite specificity
the immune system has memory - when exposed to infection the body remembers this - 21In adaptive immunity how do immune cells respond to foreign molecules (pathogens)?using receptors which can bind to antigens
antigen specific T cell receptor
antigen specific B cell receptor (which is actually and antibody)
massive cell division then effector function - 22In innate immunity how do immune cells respond to foreign molecules (pathogens)?using pattern recognition receptors and Fc receptors
identify PAMPs and DAMPs
-pathogen-associated molecular patterns which are associated with microbial pathogens or cellular stress
and damage-associated molecular patterns
which are associated with cell components released during cell damage - 23What are Fc receptors? How do they work?protein found on the surface of certain cells e.g. B cells, neutrophils
that contribute to the protective functions of the immune system
bind to antibodies attached to invading pathogens
stimulates cytotoxic cells to destroy microbes
or infected cells by antibody-mediated phagocytosis - 24What is innate immunity?the immunity that happens in the minutes or hours after infection
non-specific - 25What are skin macrophages also known as?Langerhans cells
- 26In health, white cells are in blood and lymph nodes and not in tissue. If bacteria were to invade the tissues how are they therefore killed?bacteria invades tissue
endothelial cell cytokines (TNF-a and IL-1B) released by macrophages and increase adhesion molecules
blood vessel becomes sticky
neutrophil sticks on vessel, moves into tissue and kills bacteria
happens within hours - 27The macrophage releases substances that aid in the destruction of the bacteria. However, how does the macrophage know the bacteria is there in order to produce these pro-inflammatory cytokines?the toll-like receptor molecules on the surface of mammalian cells recognise components of bacteria and viruses (PAMP) that are shared by pathogens but distinguishable from host molecules
TLRs activate immune cell responses
start to make pro-inflammatory cytokines
there are 13 - but last three not found in humans - 28Give an example of TLRs and what they recogniseTLR5 - flagella
TLR4 - lipopolysaccharides from gram-negative bacteria - 29Why is pus yellow?lots of dead white blood cells
major protein in neutrophil is yellow - 30What is a spot?inflammation and tissue injury caused by white cells leaving the blood and going into a follicle to kill skin bacteria growing in the wrong place
- 31What is inflammation?when white cells leave the blood and move into the tissues, and in the process of getting rid of the bugs, kill normal tissue as well
- 32How do neutrophils kill the invading pathogens?neutrophil engulfs bacteria
neutrophils are full of and produce dangerous molecule
-free radicals, neutrophil elastase, neutrophil collagenase, myeloperoxidase, gelatinases, anti-bacterial peptides, cytokines
these may destroy normal tissues as well
after neutrophils stop moving into tissue and tissues heal in ~ a week - 33What is ulcerative colitis?caused by massive influx of neutrophils in the colon
may be identified by presence of crypt abcesses
kill nasty molecules then kill epithelium cells lining gut - 34Use a graph to explain the differences between adaptive and defective innate immunity1 million bugs injected IV
99% killed in first 12 hours
bugs get into niche inside cell and tissue
start to grow
takes time as numbers so low
after five days adaptive immunity happens
infection can be got rid of
defective innate immunity - ability to get rid of bacteria doesn't work very well, not all killed, start to grow rapidly, death by sepsis - 35In what way are our bodies already primed to deal with infections?at birth we already have T and B cells which can recognise billions of different foreign antigens
only a few lymphocytes for each antigen
they need to see and respond to pathogen quickly - 36What happens when a B cell becomes activated?B/T cell divides very quickly
B/T cell specific to pathogen recognises it through receptor antigens
B cells undergoes clonal expansions - requires T helper cells
B cells become plasma B cells which produce antibodies or memory B cells - for future response
T cells undergo clonal expansion controlled by IL-2
T cells mediate immunity - 37What happens following vaccination?after vaccinations we respond and make more lymphocytes specific for the vaccine
memory cells are also primed - 38How does a cell know what type of cell it is?cells have thousands of different receptors to sense their extra-cellular environment
receptors transmit signals from the cell surface to the nucleus to change gene expression and function - 39Describe the difference between the incidence of prototypical infectious diseases and that of immune disordersthe former has been decreasing over time, especially following the onset of vaccines
the latter e.g. crohn's disease, multiple sclerosis, asthma - has been increasing
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- University Fundamentals of Medicine (Immunology) Flashcards on Why is immunology important?, created by Ifeoma Ezepue on 30/10/2015.
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