1 / 19

Introduction to HIV Virus

Introduction to HIV Virus. What is HIV?. Human Immunodeficiency Virus Composed of 9 genes Bacteria typically have 5000 genes Humans have 20,000-25,000 genes. 2 identical copies of single strands of RNA Surrounded by viral Envelope of fatty material

calista-riley
Download Presentation

Introduction to HIV Virus

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to HIV Virus

  2. What is HIV? • Human Immunodeficiency Virus • Composed of 9 genes • Bacteria typically have 5000 genes • Humans have 20,000-25,000 genes

  3. 2 identical copies of single strands of RNA Surrounded by viral Envelope of fatty material On viral envelope are 72 spikes composed of proteins gp120 and gp 41 Structure of HIV gp=glycoprotein; number is molecular weight (daltons)

  4. Beneath is a viral matrix composed of protein p17 • RNA is surrounded by a capsid of protein p24

  5. Also contains 3 enyzmes needed for HIV replication • Reverse transcriptase • Integrase • Protease

  6. HIV Infection and Replication

  7. Entry • HIV Spikes (Ligand) g120/41 • Must Attach to at least two Receptors on Helper T-lymphocytes * CD4 * 7-transmembrane receptor • HIV Ligand is the “Key” to Unlock the Receptor on the CD4 T cell

  8. Releases contents into CD4 or Helper T-Cell

  9. HIV enzyme reverse transcriptase converts viral RNA to DNA Makes copying errors Leads to variations in HIV New viral DNA is spliced into human DNA by HIV enzyme integrase Reverse Transcription and Integration

  10. Viral DNA lies dormant until T-cell is activated Human DNA with viral DNA (provirus) now makes messenger RNA (human and viral) Translated at ribosomes to make new HIV proteins Transcription and Translation

  11. Assembly • New long Viral polypeptide chain is chopped up into smaller pieces by protease • Creating new enzymes and viral coat proteins

  12. Budding and Maturation • Assembles all viral components • Buds from host cell • Takes a piece of the host plasma membrane

  13. Effect on Immune System Activates Helper T-Cell –”The General” • Secretes Cytokines which …… • Activate macrophages, cytotoxic or killer T-cells, and natural killer cells • Control maturation and induction of antibody-producing B cells • Secrete colony stimulating factors for more white blood cells

  14. 1st Stage of Infection -Primary • Rapid viral replication • Patient exhibits flu-like symptoms • Undergoing Seroconversion • B-cells making antibodies • Patient is infectious but will not test + for HIV

  15. 2nd Stage of Infection-Clinical Latency • Strong immune defense to that particular variant of HIV • Reduced number of viruses • Lasts 2 weeks -20 years • Patient still infectious • Will test + for HIV

  16. 3rd Stage of InfectionAIDS • Virus has mutated • T-cells and B-cells are activating against all the different variants of HIV • Helper T-cells are dying • Bone marrow can’t make new cells fast enough • Immune System is overloaded and compromised

  17. Normal count = 800-1200 cells/ul • If CD4 T cell count drops below 200 cells /ul” • patient has AIDS • patient is susceptible to opportunistic infections.

  18. Types of Drugs Used on HIV • Reverse Transcriptase Inhibitors • AZT – blocks recoding of viral RNA into DNA • Protease Inhibitors • Blocks protease that cleaves viral polypeptide into functional enzymes • Best regimen is “cocktail” of both types of drugs

  19. The End

More Related