Hypersensitivity 2 Flashcards
(30 cards)
What do a lot of autoimmune responses occur after?
Significant entigenic challenge
Why may an autoimmune response become systemic?
Autoantibodies against cellular components–> DNA and RNA
Why may an autoimmune disease occur after a significant antigenic chalenge?
Immune system doesnt die down
What happens when antibodies crosslink epitopes on antigens?
Make large circulating complexes (immune complexes)
Where can immune complexes be deposited?
Lumen of small vessels–> nephron and capillaries
What do immune complexes attract?
Neutrophils that are binding to the FC region of the antibodies
How can immune complexes cause organ failure?
By closure of the vessel due to them blocking it–> blocks blood flow
Treatment for people w/ type III hypersensitivity?
High dose immunosuppressive therapies
Steroid side effects?
Weight gain, diabetes, osteoporosis, high blood pressure (heart strain)
What is type IV driven by?
T cells–> cytotoxic t cells and CD8, TH1
What do TH1 cells release upon activation?
Interferon gamma
WHat can interferon gamma activate?
Macrophages
What do macrophages release in response to activation?
TNF
TNF effect on inflammation?
Increases it
“prototype disease” of type IV hypersensitivity?
Type 1 diabetes
What does autoimmunity result from
failure or breakdown in mechanisms normally responsible for maintaining self tolerance
Future type I diabetes treatment?
Develop insulin secreting cells from stem cells and implant them back into the patient
Main contributing factors to autoimmunity?
Genetic susceptibility and environmental triggers
WHat is most genetic causes behind autoimmunity to do with?
MHC, and how MHC resents certain antigens
How can MHC present antigens?
In a way that makes them look more immunogenic
What is epitope spreading?
Weakly self reactive t cells recruit other t cells which also recognise epitopes on our self proteins–>multiple t cells
MS mode of action?
T cells attack myelin sheath around neurons
What is inflammatory bowels disease mediated by?
Cytokines
What can cause rheumatoid arthritis?
TH1s and TH2s (bc of presence of B cells (autoantibodies))
