(05) Immunity to Viruses

Question 1

TAKE A GANDER!

Question 2

1. What are three examples of non-enveloped viruses?
2. what type of immunity is most important against this type?

Answer 2

1. adnovirus, papillomavirus, and parvovirus
2. cell mediated

Question 3

1. Do viruses have a longer extracellular or intracellular period? What do they undergo during intracellular?
2. What does a non-enveloped virus have to do get out?
3. How does enveloped get out?

Answer 3

1. intracellular; replication
2. lyse the cell
3. budding (uses a section of PM)

Question 4

1. What type of immunity is more critical for enveloped viruses?
2. What are three examples of enveloped viruses?

* basically because enveloped viruses don’t have to be out and about - the antibodies can’t always get to them - so in order to kill them must target the interior of the cell using cytotoxic T-cells

Answer 4

1. adaptive, cytotoxic especially
2. herpesvirus, parainfluenza virus, influenza virus

Question 5

1. KILLED vaccines generate good antibodies but poor cell mediated immunty
2. Modified Live vaccines are required to induce cell mediated immunity
3. So for an enveloped virus - which do you need?
4. How about for an unenveloped virus?

Answer 5

3. modified live - it provides cell mediated immunity
4. can get by with the KILLED

Question 6

take a gander

Question 7

1. How do interferons work?

(interferon alpha)

2. mode of action
3. in what cells

(interferon beta)

4. mode of action
5. in what cells

(interferon beta)

6. mode of action
7. in what cells

Answer 7

1. A cell gets infected by virus, IFN a and b are produced, bind to unaffected cell, virus can’t get in
2. antiviral
3. most cels
4. antiviral
5. leukocytes
6. immune modulatory
7. lymphocytes

Question 8

1. What are an early component of the host response to virus infection?

Answer 8

1. natural killer cells (also get INF a and b, TNF-a and IL-12) - control virus but don’t eliminate

Question 9

look at this

Question 10

(Immunity to Viruses - Adaptive Specific Mechanisms: Humoral Immunity)

1. What does it mean when an antibody “neutralizes” a virus?
2. Can antibodies act as opsonins?
3. What is the fact that viral proteins leading to being used as targets for virus-specific antibodies and may lead to coplement mediated lysis of the infected cell or may direct a subset of NK cells to lyse infected cells through a process known as what?
4. At mucosal surfaces (such as respiratory and gastrointestinal tracts) virus infectin.. which type of antibody important at mucosal surfaces?

Answer 10

1. antibody binds to virus and doesn’t allow it to enter another cell
2. yes (cause phagocytosis)
3. Antibody-Direceted-Cellular Toxicity (ADCC)
4. IgA

Question 11

just read through lecture up to this point…. what a fucking mess this lecture has been

Question 12

1. Do antibodies always mean protection?

Answer 12

1. no - it is an indicator that there has been some kind of reaction

Question 13

(Immunity to Viruses)

(Evasion of Immune Responses to Viruses)

1. What is it called when the accumulation of point mutations eventually yields a variant protein that in no longer recognized by antibody to the original antigen?
2. May occur via re-assortement of an entire ssRNA between human and animal virions infecting the same cell?
3. Which is more common?

*the virus changes to avoid the immune system

Answer 13

1. Antigenic Drift
2. Antigenic shift
3. Driftee

Question 14

1. Can the virus produce products that interfere with immune function?

Answer 14

1. yes - look at this table a little bit - just get general idea a little bit

Question 15

1. Look at this table a fair amount

it just summarizes the main mechanisms of protection

1. Is speed an important virulence factor?

Answer 15

1. yes

Question 16

1. Why is it easier to test for humoral immunity to viruses than CMI?

Answer 16

1. Need live cells for CMI, Antibodies can be stored

Question 17

1. How can you test for CMI to a virus?

Answer 17

1. ALL OF THE ABOVE BITCH

Question 18

1. What is passive immunity? Transferring what or what?
2. What is active immunity?

Answer 18

1. animal doesn’t make its own antibodies, gets them from injection or mother; cells or antibodies
2. when there is a host response to infection or vaccination

Question 19

take a gander at this graph

Question 20

1. Why is colostrum especially important to cows?
2. What is the name of the type of placenta where there is no immunoglobulin transfer in utero?
3. mostly colostrum and a little in utero?
4. when mostly in utero and a little colostrum?

Answer 20

1. cause antibodies aren’t transferred acoss placenta
2. epitheliochorial
3. endotheliochorial
4. hemochorial

look at graph

Question 21

Are their test for failure of passive transer in equine/bovine? what Ig are they looking for?

Answer 21

yes; IgG

Question 22

Why is colostrum so imporant in calves and how does it work?

Answer 22

• the stomach is leaky after birth for awhile (24-36 hours) and you get intestinal absorption of immunoglobulins

Question 23

What are important contributing factors to absorption in the neonate?

Answer 23

Question 24

1. What are the largest number of cells in colostrum?
2. Are there lymphocytes? mostly what type?

Answer 24

1. neutrophils
2. yes, T cells

Question 25

(Passive Immunity - Traffic Across neonatal pig intestinal epithelium) Passage from epithelial surface from Lumen into Circulation 1. Will any antibody cross (even from different species)? 2. Which of these will cross (T cells)? live, maternal killed maternal different sow different species

Answer 25

1. yes 2. only live maternal

Question 26

1. Does Active immunity take more time to develop than passive in the host?

Answer 26

1. yes

Question 27

1. what kind of response is elicited by injected antigen? by a skin graft?

Answer 27

1. humoral response (b-cell?) ; cell-mediated response (t-cell ?)

Question 28

1. why don't you get immunity when you inject to early when the graph is too high on the left? What is this called? 2. What is the window of suscepitbility? 3. How do they get around this now?

Answer 28

1. because there are too many antibodies and they interfere; maternal resistance 2. there is intereference in terms of producing an active response yet susceptibility to disease 3. using modified live - actually replicating in the host - all that is happening in KILLED is that antigen being presented to immune system

Question 29

CVM vet student bitten by bat (suspect rabies) 1. innate or adaptive immune response? 2. humoral or CMI? 3. Active or Passive? (second one) (first one) YOU PROBABL SHULD JUST WATCH THIS AGAIN - HE WASN"T VERY CLEAR ABOUT WHAT THE RIGHT ANSWERYS ARE

Answer 29

1. adaptive 2. CMI 3, 1. adaptive 2. ? 3. active 1. passive (already has clinical disease) 2.

Question 30

can you protect from non-enveloped viruses with antibody alone? however - with enveloped viruses you need some kind of cell-mediated response

Answer 30

- yes