Micro 07 - Host Defenses Against Microbes

Front 1

Microbes elicit a variety of immune responses, many of which are __1__, but not __2__

Back 1

1. diagnostic

2. protective

*seroconversion during viral infections

Front 2

Immunity that is important during early infection in immunized hosts

Back 2

Innate immunity

Front 3

When is Adaptive Immunity most apparent?

Back 3

after Secondary Challenge of immune hosts

Front 4

Adaptive Immunity:
-__1__-specific recognition
-important in __2__ of many infections
-is the basis for all current __3__

Back 4

1. epitope
2. resolution
3. vaccines

Front 5

Define "Clearance"

Back 5

elimination of a microbe from the circulation or a particular tissue site

Front 6

Define "Killing"

Back 6

any mechanism using immune components to effect damage and death of the microbe

Front 7

Define "Resolution"

Back 7

final elimination of all the organisms from the host

Front 8

In what 2 instances may Resolution not occur?

Back 8

Chronic Latent infections

CGD patient who can't make a respiratory burst and just wall off the infection

Front 9

Specific receptor involved in innate immunity

Back 9

Toll-like receptor

Front 10

Ig's involved in Toxin Neutralization

Back 10

IgM, IgG, IgA

**MAG**

Front 11

Toxins that are more effectively neutralized

Back 11

Exotoxin > Endotoxins

Front 12

Toxins serve as excellent __1__ targets
-most toxins are __2__

Back 12

1. vaccine
2. proteins

Front 13

2 components of Virus Neutralization

Back 13

1. Serum (viremia) = cleared from blood

2. Mucosal Immunity = prevents their attachment to mucosal surface

Front 14

Phagocyte-mediated Extracellular Killing:
1. Effector cell
2. Killed organisms (2)

Back 14

1. Neutrophil

2. EC fungi and parasites

Front 15

2 groups of organisms killed by Opsonophagocytosis and Intracellular killing

Back 15

1. "pyogenic" bacteria
-Staph, Strep, Pseudomonas

2. EC fungi
-Candida, Aspergillus

Front 16

List 3 phagocytic receptors

Back 16

1. FcR (binds to Fc of IgG)
2. C3b receptor
3. Mannose receptor

Front 17

List 4 opsonins

Back 17

1. IgG
2. C3b
3. Mannose
4. LPS (on Gram-)

Front 18

By what mechanisms is intracellular killing performed by neutrophils?

Back 18

Respiratory burst

NO-dependent killing

Front 19

Macrophage-mediated intracellular killing:
- 2 types of organisms
- what is important for macrophage activation?

Back 19

1. Intracellular bacteria
*Rickettsia + Chlamydia = obligate
*BFLS-ella + LYM

2. Fungi
-Candida, Cryptococcus, Histoplasmosis

Th1 cytokines = IFN-gamma

Front 20

Pathogens killed by CTL-dependent killing

Back 20

1. viruses

2. Intracellular bacteria that escape the Phago(lyso)some
-Listeria monocytogenes, Francisella

Front 21

Eosinophil-mediated killing:
- immune components involved

- pathogens affected

Back 21

1. IgE antibody and ADCC

2. Parasites (intestinal Helminths)

*via lytic enzymes + Perforin

Front 22

Targets for NK-cell killing

Back 22

Latent viruses that inhibit MHC-I expression

Tumor cells

Front 23

NK cells are a major source of what?

Back 23

IFN-alph, beta, gamma

Front 24

2 major roles of Complement

Back 24

1. Opsonin = iC3b (most bacteria; many fungi)

2. Chemoattractant = C5a (attracts Neutrophils)

Front 25

2 pathogens in which Complement lysis is essential

Back 25

Neisseria (deficiency of C5-C9)

Haemophilus

Front 26

Cytokine that causes Apoptosis of infected cells

Back 26

TNF-alpha

Front 27

Defensins, cathelicidins, and other natural microbiocidals are especially important against these pathogens

Back 27

Anaerobic bacteria

Front 28

What are the 3 ways in which we can determine the ESSENTIAL protective immune mechanisms?

