Adaptive immune response Flashcards
Self-tolerance
Lack of response to self Ag
Central tolerance
elimination of immature lymphocytes that occurs in primary lymphoid organs
Clonal deletion, clonoal abortion
Peripheral Tolerance
elimination of mature lymph clones that occurs in peripheral lymph tissues
Clonal anergy
Autoimmunity
Loss of self-tolerance
Characteristics of central tolerance
In thymus
Positive selection-selects T cells that recognize MHC
Negative selection-clonal deletion, eliminates T that bind to strongly to self Ag
Where/what are cryptic antigens
Brain, eye, testes
antigen that is in an immune privileged site
Ag not present in thymus so no self-tolerance
Characteristics of central tolerance for B-cells
Negative selection
Inactivated by strong signals through the BCR
Can rearrange light chains to rectify self recognition
Newly formed B cells are (more/less) sensitive to inactivation
more
Mature B-cells are (more/less) sensitive to inactivation
Less
Characteristics of peripheral tolerance
Mature lymphocytes
Peripheral lymph organs
Antigen recognition without co-stimulation in absence of pathogen
Peripheral tolerance: non-self example
Allergy shots
bovine diarrhea virus
Ag feeback
Elimination of Ag decreases response
Ab feedback
High level of Ab levels make negative feedback loop
Where do Fas-FasL interactions occur
on activated B and T cells
What happens in activation induced cell death
Grow to fast so they die
