Lecture 14: Papillomavirus, Adenovirus, Parvovirus - Chap 41, 42, 45 Flashcards
(114 cards)
1
Q
Which virus is associated with warts and cervical cancer?
A
HPV (Human Papillomavirus)
2
Q
What do HPV types 16 and 18 increase the risk of?
A
Cervical, anal, penile, and oropharyngeal cancers
3
Q
How does HPV evade immune detection?
A
Hides from immune responses, allowing persistent infection
4
Q
What cells does HPV primarily infect?
A
Epithelial cells of skin or mucous membranes
5
Q
What are the key oncogenes in HPV that promote cell growth?
A
E6 and E7 proteins
6
Q
How does HPV affect p53 and RB proteins?
A
Inactivates them to promote uncontrolled cell growth
7
Q
What is the common symptom of HPV infection on the skin?
A
Benign warts
8
Q
How is HPV commonly transmitted?
A
By direct or sexual contact, and fomites
9
Q
Which method is used for HPV detection in clinical settings?
A
PCR genome analysis of cervical swabs
10
Q
Which HPV types are targeted by available vaccines?
A
Types 6, 11, 16, 18, 31, 33, 45, 52, and 58
11
Q
What virus is linked to Merkel cell carcinoma?
A
MCPyV (Merkel Cell Polyomavirus)
12
Q
What disease does JCV cause in immunocompromised individuals?
A
Progressive multifocal leukoencephalopathy (PML)
13
Q
How is JCV transmitted?
A
Inhalation or contact with contaminated water or saliva
14
Q
What type of cells are affected in JCV-associated PML?
A
Astrocytes and oligodendrocytes
15
Q
What is a distinguishing characteristic of PML lesions?
A
Demyelination with large abnormal astrocytes and oligodendrocytes
16
Q
How is PML diagnosed in patients suspected of JCV infection?
A
PCR detection of viral DNA in cerebrospinal fluid and MRI/CT scans
17
Q
What organ is primarily affected by BK virus in immunocompromised individuals?
A
Kidneys
18
Q
How do polyomaviruses, such as BK virus, maintain persistent infection?
A
Establish latent infection in organs like kidneys and lungs
19
Q
Which proteins do both HPV and polyomaviruses use to disrupt cell cycle regulation?
A
T antigen (in polyomaviruses) and E6/E7 proteins (in HPV)
20
Q
What method is ineffective for polyomavirus control and treatment?
A
No effective mode of control is currently available
21
Q
How does HPV tissue tropism vary by type?
A
Specific HPV types infect different tissues and determine disease manifestation
22
Q
Which polyomavirus is commonly associated with kidney disease?
A
BK virus
23
Q
What triggers reactivation of JCV and BK virus?
A
Immunocompromised state
24
Q
Why are JCV infections usually asymptomatic in early life?
A
The virus remains latent and does not cause symptoms in healthy individuals
25
In which population are both HPV and polyomaviruses a significant health concern?
Immunocompromised individuals
26
What does CIN stand for in relation to HPV infection?
Cervical Intraepithelial Neoplasia
27
How do HPV infections typically resolve?
Slowly and often spontaneously due to immune response
28
What is the main transmission method for HPV laryngeal papillomas?
Passage through an infected birth canal (Types 6 and 11)
29
How is HPV distributed worldwide?
Ubiquitously, with no seasonal incidence
30
Why does JCV infection lead to progressive neurological symptoms?
Due to demyelination and damage to brain cells
31
Which two types of polyomaviruses are specifically noted for opportunistic disease?
JCV and BK virus
32
Why are warts common with HPV infection?
Caused by benign outgrowth of infected epithelial cells
33
What demographic factor increases the risk of BK virus-related kidney disease?
Immunosuppression (e.g., transplant patients)
34
What type of genome do papillomaviruses and polyomaviruses have?
DNA genome
35
How would you describe the capsid structure of papillomaviruses?
Small, naked capsid
36
What is the significance of a 'naked capsid' in virus structure?
Resistant to environmental stress, aids in transmission
37
Which proteins are key for HPV's ability to manipulate the host cell cycle?
