Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
22 Cards in this Set
- Front
- Back
|
Anergy is what?
|
a state of unresponsiveness that is a state where T cells can identify self antigens, but it is anergic because CTLA-4 competes with CD28 which inhibits the co-stimulation required to activate the T cell
|
|
|
What does telomere loss cause in regard to T cells?
|
overtime telomeric shortening causes T cells to be inactive
|
|
|
What is the TH1/TH2 paradigm?
|
cytokine activity causes a T cell to differentiate into TH1 or TH2
IFN-gamma is released by TH1 to inhibit TH2 IL-4, IL-10, TGF-beta is released by TH2 and inhibits TH1 |
|
|
suppressive T-cells (Treg)
|
primarily suppressive T-cell inhibit activity of auto-reactive T cells (TH1 and TH2). these cells express Foxp3 and inhibitory cytokines. they differentiate from T0 cells and have to have physical contact with the cells that it wishes to effect.
also uniquely, they are CD4+ and CD25+ |
|
|
What is required for Treg cells to suppress an immune response?
|
1) cell to cell (direct or indirect through an APC) contact
2) Foxp3-induced gene expression 3) unique cytokines |
|
|
What cytokines to Treg cells produce?
|
IL-10, TGF-beta
|
|
|
Goldilocks hypothesis?
|
if the signal is too strong -> apoptosis
if the signal is too weak -> effector T cell if the signal is juuuuust right -> Tregs occurring in the thymus during negative and positive selection of maturation |
|
|
6 practical functions of Tregs
|
1) inhibit inflammation and hypersensitivity
2) inhibit autoimmunity 3) suppress graft rejection 4) suppress pregnancy rejection 5) inhibit responses against infection (this isn't good!) 6) inhibit response to cancer (hmmm.) |
|
|
IPEX Syndrome
|
mutation of Foxp3 causing dysfunctional Tregs and subsequent autoimmunity and hypersensitivity
mostly boys and usually die w/i first year of life |
|
|
IPEX triad
|
diarrhea
eczema (skin rashes) endocrinopathy (commonly manifested as diabetes) |
|
|
How do Tregs support pregnancy?
|
Tregs accumulate in uterus during ovulation and stay until after menstruation
miscarriages show low Tregs |
|
|
selective migration
|
dependent on chemotaxis and causes certain cells to move into specific tissue
|
|
|
what does stress do to the immune system?
|
suppresses it, yo
|
|
|
hydrocortisone (cortisol)
|
principal steroid hormone produced by adrenal cortex
blocks cytokine production impedes WBC function |
|
|
how do corticosteroids work with receptors/action/etc?
|
1) steroid crosses cytoplasmic membrane
2) steroid attaches to a receptor:HSP90 complex 3) HSP90 is released 4) steroid:receptor complex crosses the nuclear membrane and alters transcription to turn genes on and off |
|
|
what genes does corticosteroids turn on/off?
|
1) decreases inflammatory cytokines
2) decreases adhesion molecules in order to keep cell migration from blood to tissues at a minimum 3) promotes apoptosis of certain WBCs |
|
|
how do genetics play a role in immunoregulation?
|
1) MHC haplotypes influence the ability to identify and respond to Ag
2) complement defects 3) high IgE production 4) polymorphism in cytokine receptors and promoters |
|
|
what dietary supplements can be used to reduce stress and support your immune system?
|
vitamin C
zinc echinacea elderberry kombucha |
|
|
why is vitamin C important?
|
collagen formation
free-radical scavenger supports immune function maintains skin stimulates leukocyte production boosts production of complement and antibodies improves macrophage and neutrophil oxidative burst protects self from ROS inhibits bacterial activity |
|
|
why is zinc important?
|
maintains skin
maintains WBC maintain memory |
|
|
what does elderberry do?
|
increases inflammatory cytokines
antioxidant |
|
|
what does kombucha do?
|
prepared by fermenting black tea
antimicrobial activity immunostimulating hepatoprotective (detoxifier) |
