Module 2 Unit 1: Nonspecific and innate defense mechanisms

Question 1

Defends the body against microbes during the first few hours or days after infection

Answer 1

Innate Immunity

Question 2

Mediated by mechanisms that are in place even before infection and facilitate rapid responses to invading microbes

Answer 2

Innate Immunity

Question 3

Cardinal feature of the adaptive immune system

Answer 3

Memory

Question 4

TRUE or FALSE: The adaptive immune system does not remember prior encounters with microbes and resets to baseline after each encounter

Answer 4

FALSE

Innate Immune System

Question 5

This type of immunity develops as a response to infection and adapts to the infection

Answer 5

Adaptive Immunity

Question 6

Recognizes and reacts to a large number of microbial and nonmicrobial substances (antigens)

Answer 6

Adaptive Immunity

Question 7

Phagocytes express receptors for bacterial endotoxin known as _______ and other receptors for ________, which are present in bacterial cell walls

Answer 7

Lipopolysaccharide (LPS), Peptidoglycans

Question 8

Phagocyte receptors also recognize ________ in bacterial glycoproteins

Answer 8

Terminal mannose residues

Question 9

Microbial molecules that stimulate innate immunity

Answer 9

Pathogen-associated molecular patterns (PAMPs)

Question 10

Receptors of innate immunity that recognize shared structures

Answer 10

Pattern recognition receptors (PRRs)

Question 11

TRUE or FALSE: The components of innate immunity have evolved to recognize structures of microbes that are often essential for the survival and infectivity of microbes

Answer 11

True

Question 12

These are molecules recognized by the innate immune system that are released from damaged or necrotic host cells

Answer 12

Damage-associated molecular patterns (DAMPs)

Question 13

2 specific receptors in the adaptive immune system capable of recognizing millions of antigens

Answer 13

Immunoglobulin (Ig)

T cell receptors (TCRs)

Question 14

Cells capable of recognizing self-antigens in the adaptive immune system
* They die or are inactivated on encounter with self-antigens

Answer 14

Lymphocytes

Question 15

3 strategies done to deal with threats posed by microbes

Answer 15

1. Avoidance
2. Resistance
3. Tolerance

Question 16

This mechanism prevents exposure to microbes and includes both anatomic barriers and behavior modifications

Answer 16

Avoidance mechanism

Question 17

Aimed at reducing or eliminating pathogens

Answer 17

Resistance

Question 18

Molecular and cellular functions suited to resist diff. categories of pathogens

Answer 18

Mediators or effector mechanisms

Question 19

Responses that enhance a tissue’s capacity to resist damage induced by microbes

Answer 19

Tolerance

Question 20

Defenses provided by specialized cells that have the ability to recognize, sequester, and eliminate various types of organisms or harmful substances

Answer 20

Cell-mediated immunity

Question 21

Cell-free defenses provided by soluble macromolecules that circulate in the blood and extracellular fluid, and are inhospitable to foreign invaders

Answer 21

Humoral immunity

Question 22

Earliest defense mechanism active at the portals of entry, providing physical barriers and antimicrobial molecules and lymphoid cells

Answer 22

Epithelia

Question 23

Microbes that breach epithelia, as well as dead cells in tissues, are detected by

Answer 23

Macrophages
Dendritic cells
Mast cells

Question 24

Initiate the process of inflamm.

Answer 24

Cytokines

Question 25

These react against microbes and promote their destruction

Answer 25

Plasma proteins

Question 26

These are produced by viruses; inhibit infection of other cells and the killing of infected cells by NK cells