E6 and E7 proteins
38
What role does the T antigen play in polyomaviruses?
Inactivates p53 and RB to promote cell growth
39
How does the HPV genome influence its tissue tropism?
Specific HPV types target different epithelial tissues
40
Where does HPV persist in the body during infection?
Basal layer of skin or mucous membranes
41
What is the genome type of polyomaviruses like JCV and BK?
DNA genome
42
What is a key feature of the HPV genome in terms of immune evasion?
Remains hidden from immune system
43
How does JCV affect the brain in immunocompromised patients?
Causes demyelination by damaging brain cells
44
What is the structure of HPV genome?
Double-stranded circular DNA genome
45
What HPV protein binds origin and helps increase transcription?
E1 protein
46
Which HPV protein helps with the release of virions?
E4 protein
47
Which protein is responsible for EGFR activation in HPV?
E5 protein
48
What are the structural capsid proteins in HPV?
L1 and L2
49
Describe the genome structure of adenovirus.
Linear double-stranded DNA
50
What unique feature does adenovirus capsid have?
Icosahedral capsid with fibers at vertices
51
What genome structure does parvovirus have?
Single-stranded linear DNA
52
What key function does HPV's E6 protein serve in oncogenesis?
Binds p53, activates telomerase, suppresses apoptosis
53
How does E7 protein promote cancer in HPV?
Binds to p105RB, promoting cell cycle progression
54
What proteins in polyomavirus help regulate early and late gene transcription?
Large T antigen
55
Which polyomavirus protein is a major capsid and attachment protein?
VP1
56
What is the main disease mechanism in parvovirus B19 infection?
Infects erythroid precursor cells, causing lytic infection
57
What does CIN1 represent in HPV infection?
Mild changes affecting 1/3 of cervical layer
58
Describe CIN2 in HPV infection.
Moderate changes affecting 2/3 of cervical layer
59
What is CIN3 in HPV pathology?
Severe changes affecting full cervical layer, not yet cancer
60
What is progressive multifocal leukoencephalopathy (PML)?
A JCV-caused demyelinating disease in immunocompromised individuals
61
What condition can adenovirus cause in crowded environments like camps?
Pharyngoconjunctival fever
62
How is HPV typically transmitted?
Direct and sexual contact, birth canal for types 6 and 11
63
How is adenovirus transmitted?
Respiratory droplets, fecal-oral route, contaminated surfaces
64
What age group is most at risk for parvovirus B19?
Children in elementary school
65
Which demographic is at risk for severe B19 complications?
Non-immune pregnant women and those with chronic anemia
66
Who is at risk for PML with JCV reactivation?
Immunocompromised patients
67
What age group is often affected by adenovirus in crowded settings?
Children under 14
68
What diagnostic test is commonly used for HPV?
PCR genome analysis
69
How is PML diagnosed in suspected JCV infection?
PCR on cerebrospinal fluid, MRI or CT for lesions
70
What diagnostic method is used for adenovirus typing?
PCR of respiratory or fecal samples
71
How is parvovirus B19 infection confirmed?
PCR or IgM antibody test
72
What vaccine protects against multiple HPV types?
Gardasil 9
73
What HPV types are included in Gardasil 9?
Types 6, 11, 16, 18, 31, 33, 45, 52, 58
74
Is there a vaccine for adenovirus?
Yes, for military use covering types 4 and 7
75
How is parvovirus B19 infection typically controlled?
No specific treatment; managed with supportive care
76
What type of immune response is crucial for clearing parvovirus B19?
Antibody response
77
What is a control method for adenovirus in shared environments?
Good hygiene and disinfection of contaminated surfaces
78
How would you describe the virus structure of Parvovirus?
naked icoshedsral capsid
single stranded (+ or - sense) dna genome
79
What is the genome type of Papillomaviruses (HPV)?
Double-stranded circular DNA
80
What structural proteins form the capsid of HPV?
L1 and L2 proteins
81
How does HPV primarily achieve cell transformation?
