STI/STD (Exam 5)

human immunodeficiency virus

what does HIV stand for?

single stranded RNA

describe the genome of HIV

irregular (cone-shaped or conical)

describe the shape of the viral capsid for HIV

reverse transcriptase, integrase, protease

what are the three viral enzymes that are in the viral capsid of HIV?

enveloped

is HIV enveloped or naked?

gp120 and gp41

what are the two spike proteins that are on HIV?

CD4

the gp120 portion of the spike attaches to ___

T-helper cells

HIV preferentially infects…

co-receptor

gp41 attaches to …

CCR5

the co-receptor on t-helper cells is an immune signaling receptor called…

enter t-helper cells by membrane fusion

the gp41 protein, when activated by its receptor CCR5 allows the virus to…

chronic persistant

HIV is a _______ infection

True

True or False: HIV is a retrovirus

provirus

the genetic material of a virus inserted into the host DNA

HIV integrase enzyme

what enzyme permanently inserts the provirus into the T-helper cell chromosome?

transcription of the provirus

HIV genomes are replicated by ….

three large polyproteins

to simplify assembly of the virus, HIV proteins are produced as ______

HIV protease enzyme

what enzyme cuts each polyprotein into its individual proteins?

genomes and polyproteins

new HIV viruses are assembled with ____ & _____

budding

how do new viruses release from the cell?

after budding

when are polyproteins of HIV broken up?

maturation

what is the cutting/finishing process in HIV called?

mature; immature

only _____ HIV viruses can infect and replicate. _____ HIV viruses cannot replicate

block HIV protease

how could we stop HIV viruses from maturing?

1. acute phase

2. chronic phase

3. AIDS

3 stages of HIV pathogenesis

3 months

about how long does the acute phase of HIV last?

acute phase

during which phase does HIV set p a chronic persistent infection?

7-10 years

how long can the chronic phase of HIV last if untreated?

AIDS

when the replication of the virus (HIV) impairs the immune system so significantly that the immune system becomes unable to stop infections or cancer

acute phase

which phase of HIV pathogenesis is described?

initially t-helper cells are killed off by HIV infection and viral load increases; after about 6 weeks the immune system responds and starts to kill off the virus

mild flu-like

what symptoms are found during acute phase of HIV infection?

chronic phase

which phase of HIV pathogenesis is described?

if left untreated, the virus slowly replicates and destroys the body’s T-helper cells

asymptomatic

what are the symptoms of the chronic phase of HIV?

200

the transition to the third phase of HIV begins at a T-helper cell level of ___ per mL of blood

recurrent respiratory infections (fungal pneumonia), muscle wasting, prolonged diarrhea

common symptoms of AIDS

severe opportunistic infections or virus-caused cancer

cause of death with AIDS is typically…

human host or carriers

reservoirs for HIV

blood or bodily fluids contaminated with blood; sexual secretions; breastmilk

portal of exit for HIV

unprotected sex

example of person to person contact with HIV (mode of transmission)

contaminated needles or medical/dental equipment, blood transfusions, organ transplants

examples of vehicle transmission of HIV (mode of transmission)

placenta, exposure to blood during childbirth, breastmilk

examples of vertical transmission for HIV (mode of transmission)

broken skin or mucus membranes

portal of entry for HIV

primary

is HIV a primary or opportunistic pathogen?

antiretroviral therapy

what is treatment for HIV called?

antiretroviral therapy

giving of multiple drugs at the same time that block or inhibit a different part of the viral replication cycle for HIV

synergistic effect

each drug is more effective together than alone

fusion inhibitors

drug that blocks gp41 from causing membrane fusion

reverse transcriptase inhibitors

drug that blocks the creation of the provirus

integrase inhibitors

drug that blocks the integration of the provirus into the chromosome

protease inhibitors

drug that blocks the maturation of the virus

False

True or False: even with a proper medication schedule, those with HIV can never reduce their viral load to 0

post exposure prophylaxis (PEP)

treatment for HIV after exposure

72 hours

PEP needs to be done within ____ of suspected exposure

pre-exposure prophylaxis (PrEP)

treatment prior to exposure to HIV

double stranded DNA with histones

Genome of HPV

naked icosahedral

capsid structure of HPV

capsid L1

what is the spike protein for HPV?

basal layer of stratified epithelial tissues

the spike protein for HPV viruses bind to the …

cutaneous HPV

type of HPV that infects the stratified epithelium of the skin; causes wart on hands and feet

mucosal HPV

type of HPV that infects the stratified epithelium of the mouth, throat, and genitals; has both low risk types and high risk types

low risk

type of mucosal HPV that causes warts on the surface they infect

high risk

type of mucosal HPC that causes cancers of the tissues they infect

cells of the basal layers of the stratified squamous epithelium

what is HPV tropism?

broken skin or mucous membranes

how does HPV enter the body?

latent persistant infection

HPV enters basal cells and establishes a __________

stable episome

the viral genome becomes a ______ in the nucleus (HPV)

does not

the viral genome is replicated during cell division but _______ (does or does not) produce viruses (HPV)

continue undergoing mitosis; warts

HPV causes the suprabasal cells to _______ which causes the production of _____

active

HPV starts to undergo viral replication after becoming ____

non-cytopathic

is HPV replication cytopathic or noncytopathic?

the breakdown of dead cells in the top layers of the skin

what releases HPV into the environment?

chronic persistent infection

with high risk HPV, the latent persistent infection becomes a ______

provirus

instead of becoming an episome, high risk HPV becomes a _____

basal and suprabasal

with high risk HPV, viruses increase growth in these layers

lose the ability to regulate mitosis

over time, high risk HPV can cause basal cells to …

no; environmental factors play a role

can HPV on its own cause cells to lose the ability to regulate mitosis?

asymptomatic

what are common symptoms of HPV?

warts of the tissue they intect

low risk cutaneous and mucosal HPV infections cause…

itchy, inflamed, lead virus-containing fluids

irritating part of warts

90%

___% of all HPV infections are cleared by the immune system within 2 years.

<1%

___% of high risk mucosal HPV infections develop into cancers

mouth, throat, anus, genitals (cervical)

most common cancers due to HPV

infected human hosts

reservoir for HPV

viruses found in fluid form sores/warts

portal of exit for HPV

direct person to person (from uncovered lesions) and vehicle

modes of transmission for cutaneous HPV

direct person to person (sexual contact), autoinoculation (transfer from one part of the body to another), vertical transmission (through childbirth)

modes of transmission for mucosal HPV

broken skin and mucous membranes

portal of entry for HPV

primary

is HPV primary or opportunistic pathogen?

1. frequency of unprotected sexual activity

2. recent history of STI including HPV

3. Immunosupression

4. Smoking/chewing tobacco

major host factors for chronic HPV/cancer

80%

roughly ___ % of people will have an HPV infection at least once in their life

protection during sexual activity, regular screening/testing, vaccination (90% effective)

prevention for HPV