Control and Tolerance Flashcards
Name the likely disease:
Patient presents with severe abdominal pain due to mucosal tissue inflammation, swollen face, lips, and neck, and family history of these types of episodes. Lab results show no C1-INH protein in serum.
Hereditary angioedema.
What is the name of the T cell costimulatory molecule that binds to B7 to turn down the immune response?
CTLA-4
How are Fas and FasL involved in turning down the T cell response?
After T cells have been activated for a while, they start to express Fas L, which auto-interacts with Fas on the T cell surface, causing apoptosis of the cell.
Through cross-inhibition, what cells are inhibited by IFN-gamma?
TH2 cells.
Through cross-inhibition, what cells are inhibited by IL-4?
TH1 cells.
Which cells do IL-10 and TGF-beta inhibit? Which cells make them?
These cytokines inhibit ALL T-cells. Treg cells and APCs make them.
What is central tolerance?
Self tolerance gained through negative selection during development.
What are two ways in which self-reactive T cells that make it out of the thymus are dealt with in the periphery?
Clonal deletion and clonal anergy.
How does clonal deletion occur?
It is when T cells that have been active for extended periods of time begin to express FasL –> self-apoptosis.
How does clonal anergy work?
T-cells are often not activated because when they interact with an APC that is presenting self peptide, that APC is not activated, so it does not express B7 and is not making chemotactic cytokines. With the lack of co-stimulation, the T cells don’t expand.
What is fetal tolerance?
Introduction of a graft in utero leads to tolerance because the introduced Ags will be presented as self peptides in the thymus as the organism develops.
What is high dose tolerance?
The attempt to overwhelm the immune system with lots of foreign Ag to induce adult tolerance.
What is oral tolerance?
Feeding Ags to people to induce tolerance
