Lecture Notes: The Life Cycle of HIV

Introduction

• Presenter: Sarah from registerednessrn.com
• Topic: Overview of the HIV life cycle
• Key focus: Understanding the HIV life cycle to comprehend how anti-retroviral therapy (ART) works

Basic Characteristics of HIV

• HIV: A retrovirus that requires a host cell to grow and multiply
• Target Cells: Cells with CD4 receptors, specifically helper T cells
• Mechanism: Attaches to CD4 to enter and take over the cell, producing more HIV and killing the host cell

Anatomy of the HIV Virus

• Surrounded by proteins and glycoproteins
• Important Glycoprotein: gp120, crucial for attachment to CD4 receptors

Enzymes and Viral Components

• Enzymes Brought by HIV:
  • Reverse Transcriptase: Converts RNA to DNA
  • Integrase: Integrates viral DNA into the host DNA
  • Protease: Cleaves proteins for viral maturation
• Genetic Material: Single strand of RNA

Life Cycle of HIV

1. Attachment
   • gp120 attaches to CD4 receptor and co-receptors (CCR5 or CXCR4)
2. Fusion
   • Virus fuses with the host cell, releasing its contents
3. Reverse Transcription
   • Reverse transcriptase converts RNA to double-stranded DNA
4. Integration
   • Integrase helps integrate viral DNA into host DNA
5. Replication and Assembly
   • Production of viral proteins and RNA, assembling into immature virus
6. Budding
   • New virus buds from the host cell
7. Maturation
   • Protease processes proteins, maturing the virus

Importance of Understanding the HIV Life Cycle

• Anti-retroviral Therapy (ART)
  • Targets specific stages of the HIV life cycle (e.g., attachment, fusion)
  • Limits HIV replication in the blood
• Early initiation of ART is crucial for effectiveness

Conclusion

• Understanding the HIV life cycle is vital for grasping ART
• Further resources: Free video lecture on HIV and AIDS available via YouTube link