15: Manipulation of Immune Responses

Question 1

Variolation

Answer 1

Delivery of initial smallpox vaccine either intranasally or intradermally (via a scratch on the arm)

Question 2

Vaccinia

Answer 2

Another name for the virus used to vaccinate against smallpox

Question 3

Vaccination

Answer 3

Deliberate immunization that induces immune responses

Question 4

Immunization

Answer 4

Deliverate provocation of an acquired immune response by introducing antigen into the body

Question 5

By what methods are inactivated vaccines killed?

Answer 5

Chemical treatment, heat, or irradiation

Question 6

What is an attenuated vaccine?

Answer 6

A vaccine that employs weakened pathogens as the immunogen so that the pathogen’s ability to cause disease is weakened or destroyed

Question 7

What is a subunit vaccine?

Answer 7

A vaccine that employs only part of the pathogen as the vaccine immunogen

Question 8

Toxoid

Answer 8

Inactivated toxin used as a vaccine immunogen whose toxic activity has been destroyed

Question 9

How was the first completely effective vaccine formulated?

Answer 9

1. Jenner noticed that cowpox produced effects that looked like a milder version of smallpox
2. Cowpox was used as a vaccine for smallpox
3. This induced antibodies against cowpox surface antigens, which could bind to and neutralize the smallpox virus too

Question 10

Bacterial vaccines can be composed of __________.

Answer 10

Whole bacteria, secreted toxins, or polysaccharide capsule material

Question 11

T or F: Most bacterial strains are attenuated.

Answer 11

F: Very few attenuated bacterial strains currently exist

Question 12

What is the most widely used whole live bacterial vaccine?

Answer 12

BCG vaccine – derived from a bovine strain of Mycobacterium tuberculosis

Question 13

What type of vaccine is the DTP (diphtheria-tetanus-pertussis) vaccine?

Answer 13

Killed subunits/toxoids

Question 14

What type of vaccine is the inactivated polio vaccine?

Answer 14

Whole killed virions

Question 15

What type of vaccine is MMR (measles/mumps/rubella)?

Answer 15

Live attenuated virus

Question 16

What type of vaccine is pneumococcal conjugate?

Answer 16

Heptavalent/diptheria

Question 17

What type of vaccine is Haemophilus B conjugate?

Answer 17

Diptheria protein conjugate

Question 18

What type of vaccine is the hepatitis B vaccine?

Answer 18

Subunit

Question 19

What type of vaccine is the varicella vaccine?

Answer 19

Live attenuated

Question 20

What type of vaccine is the rotavirus vaccine?

Answer 20

Live attenuated

Question 21

What type of vaccine is the flu shot?

Answer 21

Killed or live attenuated

Question 22

What type of vaccine is the meningococcus C vaccine?

Answer 22

Conjugated capsule subunit

Question 23

What type of vaccine is the HPV vaccine?

Answer 23

Gardasil – virus-like particles

Question 24

T or F: Killed viruses elicit a large CD8 T cell response.

Answer 24

F: Attenuated viruses elicit a large CD8 T cell response, and killed viruses don’t

Question 25

What type of vaccine is the yellow fever vaccine?

Answer 25

Live attenuated virus

Question 26

What type of vaccine is the typhoid fever vaccine?

Answer 26

Vi polysaccharide subunit vaccines or live-attenuated oral vaccine

Question 27

What type of vaccine is the meningitis vaccine?

Answer 27

Purified capsular polysaccharide or H.influenzae polysaccharide conjugated to protein (depending on the strain)

Question 28

What type of vaccine is the bacterial pneumonia vaccine?

Answer 28

Purified capsular polysaccharide

Question 29

What type of vaccine are the cholera and plague vaccines?

Answer 29

Killed bacteria or cell extract

Question 30

What is unique about the Tuberculosis vaccine?

Answer 30

It is an attenuated vaccine, which is surprising since attenuated vaccines are typically for CD8 T cell response and TB mostly uses a TH1 immune response (to activate macrophages and form granulomas).

