Immune Therapies Flashcards
what sort of things promote protective immune response
vaccination, fight tumours, treat immunocompromised patients
what are some unwanted immune responses
chronic inflammation, autoimmunity and allergy
why would you want to manipulate the immune system?
to promote protective immune responses and to suppress unwanted immune responses
why do we vaccinate?
most effective strategy to prevent infectious disease, promote human health, to induce immunity in individuals, protect entire communities and populations
what is the evolution of the immunisation programme
1 - pre-vaccine so disease rates high
2 - vaccine coverage and disease rates decrease
3 - public loss of confidence so outbreak of disease
4 - resume confidence with vaccine
5 - eradication of disease
how do vaccines work?
stimulate adaptive immunity and generate long-term immunological memory
simplify the steps of induction of long term immunity once vaccinated
1 - innate immune system recognises antigens and activates inflammation
2 - cytokines released to recruit more innate immune
3 - dendritic and APC travel to lymph nodes to display pathogen to T and B cells
4 - T and B cells activated once pathogenic antigen receptor found, T cells turn to effector T cells, B cells make antibodies
5 - T cells help B cells to turn into plasma cells by somatic hypermutation and isotype switching
6 - highly specific antibodies produced
7 - B and T cells travel to infection and work with innate cells to eradicate infection
8 - small portion of adaptive cells remain as memory cells
how are antibodies made to be highly specific?
initially are IgM antibodies but once B cells work with T cells they learn more about the pathogen and change to plasma cells to produce high affinity antibodies - IgG
what is the aim of vaccination?
produce high affinity IgG
what is the primary response to a vaccine
low specificity IgM produced then high specificity IgG takes longer and requires T cell help
what is the secondary response to a pathogen
more rapid, more effective, high specificity IgG produced by long-lived plasma cells
what are virulence factors called and what are they recognised as
molecules expressed by bacteria to attach, invade and replicate in tissue, recognised as antigens
what are the types of vaccine?
live attenuated, inactivated, subunit, viral vector
what is a live attenuated vaccine
live whole pathogens but weakened via genetic manipulations, can replicate within host cells, have excellent life-long immunity, one dose required
what is an inactivated vaccine?
killed through chemical or physical processes, cannot replicate, weak immunity, several doses required
what are subunit vaccines
no live components just take proteins from pathogen which attach to receptors in our cells
what are the types of subunit vaccine?
recombinant, toxoid, polysaccharide, conjugate
what is a subunit recombinant vaccine
produced by genetic engineering
what is a subunit toxoid vaccine?
inactivated bacterial toxins
what is a subunit polysaccharide vaccine?
encapsulated bacteria - T cell independent so immune responses are weak as only B cells activated
what is a subunit conjugate vaccine
polysaccharide antigens linked to proteins
what is a viral vector vaccine
non-replicating type of live virus, use chimpanzee adenovirus which is used as a delivery system to carry COVID material
which types of vaccines require a second/third dose?
inactivated/subunit
what is an adjuvant?
they enhance immune response to vaccine antigens by holding antigens at the site and making sure they are not washed away in the bloodstream
