HIV/ AIDs Flashcards
HIV structure
envelope virus
surrounded by 20 sided protein capsid enclosed in a layer of viral protein
lipid envelope formed from host cell membrane
gp120 molecules stick through envelope
invading t helper cells
GP120 molecules bind to CD4 receptors on surface of t helper cell (macrophages also have CD4 receptors and can be invaded)
envelope of virus fuses with t helper cell membrane
enables viral rna to enter the cell
protein synthesis
HIV genetic material in form of RNA
reverse transcriptase used to manufacture DNA from RNA template
integrase integrates HIV DNA strand into host DNA
HIV genome can then be transcribed and translated
destroying T helper cell
infected t helper cells will be destroyed by t killer cells
- decreasing no of THC in body
loss of THC results in macrophages, B cells and T killer cells not being properly activated
- they do not function properly
- causes deficient immune system in patient
effect of destroyed THC
leaves weakened immune system
patient vulnerable to opportunistic infections
causes symptoms of HIV
acute phase
when first infected with HIV
antibodies appear in blood after 3-12 weeks
virus rapidly replicates and THCs are lost
infected THC recognised and destroyed by TKC
- reduces rate of replication but does not completely stop it
acute phase symptoms
fever, sweats, headache, sore throat, swollen lymph nodes
chronic phase
prolonged phase which can lead to development of aids after a few years of infection
may have no symptoms- tendency to suffer more from other colds or infections at this time
dormant diseases like TB or shingles may reactivate
disease phase characteristics
increased viral load and declining number of THC indicates onset of AIDs
symptoms of disease phase
lack of THC leaves immune system vulnerable to other diseases
- opportunistic infections can be fatal
people are susceptible to tumours, pneumonia, TB, dementia and weight loss
