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Flashcards in Cell Immunity 1 Deck (26):
1

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

chemokines----> induce chemotaxis

2

Chemokines are divided into families based on what?

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

3

Are there any chemokines that lack the first conserved cysteine?

Yes, two XCL1 and XCL2

4

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

G-Protein Coupled

5

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

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

6

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

Lymphocytes----most DC's enter through afferent lymphatics

7

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

selectins, chemokines, and integrins

8

Selectins are important for what ?

rolling

9

Integrins are important for what in migration?

adhesion

10

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

L-selectin---also on monocytes and neutrophils

11

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

sialylated carbohydrates on many different immune cells

12

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

P-selectin on endothelial cells

13

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

False- O-linked

14

are integrins made up of homodimers or heterodimers?

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

15

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

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

16

HEV produce what chemokine?

CCL21

17

Stromal cells around HEVS secrete what chemokine?

CCL 19

18

What does L-selectin bind?

CD34, GlyCAM-1, PNAd on peripheral lymphnode
MAdCAM-1 on mucosal lymphoid tissue

19

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

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

20

What keeps concentration of S!P low?

S1P lyase in lymphoid and peripheral tissues

21

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

CCR7

22

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

False---they are very rare

23

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

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

24

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

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

25

What promotes S1P receptor degradation?

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

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?

LAD- leukocyte adhesion deficiency
treated with bone marrow transplant