Question 31

What 6 characteristics are important for an effective vaccine?

Answer 31

1. Safe 2. Protective 3. Gives sustained protection 4. Induces neutralizing antibody 5. Induces protective T cells 6. Practical considerations (cost, side effects, administration)

Question 32

Why would you want a vaccine to induce neutralizing antibodies?

Answer 32

Some pathogens infect cells that cannot be replaced, and neutralizing antibodies prevent infection of such cells

Question 33

What is the goal of vaccination?

Answer 33

To trick the immune system to produce responses to a vaccine like it's responding to a pathogen

Question 34

What are the 3 big factors that make creating an effective vaccine difficult?

Answer 34

1. Route and amount of exposure 2. Tolerance vs. responsiveness 3. Identification of protective determinants

Question 35

T or F: Most anti-viral vaccines are live-attenuated vaccines.

Answer 35

T

Question 36

Production of strong immune responses to an antigen almost always requires that the antigen be mixed with ______ prior to administration.

Answer 36

An adjuvant

Question 37

Adjuvant

Answer 37

Any substance that enhances the immunogenicity of an antigen

Question 38

T or F: Parenteral immunization promotes strong systemic response, but it cannot prime mucosal responses.

Answer 38

T

Question 39

T or F: Mucosal immunization can produce strong mucosal response, but it cannot prime systemic responses.

Answer 39

F: Mucosal can elicit both mucosal and systemic responses

Question 40

What is the most effective parenteral route for eliciting immune response? Least effective?

Answer 40

Most effective: SubQ | Least effective: IV

Question 41

Antigen presentation to naive T cells must be accompanied by ______.

Answer 41

Co-stimulation

Question 42

T or F: Immune response to components of a pathogen does not ensure protective immunity.

Answer 42

T

Question 43

What are two broad classifications of vaccines?

Answer 43

1. Whole pathogen viruses | 2. Subunit vaccines

Question 44

What are subunit vaccines?

Answer 44

- Individual or mixtures of pathogen-derived components - Recombinant forms of pathogen-derived components - Recombinant live vectors expressing components of a pathogen

Question 45

What does depot formation do?

Answer 45

Increases the length of exposure of the immune system to an antigen by releasing the antigen slowly over an extended period of time

Question 46

T or F: Often adjuvants turn a soluble protein antigen into a particulate antigen that is more readily ingested by antigen-presenting cells.

Answer 46

T

Question 47

What are some adjuvants that specifically elicit mucosal immune responses?

Answer 47

Cholera toxin, tetanus toxin, and E.coli lymphotoxin

Question 48

What is Freund's adjuvant composed of?

Answer 48

Mineral oil (depot formation) and mycobacterial cell wall components (source of PAMPs for inflammation induction)

Question 49

What is a liposome?

Answer 49

Highly stable closed vesicle formed by a single bilayer of phospholipids

Question 50

What do ISCOMs do?

Answer 50

Deliver immunogens directly to the cytoplasm of host cells

Question 51

T or F: Attenuated vaccines are typically more effective than killed vaccines.

Answer 51

T

Question 52

What are 2 methods of attenuation?

Answer 52

1. Grow human viral pathogen in cells of non-human origin | 2. Mutate viruses using recombinant DNA (so that virulent genes can be deleted or mutated)

Question 53

How are DNA vaccines typically administered?

Answer 53

Intramuscularly or intranasally

Question 54

What is an example of a recombinant attenuated viral vaccine that is efficacious?

Answer 54

Rotovirus vaccine (Rotarix and Rotateq)

Question 55

How is rotovirus similar to influenza?

Answer 55

1. Segmented genome | 2. Antibody responses directed against surface proteins of the virus are protective via neutralization

Question 56

How can cytokine environment shape developing acquired immune responses?

Answer 56

Two types of effector CD4 T cells perform different roles in the development of acquired immunity

Question 57

T or F: Cytokines can be administered therapeutically to alter the outcome of an infection.

Answer 57

T (example: Leishmania and IL-4)