Adaptive Immune Development/Response

Question 1

What are the 2 zones of the lymph node?

Answer 1

1. B cell zone - follicle
2. T cell zone - paracortex

Question 2

How does lymph transport two and from the lymph node?

Answer 2

TO - afferent lymphatic
FROM - efferent lymphatic
drains Ag and lymph

Question 3

How do naive T cells move into lymphoid tissue (4 steps)

Answer 3

process called homing
1. rolling
2. activation
3. adhesion
4. diapedesis

Question 4

Describe the process of rolling

Answer 4

initiated with L-selectin (CD62L) on T cells and GlyCAM-1 on endothelial cells (MAdCAM-1 in mucosal)

Question 5

Describe the process of activation

Answer 5

chemokine such as CCL21 activating integrals such as LFA-1 increases affinity for its ligand ICAM-1/2

Question 6

Describe the process of adhesion

Answer 6

strong interaction between LFA-1 and ligands. LFA-1 molecules are reorganised to be concentrated in area of cell-cell contat

Question 7

Describe the process of diapedesis

Answer 7

cells extravasate by squeezing between endothelial cells. driven by chemotaxis

Question 8

What are some significant chemokines which are expressed in the lymph node?

Answer 8

chemokine gradient of CCL19/21 attracting lymphocytes with CCR7
high levels of CCL19/21 in paracortex
CXCL13 in follicles attract B cells (and some T cells) expressing CXCR5
DCs play large role in LN

Question 9

What is the interaction between DCs and T cells mediated by?

Answer 9

weak interactions between LFA-1 (T cell) and ICAM-1/2 (APC)
functional redundancy with CD2 (T cell)/CD58 (APC)