Lecture 7 - Naive T Cell Development

Question 1

What is the progression of how an animal protects itself from foreign pathogens

Answer 1

1 - anatomic barrier
2 - complement/antimicrobial proteins
3 - innate immune cells
4 - adaptive immunity

Question 2

Define each letter in the acronym ART

Answer 2

A - Avoid (anatomic barriers and behavior modification; wound licking)
R - Resist (reduce or eliminate pathogens; fever and innate)
T - Tolerate (enhance tissue’s capacity to resist damage)

Question 3

What is the job of CD8 T cells

Answer 3

Cytotoxic
MHC I activation
Kill infected, transformed, or tumorous self cells

Question 4

What is the job of CD4 T cells

Answer 4

helper
MHC II activation
activates or suppresses other immune cells

Question 5

What is the job of memory or plasma B cells

Answer 5

secrete antibodies

Question 6

Define: naive lymphocytes

Answer 6

circulating lymphocytes that have not encountered antigens, no functional activity, will differentiate to effector or memory

Question 7

Where do T cells mature? Where do B cells mature?

Answer 7

thymus; bone marrow

Question 8

What color do lymphocytes stain on histiology

Answer 8

dark blue

Question 9

T/F: the variable region of TCR is antigen specific

Answer 9

True

Question 10

T/F: ALL animals except ruminants and pigs have TCRs with gamma:delta chains

Answer 10

false - most animals have alpha:beta TCR

Question 11

T cells express _____ while B cells express _____

Answer 11

TCR; BCR

Question 12

What do the epithelial cells provide for growing cells

Answer 12

growth factors + nutrients
express MHC and Ags to thymocytes
eliminates self Ag-reactive cells

Question 13

Where do t cells develop in the thymus

Answer 13

cortex

Question 14

T/F: TCR undergo DNA recombination to create very diverse TCR

Answer 14

True

Question 15

Summarize the sequential development of cells in the thymus

Answer 15

DN1 - DN2 - DN3 (pre-TCR) - DN4 (proliferation) - DP (CD4, CD8 - TCR) - SP

Question 16

Postive selection in the cortex

Answer 16

thymocytes that bind moderately/strongly to self MHC survive (become CD4/8 single positive cells)

Question 17

negative selection in medulla

Answer 17

T cells that bind moderately to self MHC on APCs survive

Question 18

T cell precursors arrive in the thymus and differentiate for up to one week. Before emigration to the thymus, T - cell precursors reside in the

Answer 18

Bone marrow

Question 19

T/F: when T cells enter the medulla of the thymus they are mature

Answer 19

False

Question 20

After 1-2 weeks of maturation in the medulla, thymocytes must exit the thymus to become mature circulating T cells. To do so they up-regulate a certain receptor which allows them to

Answer 20

recognize high concentrations of S1P in the blood

Question 21

How do T and B cells enter the lymph nodes

Answer 21

via high endothelial venules

Question 22

the spleen ____ blood-borne pathogens

Answer 22

drains

Question 23

T/F: lymph nodes are only connected to the lymphatic system

Answer 23

False - connected to the vascular and lymphatic system

Question 24

Define: Homing

Answer 24

migration of lymphocytes to specific tissue, organ, or site of inflammation

Question 25

what chemokine does stromal cells secrete for T cell homing

Answer 25

SLC (21)

Question 26

what chemokine do dendritic cells secrete for T cell homing

Answer 26

MIP (19)

Question 27

Summarize T cell homing

Answer 27

1 - stromal cells secrete SLC
2 - dendritic cells uptake SLC and migrate to lymph node
3 - dendritic cells secrete MIP which attracts T cells

Question 28

How does lymphocyte circulation in the pig differ from other animals

Answer 28

moves through only the efferent vein to the bloodstream

Question 29

Give the component that drives T cell homing stage:

Rolling

Answer 29

L-selectin

Question 30

Give the component that drives T cell homing stage:

Activation

Answer 30

Chemokine (SLC)

Question 31

Give the component that drives T cell homing stage:

Adhesion

Answer 31

integrins

Question 32

Give the component that drives T cell homing stage:

diapedesis

Answer 32

chemokines

Question 33

What cells express Leukocyte function antigen 1 (LFA-1)

Answer 33

T-cells, neutrophils, and macrophages

Question 34

what job does LFA-1 have

Answer 34

enable migration of naive and activated T cells and used in attachment to target cells

Question 35

T/F: selectin addressins are only responsible for tissue-specific homing

Answer 35

True