Final Flashcards
where the virus causes the cell to proliferate in an uncontrolled manner.
Transformation
usually an acute process where viral progeny are released by death (lysis) of the cell
Lytic
What is the sense orientation of Virus Genetic code?
= same orientation as mRNA
What is the anti-sense (-) orientation orientation of Virus Genetic code?
Opposite orientation as mRNA
The virus attachment phase requires
spike proteins on the virus (or viral membrane) binding to specific receptors on the target cell.
The steps of a virus’s life cycle
Attachment Penetration Uncoating Replication Assembly Release
release of viral agent into the blood
viremia
almost exclusively infect plants
viroids
many infected individuals never show clinical signs or symptoms, with many if not most infections occurring ‘below the waterline.’
“Iceberg” concept of infectious disease
What is/causes surface immunity
IgA is the major antibody active at mucosal surfaces and secretions within and outside the body
Several mechanisms appear to act in concert to prevent any destructive immune reactions to our food and yet protect us from GI pathogens.
Oral tolerance
MALT
mammary associated lymphoid tissues
BALT
bronchial associated lymphoid tissues
GALT
Gut associated lymphoid tissues
sIgA Functions
neutralize toxins and viruses at mucosal surfaces, and block colonization
decrease unwanted immune reactions to food
‘sticky’ and binds to mucus, Keeps it from being flushed out.
insensitive to acids and proteolytic enzymes
What is sIgA bad at?
poor activator of complement (C’)
‘inconsistent opsonizer.’
Oral tolerance
Several mechanisms appear to act in
concert to prevent any destructive immune reactions to our food
anergy
immune unresponsiveness
Describe Poliovirus
positive-stranded RNA enterovirus
binds to and is replicated in the oropharynx and the GI mucosa
Salk Polio vaccine
(non-infectious) induces great IgG protection, which neutralizes systemic viruses
Sabin Polio vaccine
(infectious, attenuated) induces great sIgA protection, which neutralizes the virus before it even can start an infection
induces a very good surface sIgA response, as well as a good IgG response.
Majority of Influenza viruses deaths come by?
Directly cause death through viral pneumonia, or more commonly weaken the innate immune system (e.g., breach in the barrier lung epithelial) leading to secondary bacterial pneumonias.
Which family is the Influenza virus apart of?
members of the Orthomyxovirus family
Characteristics of influenza virus?
enveloped virus
segmented, [-]ssRNA genome, which has the ability to mutate frequently
must bring functional RNA-dependent RNA- polymerases into the host cell for replication to occur
Influenza N protein is called?
neuraminidase
Influenza H protein is called?
hemagglutinin
Where does Influenza Replicate?
in the nucleus of the cell
is the process in which two or more strains of a virus, while infecting the same cell, swab genetic material to form a new viral strain that combines the genetic and phenotypic characteristics of both.
Antigenic Shift
Flu Hemagglutinin protein Function
facilitate viral attachment and fusion with the cell membrane
Flue Nuraminidase protein function
helps viral release by cleaving neuraminic acid on the cell surface
Diagnosis of Influenza can be determined quickly by?
Influenza viruses agglutinate RBCs
Hemagglutination inhibition assay is a fast easy way to determine if a patient has developed neutralizing antibodies to a certain influenza strain.
are chemically related antiviral drugs known as adamantanes with activity against influenza A viruses but not influenza B viruses
Amantadine and rimantadine
Mechanism of anti viral medication Amantadine and rimantadine?
act mainly by blocking uncoating and thus viral infection
Oseltamivir (Tamiflu) and Zanamivir (Relenza) Mechanism of action?
inhibit neuraminidase and thus viral release. Active against flu A and B
Both HBV and HCV infections typically cause…
A mild acute disease, but can lead to carrier status, chronic liver damage, and liver carcinoma.
The non enveloped hepatitis viruses?
HAV, and HEV
The enveloped hepatitis viruses?
HBV, HCV, HDV
The Hardy hepatitis viruses and their mode of transmission…
Naked HAV, and HEV,
transmission being fecal-oral
The unstable hepatitis viruses and their mode of transmission…
envelope HBV, HCV, and HDV cause them to be considerably less sturdy,
transmission by direct exchange of bodily fluids
Which HXV vaccines are available?
Vaccines are available for H(A,B,D)V
HDV infection is dependent on
HBV for replication
Hepatitis virus relatively common in some ‘developing’ countries, where it takes a substantial toll among pregnant women (~10-30% fatality rate in their third trimester of pregnancy…
HEV
An oncovirus that can lead to T-cell tumors. Common in japan.
HTLV I
Lentivirus that impairs immunity
HIV, untreated leads to AIDS
Class of Retro Exogenus viruses that lead to odd foamy like vacuoles in the cytoplasm of cells.
Spumaviruses
Retroviruses that are incorporated into the human genome.
Endogenous viruses
Lentiviruses cause
slowdeveloping CNS and immunosuppressive diseases
HIV The gag genes code for…
structural proteins such as the nucleocapsid
HIV pol genes code for…
the enzymes such as reverse transcriptase, hich are responsible for replicating and integrating the viral genome
HIV env genes code for…
the two major proteins, GP41 and GP120, which both contribute to the viral spikes
HIV binds via GP120 specifically to____, and then to a _______________
CD4 chemokine receptor (CCR5 or CXCR4)
The two enzymes that HIV carries with it…
Reverse Transcriptase
Integrase: cuts the host DNA so the viral DNA can be inserted into it
Appears to make these individuals resistant to HIV infection, even after multiple exposures
mutated CCR5 that is used by HIV to bind/fuse with the host cell membranes
CCR5 has also been given the name
CD195
probably the most communicable human disease known
Measles. Measles, or Rubeola
describe a severe, multi-organ syndrome caused by vascular system damage (i.e., capillary blockage and leakage)
Hemorrhagic fevers
insect- and rodent-borne pathogens
arboviruses and roboviruses, respectively
What family does Zika virus belong to, what is it’s vector, and what does it cause?
Flaviviruses
mosquitoes
encephalitis
What family does Chikangunya virus belong to what is it’s vector, and what does it cause?
Flaviviruses
mosquitoes
encephalitis
A ROBO-Bunyavirus that causes hemoragic Fever.
Fanta Fever
Famous Filovirus that made the news a couple years ago.
Ebola
Two human diseases caused by Prions
Kuru and Creutzfeldt-Jakob Disease (CJD)
Three Animal animal diseases caused by Prions
Scrapie (sheep),
Bovine Spongiform Encephalopathy (BSE) (cattle)
chronic wasting disease (deer and elk).
