MSK immunology 05/10/18 Flashcards
(28 cards)
What do Th1 cells do?
Activated macrophages by released IFNy
What is IL-2?
T-cell growth factor
What does a Tfh cell do?
Activates B cells
What’s the difference between B cells and T cells?
B cells - Can detect any type of antigen
T cells - can only detect peptide antigens expressed by MHC I or II
What do CD8 cells do once activated?
Differentiate into cytotoxic cells and migrate into lymph nodes in infected site and kill infected cells using granzymes and perforin
What is the function of B cells?
become plasma cells - effector B cells that secrete antibodies
What is an important antibody in Type 2 and 3 hypersensitivity?
IgG
What is autoimmunity?
The presence of adaptive immune responses against self-tissue/cells
What does random rearrangement of the polypeptide chain result in?
Random generation of antigen receptors that could:
- Not have a receptor
- Have a receptor for foreign antigens
- Have a receptor for host cells
What prevents autoimmunity in healthy individuals?
All new cells are tested to see if they recognize host and are killed by Apoptosis
What targets auto reactive T and B cells?
Regulatory T cells dampen down the activity of these cells
What happens when the autoreactive control measures fail?
HIgh levels of auto-antibodies
leading to significant tissue/organ damage
What are the components of auto immune diseases?
Genetic suscptibility
Loss of immune regulation
Activation of auto-reactive T and B cells
Hypersensitivity reactions
Autoimmune phenomena or autoimmune disease
What encodes for the expression of the development of regulatory t cells?
FOXP3
MHC genes
How many MHC molecules are presented on each antigen presnting cell(?) ?
12
6 from each parent
What gender is more likely to have an autoimmune disease?
Females
What are factors that worsen an ongoing autoimmune disease?
Molecular mimicry
Intercurrent infections
Tissue damage
Superantigens
What organs are immunoprotected?
Brain - blood brain barrier
Cornea
Testes
What is Myasthenia gravis?
Autoimmune neuromuscular disorder characterized by severe muscular weakness and progressive failure
auto-IgG antibodies
Who gets MG and whats the cause?
Any age
90% unknown
10% thymic tumour
How does MG present?
Onset typically insidious Droopy eye muscle May first appear during pregnancy or with certain anaesthetics Fatigue Muscle weakness
What is early onset MG with AChR antibodies associated with?
Increased adaptive immune response in the thymus
How does MG develop?
CD4+ T cells are activated by unfolded AChR subunits expressed by thymic epithelial cells.
Effector TH cells stimulate auto-reactive B cells to produce anti-AChR antibodies
Thymic myoid cells are attacked by these antibodies, and release AChR-immune complexes
These complexes activate other antigen presenting cells, perpetuating the response
What is the treatment of MG?
Increase neurotransmission Anti-cholinesterase agents Reduce autoimmunity Immunosuppressive drugs, corticosteroids Plasmapheresis IVIg Eculizumab Terminal pathway Complement inhibitor Eculizumab Surgery Thymectomy