Through E6 and E7 proteins binding to p53 and p105RB
82
Describe the lifecycle of HPV in keratinocytes.
HPV infects basal cells, persists in basal layer, replicates in differentiating keratinocytes, releases virions in the outer layers
83
What diseases are associated with high-risk HPV types like HPV-16 and HPV-18?
Cervical cancer, other anogenital cancers
84
How does HPV evade the immune response?
Persistence in the basal layer, hiding from immune detection
85
Describe the typical presentation of common warts caused by HPV.
Flesh-colored, scaly papules, often on hands and feet
86
What is the main diagnostic test for identifying HPV infections?
PCR for HPV typing, Pap smear for cellular changes
87
What vaccines are available for HPV prevention?
Gardasil (covers types 6, 11, 16, 18) and Gardasil 9 (covers 9 types)
88
What is the structure of Adenovirus?
Non-enveloped, icosadeltahedral capsid with fibers
89
What genome type is found in Adenoviruses?
Linear double-stranded DNA
90
How do Adenovirus fibers contribute to infection?
Act as viral attachment proteins for host cell entry
91
Describe the Adenovirus lifecycle.
1) Entry via receptor-mediated endocytosis, 2) DNA replication in nucleus, 3) Assembly and release by cell lysis
92
Which infections are commonly caused by Adenoviruses?
Respiratory infections, conjunctivitis, gastroenteritis
93
How does Adenovirus spread among hosts?
Aerosols, direct contact, fecal-oral route, and contaminated surfaces
94
What age group is most commonly affected by Adenovirus infections?
Children under 14 years, especially in crowded areas
95
Which diagnostic method is commonly used for Adenovirus infections?
PCR for viral DNA, cell culture for isolation
96
How is Adenovirus controlled in high-risk settings like military camps?
Live oral vaccines for serotypes 4 and 7 are used for military personnel
97
What type of genome does Parvovirus B19 have?
Single-stranded linear DNA
98
Why does Parvovirus B19 need mitotically active cells for replication?
It lacks polymerase and relies on host cell division machinery
99
Describe the lifecycle of Parvovirus B19.
1) Infects erythroid precursor cells, 2) Replicates in nucleus, 3) Released by cell lysis
100
What condition is associated with Parvovirus B19 infection in children?
Erythema infectiosum (Fifth disease) with 'slapped-cheek' rash
101
Which populations are at increased risk of severe disease with Parvovirus B19 infection?
Immunocompromised individuals, pregnant women, individuals with chronic anemia
102
How is Parvovirus B19 primarily transmitted?
Respiratory droplets and oral secretions
103
What are the clinical symptoms of Parvovirus B19 in adults?
Joint pain (arthralgia), fatigue, mild flu-like symptoms
104
How can Parvovirus B19 infection be diagnosed?
Serology for IgM antibodies, PCR for viral DNA
105
Why is quarantine not effective in preventing Parvovirus B19 spread?
Contagious period precedes symptom onset
106
What is the biphasic nature of Parvovirus B19 disease?
Initial viremia with flu-like symptoms, followed by immune response causing rash and joint pain
107
Describe the main prevention strategy for HPV transmission.
Vaccination, safe sexual practices, and screening programs
108
What treatment is recommended for Parvovirus B19 in immunocompromised patients?
IV-IgG therapy to boost antibody response
109
How does Parvovirus B19 infection affect pregnancy?
Risk of fetal anemia and hydrops fetalis
110
What role do HPV E6 and E7 proteins play in oncogenesis?
E6 binds p53, preventing apoptosis; E7 binds p105RB, promoting cell cycle progression
111
In what form does HPV persist in infected cells?
As episomal DNA in the nucleus of basal epithelial cells
112
How does Adenovirus evade immune detection during infection?
Encodes proteins that inhibit MHC I presentation and TNF-α response
113
What environmental factors make Adenovirus highly transmissible?
Resistance to drying, detergents, and gastrointestinal conditions
114
How is Parvovirus B19's lack of polymerase significant in its replication?
It must infect dividing cells to replicate, often affecting erythroid precursor cells
