Exam Dos Flashcards
what did Issacs and Lindenmann demonstrate
what year
what virus did they use
normal cells produce antivirals
1957
flu
IFNs are chemical messenger proteins called _____
cytokines
how many types of IFNs are there
what are they called
3
type 1, 2, 3
why interferon type is described and give examples:
- antiviral & antitumor activity
- upregulates immune response
- antiviral activity
- type 1: IFN-a, IFN-b
- type 2: IFN gamma
- type 3: IFN lambda
what is the importance of the Type 1 IFN pathway
slows down progression of a viral infection
what are the steps to activating the type 1 IFN pathway
- gene expression of IFN a/b
- IFN a/b bind nearby cellular receptors and trigger 2,5 oligo (A) synthase, ribonuclease, protein kinase
- cells are in antiviral state
- dsRNA activates oligo and kinase
- oligo activates ribonuclease
- kinase phosphorylates EIF2-p
are the three enzymes produced by the type 1 IFN pathway initially active
no
what happens when protein kinase phosphorylates EIF2-p
translation is inhibited for the host and virus
are IFNs a part of the adaptive or innate immune response
innate
how long does the viral dsRNA need to be to activate the type 1 IFN pathway
at least 30 nucleotides
what are the (2) things that IFNs do
- directly interfere w/ viral replication in host cells
2. upregulate immune response
more than ____ interferon-stimulated genes w/ direct antiviral activity have been indentified
20
what type of kinase is PKR
serine and threonine kinase
how have some viruses evolved to avoid the IFN1 pathway
bind PKR to inactivate it
bind and sequester dsRNA
how did the first IFN medications go
why
poorly!! there were lots of unanticipated side effects
there were contaminants
what did Hans Strander do in 1974
treated cancer using purified IFN
what bacteria was used to produce purified IFN
E. coli
which populations are most vulnerable to infection
the elderly and newborns
what type of immunity do deficiencies and malnutrition affect
innate and adaptive
t/f: glucocorticoids can suppress the immune response
true
t/f: hormone therapies can lead to an increased risk for viral infections
true
____% of population is resistant to HIV
5
____ is a key co-receptor for HIV
CCR5
what is a normal T helper cell titer
1000 Th/uL
what is an hallmark of HIV infections
opportunistic infections
why do opportunistic infections happen in the midst of an HIV infection
because of decreased immunity by decreased Th cells
what is host range
the range of cells that can act as a host for virus
what can lead to species resistance
virus-receptor interactions (so viruses can’t bind)
incompatible host factors (don’t support viral replication)
_______ ie (______) immunity protects us against any potential pathogen, regardless of the species or type of microbe
nonspecific
innate
Name that immunity:
trapping of viruses by mucus and phagocytes in mucosal tract
mechanical immunity
Name that immunity:
engulfing and ingesting viruses infected cells
phagocytosis
which cells contain pattern-recognition receptors
neutrophils
macrophages
monocytes
what do pattern-recognition receptors recognize on viruses
pathogen associated molecular patterns
what is the default setting for Natural Killer cells
what is the end result of invoking NK cells
to kill unless told otherwise (ie from normal cells)
death
how do NK cells recognize viral infected cells or tumor cells
these cells have a declined expression of certain surface molecules
t/f: viruses cannot trigger apoptosis
false!
they sure can
when is apoptosis good during an infection
when it happens EARLY in infection bc it limits virus production
how can apoptosis be bad during in an infection
it can promote release of the virus if it happens later in the infection
how long does it take for specific immunity to kick in
days to weeks
what cells are part of the adaptive immune response
antibodies/ b cells
t cells
Identify that antibody:
- found in blood and tissues, high abundance
- found in mucous and saliva
- 1st antibody made which indicates a recent or current infection
IgG
IgA
IgM
which antibody typically lasts for a very long time
IgG
what 2 ways do antibodies help fight viruses
-neutralize by binding free virus
-bridge virus particles together in aggregates for easier elimination via WBC
-
what is the key to controlling viruses BEFORE they infect cells
antibodies
when is IgM at its highest concentrations
around 10 days-2 wks
when do IgG concentrations spike
around 15 days into an infection
____ recognize cells that contain foreign antigens and assist other cells
T cells
what are the 3 Tcell populations and what do they do?
Cytotoxic (killers)
Helper (release cytokines)
Regulatory (control immune response)
cells that process antigens and present them to adaptive immune cells
give an example!
antigen presenting cells
dendrites
list the ways viruses can evade immune response (6)
- rapid mutation to escape neutralizing antibodies
- latency and mimicry
- excessive soluble viral antigen production
- inactivating cytokine signals
- inactivate immune cells
- block cellular pathways
Vaccines _____ immunization and (are/ aren’t) the same thing
cause
aren’t
what are the 2 traditional vaccines
live attenuated
inactivated
what are some of the problems with traditional vaccines (6)
- shelf life limitations
- low yield
- improper attenuation/activation
- reversion of attenuated virus
- not all can be cultivated
- not all viruses can be prevented
what are the 4 new generation vaccines
- mRNA
- protein only
- DNA vaccines
- virus vectors
what is a virus vector vaccine
a significant gene gets genetically engineered into harmless virus
where do enteroviruses typically grow
intestines
what type of genome (big or small; envelope or no; rna or dna) does an enterovirus have
how are they transmitted
small, nonenveloped, +ssRNA
oral-fecal route
There are over __ human enteroviruses ___ of which don’t cause disease. ___ of them lead to recognizable associated infectious diseases.
70
50
20
which dynasty does polio date back to
18th
New York City in what year was one of the worst in recorded history for polio
how many deaths
1916
6000
What year did Enders, Robbins, and Welter cultivate poliovirus in human tissue
1949
what led to polio vaccine production
ability to grow in monkey kidney cells
Was it inactivated or attenuated?
1st polio vaccine?
2nd?
inactivated
attenuated
what season does polio cases rise
summer months
what is the average incubation period for polio
how long does it last in fecal matter
6-20 days
3-6 weeks
___% of polio cases are asymptomatic
95
t/f:
polio can be shed in feces and transmitted to others via asymptomatic carriers
true