Retrovirus

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Retrovirus
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Retrovirus

• Retroviridae
• Retrovirus
• HTLV (human T-cell lymphotropic virus)
• Lentivirus
• HIV

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Common Properties

• Spherical, 100nm enveloped
• Two copies of ssRNA
• Reverse transcriptase and Integrase
• Replication DNA intermediate
• Structure genes gag, pol , env genes
• Tissue tropism determinated by receptor
• Budding

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HumanImmunodeficiencyVirus (HIV)
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Clinical case

• A 32-year-old ex-heroin addict had a
  mononucleosis-like illness for 2 weeks,
  occasional nigh sweats and fever for 3 years and
  then presented with thrush, cytomegalovirus
  retinitis, and pneumocystis pneumonia. His CD4 T
  cell count is less than 200/ul.

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HIV

• CD4 T helper lymphocyte
• AIDS (acquired immunodeficiency disease syndrome)
• Fatal
• 40 million
• 1.5 million (2004) 10 million (2010)

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Biological Properties

• Structure

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Biological Properties

• Replication
• Receptor CD4 antigen
• Main host cell CD4 T4 helper cells
• Co-receptor CCR5, CXCR4

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Biological Properties

• Typing and Variation
• HIV-1
• HIV-2
• High variation
• gp120

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Pathogenicity

• Source human
• Transmission
• Sexual transmission
• Blood transmission
• Vertical transmission
• Route not involved in transmission close
  personal contact

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Clinical Findings

• Acute infection
• Clinical latency
• AIDS related complex
• AIDS
• Kaposi's sarcoma
• Opportunistic infection

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Pathogenesis

• Virus tropism for CD4 T cells and macrophages
• Reduction in the number of CD4 T cells

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Pathogenesis

• CD4 T cells and memory cells
• Lytic infection of CD4 T cells
• Syncytia formation
• CTL effect on the viral proteins on the cell
  surface
• Free gp120-CD4 Ag
• Auto-immune defense-gp120
• Apoptosis
• Cellular latency T4 cells
• CD8 cells apoptosis

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Microbiological Diagnosis

• Serology
• Genomics
• Viral particles

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Treatment and Prevention

• Prevention
• Education
• Vaccine no effective in practice
• Treatment
• Highly active anti-retroviral therapy (HAART)
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