Back 28

1. infections in the IC'ed
2. MICROBIAL EVASION mechanisms underscore the most effective defense mechanisms of the host
3. Empiric evidence from successful VACCINES

Front 29

List 3 toxigenic bacteria

Back 29

Staphylococcus
Clostridium
Pseudomonas

Front 30

List the intracellular bacteria

Back 30

Obligate = Rickettsia and Chlamydia

Faculative = BFSL-ella + LYM
-brucella
-francisella
-Salmonella
-Legionella
-Listeria
-Yersinia
-Mycobateria

Front 31

List 3 latent/chronic viruses

What is one acute virus

Back 31

HSV
HCV
HIV

Influenza

Front 32

What are enveloped viruses susceptible to?

Back 32

Complement-mediated lysis

Front 33

Fungi that pose a significant immunological challenge

Back 33

Subcutaneous/Systemic
-Blastomyces
-Histoplasma
-Coccidiomycosis

Front 34

How are Protozoan parasites fought off?
-Plasmodium, Toxoplasma

Back 34

with Antibody

Front 35

How are GI or tissue helminths dealt with?
-Schistosoma, Ascaris

Back 35

IgE antibody and eosinophils or activated macrophages

Front 36

Examples of Protective Immunity against parasites:
-IgG antibody to __1__
-__2__ killing of Toxoplasma tachyzoites.
-IFN-gamma-dependent activation of macrophages for killing of __3__ (2)
-granuloma formation in response to __4__ eggs
-__5__ elimination of Schistosomes.

Back 36

1. Malaria merezoites
2. Th1-activated macrophage
3. Leishmania and Trichinella
4. Schistosome
5. Eosinophil + IgE-mediated

Front 37

5 major effectors used against extracellular bacteria

Back 37

1. Antibody
2. Complement
3. Neutrophil
4. Th2 cell
5. NK cells cytokines

Front 38

Defense effectors of IC bacteria

Back 38

++ Th1 cell
++ Macrophage
+ CTL
+ NK cell
+/- Neutrophil

Front 39

Antibodies are most effective against what types of infections? (2)

Back 39

1. Extracellular bacteria

2. Cytolytic viruses

*prevents entry and mediates clearance to a killing compartment

Front 40

What is Complement most effective at protecting against?

Back 40

1. LYSING Meningococcus and Enveloped Viruses

2. CLEARING all EC pathogens via opsonic iC3b

Front 41

What is the Th1 response most effective against?

Back 41

Intracellular pathogens (bacterial, viral, fungal) via activation of Macrophages and CTL

Front 42

What is CTL-mediated immunity most effective against?

Back 42

Intracellular pathogens (viral and some bacterial)

Front 43

What are Neutrophils most effective against?

Back 43

Extracellular bacteria and fungi

(chemotaxis, phagocytosis, respiratory bursts)

Front 44

What are NK cells most effective against?

Back 44

Viruses (IFN; lysis)
Bacteria (IFN-gamma)

*recognize cells lacking MHC-I

Front 45

Macrophages mediate responses to __1__ pathogens and clear __2__ pathogens

Back 45

1. intracellular (respiratory burst, NO)

2. Extracellular

Front 46

What are Respiratory bursts effective against?

Back 46

Phagocytized microbes
-staph
-Aspergillus

Front 47

Nitric Oxide is effective against?

Back 47

a limited # of microbes
-M. tb.
-Listeria

Front 48

What is IFN-alpha,beta most effective against?

Back 48

Viruses

Front 49

What is IFN-gamma most effective against?

Back 49

Intracellular bacteria, fungi, or parasites

(activates macrophages)

Front 50

Patients with Antibody deficiencies present with what infections and when?

Back 50

Extracellular bacterial infections at >6 months of age

Front 51

How do patients with Complement deficiencies present?

