PHD - Papillomaviruses and Polyomaviruses (Kasman) Flashcards
Human polyomaviruses and papillomaviruses share which of the following characteristics?
A. Circular RNA genome
B. Infections are mostly asymptomatic
C. Icosahedral, enveloped capsids
D. Transmission by respiratory route
E. Preventable by vaccination
B. Infections are mostly asymptomatic
Most people will be infected with HPV at some point in their lifetimes and will not know it. Only certain strains of HPV will produces symptoms (warts, malignancies, etc.)
A is not correct because HPV is circular DNA genome
C is incorrect because HPV are icosahedral with naked capsids
D is incorrect because HPV is transmitted through direct contact
E is incorrect becaue some forms of HPV and all polyomavirus cannot be prevented via vaccine
High risk papillomavirus strains differ from low or no risk strains in which one of the following ways?
A. Infectivity
B. Resistance to disinfectants
C. Immunogenicity
D. Transmissibility
E. Oncogenicity
E. Oncogenicity
Higher number strains of HPV (especially HPV-16)typically lead to cancer, while lower number strains are asymptomatic or cause warts.
Infectivity, immunogenecity, and transmissibility will all be similar throughout the strains. Viruses are not erradicated by disinfectants.
HPV vaccines currently in use consist of adjuvant and which of the following?
A. Attenuated live viruses
B. Formalin-inactivated whole viruses
C. Pure viral capsid protein expressed from recombinant plasmids
D. Recombinant DNA
E. Viral genomic DNA
C. Pure viral capsid protein expressed from recombinant plasmids
HPV vaccines consist of L1 capsid protein
True or false, a person with a common wart on his/her hand could transmit HPV to his/her genitals resulting in genital warts. Why or why not?
A. False. Skin warts are caused by a different strain of HPV than genital warts
B. False. A skin wart induces immunity to all other HPV strains.
C. True. Warts shed skin cells which contain infectious virus.
D. True. The hand wart indicates viremia, and therefore hematogenous spread to other body part is possible.
A. False. Skin warts are caused by a different strain of HPV than genital warts
Types 1-3 are common cutaneous warts
Types 6 and 11 are benign genital warts
Types 16 and above can cause malignancy
Not B because a person can be infected by multiple strains
Not C because statement is not true
Not D because virus is not spread through blood (hematogenous spread), but rather through physical contact
Production of infectious human papillomavirus in vitro (in cell culture) is very difficult. Which of the following is the most likely reason for this?
A. HPV is extremely cytolytic, killing the culture before virions can be released
B. HPV prefers cooler temperatures for replication than tissue culture cells
C. Terminally differentiated cells survive poorly or not at all in tissue culture
D. p53 and pRb are downregulated in tissue culture, preventing viral early gene function
C. Terminally differentiated cells survive poorly or not at all in tissue culture
HPV infects cells and causes them to differentiate into keratinocytes, where capsid proteins will ultimately be formed
Not A because virions assembled before cell lysis
Not B because temperature can be easily controlled in lab
Not D because E6 and E7 proteins do downregulate p53 and pRB, respectivecly, but this enhances viral early gene function by causing unregulated cell proliferation
In addition to cervical cancer, human papillomaviruses are implicated in which of the following diseases?
A. Head and neck cancers
B. Hemorrhagic cystitis
C. Melanoma
D. Merkel-cell carcinoma
E. Progressive multifocal leukoencephalopathy
A. Head and neck cancers
Common locations of cancers caused by HPV are head and neck, cervix, penis, vulva, and anus.
Which of the following is a contraindication to quadrivalent and 9-valent HPV vaccination?
A. Male sex
B. Immunodeficiency
C. Mild acute illness
D. Allergy to yeast
E. Prior sexual contact
D. Allergy to yeast
The HPV vaccine is produced using recombinant DNA plasmids of L1 capsid in yeast cells.
Not A because males age 11-26 are recommended to get it to prevent penile warts
Not B or Cbecause it us a subunit vaccine and does not contain anything infectious in it
Not E because multiple strains exist
True or false: HPV and human polyomavirus infections are more pathogenic in immunocompromised individuals.
True
Lack of immune system response increases risk of carcinogenesis and pathology associated with these viruses
HPV initiates infection in which of the following cell types?
A. Actively dividing squamous epithelial cells
B. Mucosal lymph node tissues
C. Fully differentiated squamous epithelial cells
D. Vascular endothelial cells
E. Basal epithelial cells
E. Basal epithelial cells
Remember that HPV infects basal cells, but spreads via fully differentiated squamous epithelial cells (keratinocytes)
Early genes are more active in basal epithelial cells and induce differentiation to keratinocytes, which produce late genes
Your patient is a 22 year old sexually active woman who received 3 doses of Gardisil 4 at the age of 12. She has never been screened for cervical cancer. Which of the following is the correct standard of care for this patient now and going forward?
A. Cervical cancer screening never needed. She is protected for life by the vaccine
B. Cervical cancer screening needed, but not as often as an unvaccinated person
C. Cervical cancer screening needed, but only as part of prenatal care, should she become pregnant
D. Cervical cancer screening recommended now and every three years using PCR test for high risk HPV strains in cervical specimen
E. Cervical cancer screening recommended now and every three years using a serological test, which detects antibodies to high risk HPV strains in blood.
D. Cervical cancer screening recommended now and every three years using PCR test for high risk HPV strains in cervical specimen
Not A because multiple strains can infect (even with vaccine)
Not B or C because screening should be the same for all regardless of vaccination status
Not E because HPV does not enter blood, so a blood test would not detect it.
What do the late genes encode for in HPV? Where specifically are they produced?
Late genes (L1 and L2) encode for capsid proteins, which allow assembly of virions that can lyse the host cell and infect new cells
Specifically produced in terminally differentiated keratinocytes (epidermal cells, so that they can be easily spread)
Hemorrhagic cystitis is common in patients undergoing immunoablation for human stem cell transplant. Which virus commonly causes this? How is it treated?
BK virus
Treat with cidofovir and ciprofloxacin
JC virus, a human polyoma virus, commonly infects immunosuppressed patients, leading to what condition? How is it treated?
Progressive multifocal leukoencephalopathy
Treat with: reverse immunosuppression
True or False: Almost all sexually active people will acquire HPV at some point during their lifetime.
True
What diagnostic test is indicated for determining the strain of HPV that someone is infected with?
PCR
