HIV

Question 1

prevalence of HIV

Answer 1

36.7 million living with it
25.5 in sub-Saharan African
(mention high group users, vertical transmission, prevention needed) highly infectious disease
stigma around it

Question 2

describe virus and genome

Answer 2

double stranded RNA Retrovirus as it uses DNA intermidate for replication
9 genes encoding 15 proteins
better replication in activated memory cells than in naïve cells

Question 3

replication cycle

Answer 3

Binds to the t cell cd4 receptor where it uncoats and integrades into host genomy using hosty factors for conversion back into RNA and forming long ppproteins -> translation and replication of the virus
Begins as an acute infection, remains asymptomatic 10 year latency with development of AID on average
HIV RtT error prone nature results in multiple variants and errors in viral cycle driving viral diversity /quadrispecies allowing mutants with high mutagenic capacity to replicate and outcompete immune system with variants resistant to drugs
Generation time from binding to cell to replication is only 2 days
10^10 virions daily affecting up to1 % of t cells where viral mutants with resistance hence why dual treatment given
Interaion into T memotry cells leads to long lived reservoirs for latency of the of infected virus limits eradication through therapy as it comes back quickly and able to invade immune response

Question 4

tagrgers cellular

Answer 4

Cellular targets
Dendritic cell, monocytes and T cells
Cells expressing CD4 and coreceptors used in HIV entry
CCR5-in initial transmission but MIP apha, IMPb RANTES can inhbiti cell entry
Ccx4- allows infection of naïve cells 50% of cases SD1 inhibits entry, seen in advanced disease

those with polymorphism in sucrptible individuals can allow transmission