Chapter 9 (exam 2)

Question 1

T cells are always generated in which form?

Answer 1

naive form (inactive form)

Question 2

T cells develop in the ________ and then enter the bloodstream

Answer 2

thymus

Question 3

Once T cells reach a secondary lymphoid organ, they leave the bloodstream and migrate through lymphoid tissue, returning via……

Answer 3

lymphatics to blood

Question 4

Mature circulating T cells who have not encountered antigens are called what?

Answer 4

naive T cells

Question 5

Once T cells encounter antigen w/ MHC, then they proliferate and differentiate into cells called what?

Answer 5

effector T cells

Question 6

Adaptive immune responses are initiated where?

Answer 6

in the secondary lymphoid organs (spleen, lymph nodes, MALTs (Peyer’s patch in the gut)

Question 7

T and B cells are partitioned into distinct _________ of secondary lymphoid tissues by the action of chemokines

Answer 7

regions

Question 8

Secondary lymphoid tissues are specialized sites where antigen and _______________ interact

Answer 8

lymphocytes

Question 9

Lymph nodes can have no antigen present (antigen free) or have antigen cargo on what cells?

Answer 9

dendritic cells

Question 10

The antigen on dendritic cells will be delivered to where?

Answer 10

B and T cell zones (all secondary lymphoid organs have seperated B cell zones and T cell zones)

Question 11

B and T cells enter from where when coming into a lymph node?

Answer 11

HEV (high endothelial venules)

Question 12

The spleen will receive the antigen via arterioles which branch from central arteriole to the _________ _______

Answer 12

marginal sinus

Question 13

In the marginal zone of the spleen, the antigen is taken by APC to T cell zones or B cell _________

Answer 13

follicles

Question 14

In the Peyer’s patch of the small intestine, the antigen goes from the lumen via _______________ cells to dendritic cells in the subepithelial region

Answer 14

microfold (M)

Question 15

Stromal cells and high endothelial venules (HEVs) secrete CCL21. What happens next?

Answer 15

-macrophages or dendritic cells express a receptor for CCL21 and migrate into the developing lymph node
-dendritic cells secrete CCL19, which attracts T cells to the developing lymph node
-B cells are initially attracted into the developing lymph node by the same chemokines
-B cells induce the differentiation of follicular dendritic cells, which in turn secrete the chemokine CXCL13 to attract more B cells

Question 16

Circulating B and T cells come to secondary organs by common route. Then they move into distinct regions under the control of ______________

Answer 16

chemokines

Question 17

stromal cells and bone marrow derived cells in B/T cell zone produce cytokines. Which one?

Answer 17

CCL21

Question 18

Dendritic cells have a receptor for CCL21. Dendritic cells migrate. Then they secrete _______. What does this attract?

Answer 18

CCL19

attracts B and T cells

Question 19

How do the APCs differ in terms of location?

Answer 19

macrophages are typically in more specific tissue areas (lymphoid tissue, connective tissue, body cavities)

dendritic cells are ubiquitous (everywhere)

B cells are in lymphoid areas and can go into blood (another distinction is that they don’t engulf like the other two)

Question 20

Dendritic cells see antigens w/ TLRs on their surface, bump into it and bring it in through phagocytosis, engulf and process it to load onto…

Answer 20

MHC

Question 21

Conventional dendritic cells present in abundance at ________ ________ sites. In the absence of infection or tissue injury, they have low levels of costimulatory molecules so they are not capable of activating naive T cells. Once they seen antigen, they pick it up, process it, and present it

Answer 21

barrier tissue

Question 22

Mature conventional dendritic cells activate ________ cells. So, there is a role in adaptive immune response

Answer 22

naive T

Question 23

Plasmacytoid cells are sentinels for _______ infections and secrete large amounts of ________ interferons.

Answer 23

viral, class 1

Question 24

T/F: Plasmacytoid cells are just as effective as conventional dendritic cells in activating T cells

Answer 24

FALSE, not as efficient

Question 25

Plasmacytoid cells play a role in _________ immune response. They may help conventional dendritic cells sustain production of ________ which asks T cells to make IFN-gamma

Answer 25

innate, IL12

Question 26

Conventional dendritic cells work to activate ______ cell

Answer 26

T

Question 27

What does an up-regulation of CCR7 indicate?

Answer 27

indication for macrophage to move from current location to another (migratory macrophage) if theres no up-regulation then the macrophage will stay put as a tissue resident macrophage

Question 28

Which type of dendritic cells can activate T cell?

Answer 28

conventional cell

Question 29

Which type of dendritic cells detects viral infections and sends alerts w/ large amounts of IFN-gamma?

Answer 29

Plasmacytoid cells

Question 30

Dendritic cells arise from myeloid progenitor cells within the BM and migrate via blood to tissues throughout the body or to.....

Answer 30

secondary lymphoid organs

Question 31

Conventional dendritic cells are activated through stages to become activated ________ in peripheral lymphoid tissue

Answer 31

APCs

Question 32

Conventional dendritic cell pathway- Entry to tissue is based on chemokine receptor they access. Tissue resident DCs are phagocytic via receptors such as ________________________. At the site of infection, TLR signaling causes them to get activated. There is an induction of CCR7. Cells expressing this are sensitive to ________ and __________ produced by lymphoid tissue. CCR7 forces migration of DC to lymphoid tissue. Costimulatory molecule B7 made and MHC expressed. By the time they arrive to the lymph node, they are activators of naive T cells, present antigen, no more phagocytosis

Answer 32

Dectin, DC-SIGN, and Langerin CCL19, CCL21

Question 33

Once dendritic cells arrive and are in the process of presenting to a T cell, then they lose the ability to undergo phagocytosis with the antigen. Why?

Answer 33

bc now their only job function is to present to the T cell

Question 34

Macrophages are _____________ cells that can be induced by pathogens to present foreign antigens to naive T cells

Answer 34

scavenger

Question 35

Resting macrophages have few or no _________ and no _____. Expression of both induced following ingestion or recognition of pathogen

Answer 35

MHC class II, B7

Question 36

Tissue resident macrophages are non-migratory and don't go to ___________ zones. Macrophages in lymphoid organs (lymph node, marginal sinus) don't activate T cells, their function is to ingest foreign agents

Answer 36

T cell

Question 37

How are antigens taken up with DCs?

Answer 37

macropinocytosis and phagocytosis by tissue DCs

Question 38

How are antigens taken up by macrophages?

Answer 38

macropinocytosis and phagocytosis

Question 39

Macrophages and B cells present antigen primarily to receive help from ____________ T cells in the from of cytokines or surface molecules

Answer 39

effector