Retroviruses and HIV-1

Question 1

DNA sequence that can change its relative position within the genome of a single cell

Answer 1

transposable element

Question 2

copy themselves in two stages, from DNA to RNA by transcription then from RNA to DNA by reverse transcription

Answer 2

retrotransposons

Question 3

cut from the genome by a transposase and inserted into another region of the genome

Answer 3

DNA transposons

Question 4

retroviruses are (enveloped/noneveloped) viruses and are the only ______ viruses that contain a ________ enzyme

Answer 4

enveloped
diploid
reverse transcriptase

Question 5

retrovirus replicates through a double stranded DNA intermediate known as _______ that integrates randomly into the host cell chromosome

Answer 5

provirus

Question 6

• virus transmitted primarily by breastfeeding, sexual, and contaminated blood, solid organ transplants
• infects CD4 T cells lifelong
• most infected patients remain asymptomatic

Answer 6

HTLV-1

Question 7

HTLV-1 causes ______ when infected at birth or early in life

Answer 7

adult T cell leukemia

Question 8

the envelope glycoprotein of HIV-1 is responsible for virus binding to the _______ and co-receptor molecules on the surface of susceptible cells

Answer 8

CD4 receptor and co-receptor

Question 9

the transmembrane component is responsible for the _______ of viral and host cell plasma membrane during entry

Answer 9

fusion

Question 10

chemokine receptor used by HIV-1?

Answer 10

CCR5

Question 11

the HIV-1 glycoprotein is a target for what antibodies?

Answer 11

gp120, CD4, gp41, CCR5 coreceptor

Question 12

virus gp120 binds _____ receptor, induces conformational change that allows glycoprotein to bind ______

Answer 12

CD4

CCR5

Question 13

when _____ undergoes conformational change, allows fusion peptide to attach to lipid bilayer and fusion event

Answer 13

gp41

Question 14

converts immature virus particle to mature virus particle? last step of maturation

Answer 14

viral protease

Question 15

early on retrovirus can affect ________, attacking T cells with CCR5 on surface, then migrates to spleen, brain, lung, and kidney

Answer 15

GALT

Question 16

the _______ is the level of viremia at the end of the acute stage of infection, and the higher the number the faster the progression to AIDS

Answer 16

set point

Question 17

mean time from infection to AIDS is approximately ______

Answer 17

10 years

Question 18

clinical findings of primary or acute stage oh HIV infection?

Answer 18

headache, muscle aches, sore throat, fever, swollen lymph nods, CNS disorders, pneumonitis, diarrhea or GI complaints

Question 19

course of primary or acute stage of HIV infection?

Answer 19

lasts for weeks, get lymphadenopathy/lethargy/malaise for months

Question 20

lab findings in acute stage of HIV infection?

Answer 20

lymphopenia, thrombocytopenia, CD4/CD8 ratio decreases due to active depletion of CD4 and expansion of CD8, p24 antigenemia, virus may be present in CNS

Question 21

HIV asymptomatic period is a period of __________, however there is _______ virus replication during this period

Answer 21

clinical latency, constant

Question 22

during asymptomatic period there is constant turnover of? toward end there is an increase in due to deterioration of immune system?

Answer 22

infected T cells, viral loads

Question 23

immune evasion: external protein _______ of HIV is covered with glycosyl groups, which are identical to host proteins

Answer 23

gp120

Question 24

_____ protein downregulates MHCI

Answer 24

nef

Question 25

AIDS is defined as being HIV-1 positive and CD4 T cells below? or being HIV positive and?

Answer 25

200 cells/uL, AIDS defining condition

Question 26

common opportunistic infections of AIDS?

Answer 26

protozoa-toxoplasmosis cryptosporidosis fungal: pneumocystis jiroveci, candidiasis, histoplasmosis, coccidiomycosis bacterial: mycobacterium, salmonella viral: CMV, HSV, VZV, JC virus

Question 27

time periods: rapid progressor? typical progressor? long term non progressor?

Answer 27

2-3 years 10 years 7-25 years (viremic controller or elite controller)

Question 28

HIV rapid progressors have a high ________, represent about 10% of individuals, develop AIDS in about _____ years without CART, have an absent or weak CTL and antibody response

Answer 28

viral set point | 2-3 years

Question 29

HIV long term non-progressors maintain elevated CD4 T cell counts in absence of cART for _________ years, represent 2-5% of HIV patients, and maintain low levels of ______

Answer 29

7-25 years | viremia

Question 30

HIV viremic controllers achieve virologic control is range of ________ copies, maintain elevated CD4 T cell counts typically above ______, but with time will likely lose T cells

Answer 30

200-2000 copies | less than 500 cells

Question 31

elite suppressors or controllers maintain ________ viral loads without cART, represent less than 0.5% of patients, virus can be _______, generally have strong CTL responses

Answer 31

undetectable | isolated

Question 32

lab diagnosis of HIV: antibody antigen test to look for _____ and _____ antigen, confirmed with a _______ assay

Answer 32

HIV1/HIV2 antibodies, p24 antigen | multispot assay

Question 33

obstacles in HAART: - virus persists in ________ CD4 T cells - virus replication _______ in almost all patients after discontinuation - unlikely that pool of ______ virus can be completely eliminated

Answer 33

resting memory rebounds latent

Question 34

mycobacterial disease: - transmitted by ______ - taken up by alveolar _______ and form _______ in lungs where bacteria can go dormant - reactivated to form?

Answer 34

aerosols macrophages, granulomas M tuberculosis, M avium complex (MAC) into disseminated, lymphadenitis, or pulmonary disease

Question 35

- fungus, colonizes normal host, can cause severe pneumonia in immunocompromised - prophylactic trimethoprim sulfamethoxozole

Answer 35

pneumocytis jiroveci

Question 36

- most common fungal infection in HIV infected patients - white stuck on plaques on tongue, buccal mucosa, palate - esophagitis and skin

Answer 36

candida albicans

Question 37

- dsDNA enveloped virus - enters latent state in monocytes and can be reactivated - causes retinitis, GI tract, pulmonary, CNS, myelopathy, bone marrow suppression

Answer 37

cytomegalovirus

Question 38

- enveloped DNA virus - infects B lymphocytes and epithelial cells of throat - 90% of adults in US have antibody to virus

Answer 38

EBV hairy leukoplakia

Question 39

opprotunistic malignancies?

Answer 39

Kaposi sarcoma HHV8, CNS lymphoma due to EBV, Hodgkin lymphoma, HPV cervical and anal squamous cell carcinoma

Question 40

- parasite transmitted through undercooked meat and cat feces - CNS disease via reactivation - headache, confusion, motor weakness, fever - ring enhancing lesions on MRI, cysts

Answer 40

toxoplasmosis

Question 41

- causes meningoencephalitis - fever, malaise, headache with neck stiffness, photophobia, vomiting - abnormal CSF

Answer 41

cryptococcus neoformans

Question 42

- caused by papovavirus JCV - reactivation --> cognitive impairment, focal motor deficits, seizures - ARV to re-establish host immune system

Answer 42

PML

Question 43

AIDS virus in CNS evolves to become largely _______ tropic that targets ______ cells

Answer 43

macrophage, microglial

Question 44

- white matter pallor, microglial nodules, multinucleated giant cells - 40% reduction in frontal and temporal neurons - memory deficits, impaired executive function, poor attention, mental slowing, apathy

Answer 44

AIDS related dementia complex