How does the HIV virus infect host cells?
How does AIDS virus infect?
- HIV virus has gp120 (a surface protein) that has binding sites for CD4 molecule on the surface of CD4+ T cells.
- HIV virus gp120 also is able to bind to coreceptors CCR5 and CXCR4 on the surface of CD4 T cells. These coreceptors are invovled in allowing HIV entry into the cell.
- Individuals with homozygous mutations of CCR5 become resistant to HIV.
- Other cells that HIV infects:
- Monocytes and macrophages (serve as reservoirs of HIV and may allow entry into CNS)
- Neural cells (by two ways: through CD4 receptors OR through receptor sites for neuroleukin.
- Microglial cells of CNS
- Dendritic cells, Langerhans cells,
Proviral DNA is integrated into the Host genome (Latent stage)... it can remain like this for a while producing low-level virion production. However, it can be reactivated (possibly by infection of EBV or CMV).
Spread: blood, semen, vaginal secretions, breast milk, saliva