CBG 26 Flashcards
what does the faroe island case study show?
measle epidimic in 1781 then reintroductiom in 1848. later time round only old people that had memory cells survived. showed immunological memory can last a lifetime
has polio been eradicated?
no nearly eradicated. eradicated after vaccine but problem due to MMR vaccinations diminishing.
what are cytokines?
proteins that activate signalling pathways and regulate the immune response
what 5 things make up innate immune response physical?
1) skin
2) eyes
3) respiratory tract
4) gastrointestinal tract
5) urogenital tract
explain how skin works as an innate immune response in terms of mechanical chemical and micriobology?
sweat=flow of fluid off skin
SEBUM (fatty acids,lactic acids,lysozyme)
normal skin flora acts as barrier
explain how eyes work as an innate immune response in terms of mechanical chemical and microbiology?
flow of fluid
tears have lysozymes
normal flora
explain how respiratory tract works as an innate immune response in terms of mechanical chemical and micriobology?
flow of fluid an mucus by cilia and air flow
lysozyme in nasal secretions
normal flora
explain how the gastro intestinal tract works as an innate immune response in terms of mechanical chemical and microbiology?
flow of fluid,mucus food and saliva
acidity and proteases
normal flora
explain how the urogential tract acts as an innate immune response in terms of mechanical chemical and microbiology?
flow of fluid urine,mucus and sperm
acidity of vaginal secretions and spermine and zinc in semen
normal flora
does the innate response size stay the same for primary and secondary response?
yes
does the adaptive response stay the same for primary response and secondary response/
no secondary response is far larger
What is an antigen?
a toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.
what is an epitope?
the part of an antigen molecule to which an antibody attaches itself
what is an antibody?
a blood protein produced in response to and counteracting a specific antigen. Antibodies combine chemically with substances that the body recognizes as alien, such as bacteria, viruses, and foreign substances in the blood.
what components make up the immune system? (4)
1 physical barriers
2 cells
3 soluble effector proteins (complement and antibodies)
4 cytokines (communication)
describe immediate innate immunity (time frames)?
0-4 hrs
infection
recognition by broad non specific receptors
removal of infectious agent
describe early induced innate response? time frames etc
4-96 hrs
infection
recognition by MICROBIAL ASSOCIATED MOLECULAR PATTERNS
inflammation,recruitment and activation of effector cells
removal of infectious agent
describe adaptive immune response (time frames)?
late 96 hours + infection transport of antigen to lymphoid organs recognition by naive B and T cells clonal expansion and differentiation to effector cells removal of infectious agent
all physical innate immune responses produce what 2 things?
all epithelial cellsare joint by tight junctions
all produce antimocrobial peptides called defensins
what is the innate immune response initiated by? (3)
phagocytes
NK cells
soluble proteins
talk about phagocytes. clue- macrophages and neutrophils are both phagocytes
Phagocytes are cells specialized in the process of phagocytosis. Phagocytosis=
capture, engulfment and breakdown of bacterial pathogens
Macrophages-Reside in tissues and recruit
neutrophils-Enter infected tissues in large numbers
Recognize common molecules of bacterial cell surface using a few surface receptors
what are monocytes precursors to?
macrophages
what does monocytes do?
Can be tissue resident or recruited to sites of inflammation
Engulf and kill viruses and bacteria
Important for antigen presentation to T cells
what doe macrophages express lots of ? give 4 examples
receptors for microbial consituents mannose receptor-for cell wall scavenger receptor LPS TLr4-tol like-recognises dsRNA
explain bacteria reaching macrophage endocytic receptors and signalling receptors.
If bacterium binds to Endocytic receptors of macrophages it induces their engulfment and degradation. If bacterial components bing to signalling receptors the macrophages induce the synthesis of inflammatory cytokines
what do neutrophils do?
Highly motile, they respond rapidly to inflammatory stimuli by migrating out of the blood and into tissues in large numbers.
Recognise, engulf and kill viruses and bacteria.
Dead neutrophils are a major constituent of pus!
most common in early infection
what is the complement system? which immune system is it part of?
a part of the immune system that helps or complements the ability of antibodies and phagocytic cells to clear pathogens from an organism.
It is part of the innate immune system, which is not adaptable and does not change over the course of an individual’s lifetime.
after the bacteria has triggered macrophage signal receptors to release cytokines what happens?
more proteins/cytokines and chemokines
influx of neutrophiles
local redness and swelling (vasodilation and increased vascular permeability)
causing Inflammatory response.
Inflammatory cells migrate into tissue releasing mediators that cause pain
define inflammatory response.
Accumulation of fluid and cells at infection site (swelling, redness, heat and pain)
what is the acute complememnt and what does it enhance?
enhances phagocytosis.
Set of proteins which bind to bacterial surface
how does the complement system work?
it is lots of small proteins in blood circulating as inactive pro-proteins.
stimulation= proteases cleave proteins to release cytokines
cytokines initiate further cleavage cascade
result= amplification of the response and activation of the cell-killing membrane attack complex.
what is the complement system end result?
activation of the cell-killing membrane attack complex
what are the complement basic functions?
Opsonization – enhancing phagocytosis of antigens (coats pathogens)
Chemotaxis – attracting Macrophages and neutrophils (ALERTS other components of immune system to danger)
Cell Lysis – rupturing membranes of foreign cells
Agglutination – clustering and binding of pathogens together (sticking)
describe the 3 complement sytsem pathways briefly.
classical pathway- antigen-antibody complexes
MB-lectin pathway-lectin binding to pathogen surfaces
Alternative pathway-pathogen surface
what do all 3 complement pathways lead to?
complement activation
what is opsonization?
coating/flagging up antigens so that pathogens are more easily taken up by phagocytosis
is innate immunity evolutionary early?
yes and it is the first line of defence against infection
Pre-existing or very rapid response (hrs)
what is the complement system part of?
It is part of the innate immune system.However, it can be recruited and brought into action by the adaptive immune system.