Back 51

Extracellular, Pyogenic bacterial infections

Front 52

How do patients with T cell deficiencies present?

Back 52

Intracellular pathogens (viral, fungal, parasitic) at <6 months of age

Front 53

How do Phagocytic cell deficiencies present?

Back 53

with selected organisms of low virulence (extracellular bacterial and fungal)

Front 54

If a person has low levels of IgG2, what are they susceptible to?

Back 54

Capsular organisms = Streptococcus Pneumonia = Gram + diplococci

*Some Killers Have Pretty Nice Capsules
-Strep pneumo
-Klebsiella
-H. influenza
-P. aeruginosa
-Neisseria meningitidis
-Cryptococcus neoformans

Front 55

What infection may occur if a patient has an IFN-gamma receptor deficiency?

Back 55

M. avium intracellulare

Front 56

What conditions could predispose to infection by Aspergillus? (4)

Back 56

1. Methotrexate/cyclophosphamide = neutropenia
2. HIV/AIDS
3. CGD; neutropenia
4. Glucocorticoid therapy

Front 57

Phagocytic deficiency can lead to infections by these 5 organisms

Back 57

Staph
Strep
H. influenza
Aspergillus
Candida

Front 58

Complement deficiencies can lead to infection by these 3 pathogens

Back 58

Staph
Strep
Neisseria

Front 59

T cell or CMI deficiency can lead to infection by these 8 pathogens

Back 59

Mycobateria
MAC
Listeria
Candida
Histoplasma
Pneumocystis
Herpes family (CMV,HSV,EBV)
JC virus

Front 60

B cell and Antibody deficiency can lead to infection by these 6 pathogens

Back 60

Staph
Strep
H. influenza
Enteroviruses
Influenza
RSV

Front 61

2 viruses that inhibit the expression of MHC

2 viruses that mimic cytokines or their receptors

Back 61

Herpes
CMV


Pox
EBV

Front 62

3 protective immune mechanisms that vaccines may provide

Back 62

1. Neutralizing antibodies
-microbial toxins
-viruses causing acute disease

2. Opsonizing antibodies to EC bacteria

3. Cellular Immunity to Intracellular bacteria and viruses

Front 63

Example of a vaccine that induces CELLULAR IMMUNITY (CMI)

Back 63

Measles and Mumps

Front 64

How are most vaccines developed?

Back 64

Emperically = derived by experiment

Front 65

Vaccines reduce __1__, but they rarely prevent __2__.
Many of the best vaccines induce __3__ antibodies.

Back 65

1. disease
2. infection
3. neutralizing

Front 66

Most vaccines are __1__; there are very few __2__ vaccines

Back 66

1. preemptive
2. therapeutic

Front 67

What are 2 therapeutic vaccines?

Back 67

Rabies

Hepatitis

Front 68

Current vaccines are all directed against __1__, not __2__.
We have few effective vaccines against __3__ microorganisms

Back 68

1. epitopes
2. microbial patterns
3. complex (i.e. parasites)

Front 69

What is an example of when a lethal dose is less than the immunizing dose?

Back 69

Tetanus toxoid

Front 70

Example of when an infection outpaces the immune response

Back 70

Rabies

Front 71

Example of when multiple antibody isotypes are advantageous

Back 71

HiB conjugate

Front 72

Example of when pre-exposure antibodies might prevent disease or spread of infection

Back 72

Polio

Front 73

2 vaccines that cause toxin neutralization

Back 73

Diphtheria
Tetanus

Front 74

2 vaccines that inhibit bacterial attachment

Back 74

Pertussis
Neisseria

Front 75

2 vaccines that elicit antibodies to Polysaccharides

Back 75

Hemophilus
Neisseria

Front 76

Virus vaccine that elicits Antibody neutralization of the virus

Back 76

Polio

Front 77

Virus vaccine that is presented as MHC-epitopes

Back 77

Measles
VZV

Front 78

When are parasite vaccines important?

Back 78

where reinfection is common
-Malaria
-Toxoplasmosis