Specific Acquired Immunity--Diebel Flashcards
Small amino acid sequences that are recognized by lymphocyte receptor
epitope
How often do proliferating lymphocytes double in number?
6-12 hr.
B-cells are responsible for _________ immune response
humoral (extracellular spaces)
T-cells are responsible for _________ immune response
cell-mediated
What is the only cell type to not display MHC-I molecules?
erythrocytes
MHC-I molecules are recognized by CD4+/CD8+ T-cells
CD8+
MHC-II molecules are recognized by CD4+/CD8+ T-cells
CD4+
What types of cells express MHC-II
B-cells
macrophages
dendritic cells
Lymphokines
cytokines secreted by lymphocytes
Which CD is universally expressed by T-cells?
CD3
Th1 CD4+ macrophages duties
acute inflammation, lymphokine production
Th2 CD4+ macrophage duties
M2 macrophage activation, clean up. important in parasite immunity.
Th17 CD4+ macrophage duties
acute inflammation (like Th1), famous for severe autoimmune reactions
Tfh CD4+ macrophage duties
help activate B-cells, stimulated by antigen to move from T-cell areas of lymph nodes into B-cell follicles
Treg CD4+ macrophage duties
suppress Th1, Th17, and Th2 to keep immune system in chick. part of Th family.
CD4+ T-cell activation requires that MHC-II binds TCR, but also requires which other two co-receptors to bind in order to maintain adequate specificity?
CD28 binds B7 (APC)
LFA1 and 3 bind ICAM1 and 3 (APC)
Which two cytokines generally activate T-cells?
IL-2
IL-15
Th1 activation cytokines
IL-12
IFN-gamma
Th2 activation cytokines
IL-4
Th1 deactivation cytokines
IL-10
Th1 and Th2 deactivation cytokines
TGF-beta (transforming growth factor)
Why is it adventagous to kill virally infected cells?
killing them early makes sure less virus particles are produced than if they spontaneously lysed
What is the big mediator of T-cell mediated cytotoxicity?
FAS–FAS ligand interaction –> caspase cascade
it’s FAS-T-cell ==> FAST-cell killing
How are T-cells positively selected for in thymus?
need to recognize MHC-I or MHC-II
How are T-cells negatively selected for in thymus?
killed if recognize self antigens on MHC-II of thymus epithelial cells
Your friend is out of T-cells. You spin your T-cells out and inject them into his veins so he doesn’t get TB. Why will this not work?
T-cells are specific to individuals, ie they only recognize “native” MHC-antigen presentation
Which CD molecule on a B-cell interacts with T-cells?
CD40
Which Ig makes its way through the placenta?
IgG
Normal, everyday, opsonizing immunoglobulin
IgG
Which Ig is first to appear in infection?
IgM
How long does it take for IgM to be replaced with IgG?
1-2 wk
Most abundant secretory Ig
sIgA
IgE attaches to ________ cells
mast cells
Type I hypersensitivity
IgE
histamine related
primarily Th2 CD4+ cells activate B-cells to make IgE
Type II hypersensitivity
autoantibodies produced (B-cell mediated collateral damage)
Type III hypersensitivity
immune complexes formed
occur primarily in tissues with outward fluid movement (kidney, skin, pleura, joints)
Type IV hypersensitivity
collateral, T-cell mediated cellular damage
