HUMAN PAPILLOMA VIRUS
HUMAN PAPILLOMA VIRUS
(HPV)
(HPV)
By:
By:
Nathalia Cruz
Nathalia Cruz

What is a Virus?
What is a Virus?
►
Exceptionally simple living microbes.
Exceptionally simple living microbes.
►
Contain a single type of nucleic acid (DNA or RNA) and a
Contain a single type of nucleic acid (DNA or RNA) and a
protein coat.
protein coat.
►Obligatory intracellular parasites.
Obligatory intracellular parasites.
►
Range from 20 to 14.000 nm in length.
Range from 20 to 14.000 nm in length.

►
Certain types of HPV are linked with cervical cancer.
Certain types of HPV are linked with cervical cancer.
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Divided into 2 subcategories: Genital Warts and Cervical
Divided into 2 subcategories: Genital Warts and Cervical
Dysplasia.
Dysplasia.
►
Most people do not know they have it.
Most people do not know they have it.
►
There are high risk and low risk types of it.
There are high risk and low risk types of it.

HISTORY
HISTORY
►
The papillomaviruses are part of the PAPOVAVIRIDAE
The papillomaviruses are part of the PAPOVAVIRIDAE
family of DNA tumor viruses.
family of DNA tumor viruses.
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First discovered in the early 40’s.
First discovered in the early 40’s.
►
Gained notoriety in the early 80’s when it was discovered
Gained notoriety in the early 80’s when it was discovered
that some types of HPV caused cervical cancer.
that some types of HPV caused cervical cancer.

All PV exhibit extreme specificity for infection on epithelial
All PV exhibit extreme specificity for infection on epithelial
cells.
cells.
►
The papillomavirus epitheliotrophy resides in the
The papillomavirus epitheliotrophy resides in the
interaction of specific transmission factors with the viral
interaction of specific transmission factors with the viral
regulatory region LCR.
regulatory region LCR.
►
The infection normally results in hyperproliferation of the
The infection normally results in hyperproliferation of the
host cell and may lead to transformation and
host cell and may lead to transformation and
immortalization.
immortalization.

GENITAL WARTS
GENITAL WARTS
►
Sometimes called condylomata acuminata.
Sometimes called condylomata acuminata.
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Are soft, moist or flesh colored, and appear in the genital
Are soft, moist or flesh colored, and appear in the genital
area within weeks or months after infection.
area within weeks or months after infection.
►

The transforming proteins interact with the cellular
antioncogenic regulator p53 disrupting the cell
antioncogenic regulator p53 disrupting the cell
cycle.
cycle.

LIFE CYCLE
LIFE CYCLE

HPV TYPES
HPV TYPES
►
Numbered in order of discovery.
Numbered in order of discovery.
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30 HPV types primarily infect the squamous epithelium of
30 HPV types primarily infect the squamous epithelium of
the lower anogenital tracts of both males and females.
the lower anogenital tracts of both males and females.
►
HPV types 6, 11, 42, 43, or 44 present as papillary
HPV types 6, 11, 42, 43, or 44 present as papillary
condylomas, may also present as flat lesions that may or
condylomas, may also present as flat lesions that may or
may not be visible to the unaided eye are part of the “low-
may not be visible to the unaided eye are part of the “low-
risk” HPV types.
risk” HPV types.
►


(LCR) contains all the cis-
(LCR) contains all the cis-
regulatory elements.
regulatory elements.

HOW HPV CAUSES CANCER
HOW HPV CAUSES CANCER
►
HPV DNA integrates into the host genome.
HPV DNA integrates into the host genome.
►
The proteins
The proteins
E6
E6
and E7 are produced from the resultant DNA.
and E7 are produced from the resultant DNA.
►
E6 binds and degrades p53 (a tumor suppressor gene).
E6 binds and degrades p53 (a tumor suppressor gene).
►
If the DNA is altered, the cell keeps replicating. The mutation rate of
If the DNA is altered, the cell keeps replicating. The mutation rate of
the cell increases.
the cell increases.
►
E7 binds and degrades retinoblastoma (another tumor suppressor
E7 binds and degrades retinoblastoma (another tumor suppressor
gene).
gene).

genital warts.
genital warts.
►
Imiquimod cream:
Imiquimod cream:
A patient-
A patient-
applied treatment.
applied treatment.
►
Chemical treatments (including
Chemical treatments (including
trichloracetic acid and
trichloracetic acid and
podophyllin), which must be
podophyllin), which must be
applied by a trained health care
applied by a trained health care
provider to destroy warts.
provider to destroy warts.
►
Cryotherapy:
Cryotherapy:
Uses liquid
Uses liquid
nitrogen to freeze off the warts.
nitrogen to freeze off the warts.
►
Laser therapy:
Laser therapy:

into warts.

CURE
CURE
►
There is currently no cure for human papillomavirus.
There is currently no cure for human papillomavirus.
►
Once an individual is infected, he or she carries the virus
Once an individual is infected, he or she carries the virus
for life even if genital warts are removed.
for life even if genital warts are removed.
►
The development of a vaccine against HPV is under way,
The development of a vaccine against HPV is under way,
but is still not available.
but is still not available.
►
If left untreated, some genital warts may regress on their
If left untreated, some genital warts may regress on their
own.
own.

SOURCES
SOURCES
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