Lecture 6 (Quiz 3)

Question 1

Variolation

Answer 1

First form of vaccination where scabs of small pox were ground up and blow into the nose. Began in 10th century China.

Question 2

Host Defenses

Answer 2

Complex network of tissues and effector cells including:

• Tissue barriers
• Chemical Defense
• Lymphatic System
• Diversity of WBCs: some stationary while others move, non-specific and specific

Question 3

Nonspecific Innate Immunity

Answer 3

• Immediate or rapid response
• Broad protection without specificity
• Lacks “memory”

Question 4

Specific Adaptive Immunity

Answer 4

• Takes weeks to develop
• Pathogen-specific
• “Memory” programmed is faster and stronger in response to subsequent exposures to the same pathogen

Question 5

Which lines of defense are innate?

Answer 5

First and second

Question 6

Which lines of defense are adaptive?

Answer 6

Third line

Question 7

First Line Defenses (4)

Answer 7

1. Physical Defense
2. Chemical Defense
3. Normal Microbiota
4. Genetics

Question 8

Physical Defense Include (2)

Answer 8

Physical barriers and mechanical defenses

Question 9

Types of Physical Barriers (3)

Answer 9

1. Skin
2. Mucous Membranes
3. Goblet Cells

Question 10

Skin

Answer 10

3 layers of skin act as a barrier made up of epidermis cells that are cemented together by keratin. Surface is salty, acidic, and sloughs off.

Question 11

Mucous Membranes

Answer 11

Line respiratory, intestinal, and genitourinary tracts. Can be ciliated or not to assist with with the removing of pathogens.

Question 12

Goblet Cells

Answer 12

Make sticky mucous that layers organ tracts. Made up of ciliated columnar epithelium for additional protection and can at times trap pathogens to be later removed by cilia in the mucous.

Question 13

Mechanical Defenses (4)

Answer 13

1. Shedding of skin cells
2. Mucociliary escalation
3. Flushing action - tears, sweat, urine, ear wax
4. Expelling of bacteria - diarrhea, vomiting, defecation

Question 14

Types of Chemical Defenses (2)

Answer 14

Enzymatic and Chemical

Question 15

Examples of Enzymatic Defense (2)

Answer 15

• Lysozymes in saliva

- Digestive enzymes in gastrointestinal tract

Question 16

Examples of Chemical Defenses (3)

Answer 16

• Acidic pH of stomach and vagina (increases in the elderly and in those who use antacids)
• Bile secreted into intestinal tract
• Endogenous and exogenous chemical mediators

Question 17

Endogenous Mediator

Answer 17

Something that our body makes that is antibacterial or antipathogenic. Ex: Sebaceous gland that makes sebum on the skin.

Question 18

Exogenous

Answer 18

Something not made by our body that fights a pathogen. Ex: Acid made from bacteria that live on our skin and eat the sebum.

Question 19

Normal Microbiota

Answer 19

Microbial life found in and on healthy people usually on the skin or mucous membranes. NOT found in deep tissues. 10^13 “self” cells and about 10x more bacteria in or on us.

Question 20

Acquisition of Normal Flora (2)

Answer 20

1. Lactobacilli - rapid growth in vagina before birth which becomes the first normal flora for most infants (doesn’t occur if delivered by C-section)
2. Other flora - from personal contact, breathing, and eating

Question 21

Defense Against Infectious Disease (3)

Answer 21

1. Occupy binding sites
2. Compete for available nutrients
3. Produce antimicrobial substances

Question 22

Normal Flora in Female Genitourinary Tract

Answer 22

Lactobacilli is the majority of microbiota in most women. Produce lactic acid which lowers the pH and protects the vagina from invading pathogens.

Question 23

Vaginal pH + Age

Answer 23

• Childhood/Menopause - slightly alkaline
• Child-bearing years - pH = 3.6-4.5 from the estrogen produced causing glycogen to be fed to the normal flora in the vagina which lowers the pH from making lactic acid
• During menstrual cycle, estrogen levels drop and the pH rises which makes the vagina more susceptible to infection

Question 24

Genetics Affects on Immunity (3)

Answer 24

1. Cell receptors required for infection - interspecies restrictions. Ex: not getting distemper from your pet
2. Intraspecies restrictions - Ex: innate resistance to HIV and limited spread of the bird flu
3. Cell Physiology & Resistance - Ex: sickle cell anemics having a natural resistance to malaria (important reason sickle cell anemia is still in population)

Question 25

Second Line Defenses (4)

Answer 25

1. Cellular 2. Antimicrobial Proteins 3. Inflammatory Response 4. Fever

Question 26

Cells involved in Cellular Defense (4)

