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34 Cards in this Set
- Front
- Back
the HIV responsible for causing AIDS in much of West Africa
the HIV responsible for AIDS throuhout the rest of the world |
HIV-2
HIV-1 |
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enzymes in the HIV virus that are responsible for the insertion of HIV DNA into host DNA
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reverse transcriptase and integrase
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structure of the genetic material carried in the HIV virus
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2 strands of ssRNA(+)
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blood protein that is an indicator of HIV progression
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p24 capsid protein
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matrix protein that forms the inner surface of the viral membrane
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p17 matrix protein
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outer membrane receptor molecules of the HIV virus that are involved in adsorption and penetration
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gp120 and gp41
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HIV replication is promoted by ____
HIV replication is suppressed by ____ |
pro-inflammatory cytokines that activate NF-kB
CTL, chemokines, neutralizing Abs, anti-inflammatory cytokines |
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half life of activated T cells that are infected by HIV
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about 1 day
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half life of macrophages and dendritic cells that are infected by HIV
Why is this important |
months/years
HIV evolved adaptations that allow replication in non-dividing macrophages...these cells serve as the the viral reservoirs |
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cells that assist the HIV virus in persistent infection for months to years
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central memory T cells (long half life)
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the major hallmark of AIDS
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destruction of CD4+ T cells
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two possible ways that CD4 T cells are affected by AIDS
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directly kill
indirectly impair |
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receptor for HIV on CD4+ cells
co-receptors that allow for infection of macrophages and dendritic cells |
CD4
CCR5 and CXCR4 |
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infection of CD4-negative macrophages occurs through the ___
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CCR5 coreceptor
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protein on dendritic cells that mediates the capture of HIV
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DC-SIGN protein
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stages of the HIV life cycle
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virus binding to host cell (gp120 and gp41)
penetration and uncoating replication and transcription (RT then integrase) snythesis/assembly of nucleocapsid (self assembly) virion release |
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a 32-base pair deletion in what gene renders resistance to HIV infection in homozygotes and slower progression in heterozygotes
associated w/ an inefficient entry of macrophages |
CCR-5 gene
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detection assays for HIV
Which is useful in monitoring the affect of anti-viral therapy ? |
reverse transcriptase activity (detects virus in culture)
immunofluorescence (detects antibodies) ELISA (antibodies) western blot (antibodies) PCR (RNA levels) PCR - useful in monitoring anti-viral therapy |
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what determines the rate of CD4 depletion in HIV infection
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plasma "set point" for HIV RNA
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CD4/CD8 ratio in infected individuals
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less than one
normal ratio is 2:1 |
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cells that control HIV viremia in the acute infections (2-4 weeks)
they persist until late in infection and may cause continuing destruction of CD4 cells during the latent phase of the infection |
CD8+ cytotoxic T lymphocytes
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natural history of an HIV infection
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acute/primary phase (months)
latent phase (3-10 years) immune collapse characterized by AIDS |
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3 most common symptoms of acute HIV infection
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fever
fatigue rash |
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four stages of the progression from acute infection to AIDS
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Stage I: asymptomatic
Stage II: mucocutaneous manifestations Stage III: chronic diarrhea, severe bacterial infections, TB Stage IV: toxoplasmosis of brain, candidiasis of lungs, Kaposi's sarcoma |
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immunosuppression in HIV infection is caused by ___
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depletion of CD4+ lymphocytes and the absence of memory cells
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auto-antibodies detected in HIV infection
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lymphocytes
platelets neutrophils RBCs nerves (myelin) ANA thyroglobulin |
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One of the ways HIV virus can survive anti-retroviral therapy is due to its ability to infect ________ and _______ cells
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macrophages and DC cells.
CD4+ T cells is also a viral reservoir |
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What change to a marcrophage can render a person resistant to HIV infection
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Polymorphism of CCR5 (delta32-CCR5)
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How do Dendritic cells (DC) promote the replication of HIV virus
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1. They are suceptible to direct infection
2. Can pass the virion onto CD4+ cells |
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Host immune response to HIV virus
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Abs are made to neutralize HIV virus but it can't handle the infection due variety of antigens on viral envelope...can result in AUTO-ANTIBODIES BEING MADE
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What other mutations besides delta 32 CCR5 render resistance to HIV
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mutations in genes encoding stromal cell derived factor-1 (SDF), its a ligand for CXCR4
Mutations in HLA - B27 and DR6 render resistnace |
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How does HIV get so much genetic diversity
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Inaccurate enzymatic machinery reults in mutant virions
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VIRAL REPLICATION IN THE GI during Acute and chronic infection of HIV
Note: the GI is constantly stimulating an immune response to foods, bugs... |
Acute - Activated CD+ Tcells express CCR5 and are rapidly eliminated from the lamina propria by high HIV replication this may be why we see high serum titers of HIV in acute phase...as these CD4+T-cells are destroyed the lower levels of levels result in lower levels of HIV viurs in effector sites
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TH1 and TH2 response during HIV infection, what are the implications of this
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TH1 response during acute infection but shifts to Th2 w/ disease progression...results in impaired cell-mediated response (CTLs)
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