Immune system 2 -- Lecture 26 Flashcards
antigens contain one or more ___ that are the focus of an adaptive immune system
epitopes
how does the adaptive immune system attack epitopes?
antibodies bind to ___
epitopes
how does the adaptive immune system attack epitopes?
antibodies (definition)
proteins made by cells of the adaptive immune system
how does the adaptive immune system attack epitopes?
antibodies mark ___
antigens for destruction
how does the adaptive immune system attack epitopes?
___ bind to epitopes
antibodies
antibody structure:
tetramer (definition)
2 light and 2 heavy chain proteins held together by disulfide bridges
antibody structure:
variable regions of the antibody:
bind to ___
could be any of 1X10^10 combinations of ___
bind to epitopes
amino acids
antibody structure:
constant (invariable) regions of the antibody:
are recognized by ___
phagocytes
antibody structure:
antibodies can circulate freely or be attached to the membrane of an ___
immune cell
antibody function:
do antibodies kill pathogens?
no
antibody function:
the ___ of antibodies to a pathogen ___ that pathogen for destruction by ___
binding
marks
phagocytes
antibody function:
1) the ___ regions of antibodies bind to epitopes on pathogens
variable
antibody function:
2) ___ on phagocytes bind to the ___ regions of the antibodies
receptors
constant regions
antibody function:
3) phagocytosis (what occurs)
the pathogen is engulfed and destroyed
antibody function:
the binding of antibodies to pathogens also blocks them from entering into ___ and ___
cells and tissues
cells of the adaptive immune system:
B cells (what do they do)
make antibodies
activate other cells of the immune system
cells of the adaptive immune system:
T cells (what do they do)
activate other immune cells
can recognize and kill cells of the body infected w/ pathogens
B cell activation:
how does a B cell become activated?
when a circulating B cell’s attached antibody binds to an epitope
B cell activation:
after a B cells activates, it begins:
1) producing and secreting more of its antibody into circulation
2) diving (clonal expansion)
3) activating other cells of the immune system
2 kids of adaptive immune responses:
the 1st encounter w/ a foreign antigen is called the ___
primary immune response
2 kids of adaptive immune responses:
primary immune response:
only a few B cells present whose antibodies can recognize the epitopes present on the new pathogen and become activated (slow response)
Memory B cells remain in large numbers after the infection is over
2 kids of adaptive immune responses:
the 2nd encounter w/ an antigen is called the ___
secondary immune response
2 kids of adaptive immune responses:
secondary immune response:
this time numerous memory B cells are present that can quickly produce the proper antibodies
this immune response is faster and more effective
vaccines:
vaccinations (what are they)
when antigens from a pathogen are safely introduced into the body (usually by injection)
vaccines:
vaccinations cause a ___ immune response leading to the production of ___ ___ cells
primary immune response
‘memory’ B cells
vaccines:
when exposed to that pathogen in nature (because of the ___ response to the vaccinations), numerous memory B cells exist that can quickly respond to the pathogen (much faster ___ immune response)
primary
secondary
booster vaccinations:
vaccines may not produce enough ___ to give ___
memory B cells
life-long immunity
booster vaccinations:
may need occasional ___ vaccination
examples:
booster
tetanus and diphtheria – every 10 years
booster vaccinations:
there are various medical conditions associated with a ___
malfunctioning immune system
autoimmune diseases:
immunological tolerance (what is it)
not attacking self-antigens by the immune system
autoimmune diseases:
negative selection (what is it)
immune cells that react against self antigens are killed during development
autoimmune diseases:
many autoimmune diseases are caused when ___ immune cells evade negative selection
autoreactive immune cells evade negative selection
autoimmune diseases cause ___
examples
treated w/
inflammation and organ damage
MS, Type I diabetes
immunosuppressive medications
allergies:
refers to a…
greatly heightened immune response to an antigen (allergen)
allergies:
allergens can be…
foods, medicines, pollen, pet dander, etc.
allergies:
allergic reactions can be mild or progress to…
systemic anaphylaxis – a severe and life-threatening allergic reaction
evading the immune system:
to evade the host immune system:
antigen switching
antigenic drift
evading the immune system:
to evade the host immune system:
antigen switching
pathogens can change their surface antigens
evading the immune system:
to evade the host immune system:
antigenic drift
through mutation during replication, viruses can alter the epitopes on their surface antigens
