Basic Immunology

Question 1

List two IgE receptors

Answer 1

1. Low affinity IgE receptor: on B cells, and enhance B cell ability to present antigen to T cell
2. High affinity IgE receptor: on mast cells and basophils and APCs

Question 2

Two cytokines needed to IgE class switching

Answer 2

IL4 and IL13

Question 3

Two cytokines that prolong eos survival

Answer 3

IL-3, IL-5 and GM CSF

Question 4

What is needed for eos adhesion

Answer 4

Selectin L and E needed for slow rolling and tethering

Integrin VLA4 binds to VCAM and LFA 1 binds to ICAM1 to adhere tightly to the endothelium

Question 5

What are the categories of chemokines?

Answer 5

1. CC - migration of monocytes, lymphocytes and other cell types
2. CXC (have 1 AA btwn the two cysteine residues) - neutrophil migration

Question 6

TH2 Cytokines (3)

Answer 6

IL4, IL5, IL10

Question 7

TH1 cytokines (5)

Answer 7

IL2, INy, LTa, TNFb, TNFa, GM-CSF

Question 8

DDx for elevated IgE

Answer 8

1. Parasite
2. Infections
3. Cutaneous disease
4. Neoplastic disease
5. PID

Question 9

name 3 mechanisms of basophil activation and the effector mediators in each

Answer 9

1. anaphylaxis - IgE mediated cross linking leading to release of mast called and basophil activation
2. infections - parasites and helminths activate basophils by release of pro inflammatory mediators
3. allergic disease - basophils are activated by asthma and AR and antigen specific T cell inflammation

Question 10

mechanism of FPIES

Answer 10

• antigen specific t cell inflammation leading to increased gastric permeability and fluid shifts

Question 11

what is cytokine release syndrome?

Answer 11

similar to TLS

caused by Rituximab most commonly leads to cytokine release causing fevers, chills, rigors, and hypotension

Question 12

TLR4

name the ligand and cellular distribution

Answer 12

TLR4- LPS- macs, DCs, mast cells

Question 13

TLR3
ligand
cell

Answer 13

TLR3- dsRNA (viruses)

NK cells

Question 14

TLR5

Answer 14

flagellin

intestinal epithelium

Question 15

TLR7

Answer 15

ssRNA 
DC
NK cells
Eos
B cells

Question 16

TLR8

Answer 16

ssRNA

NK cells

Question 17

TLR9

Answer 17

DNA with unmethylated CpG
DCs, eos, B cells, basophils

Herpes virus

Question 18

Name the cytokines involved in acute and chronic AD

Answer 18

acute - is a TH2 predominant response with IL-4,5,13

chronic becomes a TH1 predominant response with IDECs, IL-12, IL-18
TH1 secretes IFN-g, IL-5 and IL-31

Question 19

molecules needed for firm adhesion of neutrophils in the endothelium

Answer 19

1. slow rolling - needs TNF and IL1 which upregulates E selectin
2. tight binding - needs B2 integrins (CD11:CD18) upregulated on neutrophil surface
   binding of ICAM1 slows down rolling to mediate firm adhesion
3. Diapedesis
   - cell crawls through junctions between endothelial cells and migrates through
   - LAD1 is caused by defect in CD18 subunit

Question 20

TSLP is secreted by what cells and what are the effects?

Answer 20

Thymic stromal lymphopoeitin

1. secreted by keratinocytes and epithelial cells
2. drives TH2 cell activation, activates mast cells and regulates basophil hematopoesis