Innate/adaptive immunity Clark week 5

Question 1

Sentinel cell?

Answer 1

Mast cell

Question 2

Mast cell function?

Answer 2

Has TLR, Fc, and compliment receptor to identify antigen. Then releases granules consisting of histamine. This leads to vasodilation and increased permeability. Mast cell plays role in allergies because cross linking of IgE antibody receptors will cause release of granules.

Question 3

Adhesion at endothelium? 2 pairs

Answer 3

Selectins attach to sugars on leukocyte

CAMs attach to integrins on leukocyte

Question 4

IL-1 and TNF function?

Answer 4

Cytokines released from neutrophil/macrophage that activate vascular epithelium (promote adhesion).

Question 5

IL-6

Answer 5

Cytokine that causes liver acute phase proteins such as C-reactive protein, which then acts as an opsonin.

Question 6

Initial immune response in 3 steps

Answer 6

1. Mast cell binding and release of cytokines/histamine
2. Increased vascular permeability and adhesion
3. Neutrophil extravasation

Question 7

What is the function of a co-stimulatory molecule? ex CD80/86 or B7. Also CCR7.

Answer 7

Needed for binding to naive T-cell. It is another mechanism to prevent self-recognition.

Question 8

What is the different role of IL-2 and IL-12?

Answer 8

IL-12 directs naive T cell toward activation. IL-2 is expressed when activated.

Question 9

Function of CD8 cytotoxic T cell?

Answer 9

Recognizes MH1 with de novo antigen. Destroys cell by phagocytosis.

Question 10

Function of CD4 T-helper cells?

TH1 vs TH2?

Answer 10

To activate mature B cells.
TH1 also activates macrophages
TH2 is more specific for helminthes and IgE production

Question 11

Function of CD4 T-helper 17 cells?

Answer 11

Enhance neutrophil/inflammatory response.

Question 12

What is the function of regulatory T-helper cells?

Answer 12

Suppress T-cell response

Question 13

What did Dr. Clark mean when he said lymph nodes are a crossroads of the immune system?

Answer 13

Mature B cells (but no activated) and naive T cells enter through arterial flow and can enter the node through the High endothelial Venule (HEV). Antigen, dendritic cells, and other lymphocytes can enter through the afferent lymphatic flow to intermingle with cells from blood near the HEV. All cells in the node leave through efferent lymphatic flow.

Question 14

What is a germinal center?

Answer 14

Location in the lymph node of B cell activation and proliferation. It is located around a follicular dendritic cell. Neighboring T cells participate in activation.

Question 15

Where are the following located?
ICAM
MAdCAM
VCAM

Answer 15

Integrins/addressins are all used with CAMs for directing lymphocytes.
ICAM - HEV or APC
* bindsLFA-1 integrin on all T cells
MAdCAM - Mucosal endothelium
VCAM - Vascular activated endothelium

Question 16

T-helper 1 cells release what cytokine to increase macrophage activity?

Answer 16

IFN-gamma

Question 17

T-helper 2 cells release what cytokine to cause isotype change to IgE to activate eosinophils?

Answer 17

IL4

Question 18

Th17 releases what to increase neutrophils?

Answer 18

IL-17

Question 19

Treg cell release what cytokine to suppress T cell activity?

Answer 19

IL-10

Question 20

What are the function of 2 protein granules released by cytotoxic T cells?

Answer 20

Perforin - creates hole in membrane

Granzymes - Serine proteases to activate apoptosis by caspases

Question 21

In B cell differentiations, what results from the following differentiation cytokines?
IFN-gamma
TGF-beta
IL-4
IL-2, IL-4, and IL-5 (same as proliferation cytokines)

Answer 21

IFN-gamma - IgG2a or IgG3
TGF-beta - IgA or IgG2b
IL-4 - IgE or IgG1
IL-2, IL-4, and IL-5 (same as proliferation cytokines) - IgM

Question 22

Killer T cells?

Answer 22

Recognizes lack of MHC I molecules, thus working with cytotoxic Tcells.