Tuesday 1 - D - regulation of the immune system

Question 1

What CD interaction between T cells and activated B cells (or APCs) first stimulates the production of IL-2

Answer 1

CD28 to CD80,86

Question 2

What CD interaction between T cells and activated B cells (or APCs) is inhibitory and trumps all

Answer 2

CTLA-4 (cytotoxic t lymphocyte associated protein 4) to CD80,86

Question 3

CCR7

Answer 3

Chemokine receptor 7

used by dendritic cells for trafficking to the lymph node

Question 4

what TXN factor in APCs is primarily responsible for generation of pro-inflammatory cytokines?>

Answer 4

NFkappaBeta

Question 5

inborn lack of Treg cells is the cause of what

Answer 5

IPEX - immunodysregulation polyendocrinopathy enteropathy X-linked syndrome

mutations it Foxp3

6-9 months post birth

rashes, hair falling out, diarrhea

Villus atrophy in the GI system

autoantibodies may also attack the liver causing diabetic like Sx.

Question 6

besides suppressing t cells, what else does IL-10 do?

Answer 6

it can cause class switching of b cells to IgA

Question 7

TGF-beta

Answer 7

produced by Treg cells, stops t cell proliferation

Question 8

IL-35

Answer 8

auto-inducer for Treg cells

Question 9

what happens when a Treg cell meets an APC

Answer 9

touches it with CTLA4

makes the APC break down tryptophan into kynurenin, which is a growth inhibitor of T cells

Question 10

antigens given subcutaneously with stimulate what type of t cell response more?

what about if given IV?

Answer 10

sub cu - Th1

IV - Th2

Question 11

how does Th2 shut down:

Th1
Monocytes and other APCs

Answer 11

IL4 shuts down Th1

IL10 shuts down Monocytes and other APCs

Question 12

IFN - gamma

produced by what, effects what

Answer 12

made by Th1 cells

promotes activation of angry macrophages

stops Th17, Th2

Question 13

describe antibody dependant b cell suppression

Answer 13

basically this happens when there is so much IgG in a particular area, that it binds all of the antigen and makes it hard for the B cells to bind as well

Question 14

what is the worst kind of defect that you can have with regards to cytokine receptors

Answer 14

the gamma chain. If you don’t have the gamma chain portion, then you cannot get high affinity binding for ANY interleukin.

the gamma chain holds JAK3

Question 15

CCR5

Answer 15

Chemokine receptor gene - 5

mutations in it provide a resistance to HIV

Question 16

why do you often see high eosinophils linked with high IgE

Answer 16

because they are both stimulated by IL-5

Question 17

Tx for IPEX?

can you vaccinate these patients?

Answer 17

partial engraftment of bone marrow is usually Tx of choice.

IVIG - intravenous immunoglobulin. blocks the immune system from ever being stimulated so you don’t get run away Th2.

DON’T give vaccines to IPEX patients

Question 18

APECED

Answer 18

autoimmune polyglandular syndrome (APS) type 1.

Lack the AIRE gene.

Cannot negatively select for T cells - (Usually dendritic cells display self antigen because of a functional transcription error, and show them to T cells. If the T cells recognizes it, it is normally killed. in APECED this doesn’t happen).

development of autoantibodies against endocrine glands, liver, skin, blood cells, and platelets.

increased susceptibility to infection with Candida Albicans.