Module 9 Flashcards
Immunology
Immunology
study of the immune system and immunity
immunity
ability of an organism to resist infection
innate immunity
fast and non specific
adaptive immunity
specific and memory based
what is innate immune system comprised of? (6)
barriers
chemicals
phagocytes
fever
inflammation
complement system
physical barriers prevent infection in 2 ways:
deny entry (skin, mucous membrane, endothelial cells)
mechanical defences to remove potential threats (shedding skin, mucociliary sweeping, peristalsis, flushing)
chemical barriers (4)
body fluids(pH regulation, nutrient availability, enzymes)
antimicrobial components
cytokines
mediators of infection
Complement system
boosts innate immunity and adaptive immunity with plasma proteins
cytokines
molecular messengers that bind to receptors starting a signalling cascade
chemokines
subclass of cytokines
recruit cycling immune cells to injury site
interferons
subclass of cytokines
activate antiviral response without having any antiviral properties
blood and lymphatic system
circulate and distribute immune cells
secondary lymphoid organs
connect lymph system
lymph nodes
mucosa
spleen
Erythrocytes
RBC
Leukocytes
WBC
monocytes
immature and undifferentiated
come from myleoblast cells
granulocytes
can be stained
are toxins and enzymes which destroy their targets
Dedric cells
antigen presenting cells residing in skin and mucous membrane
come from monocytes
macrophages
antigen presenting cells residing in tissues and organs
come from monocytes
neutrophils
eliminate/destroy extracellular bacteria
come from myleoblast cells
eosinophils
protect against protozoa and helminths
come from myleoblast cells
basophils
role in inflammation and allergic reactions, found in blood
come from myleoblast cells
mast cells
role in inflammation and allergic reactions, found in tissue
comes from myeloid stem cells
natural killer cells
kill virus infected and cancerous cells
come from lymphoid stem cells
tissue damage activates _______
phagocytes (macrophages)
what happens when phagocytes (macrophages) are activated
cytokines and chemokines released
neutrophils and T cells released
how do neutrophils enter injury site
stick to capillary wall
rolling and squeezing through cellular junction
how does innate immunity work
PRR (receptor) recognizing PAMS (substrate) then using signal transduction and phagocytosis
how is uptake of extracellular pathogens done
phagosome holds pathogen
fuses with lysosomes containing digestive enzymes
creates phagolysome
undigested waste is released from cell.
acute inflammation
normal response to promote healing
production of activators
influx of phagocytes
fever
non localized inflammatory response
induced by cytokines, LPS
acts on prostaglandins
limits pathogen growth
components of adaptive immunity 2
humoral
cell mediated
antigen
part of a pathogen that the antibody can bind to
immunogen
antigen capable of inducing immune response
all immunogens are antigens, not all antigens are immunogens
hapten
binds to carrier molecule to form a complete antigen
what does immunogenicity depend on
complexity, physical/structural form, dose
epitope
specific regions on antigen that antibodies can recognize
FAB region
V part of the antibody
fragment of antigen binding
variable to account for diversity and specificity
provides function of antibody
Fc region
fragment of crystallization
I part of antibody
binds to complement and phagocytes
IgA (function, property, distribution (3))
neutralization
major secretory antibody
dimer in secretion, monomer in blood
IgD (function, property, distribution (3))
b cell receptor
activate B cells
B cells
IgE (function, property, distribution (3))
Fc binds to and activates mast cells and basophils
parasite immunity
blood and lymph
IgG (function, property, distribution (3))
opsonization. neutralization, agglutination, immune activation, cell mediated cytotoxicity
circulatory antibodies, can cross placenta
blood, lymph, extracellular fluid
IgM (function, property, distribution (3))
Neutralization, agglutination, complement activity
first to appear
blood and lymph
MHC1
found on all nucleated cells
present in self and non self antigens
MHC2
found on macrophages, Dedric cells, B cells
present non self antigens
APC
antigen presenting cells
process the pathogen then express the antigen
MHC3
presents B cells vs phagocytes where antigen processing occurs in the phagolysome
where does t cell selection occur
what happens if it does occur
thymus
failure leads to autoimmunity
positive T cell selection
TCR with weak interaction divide and grow
