Restraining Immune System

Question 1

activated HELPER T-cells secrete ______ and _____, which _____ immune system

Answer 1

TNF
IFN-y
ACTIVATE

Question 2

activated REGULATORY T-cells secrete _____ and ____ , which _____ immune system

Answer 2

TGFB
IL-10
RESTRAIN

Question 3

regulatory T cell that:
REDUCES CTL killing
binds to receptors on T cells
reduces proliferation

Answer 3

TGFB (Transforming GF beta)

Question 4

regulatory T cell that:
BLOCKS co-stimulatory signals
binds to receptor on T cells
reduces proliferation

Answer 4

IL-10

Question 5

in a NAIVE cell, B7 binds to _____
in an EXPERIENCE cell, B7 binds to ______ making it HARDER for T cells to be reactivated and _______ adaptive immune system (DEACTIVATION)

Answer 5

CD28
CTLA-4
SHUTS DOWN

Question 6

T cells live a long time until activated

Once activated, experienced T cell’s Fas protein are MORE sensitive

Answer 6

AICD (activation-induced cell death)

Question 7

once an invader has been vanquished, ___% of T cells usually DIE OFF

Answer 7

90%

Question 8

once infection has been dealt with, ______ feedback loop must be broken, immune response MUST be able to be turned OFF to prevent ______ damage

Answer 8

positive

autoimmune

Question 9

intestines are home to ____ # of bacteria of _____ different types
SA is approx _____ meter^2

Answer 9

1x10^14
1000
200 m^2

Question 10

to avoid immune system overreaction, special macrophages found beneath intestinal wall
\_\_\_ is major antibody class and DOES NOT CAUSE INFLAMMATION

Answer 10

IgA

Question 11

IgA ___ and _____ invaders in order to move them back into intentional tract to be _______ in stool
DOES NOT FIX COMPLEMENT

Answer 11

binds
neutralizes
flushed out

Question 12

to induce reg T cells in NON-BATTLE conditions:
epithelial cells produce ____ –> TGFB causes cells in ______ to become _____ cells –> release _____ that encourage calmer _____ immune system

Answer 12

TGFB
peyer's patches
reg T cells
cytokines
mucosal

Question 13

to induce reg T cells in BATTLE conditions:

epithelial cells produce ____ –> DENDRITIC cells also producing ______ –> T cells commit to becoming _______ cells

Answer 13

TGFB
IL-6
Th17

Question 14

Need combination of ____ & _____ to become Th17

Answer 14

TGFB

IL-6

Question 15

inducible regulatory T cells (iTreg) shorthand name is _____, produce _____, develop from ____ under influence of TGFB

Answer 15

CD4+
cytokines
Th0

Question 16

TGFB is a cytokines that causes naive cells to become ___ or ____ (unsure how this trigger decides which to become)

Answer 16

Th17

iTreg

Question 17

potential hypothesis for TGFB
if invasion DC make IL-6 with TGFB –> ______
NO danger, only TGFB produced by epithelium –> _____

Answer 17

Th17

iTreg

Question 18

iTreg develop in ____, fxn to restrain immune system from _______, two subtypes are ___ & _____

Answer 18

MALT
over reaction
Tr1
Th3

Question 19

nTreg develop in ______, fxn to provide ______ against T cells, REQUIRE _______ and are ____ SPECIFIC

Answer 19

thymus
protection
direct cell-cell contact
antigen

Question 20

virgin T cells express _____ for co-stimulation
activated APCs make lots of ____ which binds to ______
experienced T cells make MORE of _____ –> makes it hard for reactivation

Answer 20

CD28
B7
CD28
CTLA-4

Question 21

CTLA-4 binds to B7 with an affinity of ______x higher than CD28

Answer 21

1000

Question 22

____ amplifies the signal and LOWERS the # of TCR crosslinks needed for activation

Answer 22

CD28

Question 23

____ COMPETES with B7, making co-stimulation and activation MORE difficult

Answer 23

CTLA-4

Question 24

lifespan of neutrophil

Answer 24

die after few days

Question 25

lifespan of NK cells

Answer 25

1-2 weeks

Question 26

lifespan of macrophages

Answer 26

months

Question 27

live for week after reaching lymph node

Answer 27

dendritic cells

Question 28

die after 5 days of making 2000 antibodies/second

Answer 28

plasma B cells

Question 29

longest lived has half life of 3 weeks

Answer 29

antibodies SPECIFICALLY IgG

Question 30

____ are exception to “LIFE IS SHORT rule”

Answer 30

t cells

Question 31

____ T cells are insensitive to ligation of their Fas protein

Answer 31

virgin T cells

Question 32

experience T cells that are activated and reactivated become _______ sensitive to ligation of their ______ and once exhausted are targets for _____ or _____

Answer 32

increasingly
Fas protein
suicide or homicide (AICD)

Question 33

virgin T cells express LESS _____ than experience T cells; repeated activation causes _____ Fas protein on T cells

Answer 33

Fas protein

more