Exam 1: Immune Response to Viral Infections

Question 1

What does the interaction between host and virus affecting development and outcome of an infection includes?

Answer 1

Host’s primary physical barriers
Host’s immunological ability to control and eliminate the invading viruses
Viral ability to evade destruction
Ability of virus to spread in the body

Question 2

What are the 2 types of host response to virus infection?

Answer 2

Non-specific

Specific

Question 3

What is the non-specific host response in the skin?

Answer 3

Intact, impermeable barrier

Question 4

What is the non-specific host response in the respiratory system?

Answer 4

Cilia, mucous

Question 5

What is the non-specific host response in the GI tract?

Answer 5

Acid, lymphoid tissue

Question 6

What is the non-specific host response in the urinary tract?

Answer 6

Flushing effect of urine flow

Question 7

What is the on-specific host response in conjunctiva?

Answer 7

Tears

Question 8

What is the non-specific host response for phagocytosis?

Answer 8

Neutrophils, macrophages

Question 9

What is the non-specific host response for interferons?

Answer 9

Help overcome virus infections

Question 10

What is the specific humoral response to virus infections?

Answer 10

Immunoglobulins
Neutralize virus infectivity
Elimination of infectious virus
Mediated by plasma cells (B-lymphocytes)

Question 11

What is an antigen?

Answer 11

A molecule which induces the formation of antibdoy

Question 12

What is an epitope?

Answer 12

A single antigenic determinant as a smallest unit of antigen

Question 13

What is an antibody?

Answer 13

A molecule produced by animals in response to antigen

Question 14

What is humoral immunity?

Answer 14

B lymphocytes respond to an antigenic stimulus by producing and secreting specific immunoglobulins called antibodies

Question 15

What is cell-mediated immunity?

Answer 15

Responds to an antigenic stimulus by the activation of several kinds of T lymphocytes and the production and secretion of several kinds of lymphokines

Question 16

What happens when an immune system goes wrong?

Answer 16

Causes tissue damage in vital organs

Virus evades the immune system and establishes a persistent infection

Question 17

Describe IgM

Answer 17

Earliest antibody produced
Pentamer of 5 IgG molecules
Formed after a week of infection
Persists for 4-6 weeks
Does not cross the placenta from dam to fetus in any speices

Question 18

Describe IgG

Answer 18

Formed later than IgM
Persists for months or years
Responsible for immunity against reinfection

Question 19

Describe IgA

Answer 19

Dimer of 2 IgG molecules
Found in body secretions (saliva, respiratory secretions, tears, and intestinal contents)
Important resistance to infection of the respiratory, intestinal, and urogenital tracts
Not routinely measured

Question 20

What is cellular immune response?

Answer 20

Elimination of virus infected cells

Mediated by T-lymphocytes, macrophages, neutrophils, and cytokines

Question 21

What do T helper cells (Th) do?

Answer 21

Stimulate cytotoxic cellular response and activate B cells

Question 22

What do T suppressor cells (Ts) do?

Answer 22

Control and regulate the cytotoxic cellular response by suppressing Th cells

Question 23

What are cytotoxic T cells (Tc)?

Answer 23

Main effector cells which kill virus-infected target cells

Question 24

What do delayed hypersensitivity T cells (Td) do?

Answer 24

Release macrophage activation factor

Question 25

What do NK cells do?

Answer 25

Direct killing of virus infected cells | No memory, no MHC restriction, and no dependence on antibody

Question 26

What does interleukin do?

Answer 26

Modulate immune response

Question 27

What are antigen presenting cells?

Answer 27

A variety of cell types which carry antigen in a form that can stimulate lymphocytes Monocytes/macrophages and dendritic cells

Question 28

Where are MHC class I glycoproteins found?

Answer 28

The plasma membrane of most cell types

Question 29

Where are MHC class II glycoproteins found?

Answer 29

APCs

Question 30

What is artificial passive immunization?

Answer 30

Injection of antibodies that can temporarily protects infection

Question 31

What is natural passive immunity?

Answer 31

The transfer of maternal antibody from dam to fetus or newborn

Question 32

What antibody can cross the placenta?

Answer 32

IgG

Question 33

What animals is postnatal transfer (colostrum) important for?

Answer 33

Domestic animals

Question 34

What is the most applicable way of preventing viral disease?

Answer 34

Immunization

Question 35

Describe live-virus vaccines

Answer 35

Replicates in the host, induce a lasting immune response without causing disease Produce subclinical infection

Question 36

What is the administration routes of live-virus vaccines?

Answer 36

``` Subcutaneous Intramuscular Oral Aerosol Eye drop Drinking water ```

Question 37

What are naturally occurring viruses used as a vaccine?

Answer 37

Cowpox for small pox Herpesvirus of turkeys for Marek's disease vaccine in chickens Bovine rotavirus used to protect porcine rotavirus infection in piglets

Question 38

Describe virulent viruses used as vaccines

Answer 38

Given by an unnatural route Wild-type infectious laryngotracheitis virus given by blushing cloaca ---produces minimal diseases but induces good immunity

Question 39

How do we get attenuated live virus vaccines?

Answer 39

By serial passage through cell cultures, laboratory animals, or embryonic eggs

Question 40

What do virus-vectored vaccines use?

Answer 40

Vectors to carry the genes for the protective antigens of other viruses

Question 41

What are examples of virus-vectored vaccines?

Answer 41

Folwpox, adenoviruses, herperviruses | Vaccinia-rabies constructs used for vaccination of foxes and raccoons

Question 42

What are inactivated vaccines made from?

Answer 42

Virulent virus and use chemical or physical agents to destroy infectivity while maintaining immunogenicity

Question 43

What do virus subunit vaccines produce?

Answer 43

Large amounts of viral protein by recombinant DNA technology

Question 44

What is the administration route for a live vaccine?

Answer 44

Natural or injection

Question 45

What is the administration route for an inactivated vaccine?

Answer 45

Injection

Question 46

What is the level of antigen per dose in live vaccines?

Answer 46

Low

Question 47

What is the level of antigen per dose in inactivated vaccines?

Answer 47

High

Question 48

What is the cost of live vaccines?

Answer 48

Low

Question 49

What is the cost of inactivated vaccines?

Answer 49

High

Question 50

Is an adjuvant needed for live vaccines?

Answer 50

No

Question 51

Is an adjuvant need for inactivate vaccines?

Answer 51

Yes

Question 52

What is the antibody response for live vaccines?

Answer 52

IgG, IgA

Question 53

What is the antibody response for inactivated vaccines?

Answer 53

IgG

Question 54

What is the cell-mediated immunity like in live vaccines?

Answer 54

Good

Question 55

What is the cell-mediated immunity like for inactivated vaccines?

Answer 55

Variable

Question 56

Are live vaccines heat labile?

Answer 56

Yes

Question 57

Are inactivated vaccines heat labile?

Answer 57

No

Question 58

Is there interference with live vaccines?

Answer 58

Occassionally

Question 59

Is there interference with inactivated vaccines?

Answer 59

No

Question 60

Are there side effects with live vaccines?

Answer 60

Yes

Question 61

Are there side effects with inactivated vaccines?

Answer 61

Yes

Question 62

Is there reverse to virulence with live vaccines?

Answer 62

Possible

Question 63

Is there reverse to virulence with inactivated vaccines?

Answer 63

No