negative t cell selection
TCR with strong interaction die
Th1
increase cytotoxic t cells, neutrophile, natural killer, and macrophages
cell mediated immunity
Th2
activation of B cells
antibody mediated immunity
Th17
increase and recruit neutrophils
amplify innate immunity
memory T cells
MHC1
remember pathogens
strong response on secondary infection
Regulatory T cells
MCH2
tolerance and prevention of autoimmune response
control Th immunity
Cytotoxic t cells
MHC1
destroy cells with intracellular pathogens
cell mediated immunity
what activated helper t cells MHC11
APCs
divisions of cytotoxic t cells
effector (kill)
memory
how many antigens can B cell receptors recognize
1
where does b cell selection ocurr
bone marrow
positive b cell selection
working receptor
negative b cell selection
eliminate strong interaction with self
acquired immune system is characterized by (4)
2 branches (humoral and cell mediated)
created immunity
discriminates danger and non danger
recognizes type of danger
vaccination leverages _________ immunity
adaptive
person for modern approach to vaccination
Edward jenner
live attenuated vaccines
non pathogenic viable microbes
mimic real infection
not safe for immunocompromised
risk of reversion
whole inactivated vaccines
pathogen is dead
no risk of infection
weaker immunity (need higher dose and boosters)
subunit vaccines
immunogenic pieces of microbes
limited side effects
limited longevity (need boosters)
subunit toxoid vaccine
inactive toxin, does not prevent infection but limits effects of toxins
subunit conjugated vaccine
low immunogenic antigen
effective in young
costly
vaccine interactions
subunit viral like particles vaccine
proteins assemble as capsid to mimic virus
complicated
low immunogenicity
viral vector vaccine
virus expressed antigen
mimics natural infection
risk of genomic integration
RNA vaccine
RNA strand to translate
highly adaptible
strong cell mediated immunity, weak humoral
DNA vaccine
DNA strand to transcribe
highly adaptible
risk of genomic integration
why are boosters required
secondary infections produce more effective antibodies that bind with higher affinity
levels remain high longer
factos affecting vaccine efficacy (8)
intrinsic host
perinatal host
extrinsic
behavioural
nutritional
environmental
vaccine
administration
herd immunity depends on
vaccine: purpose, efficacy, mode of transmission, R value
R value
number of people that can be infected from a single case
higher is more spreadable
hypersensitivity
overactive and harmful response to foreign antigens
immunodeficiency
failure to mount adequate immune response in presence of danger
autoimmunity
harmful response to self antigens
Type 1 hypersensitivity
IgE and mast cells, allergen specific
stage 1: contact with allergen triggers B cells
stage 2: contact with allergen resensitized mast cells where the degranulate producing pro inflammatory chemicals
Type 2 hypersensitivity
IgG or IgM
complement and cell lysis
Type 3 hypersensitivity
IgG or IgM
inflammatory mediums
Type 4 hypersensitivity
T cells
increased macrophages and cytotoxic t cells
delayed reaction
localized anaphylaxis
reaction at site of entry
generalized anaphylaxis
reaction in whole body
massive release of histamine
anaphylactic shock
how to treat mild anaphylaxis and anaphylactic shock
mild: anti histamines, steroids, brochodialators, drugs reversing mast cell damage
shock: epinepherine
which groups are most immunodeficient
elderly (decreased t and b cell production)
kids (immune system not fully developed)
primary deficiencies
inherited and congenital
secondary deficiencies
acquired due to exposure in life
Monocolonal antibodies
recognize a single epitope
polycolonoal antibodies
recognize multiple epitopes
Neutralization
when artigen bind to virus blocking viral entry into target cell preventing plaque formation
preciptin ring test
measure of biological activity
mechanisms of antibody-antigen assay
precipitation
flocculation
neutralization
complement action
hemiaggulgination
blood typing and cross match
western blot
protein
enzyme immunoassay (EIA)
antigen binds to surface, antibody-enzyme complex attached to antigen creating a colour change
Direct ELISA
antibody binds to wall
blocking agent added
sample is added and washed (only bind if antigen is present)
substrate is added to detect is antigen stayed
indirect ELISA
antigen must be bound to wall before direct steps can take place
immunoblots
identify specific proteins transferred to an absorbent membrane
immunostaining
stains specific molecules on/in cells
