Immunomodulation and suppression Flashcards
What is meant by immunomodulation?
The act of manipulating the immune system using immunomodulatory drugs to achieve a desired immune response
What are the 3 possible outcomes of immunomodulation?
1) Immunopotentiation (enhancement of the immune response by increasing its rate or duration)
2) Immunosuppression
3) Induction of immunological tolerance
What are the 7 mechanisms of immunomodulation?
1) Immunization
2) Replacement therapy
3) Immune stimulants
4) Immune suppressants
5) Anti-inflammatory agents
6) Allergen immunotherapy (desensitization)
7) Adoptive immunotherapy
What are biologics?
Medicinal products produced using molecular biology techniques including recombinant DNA
What are the 3 main classes of biologics?
1) Substances that are (nearly) identical to the body’s own key signalling proteins
2) Monoclonal antibodies
3) Fusion proteins
Adalimumab is a Human IgG anti-TNF monoclonal Ab, what is its structure?
Human Fc portion and Human Fab portion that binds to TNF
Etanercept is a fusion protein anti-TNF monoclonal Ab, what is its structure?
Human Fc portion bound to a human TNFR2 (TNF receptor) which in the body serves to mop up extra TNF)
What is TNF?
An important pro-inflammatory cytokine
Infliximab is a chimeric mouse-human anti-TNF monoclonal Ab, what is its structure and how is it produced?
Mouse Fab portion
Human Fc portion
Mice are modified to produce a human Fc portion and are given TNF so produce an Ab against TNF with a mouse Fab portion and a human Fc portion
Cetrolizumab is a humanised monovalent Fab-PEG anti-TNF monoclonal Ab what is its structure?
Human Fab region bound to a polyethylene glycol - this makes the Fab region more stable and less digestible
What 3 treatments or processes lead to immunopotentiation?
1) Immunisation
2) Replacement therapies
3) Immune stimulants
What is passive immunisation?
Transfer of specific, high titre antibody from donor to recipient.
What kind of protection does passive immunisation provide?
Immediate but transient protection
What are the 2 main problems with passive immunisation?
1) Risk of transmission of viruses (Ab are blood borne)
2) Serum sickness (occurs when suddenly a large number of immune complexes form within the circulation)
What are the 2 types of passive vaccinations?
1) Pooled specific human immunoglobulin
2) Animal sera
What are the 5 main uses of passive immunisation?
1) Hep B prophylaxis and treatment
2) Botulism
3) VZV (in pregnancy)
4) Diphtheria
5) Snake bites
What is active immunisation?
To stimulate the development of a protective immune response and immunological memory
What are the 4 kinds of immunogenic material used in active immunisation?
1) Weakened forms of pathogens
2) Killed, inactivated pathogens
3) Purified materials (proteins, DNA)
4) Adjuvants
What are the 3 problems associated with active immunisation?
1) Allergy to any vaccine component
2) Limited usefulness in immunocompromised
3) Delay in achieving potential
What are the 6 types of immune replacement therapy?
1) Pooled human immunoglobulin
2) G-CSF/GM-CSF
3) IL-2
4) alpha-interferon
5) beta-interferon
6) gamma-interferon
What is pooled human immunoglobulin replacement therapy used in the treatment of?
Immune deficient states
What does G-CSF/GM-CSF replacement therapy do?
Acts on the bone marrow to increase production of mature neutrophils
What does IL-2 replacement therapy do, is it used often?
Stimulates T cell activation - rarely used
What is alpha-interferon replacement therapy used in the treatment of?
Hepatitis C
What is beta-interferon replacement therapy used in the treatment of?
MS
What can gamma-interferon replacement therapy be useful in the treatment of?
Certain intracellular infections (atypical mycobacteria), also used in the chronic granulomatous disease and IL-12 deficiency
What 5 types of drugs are immunosuppressants?
1) Corticosteroids
2) Cytotoxic agents
3) Anti-proliferative/activation agents
4) DMARDs
5) Biologic DMARDs
What are the 6 effects of corticosteroids on the immune system leading to immunosuppression?
1) Decreased neutrophil margination (movement into tissues)
2) Reduced production of inflammatory cytokines
3) Inhibition of phospholipase A2 (reduced arachidonic acid metabolites production)
4) Lymphopenia
5) Decreased T cell proliferation
6) Reduced immunoglobulins production