Immune Diseases Flashcards
What is Digeorge syndrome?
no T cells made b/c thymus doesn’t develop (bubble boy)
X linked SCID
absence of T cells b/c IL-7 receptor on lymphoid progenitor isn’t there and therefore can’t become T cells.
RAG SCID
VDJ region stitching problem (affects variable region of TCR on T cells and antigen binding region of B cells)
XLA disease
B cells don’t develop b/c BTK checkpoint is missing while B cell is developing in the bone marrow (therefore can’t make any antibodies!)
Which disease can use IgG infusions to treat? a) Digeorge syndrome b)xlinked scid c) rag skid d) XLA disease
D) XLA disease
Clonal deletion of T cells
Central tolerance: T cells that are self are given a signal to do apoptosis
Regulatory T cells
Peripheral tolerance: T cells that suppress self reactive B and T cells
Receptor editing
central tolerance: B cells that are self reactive will do a gene rearangement in their variable region to become not self reactive
Myasthenia Gravis
antibodies bind to receptors on eye muscle cells and don’t allow acetylcholine from nerve cell to bind to muscle receptors
Lupus
antibodies bind to DNA and form “immune complexes” that deposit in blood vessels and damage glomulerus of kidneys
Type 1 diabetes
T cells attack pancrease cells, which causes a decrease in insulin production
Psoriasis
T cells (TH17) release IL17 which causes an immune response that causes neutrophils to damage the skin
What is sensitization?
first exposure to allergen. The T helper cells interact with B cells and cause them to start making IgE (from IgG). IgE will bind to receptors on surface of mast cells
What do TH2 cells do during initial sensitization?
They release IL4 and IL5, which activate eosinophils
2nd exposure to allergen
IgE on mast cells bind to allergen and do cross linking. The mast cell will release TNF, histamines and prostaglandins. Meanwhile the esosinophils release proteases
What does histamine and TNF do during the 2nd exposure to a allergen?
TNF causes neutrophils to exit the blood into the tissue. Histamines cause fluid to leak out of blood vessels into the tissue (hives)
What is allergy tolerance?
B cells produce IgG4 instead of IgE (these bind to mast cells instead and prevent an immune response)= allergy immunotherapy
What happens if a self T cell escapes clonal killing and sees a self antigen?
Peripheral monitoring….
The t cell will get signal 1, but will not get signal 2 from the dendritic cells
