HIV
Mechanism of HIV
Entry to the cell
Occur when HIV virus comes into contact with the host cell
Introduces viral material into the cell
HIV enters macrophages and CD4-positive T cells
- adsorption of glycoproteins on its surface to receptors (target cell)
- fusion of viral envelope ( with cell membrane)
- release of HIV capsid
Fusion
high affinity attachment of the CD4 binding domains of gp120 to CD4
once bound with CD4 protein, envelope undergoes structural change, exposing the chemokine binding domains of gp120 and allowing them to interact with the target chemokine receptor.
Release
HIV RNA
Enzyme : reverse transcriptase, integrase, ribonuclease, and protease
During microtubule-based transport to the nucleues, viral single -strand RNA genome is transcribed into double strand DNA, then intergrated into host chromosome
Replication and transcription
Reverse transcription
(reverse transcriptase)
liberate single stranded RNA genome (viral proteins)
copy it into complementary DNA (cDNA)
Dna polymerase - creates a sense DNA from antisense cDNA
Integration
(integrase)
integration of viral DNA into the host cell's genome
Latent stage of HIV infection - integrated viral DNA may then lie dormant
Viral replication
intergrated DNA provirus is transcribed into RNA
- RNA splicing to produce mature mRNAs
mRNAs export from nucleus into cytoplasm
translated into regulatory proteins (Tat and Rev)
Asembly and release
transported to plasma membrane
Gag polyprotein associate with inner surface of PM + HIV genomic RNA --> virion
virion begins to bud from host cell
budded virion is immature - gag polyprotein need to cleaved int marix, capsid and nucleocapsid proteins.
Mature HIV virion
- various structural components
- able to infect another cell
HIV assembling on the surface of an infected macrophage.
Env polyprotein
-goes through the endoplasmic reticulum and is transported to golgi complex.
- cleaved by furin - form 2 HIV envelope ( gp41 and gp 120)
Spread within the body
cell-free spread
virus particles bud from an infected T cell
enter blood/extracellular fluid
then infect another T cell
Cell-to-cell spread
1. infected T cell transmit virus directly to a target T cell via virological synapse.
2. an antigen presenting cell (APC) transmit HIV to T cells by productive infection or transfer of virions.
HIV life cycle
Problem and Cure
DIFF. HIV & AIDS
HIV : Virus that may cause infection
AIDS : Condition or a syndromea
Being infected with HIV can lead to having AIDS
Alternative Cure
Optimal Outcome : STERILIZING CURE
Basically go in Surgically/Medically removed every last replication competent virus in the body
US 5011695A : Sterilization of blood
Similar with physiologically innocuous sterilant
Introduction
Human Immunodeficiency Virus
Structure
Spherical
120nm in diameter
Composed of two ssRNA
ssRNA tightly bound to p7 (nucleus capsid protein)
ssRNA enclosed by conical capsid
Matrix composed of viral protein
p17 surrounds capsid
Infection occurs by transfer of
Blood
Semen
Vaginal fluid
Pre-ejaculate
Breast milk
Classification
Group
Group VI (ssRNA-RT)
Order
Unassigned
Family
Retroviridae
Subfamily
Orthoretrovirinae
Genus
Lentivirus
Species
HIV 1
HIV 2
Types of HIV
HIV 1
LAV & HTLV-III
More virulent
More infective
HIV 2
Lower infectivity
Largely confined to West Africa
West Africa
Know More
Symptoms of HIV
Early Stage of HIV
Fever
Chills
Rash
Night sweats
Muscle aches
Sore throat
Fatigue
Swollen lymph node
Mouth ulcers
Progression to AIDS
Recurring fever
Rapid weight loss
Profuse night sweat
Extreme but unexplained tiredness
Prolong swelling of lymph node
Diarrhea
mouth,anus or genital sore
Pneumonia
Blotches
Depression
Memory loss