HIV/AIDS Flashcards
genus of HIV
Lentivirus
criterion for differentiation @ HIV types: enumerate
(1) genetic make-up
(2) geographic distribution
majority of cases; pandemic, from sub-Saharan Africa
A. HIV-1
B. HIV-2
C. HIV-3
A
HIV-1 has subtypes M, N and O. Which causes global epidemics?
M (majority)
HIV-1 subtype Localized to Cameroon, Gabon &
Equatorial Guines
O
HIV-1 subtype in Cameroon only
N
subtype E of HIV-1 is now classified as __
CRF (circulating recombinant form)
Why is HIV capable of producing circulating recombinant form?
Because its segmented linear genome is prone to mutation
(1) No cases in the Philippines
(2) No HIV-2 pandemic
(3) Less pathogenic than HIV-1
Which is false about HIV-2?
(1)
we have 1 case; however it is more seen in West Africa
What is the genome of HIV?
A pair of (+) ssRNA
shape of capsid containing RNA
Conical
T or F: HIV is a naked virus.
F. It has an envelope
In the viral envelope of HIV-1, the peplomer cap is also known as __
gp120
In the viral envelope of HIV-1, the peplomer stalk is also known as __
gp41
gp120 and gp41 come from __
gp160
enumerate the 3 major genes of HIV
Envelope
Polymerase
Group Specific Antigen
codes for capsid protein, matrix protein, nucleocapsid
Group Specific Antigen
codes for reverse transcriptase, protease, integrase,
and ribonuclease; unique for HIV
Polymerase
encode for (1) surface protein, (2) transmembrane protein
Envelope
identify the accessory gene: essential for replication specifically for elongation
TAT gene (transcriptional activator)
identify the accessory gene: bringing mRNA into translations
REV gene (regulator of viral gene expression)
enumerate the 2 main differences of HIV-1 & HIV-2
(1) structure
(2) weight of each of the component of the virion
HIV-2 __ HIV-1 (weight)
A. >
B. <
C. =
A
envelope precursor of HIV-2
gp140
HIV binds to CD4 antigen on cells such as Macrophages
and T-Helper cells via the ___
HIV surface glycoprotein, gp120
Once HIV has attached & chemokines stabilize the interaction, __ changes –> exposing hydrophobic
regions that embed in the membrane of host cell.
gp41
Which co-receptor isn't one of those which HIV has to attach to? A. CKR5 B. CCR5 C. CR5 & CXCR4 D. R4
C
R5 dapat
another name for CXCR4
fusin
Which is false about HIV?
a. There is fusion between the membranes of the virus and the host cell before entry of nucleocapsid.
b. Initial infection of HIV is abundant in the mucosa.
c. There is formation of syncytia with the isolation of
the virus in cell lines.
C
No syncytia
Initial infection of HIV is __
A. T-tropic
B. M-tropic
C. Both
B
Later infection of HIV is __
A. T-tropic
B. M-tropic
C. Both
A
HIV that target T-lymphocytes uses the
__ receptor
CXCR4
enumerate three steps by which a co-receptor (i.e. CKR5) works
(1) Attachment
(2) Binding to second receptor
(3) Fusion
CK5 receptor is receptor for __ HIV
A. T-tropic
B. M-tropic
C. Both
B
aka initial infection of HIV
functions primarily to convert +ssRNA genome into a
complete double stranded DNA form (not the
complete virion)
identify the enzyme
reverse transcriptase enzyme
T or F
the virion utilizes the host cell’s DNA dependent RNA
polymerase for transcription
T
allows integration of the dsDNA form into the host
cell’s chromosome
identify the enzyme
integrase enzyme
Which is false?
A. dsDNA is translated into viral proteins in the
ribosomes of the host
B. replication of the viral genome happens in the nucleus
C. in latency, viral genome (dsDNA) undergo no production/very little replication of new virion
D. the virus exits the cell via budding
B
cytoplasm, not nucleus
What allows maturation of HIV outside the host
cell to its functional components? How does it activate maturation?
protease enzyme, cleaving chunk of protein
Which is not a mode of transmission for HIV? A. sexual B. parenteral C. arthropod-borne D. vertical
C
Which doesn't the CD4 T-cell release? A. IL-1 B. IL-2 C. IL-4 and IL-10 D. IFN-γ
A
role of IL-2
stimulates T cell proliferation of cytotoxic
T cell which releases cytokines that inhibit viral
replication
What do IL-4 & IL-10 do?
stimulate maturation of antibody
response of B cell which produces virus-specific
antibodies)
two main characteristics of primary HIV infection: enumerate
rapid rise in
plasma virus and a rapid decline in circulating CD4 +
T - cells.
True or False.
In HIV patients, opportunistic infections are a precursor to T cell decline.
F
Opportunistic infections happen because there is T-Cell depletion, hence they happen only once T-cell decline is so intense.
The HIV - specific antibody response takes longer to
initiate and results in seroconversion. What is seroconversion?
when the patient has detectable level
of antibodies against the infectious agent
___ Sarcoma may be seen in AIDS patients
Kaposi’s
most common way of diagnosing AIDS
ELISA
Identify the diagnostic method - Blood HIV load varies markedly during infection and viral turnover is always rapid - Used to monitor titer of HIV - Employed when a person is in therapy
Plasma Viral Load
only HIV detection method in establishing acute conditions for children < 6 months
PCR
Which is false?
A. HIV dried in salt solution on stainless steel surfaces
may still be detected after a week
B. Disinfectants are more effective where HIV has dried on surfaces or in the presence of large amounts of protein
C. If HIV is associated with large number of
protein, it has a higher likelihood of retaining their viability.
D. HIV is labile to heat and drying.
B
less, not more
identify the type of HIV drug
o Competitive inhibitors of reverse transcriptase
o AZT, DDI, DDC, d4T, 3TC, Abacavir, succinate, Previon
nucleoside inhibitors
identify the type of HIV drug
o Reverse transcriptase inhibitors, but bind to sites other
than the active site of the enzyme
o Nevirapine, Atervidine, Delavirdine, Efavirenz
non-nucleoside inhibitors
HIV may be treated via HAART. What does HAART mean?
Highly active anti-retroviral therapy
