HIV, Retroviruses, Lentiviruses (18,30) Flashcards
(50 cards)
What is NOT a challenge in developing an AIDS vaccine?
a. There is a lack of knowledge on which antigens are needed for protection
b. There is a need for B cell approach vaccines as they are more successful than T cell approach vaccines
c. There is no immunological correlate of protection
d. Candidates need to elicit broadly neutralising antibodies to HIV as well as control HIV infection
b. There is a need for B cell approach vaccines as they are more successful than T cell approach vaccines
What is correct about Merck’s vaccine?
a. It elicited a robust neutralising antibody response in male Thai participants
b. It contained canary pox and gp120
c. It did not prevent HIV in subjects with pre-existing adeno5 antibodies
d. It had an efficacy of 31% against HIV subtype E
c. It did not prevent HIV in subjects with pre-existing adeno5 antibodies
What is INcorrect about the Sanofi study (RV144)?
a. The study demonstrated that HIV elicits cell mediated responses as opposed to neutralising antibody responses
b. It showed that vaccines would be most effective when delivered early and in low risk individuals
c. There was no difference in the amount of HIV infections recorded in the placebo group and vaccine group
d. It showed that protection is possible but boosting may be important
c. There was no difference in the amount of HIV infections recorded in the placebo group and vaccine group
What does 90-90-90 refer to?
a. The UNAIDS target of having 90% diagnosed, 90% on treatment and 90% virally suppressed
b. That 90% of retroviruses mutate 90% of their genome in 90% of the world’s population most susceptible to HIV infection
c. The UNAIDS target of eradicating AIDS in 90% of the world’s population
d. The WHO target of having 90% of AIDS suffers on HAART treatment by 2090
a. The UNAIDS target of having 90% diagnosed, 90% on treatment and 90% virally suppressed
What must be carried out to eliminate or silence HIV infected cells?
a. The viral genome must not be epigenetically modified
b. A HIV RNA assay must reveal that there is an undetectable viral load
c. Vaccines will only work against ‘silent’ HIV DNA
d. The latent infection must first be activated (e.g. HDACi)
d. The latent infection must first be activated (e.g. HDACi)
• Monkeys can be protected by SIV by immunisation with a live attenuated vaccine.
T
• The Sanofi study showed that AIDS vaccines will be most successful if based on neutralising antibody responses as opposed to cell mediated immunity.
F
• Late HAART era patients still have a 10year shorter life expectancy than those without HIV.
T
• Current HAART treatment often leads to death from AIDS as CD4+ T cells cannot be saved from depletion.
F
• When HAART is stopped, the amount of HIV RNA plummets rapidly.
F (RNA increases, rebound)
• HIV DNA in infected cells is always detectable.
T
Which statement about HIV prevalence in 2012 is INcorrect?
a. About 35.3 million people were infected
b. 2.3 million new infections arose
c. 1.6 million people died
d. 25 million infected people resided in Latin America
d. 25 million infected people resided in Latin America
What is cause of 70% of HIV cases acquired in Australia?
a. Injecting drug use
b. Male homosexual contact
c. Heterosexual contact
d. Undetermined causes
b. Male homosexual contact
What is cause of 80% of HIV cases acquired throughout the world?
a. Injecting drug use
b. Male homosexual contact
c. Heterosexual contact
d. Undetermined causes
c. Heterosexual contact
What does not influence a heterosexually transmitted HIV epidemic?
a. Social factors like large sexual networks
b. Behavioural factors like condom use
c. Social factors like high viral loads
d. Biological factors like low rates of circumcision
c. Social factors like high viral loads
What is a feature of HIV as a lentivirus?
a. It is enveloped and has helical symmetry
b. It has a diploid linear 9.2kb +ssRNA genome
c. HIV1 is the only human virus
d. The disease progresses rapidly
b. It has a diploid linear 9.2kb +ssRNA genome
What is a feature of the HIV-1 genome?
a. Pol encodes enzymes like RT, IN and PR
b. Env encodes structural proteins such as MA, CA and NC
c. Gag encodes envelope proteins SU and TM
d. Tat and Rev are spliced from the gag-pol polyprotein
a. Pol encodes enzymes like RT, IN and PR
What is correct about reverse transcription?
a. It cannot be targeted by antiviral drugs
b. The process has a low error rate
c. It leads to the formation of LTRs in viral cDNA
d. It requires host cell integrase and reverse transcriptase
c. It leads to the formation of LTRs in viral cDNA
What is a feature of HIV integration?
a. HIV cDNA integrates at OriP in host DNA
b. Integration cannot occur in terminally differentiated cells
c. Viral integrase is resistant to antiviral drugs
d. The 5’ LTR of the provirus acts as the HIV gene promoter
d. The 5’ LTR of the provirus acts as the HIV gene promoter
What is NOT a feature of the LTRs in the HIV provirus?
a. U5 at the 5’ end contains a polyadenylation signal
b. U3 at the 5’ end contains enhancer sequences and transcription start signals
c. NfKb is produced by activated T cells and can bind to the 5’ LTR
d. The 5’ LTR contains a cap site between U3 and R
a. U5 at the 5’ end contains a polyadenylation signal
What acts as the HIV gene promoter following integration into host DNA?
a. The 3’ LTR
b. Gag-pol sequence
c. The 5’ LTR
d. The Rev responsive RNA element
c. The 5’ LTR
What is a feature Tat?
a. It binds to RREs on the 4kb and 9kb HIV RNA transcripts and exports them to the cytoplasm
b. It regulates structural gene expression
c. It represses transcriptional to initiate HIV latency
d. It binds 5’ TAR and activates CDK9 which phosphorylates and activates RNApolII
d. It binds 5’ TAR and activates CDK9 which phosphorylates and activates RNApolII
Which statement about HIV accessory proteins is correct?
a. Vpu promotes infectivity by blocking cell defences and targeting ssCDNA
b. Nef down modulates MHC1 and Cd4
c. Vpr regulates particle release and Env processing and the degradation of MHC1 and CD4
d. Vif aids the nuclear import of cDNA and is involved in cell growth arrest
b. Nef down modulates MHC1 and Cd4
a. Vpu promotes infectivity by blocking cell defences and targeting ssCDNA (Vif)
c. Vpr regulates particle release and Env processing and the degradation of MHC1 and CD4 (Vpu)
d. Vif aids the nuclear import of cDNA and is involved in cell growth arrest (Vpr)
What is a feature of the CCR5 co recptor?
a. Highly pathogenic, used late in infection, macrophage tropism
b. Naturally binds SDF1, T cell tropism, moderate pathogenicity
c. No syncytium, used early in infection, macrophage tropism
d. Moderate pathogenicity, induces syncytium, t cell tropism
c. No syncytium, used early in infection, macrophage tropism
