(05) Immunity to Viruses Flashcards
TAKE A GANDER!
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- What are three examples of non-enveloped viruses?
- what type of immunity is most important against this type?
- adnovirus, papillomavirus, and parvovirus
- cell mediated
- Do viruses have a longer extracellular or intracellular period? What do they undergo during intracellular?
- What does a non-enveloped virus have to do get out?
- How does enveloped get out?
- intracellular; replication
- lyse the cell
- budding (uses a section of PM)
- What type of immunity is more critical for enveloped viruses?
- 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
- adaptive, cytotoxic especially
- herpesvirus, parainfluenza virus, influenza virus
- KILLED vaccines generate good antibodies but poor cell mediated immunty
- Modified Live vaccines are required to induce cell mediated immunity
- So for an enveloped virus - which do you need?
- How about for an unenveloped virus?
- modified live - it provides cell mediated immunity
- can get by with the KILLED
take a gander
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- How do interferons work?
(interferon alpha)
- mode of action
- in what cells
(interferon beta)
- mode of action
- in what cells
(interferon beta)
- mode of action
- in what cells
- A cell gets infected by virus, IFN a and b are produced, bind to unaffected cell, virus can’t get in
- antiviral
- most cels
- antiviral
- leukocytes
- immune modulatory
- lymphocytes
- What are an early component of the host response to virus infection?
- natural killer cells (also get INF a and b, TNF-a and IL-12) - control virus but don’t eliminate
look at this
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(Immunity to Viruses - Adaptive Specific Mechanisms: Humoral Immunity)
- What does it mean when an antibody “neutralizes” a virus?
- Can antibodies act as opsonins?
- 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?
- At mucosal surfaces (such as respiratory and gastrointestinal tracts) virus infectin.. which type of antibody important at mucosal surfaces?
- antibody binds to virus and doesn’t allow it to enter another cell
- yes (cause phagocytosis)
- Antibody-Direceted-Cellular Toxicity (ADCC)
- IgA
just read through lecture up to this point…. what a fucking mess this lecture has been
- Do antibodies always mean protection?
- no - it is an indicator that there has been some kind of reaction
(Immunity to Viruses)
(Evasion of Immune Responses to Viruses)
- 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?
- May occur via re-assortement of an entire ssRNA between human and animal virions infecting the same cell?
- Which is more common?
*the virus changes to avoid the immune system
- Antigenic Drift
- Antigenic shift
- Driftee
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- Can the virus produce products that interfere with immune function?
- yes - look at this table a little bit - just get general idea a little bit
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- Look at this table a fair amount
it just summarizes the main mechanisms of protection
- Is speed an important virulence factor?
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- yes
- Why is it easier to test for humoral immunity to viruses than CMI?
- Need live cells for CMI, Antibodies can be stored
- How can you test for CMI to a virus?
- ALL OF THE ABOVE BITCH
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- What is passive immunity? Transferring what or what?
- What is active immunity?
- animal doesn’t make its own antibodies, gets them from injection or mother; cells or antibodies
- when there is a host response to infection or vaccination
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take a gander at this graph
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- Why is colostrum especially important to cows?
- What is the name of the type of placenta where there is no immunoglobulin transfer in utero?
- mostly colostrum and a little in utero?
- when mostly in utero and a little colostrum?
- cause antibodies aren’t transferred acoss placenta
- epitheliochorial
- endotheliochorial
- hemochorial
look at graph
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Are their test for failure of passive transer in equine/bovine? what Ig are they looking for?
yes; IgG
Why is colostrum so imporant in calves and how does it work?
- the stomach is leaky after birth for awhile (24-36 hours) and you get intestinal absorption of immunoglobulins
What are important contributing factors to absorption in the neonate?
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- What are the largest number of cells in colostrum?
- Are there lymphocytes? mostly what type?
- neutrophils
- yes, T cells
(Passive Immunity - Traffic Across neonatal pig intestinal epithelium)
Passage from epithelial surface from Lumen into Circulation
- Will any antibody cross (even from different species)?
- Which of these will cross (T cells)?
live, maternal
killed maternal
different sow
different species
- yes
- only live maternal
- Does Active immunity take more time to develop than passive in the host?
- yes
- what kind of response is elicited by injected antigen? by a skin graft?
- humoral response (b-cell?) ; cell-mediated response (t-cell ?)
- why don’t you get immunity when you inject to early when the graph is too high on the left? What is this called?
- What is the window of suscepitbility?
- How do they get around this now?
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- because there are too many antibodies and they interfere; maternal resistance
- there is intereference in terms of producing an active response yet susceptibility to disease
- using modified live - actually replicating in the host - all that is happening in KILLED is that antigen being presented to immune system
CVM vet student bitten by bat (suspect rabies)
- innate or adaptive immune response?
- humoral or CMI?
- 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
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- adaptive
- CMI
3,
- adaptive
- ?
- active
- passive (already has clinical disease)
2.
can you protect from non-enveloped viruses with antibody alone?
however - with enveloped viruses you need some kind of cell-mediated response
- yes