note: numbers are not in accordance to the diagram above.
Glycoprotein of HIV (gp120) binds to the coreceptor CD4 of helper-T cell.
The phospholipid bilayer of HIV fuses with the plasma membrane of helper-T cell, to insert capsid into the helper-T cell.
Capsid is broken down by hydrolysis (require enzyme from virus), releasing viral RNA and reverse transcriptase into the cytoplasm of helper-T.
4) Synthesis of DNA from RNA
Reverse transcriptase transcribes the single-stranded RNA codon by codon (A-T, G-C, etc.) to form a single-stranded DNA. The single-stranded DNA is then copied by reverse transcriptase to form a double-stranded DNA.
The double-stranded DNA moves into the nucleus to be integrated into the host genome/chromosome. The viral genome will replicate along when the cell replicate.
The viral DNA is transcribed inside the nucleus of helper-T cell to form mRNA.
Viral mRNA diffuse out of nucleus. The viral components are synthesised actively using raw materials from the host (helper-T).
The viral components that are newly synthesised are being assembled into a complete cell.
The daughter virus buds off from the helper-T cell.
This new virus released will later mature and infect other cells in the body.
HIV can destroy helper-T, B-cells and macrophage (because they have CD4 coreceptor). As a result, various pathogen enters and infect body cells. The immune system of the patient is weakened.
Symptoms of HIV Infection:-
Frequent fever & diarrhea
Muscle & joint aches
Mouth thrush (fungal infection)
Pneumonia (bacterial infection on lungs)