Basic Virology Slackers Facts by Mike Ori. Disclaimer The information represents my understanding...
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Basic Virology Slackers Facts by Mike Ori
Basic Virology Slackers Facts by Mike Ori. Disclaimer The information represents my understanding only so errors and omissions are probably rampant. It
The information represents my understanding only so errors and omissions are probably rampant. It has not been vetted or reviewed by faculty. The source is our class notes.
The document can mostly be used forward and backward. I tried to mark questionable stuff with (?).
If you want it to look pretty, steal some crayons and go to town.
Finally…
If you’re a gunner, buck up and do your own work.
Are viruses alive
It depends an who you ask. Dr. A says yes. They are obligate intracellular parasites that carry
enough genes to reproduce themselves within the defined environment of their host.
How is genetic information encoded in viruses
Genetic information is encoded in either RNA or DNA depending on the virus. It is important to note that viruses do not contain both RNA and
DNA.
What is a virion
A functioning virus particle. Distinguished from an defective particle.
Describe the range of size and complexity in the viraverse (viral-universe - a shiny new word)
Viruses range from the edge of detection with EM to about one-quarter the size of an E. coli.
A,B,C,D Collie omitted for clarity
E. Collie
Chickenpox virus
Pine cona virus
List the patterns of viral growth.
AcuteLatent
ChronicSlow chronic
Set point escape
What is the expected growth pattern for an acute virus.
Initial rise and fall of viremia without resurgence. Done in one.
Describe the expected viremia pattern for a latent virus
Initial acute rise followed by virus free periods punctuated by less intense periods of viremia.
Describe the expected viremia pattern for chronic infection
Initial acute rise in viremia with a fall that does not reach zero. Viremia is detectable in blood
or tissues
Describe the expected viremia pattern with slow chronic infection.
Viremia increases slowly over time.
Describe the viremia associated with set point escape
Really a combination of chronic viremia and rapidly rising slow chronic response. Initial acute infection
followed by a drop in viremia that does not return to zero (aka set point). Eventually, the virus escapes the
immune system in a chronic escalation.
Set point (chronic) Slow chronic-like escape
List the prototypical virus for each pattern
Acute – influenzaLatent – HSV-1
Chronic – Hep BSlow chronic - ??
Set point escape - HIV
What is a viral envelope?
A lipid bilayer derived from host membranes. Most often the source is the plasma
membrane but it may also be the ER/golgi or the nuclear membrane (herpes)
What is the a capsid?
A capsid is a protein structure that surrounds and protects the viral genome. The capsid organizes and provides shape to the virus.
What is nucleocapsid
Nucleocapsid proteins are proteins that organize the genome in enveloped viruses that do not
have an icosohedral core.
What are viral spikes
Proteins that extend from the virus that allow it to interact with its environment.
What are matrix proteins
In enveloped viruses, matrix proteins link the nucleocapsid to the spikes and membrane
Will you take the blue or the red pill coppertop?
What is a capsomere
A capsomere is an aggregation of proteins that forms a modular building component of naked
capsid virus (cubic, icosahedral) and that of enveloped icosahedral virus..
Describe the structure of naked capsid virus.
A naked capsid virus consists of a genome packaged by core proteins surmounted repeating capsomeres organized into an
icosahedral shell from which protein spike protrude.
What is the relative antigenicity of viral structural proteins?
Spikes are more apt to be exposed to the immune system and hence are more likely to
be antigenic. Antibodies directed against spikes should be more efficacious.
What are the functions of spikes
1. Enzymatic (influenza neuroaminidase)2. Fusion with host cells
3. Eliciting immune response
What is tropism
The propensity of a virus to infect specific tissues.
What is the basis for tropism
Access to the tissue and receptors on the tissue
If you were working in a bioweapons lab, what part of the virus would you change to alter its
tropism
The spikes.
What is troopism
An actor’s propensity to form travelling groups.
What is the basis for virus classification. Consider old and new.
Old school: phenotypic and disease characteristics of the virus.
New school: Genetic analysis
Is herpesviridae a fmily, genus, or species designation
A family.XXXviridae
Is simplexvirus a family, genus, or species
GenusXXXvirus
Genius
Is herpes simplex 2 virus a family, genus, or species