HIV pathogenesis Flashcards
HIV originated from an animal
yep…primates
HIV-1 and HIV-2 differ by ~40% nucleic acid composition of _____
env
The ____ region is two to three times less divergent than env
pol
HIV-1 gag is even less divergent as it codes for
relatively inflexible core proteins
Retroviruses have 3 major genes:
- Gag: encodes __________
- Pol: encodes _____________
- Env: encodes _________
- Gag: encodes core proteins
- Pol: encodes reverse transcriptase, protease, integrase
- Env: encodes envelope proteins
HIV 2 major envelope proteins
gp41 and gp120
Envelope covers a core of nucleocapsid proteins including ____
p24
HIV structure is an
Icosahedral structure with lipid envelope
Gp120 binds to _____ cell receptor with high affinity
CD4
Cellular targets with CD4 receptors (6)
- T-cells
- dendritic cells
- macrophages
- glial cells in CNS
- Gut epithelium
- Bone Marrow progeito cells
HIV co-receptors (2) later one is associated with a more rapid decline in CD4+ cells
CCR5 and CXCR4
HIV-1 characterized by _____ replication. Rapid replication rates serve as a mechanism for virus ______
error-prone replication and Rapid replication rates serve as a mechanism for virus evolution
characterized by progressive immune system deterioration that predisposes persons to opportunistic infections and neoplasms
Chronic infection with HIV
Syndrome caused by infection with HIV characterized by advanced immunodeficiency and/or opportunistic diseases indicative of at least moderate deficiencies in cell mediated immunity; CD4 cell count < 200 cells/mm3
AIDS
incubation period for HIV
signs and symptoms occur within 5-30 days
acute retroviral syndrome is characterized by
mononucleosis-like illness with fever, pharyngitis, rash, lymphadenopathy and aseptic meningitis
HIV disease progression clinical latency
clinical latency is where someone is HIV positive but they are asymptomatic— viral load is low
in the acute infection of HIV disease the viral replication in the regional lymph nodes leads to exponential viral growth and widespread
dissemination
destruction of gut associated lymphoid tissue
early destruction of T cells in lamina propria which releases LPS into circulation
_______ recognize viral antigen in setting of MHC Class II molecules on antigen-presenting cells
CD4+ T-cells
_______ recognize antigen in setting of MHC Class I molecules
CD8+ T-cells
__________ kill virally-infected cells with “_________ help”
CD8+ T-cells with CD4 help
why is there a conondrum during primary infection, were there are high levels of viremia?
viremia stimulates widespreaad activation of CD4 cells- the very target of HIV
T-cell activation is followed by a precipitous decline of _____ cells due to massive targeted infection by HIV. Cytotoxic T lymphocyte recognition leads to some decline in viremia; but responses are not sustained without appropriate
CD4 and CD4 help
The hallmark of the immunodeficiency of AIDS is a depletion of
activated CD4+ T-helper lymphocytes
what is someone is CCR5 heterozygote or homozygote?
Slower rates of progression and Relative resistance to infection
Humoral response in HIV is protective
NOPE
During acute infection, HIV antibody responses are absent
Humoral immunity emerges, but is not protective
Control of viremia corresponds with onset of HIV-specific CTL responses
in HIV, older persons progress rapidly
yep
The HIV virus can be detected with __________, even in patients effectively treated with ART.
ultrasensitive assays
HIV viral reservoir
reservoir is established during acute HIV infection and it consists of long lived infected cells or cells that harbor non-replicating virus