Answer 26

Interferons

Question 27

General Features of Innate Immunity

Answer 27

``` Barrier defense Complement activation Pattern recognition Inflammation Phagocytosis Target cell lysis ```

Question 28

These take action once invaders breach the barriers as a result of pattern recognition mediated by the binding of PRMs to PAMPs furnished by pathogens and to DAMPs emanating from damaged host cells

Answer 28

Innate leukocytes

Question 29

PRMs expressed by innate leukocytes

Answer 29

Pattern recognition receptors (PRRs)

Question 30

PRRs are located in the _____ of an innate leukocyte, or are soluble molecules free in the leukocyte's cytoplasm, or are fixed in the membranes of _____

Answer 30

plasma membrane, endosomes

Question 31

These activate events responsible for the influx of innate and adaptive leukocytes into the site of injury or infection

Answer 31

Proinflammatory cytokines

Question 32

TRUE or FALSE: Like acute inflammation, chronic inflammation is a normal process, so there is nothing to worry about and will reside on its own.

Answer 32

False | Prolonged inflammation is immunopathic and undermines homeostasis

Question 33

Phagocytosis translates to

Answer 33

"eating of cells"

Question 34

Phagocytosis is carried out by 3 types of PRR-expressing cells namely

Answer 34

Neutrophils Dendritic cells Macrophages

Question 35

_____ and _____ engulf pathogens, dead host cells, cellular debris, and host macromolecules

Answer 35

Macrophages, Dendritic cells

Question 36

Cells that carry out target cell lysis

Answer 36

Neutrophils Macrophages NK cells

Question 37

Cancer cells and infected cells express these components on their surfaces that mark them as target cells for destruction

Answer 37

DAMPs and/or PAMPs

Question 38

A phospholipid-based substance made in the lung that acts to trap microbes and can directly lyse bacteria

Answer 38

Pulmonary surfactant

Question 39

A prominent enzyme in tears and saliva that breaks down peptidoglycan in the cell walls of gram-positive bacteria

Answer 39

Lysozyme

Question 40

Lysozymes lack _____, making them a prototype of an innate immune protein since they do not affect host cells

Answer 40

Peptidoglycan

Question 41

Lysozyme is made by

Answer 41

epithelial cells, phagocytes, and Paneth cells

Question 42

An ancient form of defense because they are found in most species

Answer 42

Antimicrobial peptides

Question 43

3 classes of antimicrobial peptides

Answer 43

1. Defensins 2. Catelicidins 3. Histatins

Question 44

Key property of defensins | * Underly their specificity for pathogenic membranes

Answer 44

Amphipathicity

Question 45

30-40 amino acid peptides that have 3 disulfide bonds

Answer 45

Defensins

Question 46

Alpha defensin produced by Paneth cells

Answer 46

Cryptidins

Question 47

Neutrophils produce _____ and store them in primary granules

Answer 47

alpha-defensins

Question 48

Type of defensin made in the urogenital and respiratory tracts, skin, and tongue

Answer 48

beta-defensins

Question 49

Antimicrobial peptide class that lacks disulfide bonds in the alpha-defensins

Answer 49

Cathelicidins

Question 50

Antimicrobial peptide class produced by epithelial cells, phagocytes, and keratinocytes

Answer 50

Cathelicidins

Question 51

Antimicrobial peptide class produced in the parotid, sublingual, and submandibular glands in the oral cavity

Answer 51

Histatins

Question 52

Histidine-rich and target fungal membranes

Answer 52

Histatins

Question 53

A small protein of the S-100 family with potent antimicrobial activity against E. coli

Answer 53

Psoriasin

Question 54

S-100 protein that kills S. aureus | * related to psoriasin

Answer 54

Calprotectin

Question 55

Bind carbohydrates on bacterial cell walls, preventing them from contacting the intestinal epithelial cells; are also directly bactericidal

Answer 55

RegIII proteins

Question 56

2 surfactant proteins that are members of a class of microbe-binding proteins (collections); present in the lungs and secretions of other mucosal epithelia

Answer 56

SP-A & SP-D

Question 57

Prevent infection by blocking and modifying surface components and promoting pathogen clearance

Answer 57

SP-A & SP-D

Question 58

Binds the complex polysaccharides coating many of the capsulated forms * Klebsiella pneumoniae

Answer 58

SP-A

Question 59

Binds the exposed cell wall lipopolysaccharide of the non-encapsulated form * Klebsiella pneumoniae

Answer 59

SP-D