Autoimmune Flashcards
Define Autoimmunity
The immune system no longer effectively differentiates between self and non-self antigens
What type of antibodies mediate a normal and healthy type of “autoimmunity”?
anti-idiotype antibodies: regulate the immune system
-these are antibodies against antigen-binding sites of immunoglobulins
What is immune tolerance?
no measurable/ clinically evident immune response to a specific (usually self) antigen
Abnormal autoimmune response to self-antigens implies a loss of ___________ ____________.
Immune tolerance
Central tolerance occurs where?
For T cells: thymus
For B cells: bone marrow
What is central tolerance?
self-reactive B and T cells are deleted during maturation
Peripheral tolerance
self-reactive T cells that escaped negative selection in the thymus are either suppressed, induced to cell death or undergo anergy
Describe the inaccessible self-antigen theory of autoimmunity
immune rxn develops to a self-antigen not normally exposed to the immune system, like an intracellular antigen - which are released as a result of injury
***Not usually pathogenic!
What type of dysfunctional cell is associated with numerous autoimmune diseases, including SLE, primary biliary cirrhosis, thyroiditis, MS, myasthenia gravis, RA, and scleroderma?
Suppressor T cells (defects)
What type of cells become autoreactive in many autoimmune diseases?
Helper T cells
DNA hypomethylation (give an example)
key mechanism in autoimmunity
causes upregulation of leukocyte function antigen1 and B cell activation without the presence of antigen
Example- drug induced lupus
Some rheumatic diseases are marked by autoantibodies to partially degraded _________ __________ proteins, such as ____________ or __________.
1 - connective
2 - tissue
3 - collagen
4 - elastin
Describe molecular mimicry, another mechanism of autoimmunity
antibodies against foreign antigens cross react with self antigens
ex. Rheumatic heart disease
