Viral Pathogenesis II (Exam 1)

Question 1

An increased susceptibility leads to increased viral _________.

Answer 1

replication

Question 2

List the 6 factors of a host that determines the manifestation of viral disease.

Answer 2

1. immune status
2. genetics
3. age
4. nutrition
5. fever
6. body surface barriers

Question 3

Which host factor can determine the severity of viral disease by Rotavirus?

Answer 3

age

Question 4

What two specific Rotaviruses are more severe in younger animals due to the immune maturation stage of target cells?

Answer 4

Canine Parvovirus
Feline Panleukopenia

Question 5

Canine Parvovirus infects ________ while Feline Panleukopenia infects ________.

Answer 5

cardiomyocytes
cerebellar neurons

Question 6

An elevated host temperature (inhibits/enhances) viral replication and (inhibits/enhances) inflammation and clearance of the virus.

Answer 6

inhibits
enhances

Question 7

(T/F) Both the virus and the host immune system evolve in response to the other.

Answer 7

True

Question 8

In many viral infections, _______ may be more important than other immune system resistance mechanisms.

Answer 8

interferons

Question 9

List two parts of the innate immune response that are important in inhibiting viral replication.

Answer 9

interferons
cytokines

Question 10

______ function in limiting viral infection of cells, as part of the innate immune system.

Answer 10

NK cells

Question 11

Viruses evolve to turn on and off ______ of the immune system for its replication needs.

Answer 11

cytokines

Question 12

Which virus has evolved to control cytokines to benefit in replication?

Answer 12

Herpes Simplex Virus

Question 13

_______ are a major target cell or reservoir for viruses, specifically lentiviruses.

Answer 13

macrophages

Question 14

________ allow for a faster and greater immune response against a virus.

Answer 14

vaccines

Question 15

________ immunity prevents the initial entry of a virus and decreases the initial viral load in the blood.

Answer 15

humoral (antibody)

Question 16

________ immunity functions in recovery from an established viral infection via viral lysis.

Answer 16

cell-mediated

Question 17

If a fetus is infected by a virus early in gestation, a virus can avoid immunity by what mechanism?

Answer 17

tolerance

Question 18

What virus infects calves early in gestation leading to tolerance and lifelong viral shedding?

Answer 18

BVD

Question 19

Which virus infects neurons and therefore, avoids immunity by infecting an immune-privileged site?

Answer 19

Alpha Herpes Virus

Question 20

(T/F) Viruses can evade immunity by downregulating viral proteins and surface proteins so antibody cannot bind.

Answer 20

False - only viral proteins (cannot downregulate surface proteins)

Question 21

What type of viruses can downregulate viral proteins to evade a host’s immune system?

Answer 21

herpes virus (bovine 1, equine, canine, feline)

Question 22

Viruses can evade the host’s T cell response by infecting cells without _________.

Answer 22

Class I MHC

Question 23

Which two viruses evade a host’s immune system by infecting cells without MHC I (neurons) and cause a latent or persistent infection?

Answer 23

Alpha Herpes Virus
Canine Distemper Virus

Question 24

Viruses can evade the host’s immune system by integrating their genome into the host genome. Which type of virus can do this?

Answer 24

retroviruses (bovine leukemia virus)

Question 25

A virus can evade a host's immune system by infecting which two immune cell types?

Answer 25

lymphocytes macrophages

Question 26

Which two viruses infect lymphocytes and macrophages, leading to a loss of function and evasion of the immune system?

Answer 26

FIV Canine Distemper

Question 27

Viruses which cause Aleutian Disease in mink and African Swine Fever in swine can evade a host's immune system by induction of non-neutralizing _________, so the viral infection cannot be prevented.

Answer 27

antibody

Question 28

Viruses can evade the immune system through subtle mutation of viral genes which allow for a replication and evasion advantage. What is the process called?

Answer 28

antigenic drift

Question 29

What may be responsible for large numbers of serologically distinct strains of many viruses?

Answer 29

antigenic drift

Question 30

What process occurs when a virus can reassort and obtain segments from two different viruses and cause severe epidemics?

Answer 30

antigenic shift

Question 31

Antigenic shift is responsible for epidemics of what viral disease?

Answer 31

influenza

Question 32

_________ and ________ viruses inhibit MHC function by interfering with transport or loading of MHC complex so T cells cannot recognize them.

Answer 32

herpes adeno

Question 33

When immune response to a viral infection causes the actual disease, this is called:

Answer 33

immunopathology

Question 34

When a persistent virus leads the immune response to cause more damage, this process is called:

Answer 34

bystander effect

Question 35

Distemper, Visna, Caprine Arthritis, and FIP are all examples of __________.

Answer 35

immunopathology

Question 36

Which two viruses are examples of viruses which cause immune complex diseases?

Answer 36

Equine Infectious Anemia African Swine Fever

Question 37

List two viruses which cause immunosuppression, and therefore, can predispose a host to opportunistic infections.

Answer 37

Canine Distemper FIV

Question 38

When a virus remains for a long period without killing cells and is not eliminated by the immune system, this is called a _________ infection.

Answer 38

persistent

Question 39

Match the virus to which cell type it causes a persistent infection in: Alpha Herpes Virus Lentiviruses Retroviruses

Answer 39

1. neurons 2. lymphocytes / macrophages 3. lymphocytes

Question 40

(T/F) Animals with a latent, persistent viral infection will continuously shed the virus and are a source of infection for other hosts.

Answer 40

False - only shed during episodes or none

Question 41

(T/F) Chronic viral infections can be cytopathic or immunopathologic.

Answer 41

True