Immunoregulation

Question 1

Treg cells

Answer 1

express the cell surface markers CD4, FoxP3, CD25
-express high levels of CTLA-4, which inhibits activation of T cells
requires TGF-beta for development

Question 2

What do treg cells prevent

Answer 2

excessive immune responses to foreign antigens

immune responses to self antigens missed by tolerization

Question 3

Treg mechanisms of action

Answer 3

• production of suppressive cytokines IL-10 and TGF-beta
• binding of CTLA-4 to B7 molecules on APCs, reducing ability ability of APC’s to activate T cells
• consumption of IL-2, depriving other cell types of this important growth factor

Question 4

2 mechanisms of antibody feedback

Answer 4

antibody helps eliminate antigen

immune complex-bound antibodies inhibit B lymphocyte activation

Question 5

Tolerance

Answer 5

block of antigen-induced differentiation of B and T cells, an induced state of unresponsiveness to antigen

Question 6

Central tolerance

Answer 6

occurs in bone marrow or thymus

Question 7

peripheral tolerance

Answer 7

occurs in periphery

Question 8

Characteristics of tolerance

Answer 8

antigen-specific

acquired

Question 9

Immature lymphocytes

Answer 9

easier to tolerize than mature

Question 10

Clonal deletion

Answer 10

death of antigen specific lymphocytes

Question 11

clonal anergy

Answer 11

functional inactivation of viable lymphocytes

Question 12

1st mechanisms of peripheral tolerance

Answer 12

treg cells in periphery

Question 13

2nd mechanism in peripheral tolerance

Answer 13

T-cells - APC interaction without costimulatory molecules, self-antigens, without co-stimulator-producing inflammation

Question 14

B lymphocytes tolerance

Answer 14

can see non-peptide antigens

Question 15

Receptor editing

Answer 15

B cell rearranges light chain genes again to produce a completely different antigen specificity

Question 16

Maturation of thymocytes

Answer 16

double negative to double positive to single positive

Question 17

Positive selection

Answer 17

gets rid of the free loaders via neglect

Question 18

negative selection

Answer 18

get rid of dangerous cells

Question 19

what does mutation in AIRE causes

Answer 19

widespread autoimmune disease

Question 20

What are monokines produced by

Answer 20

macrophages

Question 21

What do monokines regulate

Answer 21

phagocytic cells

Question 22

What are lymphokines produced by

Answer 22

activate T cells

Question 23

What do lymphokines regulate

Answer 23

lymphocytes, macrophages, neutrophils, eosinophiles

Question 24

What are colony stimulating factors produced by

Answer 24

lymphocytes
macrophages
bone marrow
stromal cell

Question 25

What do colony stimulating factors regulate

Answer 25

granulocyte and monocyte production in bone marrow

Question 26

cytokines

Answer 26

protein hormone like molecules

Question 27

Type 1 IFN

Answer 27

upregulate the expression of class I MHC
activate NK cells
block viral replication

Question 28

biological actions of TNF-alpha

Answer 28

activates macrophage/neutrophils
increase adhesiveness of vascular endothelim for neutrophils
fever generation
neutrophilia
DIC/shock

Question 29

IL-2

Answer 29

produced by CD4 T cells and autocrine and paracrine growth factor for T cells
increase NK cell cytotoxicity and induced NK cells to become lymphokine-activated killer cells

Question 30

IL-4

Answer 30

produced by CD4 T cells, mast cells, basophils

B cell isotypes switching to IgE

Question 31

TGF-beta

Answer 31

produced by activated T cells and macrophages
induces TH17 cells
inhibits T cell proliferation/differentation into CTLs
inhibit macrophage activation
induces B cells to produce IgA antibody at mucosal sites
initiates would healing

Question 32

Interferon gamma

Answer 32

activates macrophages
produced by CD8 T cells and NK cells
directs immune response toward cell mediated immunity
upregulates class I and class II MHC expression
isotype switching to IgG