HIV AIDS and Oral complications of HIV
Human influenza virus (HIV) , the cause of the
acquired immune deficiency syndrome (AIDS),
continues to spread, being described as a global
health emergency by the World Health
Organization (WHO) in 2003.
Infection transmitted via,
routes of transmission-
Sexual intercourse (vaginal and anal)
Contaminated blood, blood products and organ
contaminated needles ( intravenous drug abuse,
injection, needle tract injury )
Vertical transmission (parentally, perinatally,
HIV belongs to the lentivirus group of the
retrovirus family. There are at least two types,
HIV-1 and HIV-2.
Retroviruses are characterized by the possession
of the enzyme reverse transcriptase, which allows
viral RNA to be transcribed into DNA, and then
incorporated into the host cell genome. Reverse
transcription is an error-prone process with a
significant rate of misincorporation of bases.
This, combined with a high rate of viral turnover,
leads to considerable genetic variation and a
diversity of viral subtypes.
1. Entry and integration-
Infection of a CD4+ cell
occurs via a direct interaction between the gp120
envelope proteins and a conserved CD4 binding
site. Binding of CD4 to gp120 is not sufficient for
cell entry, and a family of co-receptors has been
identifi ed, the normal function of which is to
bind small chemotactic peptides termed
‘chemokines’. The ability of HIV to infect different
cell types depends on the ability of gp120 to bind
differentially to these different chemokine
• viruses with gp120 that preferentially binds the
CCR5 chemokine receptor found on cells of the
monocyte/ macrophage series (macrophage
• viruses that bind preferentially to the CXCR4
chemokine receptor found predominantly on
lymphocytes (tropic for lymphocyte cell lines).
Binding of the virus through these...