Week 5 Flashcards
(45 cards)
What is the “other” name for factor 2?
thrombin
What factors are in the intrinsic pathway?
-Factors VIII, IX, X, XI, and XII; factor VIIIa is a cofactor
What factors are in the extrinsic pathway?
Tissue factor (TF) and Factor VII
Which factors require vitamin K-dependent gamma carboxylation?
Factors II, VII, IX, X, Proteins C and S
Why does Warfarin (Coumadin) when started need to be “bridged” with heparin?
-since Warfarin blocks proteins S and C it can caused increased clotting before it starts working correctly
Anti-thrombin 3 interacts with which drug?
Heparin
-ATIII leads to thrombin inactivation; also blocks the activity of factors VIIIa, IXa, Xa, and XIa
Why is aspirin an irreversible platelet inhibitor?
-blocks COX 1 (platelets don’t have nuclei so can’t make more)
How does activated protein S affect the coagulation cascade?
-degrades factors Va and VIIIa via proteolysis thereby decreasing thrombin production
GP 1b deficiency causes what syndrome?
Bernard Soulier syndrome
What CD is the IL-2 receptor?
CD25
What marker targets APCs to the lymph nodes?
CCR7 (in lymph nodes activates T cells)
What signals does an immunogenic DC produce to activate T cell proliferation and pro-inflammatory cytokines?
CD86hi, MHC2 hi, CD40 hi, CCR7 hi
-pro-inflammatory cytokines = IL-12 and TNF-alpha
What signals do tolerogenic DCs produce to stimulate clonal deletion or anergy of antigen-specific T cells?
CD86 lo, MHC 2 lo, CD40 lo, CCR7 lo
what are the 4 types of Treg mechanisms to control proliferation/ actions of other T cell populations?
- immunosuppressive cytokines (IL-10, TGF-beta, IL-35)
- IL-2 consumption
- cytolysis (granzyme mediated)
- modulation of DC maturation and function (kynurenin causes cell cycle arrest and CD 152/ CTLA4)
What are the 4 main mechanisms of B cell tolerance?
- clonal deletion (inhibition of survival signals or activation death receptors)
- receptor editing (continued V(D)J recombination)
- B-cell intrinsic mechanisms (anergy, down-regulation of BCR, upregulation CD5)
- lack of T-cell help or survival factors
What cytokines do Th1 cells produce?
-IFN-gamma, TNF-beta, IL-2
What cytokines do Th2 cells produce?
-IL-4, IL-5, IL-9, IL-10, IL-13
What cytokine does Th17 produce?
IL-17A (neutrophil recruitment/ inflammation)
-TNF-alpha
What are the 2 mechanisms for antibody-dependent B cell suppression?
- IgG can cross-link Ag receptor with Fc receptor on same cell
- IgM and IgG can act to modulate immune response through Fc-dependent mechanism and immune complex formation with antigens
What is the 1 mechanism of antibody-dependent B cell augmentation?
by activating complement, immune complexes may become localized via interactions with CR2 on follicular dendritic cells (facilitates immune response by maintaining source of Ag)
What gene is mutated in IPEX?
- lack of both CD4+/CD25+ cells and CD4+ Foxp3 positive cells
- mutation in FOXP3 gene (make Treg cells)
What are the key features of IPEX? Physical manifestations?
- autoimmune problems
- intractable watery diarrhea, FTT, dermatitis, autoimmune diabetes in infancy
What abnormalities present in a WBC differential for IPEX?
- normal WBC count, normal HgB, normal platelet count
- elevated percentage eosinophils and elevated IgE
Treatment for IPEX?
- immunosuppressive therapy
- bone marrow transplant