IMMUNOLOGICAL MEMORY & PRINCIPLES OF VACCINATION Flashcards
innate immune system function
Recruits immune cells to the site of infection
through the production of chemical mediators
called cytokines.
Also activates complement system or cascade
Responsible for the identification and removal
of foreign material from our tissues by
specialised white blood cells.
Activation of the adaptive immune system
through a process known as “antigen
presentation”
adaptive immune system function
Recognition of “self” antigen from “non-self”
To generate “immunological memory”
Cells of the adaptive immune response “remember”
the biological signature of a specific antigen.
self antigens are normal antigens found on cells in the body. they are typically not a threat.
while
non self antigens are found on pathogens invading the body, they do not originate in the body.
where are memory b cells generated
in specialised areas of the lymph node called germinal centres
naive b cells ?
mature B cells that have not yet encountered their specific antigen:
memory b cells have immunoglobulins on their surface to help distinguish between them and naive b cells
do memory b cells have to undergo class switch upon second exposure to the same antigen
no
speeds up secondary response
what happens in affinity maturation during in immunological memory
this basically means that memory B cells develop a higher affinity to anotibodies than before their first exposure to the antigen, therefore upon second exposure a better immune response is induced
what is the development of memory b cells dependent on?
CD4 T cells
note that the activation of memory B cells into antibody secreting plasma cells is also dependent on CD4 T cells
after cytotoxic T cell response, what happens to the large numbers of CD8 cells remaining at and around the site of infection
about 90% die after infection is cleared, remaining 10 % provide CD8 memory T cells , which ameliorates secondary response to the same antigen
CD8 memory T cells not the same as memory B cells
the generation of memory CD8 cells occur without the presence of CD4 T cells , true or false?
false
The generation of memory CD8 T cells does not occur
in the absence of CD4 T cells
advantages and disadvantages of immunological memory
Provides long lasting protection against infection disease.
Forms the basis of vaccination
Allergy
Transplant rejection
Autoimmunity
properties of an ideal vaccine
Safety – there should be no side effects from the
vaccine and no risk of procedural errors in vaccine
manufacture which may expose individuals to
pathogens or their toxic products
Price – essential in many parts of the world with high
rates of endemic disease and few economic resources
Stability – essential in many parts of the world with
limited refrigeration facilities
Ease of administration – children are the main
target for vaccination and therefore oral vaccines are
preferred over injection vaccines
origination of the word vacinnation
comes from the word vaccinia, meaning cowpox virus
Edward Jenner: pioneer of modern vaccination
vaccine types
live attenuated vaccine(LAV)
inactivated (killed antigen)
subunit(purified antigen)
toxoid(inactivated toxins)
describe attenuated pathogen in LAV
how is attenuation achieved
viable pathogens that
cause infection but do not cause disease
by growing the organism in cells of another species so the pathogen becomes adapted to the cells and grows poorly in human cells.
As they can infect cells they stimulate cell-
mediated immunity as well as antibody immunity
other members of the household can become naturally immunised upon contracting the attenuated pathogen
A problem is the possibility of reversion to full
pathogenicity.
