I and D

Question 1

Name key structures of bacteria

Answer 1

Double stranded DNA, RNA, Proteins and Plasmids that encode antibiotic resistance
No organelles
Ribosomes (30s/50s) translate genome into proteins

Question 2

What is Horizontal gene transfer?

Answer 2

Horizontal gene transfer is how bacteria share information such as pathogenic traits, antibiotic resistance and virulance factors

Question 3

Describe gram positive and gram negative bacteria

Answer 3

Gram Positive Bac: Thick cell walls that stain purple

Gram Negative Bac: Thin cell wall with additional outer membrane that stain poorly and remain pink.

Question 4

What’s so special about the outer layer of gram neg bacteria?

Answer 4

The outer membrane of gram negative bacteria has lipopolysaccharides (LPS) and can be resistant to a lot of antibiotics. Breakdown of the LPS can lead to shock known as endotoxin

Question 5

What is Selective toxicity?

Answer 5

Selective toxicity means that the drug must be more toxic to the microbe than to the person.
Major targets of antibiotic medication

Question 6

What are the main antibacterial targets?

Answer 6

Outer membrane (LPS)
Cell wall (transpeptidase)
Nucleic acid (DNA topoisomerase & RNA polymerase)
Ribosome Protein synthesis (30s/50s)

Question 7

What are the main antifungal targets?

Answer 7

Fungal cell wall (Beta glucan synthesis)
Fungal membrane (Ergosterol)
Nucleic acid (DNA and RNA synthesis)
Cytoskeleton (Microtubules)

Question 8

What are the main antiviral targets?

Answer 8

Entry and exit
Replication
Processing (protease inhibitor)

Question 9

What are the main anti-helmintic targets?

Answer 9

Paralysis

Microtubules

Question 10

What do TLRs 2, 4, 5, and 9 each detect?

Answer 10

TLR2 detects fungi and gram pos bacteria
(peptidoglycan/lipoteichoic acid)

TLR4 detects gram negative bacteria (LPS)

TLR5 detects flagellin

TLR9 detects viruses (unmethylated CpG DNA)

Question 11

Name the three types of cytokines, who produces them and what they stimulate

Answer 11

• TNFalpha, produced by mast cells and macrophages; stimulates local and systemic inflammation
• IL-1, produced by many cells; stimulates production of inflammatory mediators
• IL-6, produced by macrophages (and others); stimulates IL-17 T-cells

Question 12

Name the two types of chemokines, who produces them, and describe their function

Answer 12

1. IL-8 produced by neutrophils, tell WBC where to go

2. MCP-1/CCL2 produced by monocytes, ttell WBC where to go

Question 13

What are he effects of leukotrienes and protaglandins?

Answer 13

Vasodilitation and bronchoconstriction

Question 14

What is the role of anti-viral cytokines?

Answer 14

To respond to viruses and produce “anti-viral” states in adjacent cells that slows the spread of the virus.

Question 15

Identify the major resident innate leukocyte types

Answer 15

1. Macrophages
2. Mast cells
3. Dendritic cells
4. Natural killer cells

Question 16

What is the function and mechanism of action of mast cells?

Answer 16

live near blood vessels and kick-start inflammation by releasing TNFalpha, histamines, prostaglandins, and leukotrienes –> endothelial activation, vasodilitation, and vascular permeability and smooth muscle contraction

Question 17

What is the function and mechanism of action of macrophages?

Answer 17

They eat stuff and when PRRs are activated they release cytokines and chemokines to promote inflammation; kill via endocytosis of microbe then phagolysosome forms producing ROS and NO to kill the microbe.

Question 18

What is the function and mechanism of action of dendritic cells?

Answer 18

Bridge between the innate and adaptive immune system; “See, eat, show” in MCH molecules; produce cytokines and chemokines; collect information and provide information to other cell types for appropriate response

Question 19

What is the function and mechanism of action of natural killer cells?

Answer 19

They act like T-cells but are much fast and less potent.

Question 20

List the Four steps of extravasation

Answer 20

1. Selectins (adhesion molecule)–> slow down signal with low affinity; when rapidly moving cells brush up against the vessel wall, selectins can capture their ligands
2. Chemokines (chemotactic factor) –> stop signals
3. Integrin (adhesion molecule) –> stop (glue like); ligands are called Cellular Adhesion Molecules (CAMs)
4. Multiple (chemotactic factor) –> guide molecule into tissue

Question 21

Deficiencies in immune cell migration cause increased bacterial and fungal infections. Name the two diseases, their deficiencies and explain why the person is infection prone.

Answer 21

Leukocyte adhesion deficiency type 1 (LAD-1), deficient in CD-18.

Leukocyte adhesion deficiency type 2 (LAD-2), deficiency in selectin ligand

Infections are caused by lack of neutrophils (inability to produce pus)

Question 22

Name 4 key players and their role in the complement pathway

Answer 22

1. C3a –> inflammation
2. C3b –> opsonization and phagocytosis
3. C5a –> Inflammation
4. Molecular attach complex –> hole in bacteria cell wall/bacterial lysis

Question 23

Describe how cytokines released from macrophages act locally

Answer 23

By activating phagocytosis, oxidation species, and prostaglandins. TNF and Il-1 activate endothelial cells which leads to vasodilitation, increased permeability, and increased CAMs and chemokines (CCl-2 and IL-8)

Question 24

Describe how cytokines released from macrophages act systemically

Answer 24

IL-1, IL-6, TNF –> induce fever, increased cardiac output & increase WBC count and acute phase proteins from liver

Question 25

What are the two main roles of the complement system?

Answer 25

1. Opsonization which produces C3b to bind to the outside of bacteria making it easier and tastier for phagocytes 2. Cytolysis from C5-C9 which forms MAC to punch a hole in the bacteria's cell wall

Question 26

Name a few similarities between the classical pathway and the lectin pathway. And why is the alternative pathway so different?

Answer 26

They are both... 1. activated by the presence of a pathogen 2. Form complexes in the beginning 3. Use many of the same C's The alternative pathway is different bc it is activated by spontaneous hydrolysis and is not good at differentiating self from non-self.

Question 27

TLR 2, TLR4, and TLR9 recognize what pathogens?

Answer 27

TLR2 --> peptidoglycan/lipoteichoic aicd TLR4 --> LPS TLR9 --> Unmethylated CpG DNA

Question 28

TLR signal through _____ activating ______ and ______

Answer 28

TLR signal through MyD88 activating NFkappaB and interferon response factor (IRF)

Question 29

Name the 3 major cytokines

Answer 29

TNFalpha IL-1 IL-6

Question 30

What two cells produce TNFalpha and describe TNFalpha's response on the body

Answer 30

Mast cells and macrophages produce them. Local response: active phagocytosis, oxidative species and prostaglandins Systemic response: fever, hypotension, and thrombosis

Question 31

What is primary role of chemokines? and what specific cytokines are produced by neutrophils and monocytes?

Answer 31

Primary role is to tell WBCs where to go. Neutrophils produce IL-8 Monocytes produce MCP-1/CCL2

Question 32

What do leukotrienes and prostaglandins cause?

Answer 32

Vasodilation, bronchoconstriction and neutrophil chemotaxis.

Question 33

What do Mast cells produce?

Answer 33

Mast cells produce: TNFalpha, histamines, leukotrienes and prostaglandins

Question 34

What is the role of macrophages?

Answer 34

Eat stuff and when PRRs are activated they release cytokines and chemokines; they also form phagolysosomes and produce ROS and NO to kill microbe

Question 35

What is the role of dendritic cells?

Answer 35

"see, eat, show" in MCH molecules