Answer 26

1. Macrophages 2. Dendritic Cells 3. Neutrophils 4. Natural Killer Cells

Question 27

Macrophages

Answer 27

- Professional phagocytes - some move while others don't - Produce cytokines (chemical signals) that call other defense cells into area and activate them - Important in antigen processing and presenting (1st step in activating 3rd line defenses)

Question 28

Dendritic Cells

Answer 28

- Professional phagocytes that also secrete cytokines and process/present antigens - More talented than macrophages in activating and directing 3rd line defenses

Question 29

Types of Granulocytes (3)

Answer 29

1. Neutrophils 2. Eosinophils 3. Basophils

Question 30

Neutrophils

Answer 30

- Aka PMN - polymorphonuclear leukocytes (phagocytes) - Short-lived (only hours) - Don't multiply - Do NOT process or present antigens - Kill EXTRACELLULAR bacteria

Question 31

Neutrophils + Detecting Infection

Answer 31

- Adult produce 10^11 each day - Levels of PMN increase when dealing with bacterial infection - Increase of immature band cells (become PMN) cause a "shift to the left" seen with bacterial infection

Question 32

Granulocyte Stimulating Factor

Answer 32

- Aka GSF - Mechanism of Action: Glycoprotein that increases neutrophil production and activity - Indication: Neutropenia patients from chemotherapy, bone marrow transplants, and other diseases that cause neutropenia

Question 33

Granulocyte-Macrophage Colony Stimulating Face

Answer 33

- Aka GM-CSF - Mechanism of action: Also a glycoprotein that increases neutrophil production and activity. Has additional impact on antigen-presenting cells - Same indications as GSF but also includes stem cell transplants

Question 34

Two Types of Cell Movement

Answer 34

1. Chemotaxis | 2. Diapedesis

Question 35

Chemotaxis

Answer 35

- Movement of cell to site of infection - Phagocytes move along a chemokine gradient like a bread crumb trail - "Bread crumbs" = bacterial products, cytokines, complement factors

Question 36

Diapedesis

Answer 36

- Migration of cells out of blood - Squeeze between loosened endothelial cell junctions - Loosened from vasodilation and inflammation

Question 37

Factors Assisting with Pathogen Recognition (3)

Answer 37

1. Toll-like receptor (TLR) 2. Pathogen-associated molecule pattern (PAMP) 3. Pattern Recognition Receptors (PRR)

Question 38

Steps of Phagocytosis & Killing (4)

Answer 38

1. Attachment 2. Ingestion - phagocytosis 3. Creates phagosome that pumps H+ into the vesicle and drops the pH sometimes down to 4 4. Phagolysome - adds into enzymes, toxins, or oxygen radicals to break down contents

Question 39

Natural Killer Cells (NK)

Answer 39

- Important Defense against intracellular pathogens - Fights against viruses, bacteria - Also deals with tumor cell surveillance and destruction

Question 40

NK Action

Answer 40

- Attach and kill STRESSED host cells - Not a phagocyte - Recognize stress signals on cell's membrane - Attack and release toxic granule while causes cell death via apoptosis

Question 41

Lactoferrin/Transferrin

Answer 41

- Lactoferrin - found in secretions and WBCs - Transferrin - found in blood - Proteins that bind to iron and limit its availability for pathogen growth (bacteriostatic)

Question 42

Antimicrobial Peptides

Answer 42

- small peptides - can be produced by our cells or other pathogens - most tend to go after membrane but not the only mechanism they employ - attack pathogens that come into body

Question 43

Antiviral Interferons alpha & beta

Answer 43

Made by infected cells and released to signal neighboring cells

Question 44

Possible Interferon Responses (3)

Answer 44

1. Signals neighboring, uninfected cells to destroy RNA & decrease protein synthesis 2. Neighboring, infected cells are influenced to go through apoptosis 3. Activate immune cells

Question 45

Complement Systems

Answer 45

- 20-30 proteins produced by the liver - Innate "complement" to other immune cells - Tend to operate via cascade reactions - Focus on proteins C3b, C3a, & C5a

Question 46

Defense Mechanisms of Complement (4)

Answer 46

1. Lysis of Bacteria 2. Phagocyte chemotaxis 3. Bacteria Opsonization 4. Membrane Attack Complex * *Depends on what complement interacts with**

Question 47

Bacterial Opsonization

Answer 47

- "To get ready for dining" - Complement adds on factors like C3b which betters attaches to phagocytes and increases likelihood of it being eaten by said phaogcyte

Question 48

Membrane Attack Complex

Answer 48

- Insert or organize into a large poor that allows water and sodium ions to leave cell and potassium/chloride ions to enter the cell - Causes cell to eventually lyse - C3a & C5a act through this method and increasing pumping & inflammation response - Stimulates vasodilation by binding to mast cells or basophils which makes them release histamine - Also can act as bread crumbs for chemotaxis