Cell Immunity 1

Question 1

name given to a family of pro-inflammatory activation- inducible cytokines?

Answer 1

chemokines—-> induce chemotaxis

Question 2

Chemokines are divided into families based on what?

Answer 2

relative positions of TWO highly conserved CYSTEINE residues at the AMINO terminal

Question 3

Are there any chemokines that lack the first conserved cysteine?

Answer 3

Yes, two XCL1 and XCL2

Question 4

Chemokines acton a family of 18 receptors….all of which are in what class?

Answer 4

G-Protein Coupled

Question 5

What does large number of chemokines and chemokine receptors available to the immune system provide?

Answer 5

precise control over inflammation (attract different subsets of immune cells)

Question 6

What are the only type of cells that can extravasate through HEV?

Answer 6

Lymphocytes—-most DC’s enter through afferent lymphatics

Question 7

Movement of lymphocytes throughout the body is controlled by what three molecules?

Answer 7

selectins, chemokines, and integrins

Question 8

Selectins are important for what ?

Answer 8

rolling

Question 9

Integrins are important for what in migration?

Answer 9

adhesion

Question 10

What selectin is expressed on lymphocytes, especially naive t cells before they have been activate?

Answer 10

L-selectin—also on monocytes and neutrophils

Question 11

What is the ligand for E-selectin that is expressed on endothelial cells?

Answer 11

sialylated carbohydrates on many different immune cells

Question 12

What selectin binds to glycoprotein ligand on leukocytes, heparan sulfate, and fucoidan?

Answer 12

P-selectin on endothelial cells

Question 13

T - F selectins bind many proteins binding N-linked carbohydrate chains?

Answer 13

False- O-linked

Question 14

are integrins made up of homodimers or heterodimers?

Answer 14

heterodimers one of each 18 alpha and 8 beta chain—24 unique integrins

Question 15

What needs to happen for the integrin to be activated and bind with higher affinity?

Answer 15

TCR stimulation or chemokine receptor stimulation that results in conformational change of the integrin

Question 16

HEV produce what chemokine?

Answer 16

CCL21

Question 17

Stromal cells around HEVS secrete what chemokine?

Answer 17

CCL 19

Question 18

What does L-selectin bind?

Answer 18

CD34, GlyCAM-1, PNAd on peripheral lymphnode

MAdCAM-1 on mucosal lymphoid tissue

Question 19

Naive T cells exit is controlled by a gradient of what?

Answer 19

S1P-sphingosine 1-phosphate- activated receptor on T cell causes it to leave lymph and enter blood or lymph duct….if it is activated in the lymph node it will downregulate its receptor in order to stay there

Question 20

What keeps concentration of S!P low?

Answer 20

S1P lyase in lymphoid and peripheral tissues

Question 21

What chemokine receptor do immature dendritic cells express for migration into peripheral tissues?

Answer 21

CCR7

Question 22

T-F naive T cells specific to a particular antigen are common?

Answer 22

False—they are very rare

Question 23

What 3 signals do Naive T cells receive 3 signals from an activated antigen-presenting cell?

Answer 23

1: recognition of peptide bound to MHC by TCR
2: co-stimulatory
3: cytokines direct the differentiation of CD4 T cells into numerous effector subsets and direct CD8 T cells to acquire effector functions

Question 24

What receptor is crucial for cell expansion that follows the activation of a naive T cell?

Answer 24

IL-2 receptor (CD25) drives expansion (binds IL-2 ligand)

Question 25

What promotes S1P receptor degradation?

Answer 25

CD69–a C-type lectin recepor

—TCR stimulation also down regulates this protein. Botha cations leads activated T cells to be detained in the LN

Question 26

Genetic defect that is most commonly found in CD 18 and lack of expression of LFA-1, recurrent bacterial infections, delayed umbilical sloughing, abcess at infection site, neutrophils cannot migrate, WBC will show huge amounts of neutrophils?

Answer 26

LAD- leukocyte adhesion deficiency

treated with bone marrow transplant