Immune Therapies Flashcards
Why manipulate the immune response?
Promote protective immune responses
Vaccination
Fight tumours
Treat immunocompromised patients
Suppress unwanted immune responses
Chronic inflammation
Autoimmunity
Allergy.
Why do we vaccinate?
Most effective strategy to prevent infectious disease
Promote human health
Primary aim to induce immunity in individuals
Successful programmes protect entire communities and populations
What is included in the 6 in 1 vaccine?
Pertussis (whooping cough) Diphtheria Tetanus Polio Hib Hepatitis B.
How do vaccines work?
Replicate immunity from natural infection without illness. Primary aim of vaccination is to stimulate adaptive immunity and generate long-term immunological memory. Vaccination involves exposing our immune system to disease-causing microbial antigens but without causing disease.
Primary response- IgM to secondary (immunological memory- IgG). 1st then 2nd response to antigen. “Class switching”- happens when T cell talks to B cell.
Primary response
Low specificity IgM produced first
High specificity IgG takes longer
Requires T cell help
Secondary response
More rapid
More effective
High specificity IgG produced by long-lived plasma cells.
What is the most important goal of vaccination?
To create a high affinity IgG.
What are the three types of vaccines?
live attenuated
inactivated
subunit (purified antigens).
What is a live attenuated vaccine?
It is live but weakened via genetic manipulations. It has excellent life-long immunity and capable for replication within host cells. Potentially pathogenic in immune compromised individuals. Examples are MMR, BCG and rotavirus. CANT BURST OUT OF CELL TO INFECT OTHER CELLS.
What is an inactivated vaccine?
Killed through a chemical physical process. Structurally intact but dead. Cannot replicate of cause disease and provides weak immunity- takes a few vaccines to develop sufficient response. Example- polio and pertussis.
What is subunit vaccine?
No live components
Recombinant – produced by genetic engineering
Hep B
HPV
Toxoid – inactivated bacterial toxins
Diphtheria
Tetanus
Polysaccharide on outside of cell membrane– encapsulated bacteria –evade from host- T cell-independent
Conjugate – polysaccharide antigens linked to proteins
PCV/Hib/Men-C.
T cells only activatd in response to peptides not polysaccharides.
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What is an adjuvant?
Enhance immune responses to vaccine antigens
Inactivated/subunit vaccines
Aluminium/calcium salts
Maintain and prolong antigen stability
Enhance and prolong antigen presentation
Induce granuloma formation (caused by aluminium and calcium salts- makes antigen stay at site and stays in immune system for longer)
Intramuscular delivery.
diff routes of vaccine administration and examples?
BCG- intradermal
Measles and yellow fever- subcut
IM- hep b, Hib
Oral- rotavirus.
Why was there a reduction in infectious diseases?
Reduction in infectious diseases Widespread implementation of vaccination strategies Cleaner drinking water Better nutrition Better living standards.
Naturally occurring NCD increased from 2007-2017 eg. cancer, metabolic disorders, autoimmune diseases etc.
CD decreased from 2007-2017.
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What are the effects of corticosteroids?
Side effects Weight gain Risk of infection Risk of diabetes Risk of hypertension.
Aarachidonic acid
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Methotrexate?
Used at high doses as chemotherapy agent
Used at low doses to treat inflammatory arthritis
Multi-faceted anti-inflammatory effects
Slows progression of arthritis
Can be combined with biological therapies. Only works for a period of time until body stops responding.
What are biological therapies?
Genetically engineered antibodies made from human genes
Directly target specific components of immune system to inhibit activity
B-cell inhibitor (Rituximab)
Cytokine blockers (IL-1, IL-6, IL-17, TNFa)
Moderate to severe RA patients to slow disease progression
May be combined with DMARDs.
ANTI TNF- therapies?
Five anti-TNF drugs licensed for RA in the UK
All work in different ways
Infliximab binds soluble TNFa- binds to cytokine and stop it acting with its receptor
Etanercept binds and blocks TNF receptor
Patients can expect at least 20% clinical improvement
Often combined with methotrexate.
Do anti-cytokine therapies have a role in the treatment of periodontitis?
CYTOKINES DRIVE BONE DESTRUCTION IN PERIDONTAL TISSUES.
What are the barriers to the dental caries vaccine?
Biological- strep mutans dominate environments frequency exposure to dietary carbohydrates. IT IS NOT THE ONLY CARIOGENIC BACTERIA IN THE ORAL BIOFILM. Other cariogenic species likely to fill niche.
Ethical- non-life threatening conditions. Expensive. Other initiatives are ore cost effective eg. child smile, water fluoridation and dietary advice.
