Immunology - Lecture 3

Front 1

Name some cell types that have various PAMP receptors that bind directly to microbes.

Back 1

"HEP"
Hepatocytes
Epithelial Cells
Phagocytic Cells

Front 2

Which plasma proteins bind directly to PAMPS?

Back 2

C3, CRP, MBL, SAP

Front 3

What are DAMPs?

Back 3

Damage associated molecule patterns. Innate cells have receptors for DAMPs that bind to molecules released during tissue damage. They help macrophages manage the wound healing process.

Front 4

What initiates PAMP receptor cascades? Use TLR's as an example.

Back 4

Ligation of PAMP receptors initiate signal transduction cascades.

When TLR engages an extracellular pathogen, a TIR (Toll-IL-1receptor) signaling domain on the inside of the cell recruits "adaptor proteins," which activate transcription factors.

Front 5

What is NFkB's role in PAMP signal transduction cascades? What is the general result?

Back 5

After initiation through a TLR, NFkB travels to the nucleus and causes increased expression of
"CAC": cytokines, adhesion molecules and costimulators

It causes acute inflammation & stimulation of adaptive immunity.

Front 6

What is an IRF and what is its role in PAMP signal transduction cascades?

Back 6

After initiation by a TLR, IRF's (Interferon regulatory factors) cause an increase in the production of type 1 interferon IFN-a/b leading to an antiviral state.

Front 7

What are the two main type I interferon products of PAMP receptor signaling that help control intracellular infections?

Back 7

Cytokines IFN-a & IFN-b

Front 8

What cell types produce IFN alpha?

Back 8

IMBED
IFN-alpha:
macrophages, B-cells, epithelial cells, dendritic cells

Front 9

What cell type produces IFN beta?

Back 9

fibroblasts

Front 10

What cell types have receptors for type I interferons?

Back 10

Almost all cells have receptors for type I interferons and therefore all cells can respond to these ligands.

Front 11

What is the result of the signal transduction pathway activated by type 1 IFN/s?

Back 11

Binding of either INF's activates signal transduction pathways that result in production of enzymes that:

1. inhibit protein synthesis
2. degrade viral mRNA (antiviral state)

Front 12

Is a Natural Killer cell (NK cell) a member of the innate or adaptive immune response?

Back 12

Innate

Front 13

What are the two methods through which activated NK cells control infections? How are they activated?

Back 13

1. inducing apoptosis of infected cells through direct contact
2. Secreting cytokines like IFN-gamma that activate macrophages to phagocytose infected cells

NK cells are activated by a variety of receptors, like INF type I receptors, PAMP, etc.

Front 14

If a pathogen is extracellular, how can the pathogen activate an inflammatory response (influx of leukocytes) into tissue?

Back 14

It can bind to PAMP receptors on innate leukocytes residing within healthy tissues.

Front 15

Where are mast cells found?

Back 15

Mast cells (non-phagocytic) are resident cells in all CT.

They predominate in:
"SHRIMPS"
Submucosa/ lamina propria of GI tract
Hypodermis
Respiratory tract submucosa/lamina propria
I-(invalid, just needed a vowel...)
Mesentery
Papillary layer of dermis
Serous membranes

in serous membranes, in mesentery, in the papillary layer of the dermis, in hypodermic.

Think "raising the mast on a shrimp-ing boat"

Front 16

What activates mast cells?

Back 16

"CODAS"

C3a, C4a, C5a binding ot complement receptors in plasma membrane
Opiates that block neurokinin receptors that substance P binds to
DAMPs and PAMPs binding to receptors
Allergens binding to specific antibodies (IgE) already present on the mast cell surface
Substance P pain neurotransmitter released by nociceptors)

Front 17

Name some chemicals mast cells release?

Back 17

"PITCHS"
Prostaglantins and Leukotrienes
IL-4 (a cytokine)
Tryptase & other neutral proteases
Cytokines (TNF & other cytokines)
Histamine/Heparin
Serotonin

Front 18

What are the three actions of Histamine?

Back 18

1. smooth muscle contraction (bronchospasm/increased gut peristalsis)
2. neutrophil chemoattractant
3. local vasodilaiton

Front 19

How does Histamine cause vasodilation?

Back 19

Activates NO production in endothelial cells which relaxes arteriole xmm and prevents platelets from attaching to endothelium. This allows blood flow to slow and pool (leading to redness and heat production). As a result endothelial cells are pushed apart and there is an increased capillary permeability, leading to swelling (plasma leaks into tissues).

Front 20

What small role does serotonin play in the immune response?

Back 20

It is released by mast cells and causes local vasodilation by activating NO production in endothelial cells and stimulating nociceptors and substance P release = pain.

Front 21

What role does heparin play in mast cell immune response?

Back 21

Heparin is released from mast cell granules upon activation and temporarily prevents fibrin from forming (thrombin is inactivated).

Front 22

What are two functions of neutral proteases like tryptase in the mast cell immune response?

Back 22

1. cleaves C3 to C3a which stimulates more mast cell degranulation

2. cleaves fibronectin and type IV collagen to degrade the basal lamina of capillary beds, leading to swelling and attraction of fibroblasts for wound healing/scar tissue formation and activation of coagulation cascades (blood clot formed to wall off infection).