Human immunodeficiency virus (HIV)

Human Immunodeficiency Virus (HIV) Andrew Borst Isabel VanDerslice Image: http://www.npr.org/blogs/pictureshow/2011/02/22/133868260/sciviz A World Pandemic  HIV has enormous social, economic and humanitarian implications  HIV and AIDS is decimating populations, taxing health infrastructures, and crippling economies, and creating unsustainable population age distributions  Some parts of Africa have a prevalence rate of 1 in 3. For many, infection is inevitable, and treatment beyond reach.  From its discovery in 1981 to 2006, AIDS killed more than 25 million people. The Spread of HIV  Spread through sexual contact, intravenous drug use (infected blood), and mother-to-child during birthing and nursing.  Birthing transmittance rate is 15-30% for mothers infected with HIV.  To minimize risk, antiretroviral therapy is recommend prior to (for the mother) and after birth (for the baby).  Does not spread through mucous membranes, only blood contact.  HIV is a fragile virus Tip of the Day: Use condoms and clean needles! HIV-1 and HIV-2  HIV-1  Binds to CCR5 co-receptor  Most common strain of the Human Immunodeficiency Virus  What most professionals refer to when they reference HIV  HIV-2  Binds to CXCR4 co-receptor  Uncommon; mostly found in Western Africa or individuals of whom are in the later phases of disease progression. Higher HIV-2 prevalence-rates here Vaccine and Treatment  It is difficult to make a vaccine for HIV due to several characteristics of the virus  HAART: Highly active a nti- retroviral therapy is the only effective treatment, but resistance occurs, especially after many years of treatment.  Gene therapy appears to be a good candidate for future HIV treatment options. Vaccine and Treatment Anti-retroviral therapy has significantly reduced the death toll associated with AIDS.  It is difficult to make a vaccine for HIV due to several characteristics of the virus  HAART: Highly active a nti- retroviral therapy is the only effective treatment, but resistance occurs, especially after many years of treatment.  Gene therapy appears to be a good candidate for future HIV treatment options. Human hematopoietic stem/progenitor cells Human hematopoietic stem/progenitor cells modified by zinc-finger nucleases targeted to modified by zinc-finger nucleases targeted to CCR5 controls HIV-1 CCR5 controls HIV-1 in vivo in vivo Nathalia Holt, Jianbin Wang, Kenneth Kim, Geoffrey Friedman, Xingchao Wang, Vanessa Taupin, Gay M Crooks, Donald B Kohn, Philip D Gregory, Michael C Holmes & Paula M Cannon HIV-1 Infection  Transmembrane proteins on the surface of the virus interact with receptors on the host cell  Two interactions are needed for entry— CD4-gp120 and a chemokine coreceptor, usually CCR5.  The main reservoirs for HIV in the body are wherever immune cells reside, such as the spleen and intestine. HIV is also found in the follicular dendritic cell (FDC) network.  In tonsils and adenoids of HIV-infected patients, infected macrophages fuse into multinucleated giant cells that produce huge amounts of virus. HIV Infection Mechanism Co-receptor CCR5 Permits HIV-1 Entry • CCR5 is the major co-receptor used by HIV-1 and is expressed on key T-cell subsets and monocytes. • CCR5Δ32 is a relatively common allele in Western Europe • Confers an innate resistance to HIV-1 infection • CCR5 antagonists have proved to be an effective salvage therapy in patients infected with drug-resistant HIV-1 Kuby Immunology says CCR5 is only expressed on Monocytes, but this is an extremely misleading oversimplification. [...]... Normal CD4+ T-cells b) Ratio of human CD4+ to CD8+ lymphocytes in peripheral blood of individual mice to which were infected with HIV-1   Measured pre-infection and 6-8 weeks post-infection Significant reduction in CD4+/CD8+ Tcell ratio in post-infection untreated mice Effects of HIV-1 infection on human cells in HSPCengrafted NSG mice Figure 3 Analysis  a) FACS analysis of human cells in tissues of... unmodified cells  Holds true for both the location of cells and their frequency in that particular tissue Protection of human CD4+ T cells in peripheral blood of HIV-infected mice previously engrafted with ZFN-modified CD34+ HSPCs Figure 2 Analysis  a) FASC readouts showing human CD4+ and CD8+ T-cells in peripheral blood of representative animals from each of three cohorts     Uninfected: Normal... 24 hours after nucleofection     b) Mean percentage of human CD45+ cells in peripheral blood of mice 8 weeks after transplantation   Neg: No gene digestion Mock: No gene digestion ZFN: Gene digestion No statistical difference between Neg, Mock, and ZFN groups c) Fluorescence-activated cell sorting (FACS, or flow cytometry) profiles of human cells of various organs from one ZFN-treated mouse ... infection Spleen: Reduction of CD4+ Thelper cells post HIV-1 infection w/o ZFN treatment Thymus: Complete loss of CD4+ and CD8+ T-cells Small intestine: Complete loss of all human lymphocytes w/o ZFN treatment b) Immunohistochemical analysis of human CD3 expression in small intestine, and CD4 expression in spleen of representative mice Reasons for CD4+ and CD8+ T-cell Depletion in the Thymus  Proposed to... with uninfected ZFN-treated cohorts   c) Contour FACS analysis of human CD4+ T-cells in small intestine and spleen of one representative animal from each cohort   Gel shows increased levels of digestion products in infected mice indicating increased CCR5-/- cell selection Expected results were expected d) Mean +- s.d numbers of human CD4+ cells and CD4+CCR5+ per 5,000 cells analyzed from different... development   Immune hyperactivation underlies much of the pathology of AIDS Not observed in patients unless virus was present prior to treatment Could be used as a backup therapy, or done in addition to HAART My science is perfect A quick word about using proper grammar    “PCR reaction” = BAD “HIV virus = The WORST “Isabel and I’s paper” = The reason for this slide Now…any questions? ... domain Preferentially cleaves DNA at distorted duplexes caused by mismatches  Used for quantification of the CCR5 disrupted alleles NSD Mice:  NOD SCID IFγ-null Mice  Non-obese diabetic severe combined immunodeficiency interferon-gamma null mice    Lack T, B, and NK cells Deficient in multiple cytokine signaling pathways Defects in innate immunity Fun Fact: “Cel” in Cel 1 nuclease stands for celery! . Human Immunodeficiency Virus (HIV) Andrew Borst Isabel VanDerslice Image: http://www.npr.org/blogs/pictureshow/2011/02/22/133868260/sciviz A. fragile virus Tip of the Day: Use condoms and clean needles! HIV-1 and HIV-2  HIV-1  Binds to CCR5 co-receptor  Most common strain of the Human Immunodeficiency